STATE COMMITTEE OF THE RUSSIAN FEDERATION
ON CONSTRUCTION AND HOUSING AND COMMUNAL COMPLEX
(GOSSTROY RUSSIA)

System of regulatory documents in construction

BUILDING STANDARDS AND RULES OF THE RUSSIAN FEDERATION

HEATING NETWORK

THERMAL NETWORKS

SNiP 41-02-2003

UDC 69+697.34 (083.74)
Date of introduction 2003-09-01

PREFACE

1 DEVELOPED by JSC Association VNIPIenergoprom, Perm State Technical University, JSC Teploproekt with the participation of the Association of developers and manufacturers of anti-corrosion protection products for the fuel and energy complex, the Association of manufacturers and consumers of pipelines with industrial polymer insulation, JSC Firm ORGRES, JSC All-Russian Thermal Engineering Institute", "SevZapVNIPIenergoprom", JSC "TVEL Corporation", Mosgorekspertizy, JSC "Mosproekt", State Unitary Enterprise "Mosinzhproekt", JSC NTP "Truboprovod", JSC "Roskommunenergo", JSC "Lengazteplostroy", Irkutsk State technical university, JSC "Insulation Plant", Tyumen Academy of Construction and Architecture

INTRODUCED by the Department of Technical Standardization, Standardization and Certification in Construction and Housing and Communal Services of the Gosstroy of Russia

2 ADOPTED AND ENTERED INTO EFFECT on September 1, 2003 by Decree of the State Construction Committee of Russia dated June 24, 2003 No. 110 (failed state registration- Letter of the Ministry of Justice of the Russian Federation dated March 18, 2004 No. 07/2933-UD)

3 INSTEAD SNiP 2.04.07-86*

INTRODUCTION

These building codes and regulations establish a set of mandatory regulatory requirements for the design of heating networks, structures on heating networks in connection with all elements of the systems district heating in terms of their interaction in a single technological process of production, distribution, transportation and consumption of thermal energy, rational use fuel and energy resources.
Requirements for safety, reliability, and survivability of heat supply systems have been established.
When developing SNiP, regulatory materials from leading Russian and foreign companies were used, and 17 years of experience in applying current standards by design and operating organizations in Russia were taken into account.
IN building codes and rules for the first time:
standards for environmental and operational safety, readiness (quality) of heat supply have been introduced; the application of the probability of failure-free operation criterion has been expanded;
the principles and requirements for ensuring survivability in off-design (extreme) conditions were formulated, the characteristics of centralized heat supply systems were clarified;
standards have been introduced for the application of reliability criteria when designing heating networks;
criteria for choosing thermal insulation structures taking into account fire safety are given.
The following people took part in the development of SNiP: Ph.D. tech. Sciences Ya.A. Kovylyansky, A.I. Korotkov, Ph.D. tech. Sciences G.Kh. Umerkin, A.A. Sheremetova, L.I. Zhukovskaya, L.V. Makarova, V.I. Zhurina, Ph.D. tech. Sciences B.M. Krasovsky, Ph.D. tech. Sciences A.V. Grishkova, Ph.D. tech. Sciences T.N. Romanova, Ph.D. tech. Sciences B.M. Shoikhet, L.V. Stavritskaya, Doctor of Engineering. Sciences A.L. Akolzin, Ph.D. tech. Sciences I.L. Maisel, E.M. Shmyrev, L.P. Kanina, L.D. Satanov, P.M. Sokolov, Doctor of Engineering. Sciences Yu.V. Balaban-Irmenin, A.I. Kravtsov, Sh.N. Abaiburov, V.N. Simonov, Ph.D. tech. Sciences V.I. Livchak, A.V. Fisher, Yu.U. Yunusov, N.G. Shevchenko, Ph.D. tech. Sciences V.Ya. Magalif, A.A. Khandrikov, L.E. Lyubetsky, Ph.D. tech. Sciences R.L. Ermakov, B.S. Votintsev, T.F. Mironova, Doctor of Engineering. Sciences A.F. Shapoval, V.A. Glukharev, V.P. Bovbel, L.S. Vasilyeva.

1 AREA OF USE

These norms and rules apply to heating networks (with all associated structures) from the output shut-off valves (excluding them) of heat source collectors or from the external walls of the heat source to the output shut-off valves (including them) of heating points (input nodes) of buildings and structures transporting hot water with temperatures up to 200 °C and pressure up to 2.5 MPa inclusive, water steam with temperatures up to 440 °C and pressure up to 6.3 MPa inclusive, water vapor condensate.
The heating networks include buildings and structures of heating networks: pumping stations, heating points, pavilions, chambers, drainage devices and so on.
These standards discuss centralized heat supply systems (hereinafter referred to as DHS) in terms of their interaction in a single technological process of production, distribution, transportation and consumption of heat.
These rules and regulations must be observed when designing new and reconstructing, modernizing and technical re-equipment existing heating networks (including structures on heating networks).

3 TERMS AND DEFINITIONS

The following terms and definitions are used in these standards.
A centralized heat supply system is a system consisting of one or more heat sources, heat networks (regardless of the diameter, number and length of external heat pipelines) and heat consumers.
The probability of failure-free operation of the system [P] is the ability of the system to prevent failures leading to a drop in temperature in heated premises of residential and public buildings below +12 °C, in industrial buildings below +8 °C, more than the number of times established by the standards.
System readiness (quality) factor - probability working condition systems at any time to maintain the calculated internal temperature in heated rooms, except for periods of temperature decrease allowed by regulations.
System survivability [Zh] - the ability of the system to maintain its functionality in emergency (extreme) conditions, as well as after long-term (more than 54 hours) shutdowns.
The service life of heating networks is a period of time in calendar years from the date of commissioning, after which an expert examination of the technical condition of the pipeline should be carried out in order to determine the admissibility, parameters and conditions for further operation of the pipeline or the need for its dismantling.

4 CLASSIFICATION

4.1 Heating networks are divided into main, distribution, quarterly and branches from main and distribution heating networks to individual buildings and structures. The separation of heating networks is established by the project or operating organization.
4.2 Heat consumers are divided into three categories according to the reliability of heat supply:
The first category is consumers who do not allow interruptions in the supply of the calculated amount of heat and a decrease in the air temperature in the premises below those provided for by GOST 30494.
For example, hospitals, maternity hospitals, children's preschool institutions with 24-hour stay for children, art galleries, chemical and special industries, mines, etc.
The second category is consumers who allow a decrease in temperature in heated rooms for the period of liquidation of the accident, but not more than 54 hours:
residential and public buildings up to 12 °C;
industrial buildings up to 8 °C.
The third category is the remaining consumers.

5 GENERAL PROVISIONS

5.1 Solutions for the long-term development of heat supply systems for settlements, industrial units, groups industrial enterprises, districts and other administrative-territorial entities, as well as individual central heating systems should be developed in heat supply schemes. When developing heat supply schemes, the calculated heat loads are determined:
a) for the existing development of settlements and existing industrial enterprises - according to projects with clarification on actual heat loads;
b) for industrial enterprises planned for construction - according to the enlarged standards for the development of the main (core) production or projects of similar production;
c) for residential areas planned for development - according to aggregated indicators of the density of thermal loads or according to the specific thermal characteristics of buildings and structures in accordance with the master plans for the development of areas of the settlement.
5.2 Design heat loads when designing heating networks are determined based on data from specific new construction projects, and existing ones - based on actual heat loads. In the absence of data, it is permissible to follow the instructions of 5.1. Average loads on hot water supply of individual buildings can be determined according to SNiP 2.04.01.
5.3 Estimated heat losses in heating networks should be determined as the sum of heat losses through insulated surfaces of pipelines and values average annual losses coolant.
5.4 In case of accidents (failures) at the heat source, its output collectors must be provided with the following during the entire repair and restoration period:
supply of 100% of the required heat to consumers of the first category (unless other modes are provided for by the contract);
supply of heat for heating and ventilation to housing, communal and industrial consumers of the second and third categories in the amounts indicated in Table 1;

Table 1

Indicator name Estimated outside air temperature for heating design to, °C

Allowable reduction in heat supply, %, up to 78 84 87 89 91
Note - The table corresponds to the outside air temperature of the coldest five-day period with a probability of 0.92.

emergency mode of steam flow and process flow specified by the consumer hot water;
emergency thermal operating mode of non-switchable ventilation systems specified by the consumer;
average daily heat consumption during the heating period for hot water supply (if it is impossible to turn it off).
5.5 When several heat sources work together on a single heating network of a district (city), mutual redundancy of heat sources must be provided, ensuring emergency operation in accordance with 5.4.

6 HEAT SUPPLY AND HEAT NETWORK DIAGRAMS

6.1 The choice of an option for a heat supply scheme for an object: centralized heat supply systems from boiler houses, large and small thermal and nuclear power plants (CHP, TPP, NPP) or from decentralized heat supply sources (DHS) - autonomous, rooftop boiler houses, from apartment heat generators is made through technical and economic comparison options.
The heat supply scheme adopted for development in the project must ensure:
standard level of heat and energy saving;
standard level of reliability, determined by three criteria: probability of failure-free operation, availability (quality) of heat supply and survivability;
environmental requirements;
safety of operation.
6.2 The operation of heating networks and central heating systems in general should not lead to:
a) to unacceptable concentrations during operation of toxic and harmful to the population, maintenance personnel and environment substances in tunnels, channels, chambers, rooms and other structures, in the atmosphere, taking into account the ability of the atmosphere to self-purify in a specific residential area, microdistrict, settlement, etc.;
b) to a persistent violation of the natural (natural) thermal regime vegetation cover (grass, shrubs, trees) under which heat pipelines are laid.
6.3 Heat networks, regardless of the installation method and heat supply system, should not pass through the territory of cemeteries, landfills, cattle burial grounds, radioactive waste burial sites, irrigation fields, filtration fields and other areas that pose a risk of chemical, biological and radioactive contamination of the coolant.
Technological devices of industrial enterprises, from which they can be supplied to heating networks harmful substances, must be connected to heating networks through a water heater with an additional intermediate circulation circuit between such a device and the water heater while ensuring pressure in the intermediate circuit is less than in the heating network. In this case, provision should be made for the installation of sampling points to monitor harmful impurities.
Hot water supply systems for consumers must be connected to steam networks through steam-water heaters.
6.4 Safe Operation heating networks should be ensured by developing measures in projects that exclude:
contact people directly with hot water or with hot surfaces of pipelines (and equipment) at coolant temperatures above 75 °C;
the flow of coolant into heat supply systems at temperatures above those determined by safety standards;
When the central heating system fails, the air temperature in residential and industrial premises of consumers of the second and third categories decreases below the permissible values ​​(4.2);
draining network water in places not provided for by the design.
6.5 The temperature on the surface of the heat-insulating structure of heat pipes, fittings and equipment should not exceed:
when laying heat pipes in the basements of buildings, technical undergrounds, tunnels and passage channels 45 ° C;
at overhead installation, in chambers and other places accessible for maintenance, 60 °C.
6.6 The heat supply system (open, closed, including with separate hot water supply networks, mixed) is selected based on a technical and economic comparison provided by the design organization various systems taking into account local environmental, economic conditions and the consequences of making a particular decision.
6.7 Direct tapping of network water from consumers in closed systems heating is not allowed.
6.8 V open systems heating supply, the connection of some hot water supply consumers through water-to-water heat exchangers at heating points of subscribers (via a closed system) is allowed as a temporary one, provided that the quality of network water is ensured (maintained) in accordance with the requirements of current regulatory documents.
6.9 With nuclear heat sources, as a rule, open heat supply systems should be designed, eliminating the possibility of unacceptable concentrations of radionuclides in network water, pipelines, central heating equipment and heat receivers of consumers.
6.10 The SCT must include:
emergency recovery services (ABC), the number of personnel and technical equipment of which must ensure complete restoration of heat supply in the event of failures in heating networks within the time limits specified in Table 2;
own repair and maintenance bases (REB) - for districts of heating networks with an operating volume of 1000 conventional units and more. The number of personnel and the technical equipment of the electronic warfare are determined taking into account the composition of the equipment, the applied designs of heat pipelines, thermal insulation, etc.;
mechanical workshops - for sections (shops) of heating networks with an operating volume of less than 1000 conventional units;
unified repair and maintenance bases - for heating networks that are part of divisions of thermal power plants, district boiler houses or industrial enterprises.

Heat network diagrams

6.11 Water heating networks should be designed, as a rule, as two-pipe systems, simultaneously supplying heat for heating, ventilation, hot water supply and technological needs.
Multi-pipe and single-pipe heating networks may be used during a feasibility study.
Heat networks transporting network water in open heat supply systems in one direction, when laid above ground, can be designed in a single-pipe design with a transit length of up to 5 km. If the length is greater and there is no backup supply of the central heating system from other heat sources, the heating networks must be constructed in two (or more) parallel heat pipelines.
Independent heating networks for connecting process heat consumers should be provided if the quality and parameters of the coolant differ from those accepted in heating networks.
6.12 The layout and configuration of heating networks must ensure heat supply at the level of specified reliability indicators by:
application of the most advanced designs and technical solutions;
joint operation of heat sources;
laying backup heat pipelines;
installation of jumpers between heating networks of adjacent thermal areas.
6.13 Heat networks can be ring and dead-end, redundant and non-redundant.
The number and location of backup pipeline connections between adjacent heat pipelines should be determined according to the criterion of the probability of failure-free operation.
6.14 Heating and ventilation systems for consumers must be connected to two-pipe water heating networks directly using a dependent connection scheme.
According to an independent scheme, which provides for the installation of water heaters in heating points, it is allowed to connect other consumers when justifying the heating and ventilation system of buildings of 12 floors and above, if the independent connection is due to the hydraulic operating mode of the system.
6.15 The quality of source water for open and closed heat supply systems must meet the requirements of SanPiN 2.1.4.1074 and rules technical operation electrical stations and networks of the Ministry of Energy of Russia.
For closed heat supply systems in the presence of thermal deaeration, it is allowed to use process water.
6.16 The estimated hourly water consumption to determine the productivity of water treatment and the corresponding equipment for replenishing the heating supply system should be taken:
in closed heat supply systems - 0.75% of the actual volume of water in the pipelines of heating networks and the heating and ventilation systems of buildings connected to them. At the same time, for sections of heating networks longer than 5 km from heat sources without heat distribution, the calculated water flow should be taken equal to 0.5% of the volume of water in these pipelines;
in open heat supply systems - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2 plus 0.75% of the actual volume of water in the pipelines of heating networks and the heating, ventilation and hot water supply systems of buildings connected to them. At the same time, for sections of heating networks longer than 5 km from heat sources without heat distribution, the calculated water flow should be taken equal to 0.5% of the volume of water in these pipelines;
for individual heating networks of hot water supply in the presence of storage tanks - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2; in the absence of tanks - according to the maximum water consumption for hot water supply plus (in both cases) 0.75% of the actual volume of water in the network pipelines and the hot water supply systems of buildings connected to them.
6.17 For open and closed heat supply systems, additional emergency make-up with chemically untreated and non-deaerated water must be provided, the flow rate of which is assumed to be 2% of the volume of water in the pipelines of heating networks and the heating, ventilation systems connected to them and in hot water supply systems for open heat supply systems. If there are several separate heating networks extending from the heat source manifold, emergency make-up can be determined only for one heating network with the largest volume. For open heat supply systems, emergency make-up should be provided only from domestic drinking water supply systems.
6.18 The volume of water in heat supply systems, in the absence of data on actual volumes of water, can be taken equal to 65 m3 per 1 MW of calculated heat load with a closed heat supply system, 70 m3 per 1 MW with an open system and 30 m3 per 1 MW of average load with separate networks hot water supply.
6.19 Placement of hot water storage tanks is possible both at the heat source and in heat consumption areas. In this case, storage tanks with a capacity of at least 25% of the total design capacity of the tanks must be provided at the heat source. The inner surface of the tanks must be protected from corrosion, and the water in them from aeration, while continuous renewal of the water in the tanks must be provided.
6.20 For open heat supply systems, as well as for separate heating networks for hot water supply, storage tanks of chemically treated and deaerated make-up water with a design capacity equal to ten times the average hourly water consumption for hot water supply must be provided.
6.21 In closed heat supply systems at heat sources with a capacity of 100 MW or more, provision should be made for the installation of storage tanks for chemically treated and deaerated make-up water with a capacity of 3% of the volume of water in the heat supply system, and the renewal of water in the tanks must be ensured.
The number of tanks, regardless of the heat supply system, is accepted to be at least two, each 50% of the working volume.
6.22 In central heating systems with heat pipelines of any length from the heat source to heat consumption areas, the use of heat pipelines as storage tanks is allowed.
6.23 If a group of storage tanks is located outside the territory of heat sources, it must be fenced with a common shaft of at least 0.5 m in height. The embanked area must accommodate the volume of water in the largest tank and have water drainage to the sewer.
6.24 It is not allowed to install hot water storage tanks in residential areas. The distance from hot water storage tanks to the border of residential areas must be at least 30 m. Moreover, on soils of the 1st type of subsidence, the distance must, in addition, be at least 1.5 times the thickness of the subsidence soil layer.
When placing storage tanks outside the territory of heat sources, they should be fenced with a height of at least 2.5 m to prevent unauthorized persons from accessing the tanks.
6.25 Hot water storage tanks for consumers should be provided in the hot water supply systems of industrial enterprises to align the shifting schedule of water consumption by facilities that have concentrated short-term water consumption for hot water supply.
For industrial facilities with a ratio of the average heat load for hot water supply to the maximum heat load for heating less than 0.2, storage tanks are not installed.
6.26 To reduce losses of network water and, accordingly, heat during planned or forced emptying of heat pipes, it is allowed to install special storage tanks in heating networks, the capacity of which is determined by the volume of heat pipes between two sectional valves.

Reliability

6.27 The ability of designed and existing heat sources, heating networks and central heating systems in general to provide, within a given time, the required modes, parameters and quality of heat supply (heating, ventilation, hot water supply, as well as the technological needs of enterprises for steam and hot water) should be determined by three indicators (criteria): probability of failure-free operation [P], availability factor [Kg], survivability [W].
Calculation of system indicators taking into account reliability must be carried out for each consumer.
6.28 Minimum acceptable indicators of the probability of failure-free operation should be taken for:
heat source Rit = 0.97;
heating networks Rts = 0.9;
heat consumer Rpt = 0.99;
MCT as a whole Рст = 0.9 0.97 0.99 = 0.86.
The customer has the right to install in terms of reference higher performance indicators for design.
6.29 To ensure the reliability of heating networks, the following should be determined:
maximum permissible length of non-redundant sections of heat pipelines (dead-end, radial, transit) to each consumer or heating point;
locations of backup pipeline connections between radial heat pipelines;
sufficiency of diameters selected when designing new or reconstructed existing heat pipelines to ensure backup heat supply to consumers in case of failures;
the need to replace the structures of heating networks and heat pipelines in specific areas with more reliable ones, as well as the feasibility of switching to above-ground or tunnel installation;
the order of repairs and replacements of heating pipelines that have partially or completely lost their service life;
the need to carry out work on additional insulation buildings.
6.30 The readiness of the system for proper operation should be determined by the number of hours of waiting for readiness: heat source, heating networks, heat consumers, as well as the number of hours of non-design outdoor air temperatures in a given area.
6.31 The minimum acceptable indicator of readiness of the central heating system for proper operation Kg is accepted as 0.97.
6.32 To calculate the readiness indicator, the following should be determined (taken into account):
readiness of the central heating system for the heating season;
sufficiency of the installed thermal power of the heat source to ensure proper functioning of the central heating system during unusual cold snaps;
the ability of heating networks to ensure proper functioning of the central heating system during unusual cold snaps;
organizational and technical measures necessary to ensure proper functioning of the central heating system at the level of specified readiness;
maximum permissible number of standby hours for a heat source;
outside air temperature at which the set internal air temperature is ensured.

Reservation

6.33 Provision should be made for following methods reservations:
application of rational thermal schemes at heat sources that ensure a given level of readiness of power equipment;
installation of the necessary backup equipment at the heat source;
organizing the joint work of several heat sources into a single heat transportation system;
reservation of heating networks in adjacent areas;
arrangement of backup pumping and pipeline connections;
installation of storage tanks.
When laying heating networks underground in non-passable channels and channelless installation The amount of heat supply (%) to ensure the internal air temperature in heated rooms is not lower than 12 °C during the repair and restoration period after a failure should be taken according to Table 2.

table 2

Diameter of heating network pipes, mm Heat supply restoration time, h Estimated outside air temperature for heating design tо, °C

Minus 10 minus 20 minus 30 minus 40 minus 50

Allowable reduction in heat supply, %, up to
300 15 32 50 60 59 64
400 18 41 56 65 63 68
500 22 49 63 70 69 73
600 26 52 68 75 73 77
700 29 59 70 76 75 78
800-1000 40 66 75 80 79 82
1200-1400 Up to 54 71 79 83 82 85

6.34 Sections of overhead laying up to 5 km in length may not be reserved, except for pipelines with a diameter of more than 1200 mm in areas with design air temperatures for heating design below minus 40 °C.
Reservation of heat supply through heating networks laid in tunnels and passage channels may not be provided.
6.35 For consumers of the first category, it is necessary to provide for the installation of local backup sources heat (stationary or mobile). It is allowed to provide for redundancy, ensuring in case of failures 100% heat supply from other heating networks.
6.36 To reserve heat supply for industrial enterprises, it is allowed to provide local heat sources.

Vitality

6.37 Minimum heat supply through heat pipes located in unheated rooms and outside, in the entrances, stairwells, in attics, etc., must be sufficient to maintain the water temperature during the entire repair and restoration period after failure at least 3 °C.
6.38 Projects must develop measures to ensure the survivability of elements of heat supply systems located in areas of possible exposure to negative temperatures, including:
organization of local circulation of network water in heating networks before and after the central heating substation;
drainage of network water from heat use systems at consumers, distribution heat networks, transit and main heat pipelines;
warming up and filling heating networks and heat utilization systems of consumers during and after completion of repair and restoration work;
checking the strength of heating network elements to ensure that the safety margin of equipment and compensating devices is sufficient;
ensuring the necessary load on ductless heating pipelines in case of possible flooding;
temporary use, if possible, of mobile heat sources.

Condensate collection and return

6.39 Systems for collecting and returning condensate to the heat source should be closed, and the excess pressure in the condensate collection tanks should be at least 0.005 MPa.
Open condensate collection and return systems may be provided when the amount of condensate returned is less than 10 t/h and the distance to the heat source is up to 0.5 km.
6.40 Condensate return from steam traps via a common network may be used if the difference in steam pressure in front of the steam traps is no more than 0.3 MPa.
When returning condensate by pumps, the number of pumps supplying condensate to the general network is not limited.
Parallel operation of pumps and condensate drains that discharge condensate from steam consumers to a common condensate network is not permitted.
6.41 Pressure condensate pipelines should be calculated based on the maximum hourly flow of condensate, based on the operating conditions of pipelines with a full cross-section in all modes of condensate return and protecting them from emptying during interruptions in the supply of condensate. The pressure in the condensate pipeline network must be assumed to be excessive in all modes.
Condensate pipelines from condensate traps to condensate collection tanks should be designed taking into account the formation of a steam-water mixture.
6.42 Specific losses the friction pressure in condensate pipelines after the pumps should be no more than 100 Pa/m with an equivalent roughness of the internal surface of the condensate pipelines of 0.001 m.
6.43 The capacity of condensate collection tanks installed in heating networks at consumer heating points must be at least 10 minutes maximum flow condensate The number of tanks for year-round operation should be at least two, with a capacity of 50% each. At seasonal work and less than 3 months a year, as well as with a maximum condensate flow rate of up to 5 t/h, the installation of one tank is allowed.
When monitoring the quality of condensate, the number of tanks should, as a rule, be at least three, with a capacity of each that provides time for analyzing the condensate according to all the necessary indicators, but not less than a 30-minute maximum flow of condensate.
6.44 The flow rate (performance) of pumps for pumping condensate should be determined by the maximum hourly flow rate of condensate.
The pump head should be determined by the amount of pressure loss in the condensate line, taking into account the height of condensate rise from the pump station to the collection tank and the magnitude overpressure in holding tanks.
The pressure of pumps supplying condensate to the general network must be determined taking into account the conditions of their parallel operation in all modes of condensate return.
The number of pumps in each pumping station should be at least two, one of which is a reserve one.
6.45 Permanent and emergency discharges of condensate into rainwater or domestic sewage systems are allowed after it has been cooled to a temperature of 40 °C. When discharged into an industrial sewage system with constant wastewater, condensate may not be cooled.
6.46 Condensate returned from consumers to the heat source must meet the requirements of the rules for the technical operation of power plants and networks of the Ministry of Energy of Russia.
The temperature of the returned condensate for open and closed systems is not standardized.
6.47 Condensate collection and return systems should provide for the use of its heat for the enterprise’s own needs.

7 COOLANTS AND THEIR PARAMETERS

7.1 In centralized heat supply systems for heating, ventilation and hot water supply of residential, public and industrial buildings, as a rule, water should be used as a coolant.
The possibility of using water as a coolant for technological processes should also be checked.
The use of steam as a single coolant for enterprises for technological processes, heating, ventilation and hot water supply is allowed during a feasibility study.
7.2 The maximum design temperature of network water at the outlet of the heat source, in heating networks and heat receivers is established on the basis of technical and economic calculations.
If there is a hot water supply load in closed heat supply systems minimum temperature network water at the outlet of the heat source and in heating networks must provide the ability to heat the water supplied to the hot water supply to a standardized level.
7.3 The temperature of network water returned to thermal power plants with combined heat and electricity generation is determined by technical and economic calculations. The temperature of network water returned to boiler rooms is not regulated.
7.4 When calculating graphs of network water temperatures in district heating systems, beginning and end heating season at the average daily outside air temperature the following are accepted:
8 °C in areas with a design outdoor air temperature for heating design down to minus 30 °C and an average design temperature of internal air of heated buildings of 18 °C;
10 °C in areas with a design outside air temperature for heating design below minus 30 °C and an average design temperature of internal air in heated buildings of 20 °C.
The average design temperature of the internal air of heated industrial buildings is 16 °C.
7.5 If the heat receivers in the heating and ventilation systems do not have automatic individual devices for regulating the temperature inside the premises, the following should be used in heating networks to regulate the temperature of the coolant:
central quality for the heating load, for the combined load of heating, ventilation and hot water supply - by changing the coolant temperature at the heat source depending on the outside air temperature;
central qualitative and quantitative for the combined load of heating, ventilation and hot water supply - by regulating both the temperature and the flow of network water at the heat source.
Central qualitative and quantitative regulation at the heat source can be supplemented by group quantitative regulation at heating points, mainly during the transition period heating season, starting from the break point of the temperature graph, taking into account heating connection diagrams, ventilation units and hot water supply, pressure fluctuations in the heating system, the presence and location of storage tanks, the heat storage capacity of buildings and structures.
7.6 With central qualitative and quantitative regulation of heat supply for heating water in hot water supply systems to consumers, the water temperature in the supply pipeline must be:
for closed heat supply systems - at least 70 °C;
for open heat supply systems - at least 60 °C.
With central qualitative and quantitative regulation for the combined load of heating, ventilation and hot water supply, the break point of the water temperature graph in the supply and return pipelines should be taken at the outside air temperature corresponding to the break point of the control graph for the heating load.
7.7 In heat supply systems, if the heat consumer in the heating and ventilation systems has individual devices for regulating the air temperature indoors by the amount of network water flowing through the receivers, central qualitative and quantitative regulation should be used, supplemented by group quantitative regulation at heating points in order to reduce fluctuations in hydraulic and thermal regimes in specific quarterly (microdistrict) systems within the limits ensuring the quality and stability of heat supply.
7.8 For separate water heating networks from one heat source to enterprises and residential areas, it is allowed to provide different schedules of coolant temperatures.
7.9 In public and industrial buildings for which it is possible to reduce the air temperature at night and during non-working hours, regulation of the temperature or coolant flow in heating points should be provided.
7.10 In residential and public buildings in the absence of heating devices thermostatic valves should be provided with automatic control according to temperature chart to maintain the building's average indoor air temperature.
7.11 It is not allowed to use temperature control schedules for heat supply for heating networks.

Valid Editorial from 24.06.2003

Name of document	"HEATING NETWORKS. BUILDING STANDARDS AND RULES. SNiP 41-02-2003" (approved by Resolution of the State Construction Committee of the Russian Federation dated June 24, 2003 N 110)
Document type	decree, norms, list, rules
Receiving authority	Gosstroy of the Russian Federation
Document Number	110
Acceptance date	01.01.1970
Revision date	24.06.2003
Date of registration with the Ministry of Justice	01.01.1970
Status	valid
Publication	At the time of inclusion in the database, the document was not published
Navigator	Notes

"HEATING NETWORKS. BUILDING STANDARDS AND RULES. SNiP 41-02-2003" (approved by Resolution of the State Construction Committee of the Russian Federation dated June 24, 2003 N 110)

Introduction

These building codes and rules establish a set of mandatory regulatory requirements for the design of heating networks, structures on heating networks in conjunction with all elements of centralized heat supply systems in terms of their interaction in a single technological process of production, distribution, transportation and consumption of thermal energy, rational use of fuel and energy resources.

Requirements for safety, reliability, and survivability of heat supply systems have been established.

When developing SNiP, regulatory materials from leading Russian and foreign companies were used, and 17 years of experience in applying current standards by design and operating organizations in Russia were taken into account.

For the first time in building codes and regulations:

Standards for environmental and operational safety, readiness (quality) of heat supply have been introduced; the application of the probability of failure-free operation criterion has been expanded;

the principles and requirements for ensuring survivability in off-design (extreme) conditions were formulated, the characteristics of centralized heat supply systems were clarified;

standards have been introduced for the application of reliability criteria when designing heating networks;

criteria for choosing thermal insulation structures taking into account fire safety are given.

The following people took part in the development of SNiP: Ph.D. tech. Sciences Ya.A. Kovylyansky, A.I. Korotkov, Ph.D. tech. Sciences G.Kh. Umerkin, A.A. Sheremetova, L.I. Zhukovskaya, L.V. Makarova, V. I. Zhurina, Ph.D. tech. Sciences B.M. Krasovsky, Ph.D. tech. Sciences A.V. Grishkova, Ph.D. tech. Sciences T.N. Romanova, Ph.D. tech. Sciences B.M. Shoikhet, L. V. Stavritskaya, Doctor of Engineering. Sciences A.P. Akolzin, Ph.D. tech. Sciences I.L. Maisel, E.M. Shmyrev, L.P. Kanina, L.D. Satanov, P.M. Sokolov, Doctor of Engineering. Sciences Yu.V. Balaban-Irmenin, A.I. Kravtsov, Sh.N. Abaiburov, V.N. Simonov, Ph.D. tech. Sciences V.I. Livchak, A.V. Fisher, Yu.U. Yunusov, N.G. Shevchenko, Ph.D. tech. Sciences V.Ya. Magalif, A.A. Khandrikov, L.E. Lyubetsky, Ph.D. tech. Sciences R.L. Ermakov, B.S. Votintsev, T.F. Mironova, Doctor of Engineering. Sciences A.F. Shapoval, V.A. Glukharev, V.P. Bovbel, L.S. Vasilyeva.

1 AREA OF USE

These norms and rules apply to heating networks (with all associated structures) from the output shut-off valves (excluding them) of heat source collectors or from the external walls of the heat source to the output shut-off valves (including them) of heating points (input nodes) of buildings and structures transporting hot water with temperatures up to 200 °C and pressure up to 2.5 MPa inclusive, water steam with temperatures up to 440 °C and pressure up to 6.3 MPa inclusive, water vapor condensate.

Heat networks include buildings and structures of heat networks: pumping stations, heating points, pavilions, chambers, drainage devices, etc.

These standards discuss centralized heat supply systems (hereinafter referred to as DHS) in terms of their interaction in a single technological process of production, distribution, transportation and consumption of heat.

These rules and regulations must be observed when designing new and reconstructing, modernizing and technically re-equipping existing heating networks (including structures on heating networks).

2 REGULATORY REFERENCES 3 TERMS AND DEFINITIONS

The following terms and definitions are used in these standards.

A centralized heat supply system is a system consisting of one or more heat sources, heat networks (regardless of the diameter, number and length of external heat pipelines) and heat consumers.

The probability of failure-free operation of the system [P] is the ability of the system to prevent failures leading to a temperature drop in heated rooms of residential and public buildings below +12 °C, in industrial buildings below +8 °C, more than the number of times established by the standards.

System availability (quality) coefficient [Kg] - the probability of the system being operational at any point in time to maintain the calculated internal temperature in heated rooms, except for periods of temperature decrease allowed by regulations.

System survivability [Zh] - the ability of the system to maintain its functionality in emergency (extreme) conditions, as well as after long-term (more than 54 hours) shutdowns.

The service life of heating networks is a period of time in calendar years from the date of commissioning, after which an expert examination of the technical condition of the pipeline should be carried out in order to determine the admissibility, parameters and conditions for further operation of the pipeline or the need for its dismantling.

4 CLASSIFICATION

4.1 Heating networks are divided into main, distribution, quarterly and branches from main and distribution heating networks to individual buildings and structures. The separation of heating networks is established by the project or operating organization.

4.2 Heat consumers are divided into three categories according to the reliability of heat supply:

For example, hospitals, maternity hospitals, preschool institutions with 24-hour stay for children, art galleries, chemical and special industries, mines, etc.

residential and public buildings up to 12 °C;

industrial buildings up to 8 °C.

5 General provisions

5.1 Solutions for the long-term development of heat supply systems for settlements, industrial hubs, groups of industrial enterprises, districts and other administrative-territorial entities, as well as individual central heating systems should be developed in heat supply schemes. When developing heat supply schemes, the calculated heat loads are determined:

A) for the existing development of settlements and existing industrial enterprises - according to projects with clarification on actual heat loads;

b) for industrial enterprises planned for construction - according to the enlarged standards for the development of the main (core) production or projects of similar production;

c) for residential areas planned for development - according to aggregated indicators of the density of thermal loads or according to the specific thermal characteristics of buildings and structures in accordance with the master plans for the development of areas of the settlement.

5.2 Design heat loads when designing heating networks are determined based on data from specific new construction projects, and existing ones - based on actual heat loads. In the absence of data, it is permissible to follow the instructions of 5.1. Average loads on hot water supply of individual buildings can be determined according to SNiP 2.04.01.

5.3 Estimated heat losses in heating networks should be determined as the sum of heat losses through the insulated surfaces of pipelines and the average annual coolant losses.

5.4 In case of accidents (failures) at the heat source, its output collectors must be provided with the following during the entire repair and restoration period:

supply of 100% of the required heat to consumers of the first category (unless other modes are provided for by the contract);

supply of heat for heating and ventilation to housing, communal and industrial consumers of the second and third categories in the amounts indicated in Table 1;

emergency mode of steam and process hot water consumption specified by the consumer;

Emergency thermal operating mode of non-switchable ventilation systems specified by the consumer;

Table 1

Note - The table corresponds to the outside air temperature of the coldest five-day period with a probability of 0.92.

Average daily heat consumption during the heating period for hot water supply (if it is impossible to turn it off).

5.5 When several heat sources work together on a single heating network of a district (city), mutual redundancy of heat sources must be provided, ensuring emergency operation in accordance with 5.4.

6 HEAT SUPPLY AND HEAT NETWORK DIAGRAMS

6.11 Water heating networks should be designed, as a rule, as two-pipe systems, simultaneously supplying heat for heating, ventilation, hot water supply and technological needs.

Multi-pipe and single-pipe heating networks may be used during a feasibility study.

Heat networks transporting network water in open heat supply systems in one direction, when laid above ground, can be designed in a single-pipe design with a transit length of up to 5 km. If the length is greater and there is no backup supply of the central heating system from other heat sources, the heating networks must be constructed in two (or more) parallel heat pipelines.

Independent heating networks for connecting process heat consumers should be provided if the quality and parameters of the coolant differ from those accepted in heating networks.

6.12 The layout and configuration of heating networks must ensure heat supply at the level of specified reliability indicators by:

application of the most advanced designs and technical solutions;

joint operation of heat sources;

laying backup heat pipelines;

installation of jumpers between heating networks of adjacent thermal areas.

6.13 Heat networks can be ring and dead-end, redundant and non-redundant.

The number and location of backup pipeline connections between adjacent heat pipelines should be determined according to the criterion of the probability of failure-free operation.

6.14 Heating and ventilation systems for consumers must be connected to two-pipe water heating networks directly using a dependent connection scheme.

According to an independent scheme, which provides for the installation of water heaters in heating points, it is allowed to connect other consumers when justifying the heating and ventilation system of buildings of 12 floors and above, if the independent connection is due to the hydraulic operating mode of the system.

6.15 The quality of source water for open and closed heat supply systems must meet the requirements of SanPiN 2.1.4.1074 and the rules for the technical operation of power plants and networks of the Ministry of Energy of Russia.

For closed heat supply systems in the presence of thermal deaeration, it is allowed to use process water.

6.16 The estimated hourly water consumption to determine the productivity of water treatment and the corresponding equipment for replenishing the heating supply system should be taken:

in closed heat supply systems - 0.75% of the actual volume of water in the pipelines of heating networks and the heating and ventilation systems of buildings connected to them. At the same time, for sections of heating networks longer than 5 km from heat sources without heat distribution, the calculated water flow should be taken equal to 0.5% of the volume of water in these pipelines;

in open heat supply systems - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2 plus 0.75% of the actual volume of water in the pipelines of heating networks and the heating, ventilation and hot water supply systems of buildings connected to them. At the same time, for sections of heating networks longer than 5 km from heat sources without heat distribution, the calculated water flow should be taken equal to 0.5% of the volume of water in these pipelines;

For individual heating networks of hot water supply in the presence of storage tanks - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2; in the absence of tanks - according to the maximum water consumption for hot water supply plus (in both cases) 0.75% of the actual volume of water in the network pipelines and the hot water supply systems of buildings connected to them.

6.17 For open and closed heat supply systems, additional emergency make-up with chemically untreated and non-deaerated water must be provided, the flow rate of which is assumed to be 2% of the volume of water in the pipelines of heating networks and the heating, ventilation systems connected to them and in hot water supply systems for open heat supply systems. If there are several separate heating networks extending from the heat source manifold, emergency make-up can be determined only for one heating network with the largest volume. For open heat supply systems, emergency make-up should be provided only from domestic drinking water supply systems.

6.18 The volume of water in heat supply systems, in the absence of data on actual volumes of water, can be taken equal to 65 m3 per 1 MW of calculated heat load with a closed heat supply system, 70 m3 per 1 MW - with an open system and 30 m3 per 1 MW of average load - with separate hot water networks water supply

6.19 Placement of hot water storage tanks is possible both at the heat source and in heat consumption areas. In this case, storage tanks with a capacity of at least 25% of the total design capacity of the tanks must be provided at the heat source. The inner surface of the tanks must be protected from corrosion, and the water in them from aeration, while continuous renewal of the water in the tanks must be provided.

6.20 For open heat supply systems, as well as for separate heating networks for hot water supply, storage tanks of chemically treated and deaerated make-up water with a design capacity equal to ten times the average hourly water consumption for hot water supply must be provided.

6.21 In closed heat supply systems at heat sources with a capacity of 100 MW or more, provision should be made for the installation of storage tanks for chemically treated and deaerated make-up water with a capacity of 3% of the volume of water in the heat supply system, and the renewal of water in the tanks must be ensured.

The number of tanks, regardless of the heat supply system, is accepted to be at least two, each 50% of the working volume.

6.22 In central heating systems with heat pipelines of any length from the heat source to heat consumption areas, the use of heat pipelines as storage tanks is allowed.

6.23 If a group of storage tanks is located outside the territory of heat sources, it must be fenced with a common shaft of at least 0.5 m in height. The embanked area must accommodate the volume of water in the largest tank and have water drainage to the sewer.

6.24 It is not allowed to install hot water storage tanks in residential areas. The distance from hot water storage tanks to the border of residential areas must be at least 30 m. Moreover, on soils of the 1st type of subsidence, the distance must, in addition, be at least 1.5 times the thickness of the subsidence soil layer.

When placing storage tanks outside the territory of heat sources, they should be fenced with a height of at least 2.5 m to prevent unauthorized persons from accessing the tanks.

6.25 Hot water storage tanks for consumers should be provided in the hot water supply systems of industrial enterprises to align the shifting schedule of water consumption by facilities that have concentrated short-term water consumption for hot water supply.

For industrial facilities with a ratio of the average heat load for hot water supply to the maximum heat load for heating less than 0.2, storage tanks are not installed.

6.26 To reduce losses of network water and, accordingly, heat during planned or forced emptying of heat pipes, it is allowed to install special storage tanks in heating networks, the capacity of which is determined by the volume of heat pipes between two sectional valves.

7 COOLANTS AND THEIR PARAMETERS

7.1 In centralized heat supply systems for heating, ventilation and hot water supply of residential, public and industrial buildings, as a rule, water should be used as a coolant.

The possibility of using water as a coolant for technological processes should also be checked.

The use of steam as a single coolant for enterprises for technological processes, heating, ventilation and hot water supply is allowed during a feasibility study.

7.2 The maximum design temperature of network water at the outlet of the heat source, in heating networks and heat receivers is established on the basis of technical and economic calculations.

If there is a hot water supply load in closed heat supply systems, the minimum temperature of the network water at the outlet of the heat source and in the heating networks must ensure the possibility of heating the water supplied to the hot water supply to a standardized level.

7.3 The temperature of network water returned to thermal power plants with combined heat and electricity generation is determined by technical and economic calculations. The temperature of network water returned to boiler rooms is not regulated.

7.4 When calculating graphs of network water temperatures in centralized heating systems, the beginning and end of the heating period at the average daily outside air temperature are accepted:

8 °C in areas with a design outdoor air temperature for heating design down to minus 30 °C and an average design temperature of internal air of heated buildings of 18 °C;

10 °C in areas with a design outside air temperature for heating design below minus 30 °C and an average design temperature of internal air in heated buildings of 20 °C.

The average design temperature of the internal air of heated industrial buildings is 16 °C.

7.5 If the heat receivers in the heating and ventilation systems do not have automatic individual devices for regulating the temperature inside the premises, the following should be used in heating networks to regulate the temperature of the coolant:

Central quality for the heating load, for the combined load of heating, ventilation and hot water supply - by changing the coolant temperature at the heat source depending on the outside air temperature;

central qualitative and quantitative for the combined load of heating, ventilation and hot water supply - by regulating both the temperature and the flow of network water at the heat source.

Central qualitative and quantitative regulation at the heat source can be supplemented by group quantitative regulation at heating points mainly during the transition period of the heating season, starting from the break point of the temperature graph, taking into account the connection diagrams of heating, ventilation units and hot water supply, pressure fluctuations in the heating system, availability and locations of storage tanks, heat storage capacity of buildings and structures.

7.6 With central qualitative and quantitative regulation of heat supply for heating water in hot water supply systems to consumers, the water temperature in the supply pipeline must be:

For closed heat supply systems - at least 70 °C;

for open heat supply systems - at least 60 °C.

With central qualitative and quantitative regulation for the combined load of heating, ventilation and hot water supply, the break point of the water temperature graph in the supply and return pipelines should be taken at the outside air temperature corresponding to the break point of the control graph for the heating load.

7.7 In heat supply systems, if the heat consumer in the heating and ventilation systems has individual devices for regulating the air temperature indoors by the amount of network water flowing through the receivers, central qualitative and quantitative regulation should be used, supplemented by group quantitative regulation at heating points in order to reduce fluctuations in hydraulic and thermal regimes in specific quarterly (microdistrict) systems within the limits ensuring the quality and stability of heat supply.

7.8 For separate water heating networks from one heat source to enterprises and residential areas, it is allowed to provide different schedules of coolant temperatures.

7.9 In public and industrial buildings for which it is possible to reduce the air temperature at night and during non-working hours, regulation of the temperature or coolant flow in heating points should be provided.

7.10 In residential and public buildings, if the heating devices do not have thermostatic valves, automatic regulation according to the temperature schedule should be provided to maintain the average internal air temperature in the building.

7.11 It is not permitted to use “cut-off” heat supply regulation schedules for heating networks.

8 HYDRAULIC MODES

8.1 When designing new and reconstructing existing central heating systems, as well as when developing measures to increase the operational readiness and failure-free operation of all parts of the system, calculation hydraulic modes required.

8.2 For water heating networks, the following hydraulic modes should be provided:

calculated - based on the estimated flow rates of network water;

winter - with maximum water withdrawal for hot water supply from the return pipeline;

transitional - with maximum water withdrawal for hot water supply from the supply pipeline;

summer - at maximum load of hot water supply during the non-heating period;

static - in the absence of coolant circulation in the heating network;

emergency.

8.3 Steam consumption in steam heating networks supplying enterprises with different daily operating modes should be determined taking into account the discrepancy between the maximum hourly steam consumption of individual enterprises.

For saturated steam steam pipelines, the total flow rate must take into account the additional amount of steam condensing due to heat loss in the pipelines.

8.4 Equivalent internal surface roughness steel pipes should be taken:

for steam heating networks k_e = 0.0002 m;

for water heating networks k_e = 0.0005 m;

for hot water supply networks k_e = 0.001 m.

When pipelines made of other materials are used in heating networks, the values ​​of equivalent roughness may be accepted if their actual value is confirmed by tests taking into account the service life.

8.5 It is recommended that the diameters of the supply and return pipelines of two-pipe water heating networks with a joint supply of heat for heating, ventilation and hot water supply be the same.

8.6 Smallest inner diameter pipes should be accepted in heating networks of at least 32 mm, and for hot water circulation pipelines - at least 25 mm.

8.7 Static pressure in heat supply systems with water as a coolant must be determined for a supply water temperature of 100 °C. In static modes, unacceptable increases in pressure in pipelines and equipment should be excluded.

8.8 The water pressure in the supply pipelines of water heating networks during operation of network pumps must be taken based on the conditions of non-boiling water at its maximum temperature at any point in the supply pipeline, in the equipment of the heat source and in the devices of consumer systems directly connected to the heating networks.

8.9 The water pressure in the return pipelines of water heating networks during operation of network pumps must be excessive (at least 0.05 MPa) and 0.1 MPa below the permissible pressure in consumer heat use systems.

8.10 Water pressure in the return pipelines of water heating networks of open heating systems during the non-heating period, as well as in the supply and circulation pipelines hot water supply networks should be taken at least 0.05 MPa more than the static pressure of hot water supply systems to consumers.

8.11 The pressure and temperature of water at the suction pipes of network, make-up, booster and mixing pumps should not be lower than the cavitation pressure and should not exceed those allowed by the strength conditions of the pump designs.

8.12 The pressure of network pumps should be determined for the heating and non-heating periods and taken equal to the sum of pressure losses in installations at the heat source, in the supply and return pipelines from the heat source to the most distant consumer and in the consumer system (including losses in heating points and pumping stations) with total estimated water consumption.

The pressure of booster pumps on the supply and return pipelines should be determined by piezometric graphs at maximum water flow rates in pipelines, taking into account hydraulic losses in equipment and pipelines.

8.13 The pressure of make-up pumps must be determined from the conditions for maintaining static pressure in water heating networks and checked for operating conditions of network pumps during the heating and non-heating periods.

It is allowed to provide for the installation of separate groups of make-up pumps with different pressures for heating, non-heating periods and for static mode.

8.14 The flow (performance) of working make-up pumps at the heat source in closed heat supply systems should be taken equal to the water flow to compensate for losses of network water from the heating network, and in open systems - equal to the sum of the maximum water flow for hot water supply and water flow to compensate for losses.

8.15 The pressure of mixing pumps should be determined by the greatest pressure difference between the supply and return pipelines.

8.16 The number of pumps should be taken:

network - at least two, one of which is a backup; with five working network pumps in one group, a backup pump may not be installed;

Pumping and mixing pumps (in heating networks) - at least three, one of which is a backup pump, and a backup pump is provided regardless of the number of working pumps;

make-up - in closed heat supply systems at least two, one of which is a backup, in open systems - at least three, one of which is also a backup;

in the nodes of dividing the water heating network into zones (in the cutting nodes), it is allowed to install one make-up pump without a reserve in closed heat supply systems, and in open systems - one working and one reserve.

The number of pumps is determined taking into account their joint work on the heating network.

8.17 When determining the pressure of network pumps, the pressure drop at the input of two-pipe water heating networks into buildings (with elevator connection of heating systems) should be taken equal to the calculated pressure loss at the input and in the local system with a coefficient of 1.5, but not less than 0.15 MPa. It is recommended to extinguish excess pressure in heating points of buildings.

8.18 When designing a central heating system with a heat consumption of more than 100 MW, the need for integrated system protection that prevents the occurrence of water hammer and unacceptable pressures in the equipment of water heating installations of heat sources, in heating networks, and consumer heat use systems.

9 ROUTE AND METHODS OF LAYING HEATING NETWORKS

9.1 In populated areas, heating networks are usually provided for underground installation (channelless, in canals or in city and intra-block tunnels together with other utility networks).

When justified, above-ground installation of heating networks is allowed, except in the areas of children's and medical institutions.

9.2 The laying of heating networks in areas not subject to development outside populated areas should be laid above ground on low supports.

Laying heating networks along embankments highways common use I, II and III categories are not allowed.

9.3 When choosing a route, it is allowed to cross residential and public buildings with transit water heating networks with heat pipe diameters up to 300 mm inclusive, provided that the networks are laid in technical undergrounds and tunnels (at least 1.8 m high) with a drainage well installed at the lowest point at the exit from the building .

As an exception, it is allowed to cross transit water heating networks with a diameter of 400 - 600 mm, pressure Р_у<= 1,6 МПа жилых и общественных зданий при соблюдении следующих требований:

laying should be provided in through-flow monolithic reinforced concrete channels with reinforced waterproofing. The ends of the channel must extend beyond the building by at least 5 m;

water outlets with a diameter of 300 mm should be carried out from the lowest points of the channel outside the building into the storm sewer;

During installation, a 100% inspection of the welds of steel heat pipes is required;

Shut-off and control valves must be installed outside the building;

Heat pipes within the building should not have branches.

The crossing of buildings and structures of preschool, school and medical institutions by transit heating networks is not allowed. The laying of heating networks on the territory of the listed institutions is only allowed underground in monolithic reinforced concrete channels with waterproofing. At the same time, the installation of ventilation shafts, hatches and exits to the outside from ducts within the territory of institutions is not allowed; shut-off valves must be installed outside the territory.

9.4 Laying heating networks at an operating steam pressure above 2.2 MPa and temperatures above 350 °C in tunnels together with other utility networks is not allowed.

9.5 The slope of heating networks, regardless of the direction of movement of the coolant and the method of installation, must be at least 0.002. For roller and ball bearings, the slope should not exceed

(1)

Where r is the radius of the roller or ball, see

The slope of heating networks to individual buildings during underground installation should, as a rule, be taken from the building to the nearest chamber.

In certain areas (when crossing communications, laying over bridges, etc.) it is allowed to accept the installation of heating networks without a slope.

9.6 Underground installation of heating networks may be provided in conjunction with the utility networks listed below:

in channels - with water pipes, compressed air pipelines with pressure up to 1.6 MPa, fuel oil pipelines, control cables intended for servicing heating networks;

in tunnels - with water pipelines with a diameter of up to 500 mm, communication cables, power cables with voltage up to 10 kV, compressed air pipelines with pressure up to 1.6 MPa, pressure sewerage pipelines.

The laying of heating network pipelines in channels and tunnels with other utility networks other than those indicated is not permitted.

The laying of heating network pipelines must be provided in one row or above other utility networks.

9.7 Horizontal and vertical distances from the outer edge of building structures of channels and tunnels or pipeline insulation shells for ductless installation of heating networks to buildings, structures and utility networks should be taken in accordance with Appendix B. When laying heat pipelines through the territory of industrial enterprises - according to the relevant specialized standards.

9.8 The intersection of thermal networks with rivers, highways, tram tracks, as well as buildings and structures should, as a rule, be provided at right angles. When justified, it is allowed to cross at a smaller angle, but not less than 45°, and for metro and railway structures - at least 60°.

9.9 The intersection of tram tracks with underground heating networks should be provided at a distance from switches and crosses of at least 3 m (clear).

9.10 When underground heating networks cross railways, the smallest horizontal clear distances should be taken, m:

to switches and crosses of the railway track and places of connection of suction cables to the rails of electrified railways - 10;

to switches and crosses of the railway track in subsidence soils - 20;

to bridges, pipes, tunnels and other artificial structures - 30.

9.11 The laying of heating networks at the intersection of railways of the general network, as well as rivers, ravines, and open drains should, as a rule, be provided above ground. In this case, it is allowed to use permanent road and railway bridges.

The laying of heating networks at underground intersections of railways, highways, main roads, streets, passages of citywide and regional significance, as well as streets and roads of local significance, tram tracks and metro lines should be provided for:

in channels - if it is possible to carry out construction, installation and repair work in an open way;

In cases - if it is impossible to carry out work in an open way, the crossing length is up to 40 m;

In tunnels - in other cases, as well as when buried from the surface of the earth to the top of the pipeline 2.5 m or more.

When laying heating networks under water barriers, as a rule, the installation of siphons should be provided.

Heating networks crossing metro station structures is not allowed.

When underground heating networks intersect subway lines, channels and tunnels should be made of monolithic reinforced concrete with waterproofing.

9.12 The length of channels, tunnels or casings at intersections must be taken in each direction to be at least 3 m greater than the dimensions of the structures being crossed, including subgrade structures of railways and roads, taking into account Table B.3.

When heating networks cross railways of the general network, metro lines, rivers and reservoirs, shut-off valves should be provided on both sides of the intersection, as well as devices for draining water from heating network pipelines, canals, tunnels or cases at a distance of no more than 100 m from the border of the crossed structures .

9.13 When laying heating networks in cases, anti-corrosion protection of heating network pipes and cases must be provided. Electrochemical protection must be provided at the intersection of electrified railways and tram tracks.

A gap of at least 100 mm must be provided between the thermal insulation and the case.

9.14 At intersections during underground installation of heating networks with gas pipelines, the passage of gas pipelines through the building structures of chambers, impassable channels and tunnels is not allowed.

9.15 When heating networks cross water supply and sewerage networks located above the pipelines of heating networks, when the distance from the structure of the heating networks to the pipelines of the crossed networks is 300 mm or less (clear), as well as when crossing gas pipelines, it is necessary to provide for the installation of covers on the water supply, sewerage and gas over a length of 2 m on both sides of the intersection (in the clear). Cases should be provided with a protective coating against corrosion.

9.16 At the intersection of heating networks when they are laid underground in channels or tunnels with gas pipelines, devices for sampling for gas leaks should be provided on heating networks at a distance of no more than 15 m on both sides of the gas pipeline.

When laying heating networks with associated drainage at the intersection with the gas pipeline, drainage pipes should be provided without holes at a distance of 2 m on both sides of the gas pipeline, with hermetically sealed joints.

9.17 At the entrances of heating network pipelines into buildings in gasified areas, it is necessary to provide devices that prevent the penetration of water and gas into buildings, and in non-gasified areas - water.

9.18 At the intersection of above-ground heating networks with overhead power lines and electrified railways, it is necessary to provide for grounding of all electrically conductive elements of heating networks (with a resistance of grounding devices of no more than 10 Ohms), located at a horizontal distance of 5 m in each direction from the wires.

9.19 The laying of heating networks along the edges of terraces, ravines, slopes, and artificial excavations should be provided outside the prism of soil collapse due to soaking. At the same time, when buildings and structures for various purposes are located under a slope, measures should be taken to drain emergency water from heating networks in order to prevent flooding of the development area.

9.20 In the area of ​​heated pedestrian crossings, including those combined with entrances to the metro, it is necessary to provide for the laying of heating networks in a monolithic reinforced concrete channel extending 5 m beyond the clearance of the crossings.

10 PIPELINE DESIGN

10.1 Pipes, fittings and products made of steel and cast iron for heating networks should be accepted in accordance with the rules for the design and safe operation of steam and hot water pipelines PB 10-573 of the Gosgortekhnadzor of Russia. Calculation of steel and cast iron pipelines for strength should be carried out according to the standards for calculating the strength of pipelines of heating networks RD 10-400 and RD 10-249.

10.2 Electric-welded steel pipes or seamless steel pipes should be provided for heating network pipelines.

Pipes made of high-strength nodular cast iron (ductile iron) can be used for heating networks at water temperatures up to 150 °C and pressures up to 1.6 MPa inclusive.

10.3 For pipelines of heating networks with an operating steam pressure of 0.07 MPa and below and a water temperature of 115 °C and below at a pressure of up to 1.6 MPa inclusive, it is allowed to use non-metallic pipes if the quality and characteristics of these pipes satisfy sanitary requirements and correspond to the parameters of the coolant in heating networks.

10.4 For hot water supply networks in closed heat supply systems, pipes made of corrosion-resistant materials or coatings must be used. Pipes made of ductile iron, polymer materials and non-metallic pipes can be used for both closed and open heat supply systems.

10.5 The maximum distances between movable pipe supports in straight sections should be determined by strength calculations, based on the possibility of maximum use of the bearing capacity of the pipes and according to the permissible deflection, accepted as no more than 0.02 D_y, m.

10.6 To select pipes, fittings, equipment and parts of pipelines, as well as to calculate pipelines for strength and when determining loads from pipelines on pipe supports and building structures, the operating pressure and temperature of the coolant should be taken:

a) for steam networks:

When receiving steam directly from boilers - according to the nominal values ​​of pressure and temperature of steam at the outlet of the boilers;

When receiving steam from regulated extractions or turbine backpressure - according to the steam pressure and temperature accepted at the terminals from the thermal power plant for a given steam pipeline system;

when receiving steam after reduction-cooling, reduction or cooling units (ROU, RU, OU) - according to the pressure and temperature of the steam after installation;

b) for supply and return pipelines of water heating networks:

pressure - at the highest pressure in the supply pipeline behind the outlet valves at the heat source when network pumps are operating, taking into account the terrain (without taking into account pressure losses in the networks), but not less than 1.0 MPa;

Temperature - based on the temperature in the supply pipeline at the calculated outside air temperature for heating design;

c) for condensate networks:

pressure - based on the highest pressure in the network when pumps are operating, taking into account the terrain;

temperature after condensate traps - according to the saturation temperature at the maximum possible steam pressure immediately before the condensate trap, after condensate pumps - according to the temperature of the condensate in the collection tank;

D) for supply and circulation pipelines of hot water supply networks:

Pressure - based on the highest pressure in the supply pipeline during pump operation, taking into account the terrain;

temperature - up to 75 °C.

10.7 The operating pressure and temperature of the coolant must be assumed to be the same for the entire pipeline, regardless of its length from the heat source to the heating point of each consumer or to installations in the heating network that change the parameters of the coolant (water heaters, pressure and temperature regulators, reduction-cooling units, pumping stations) . After these installations, the coolant parameters provided for these installations must be accepted.

10.8 The parameters of the coolant of the reconstructed water heating networks are taken according to the parameters in the existing networks.

10.9 For pipelines of heating networks, except for heating points and hot water supply networks, it is not allowed to use fittings from:

gray cast iron - in areas with a design outside air temperature for heating design below minus 10 °C;

malleable cast iron - in areas with a design outside air temperature for heating design below minus 30 °C;

Ductile iron in areas with a design outdoor temperature for heating design below minus 40 °C.

It is not allowed to use fittings made of gray cast iron on drainage, blowing and drainage devices.

On pipelines of heating networks, it is allowed to use fittings made of brass and bronze at a coolant temperature not exceeding 250 °C.

Steel shut-off valves must be provided at the outlets of heating networks from heat sources and at the inputs to central heating points (CHS).

At the entrance to an individual heating point (IHP) with a total thermal load for heating and ventilation of 0.2 MW or more, steel shut-off valves should be provided. When the IHP load is less than 0.2 MW or the design coolant temperature is 115 °C and below, it is allowed to provide fittings made of ductile or high-strength cast iron at the input.

Within heating points, it is allowed to provide fittings made of malleable, high-strength and gray cast iron in accordance with PB 10-573.

10.10 When installing cast iron fittings in heating networks, it must be protected from bending forces.

10.11 It is not allowed to accept shut-off valves as control valves.

10.12 For heating networks, as a rule, fittings with welded ends or flanged ends should be used.

Coupling fittings can be accepted with conditional bore D_у<= 100 мм при давлении теплоносителя 1,6 МПа и ниже и температуре 115 °С и ниже в случаях применения водогазопроводных труб.

10.13 For valves and gates on water heating networks with a diameter D_y >= 500 mm at a pressure Р_у >= 1.6 MPa and D_y >= 300 mm at Р_у>= 2.5 MPa, and on steam networks D_y>= 200 mm at Р_у >= 1.6 MPa, bypass pipelines with shut-off valves (unloading bypasses) should be provided.

10.14 Valves and shutters D_y>= 500 mm should be provided with an electric drive.

When remotely controlling valves, the valves on the bypasses should also be equipped with an electric drive.

10.15 Electrically driven valves and shutters for underground installation must be placed in chambers with above-ground pavilions or in underground chambers with natural ventilation, providing air parameters in accordance with technical specifications for electric drives to valves.

When laying heating networks above ground on low supports, metal casings should be provided for valves and gates with electric drives, excluding access to unauthorized persons and protecting them from precipitation, and on transit highways, as a rule, pavilions. When laying on overpasses or high free-standing supports, use canopies (canopies) to protect the reinforcement from precipitation.

10.16 In construction areas with a design outside air temperature of minus 40 °C and below, when using carbon steel reinforcement, measures must be taken to exclude the possibility of reducing the steel temperature below minus 30 °C during transportation, storage, installation and operation, and when laying heating networks on low supports for valves and gates D_y >= 500 mm, pavilions with electric heating, preventing the air temperature in the pavilions from dropping below minus 30 °C when the networks are stopped.

10.17 Shut-off valves in heating networks should be provided with:

a) on all pipelines of heating networks outlets from heat sources, regardless of the coolant parameters and pipeline diameters, and on condensate pipelines at the inlet to the condensate collection tank; At the same time, duplication of fittings inside and outside the building is not allowed;

B) on pipelines of water heating networks D_y >= 100 mm at a distance of no more than 1000 m from each other (sectional valves) with a jumper between the supply and return pipelines with a diameter equal to 0.3 of the pipeline diameter, but not less than 50 mm; on the jumper there should be two valves and a control valve between them D_у = 25 mm.

It is allowed to increase the distance between sectional valves for pipelines D_y = 400 - 500 mm - up to 1500 m, for pipelines D_y >= 600 mm - up to 3000 m, and for above-ground pipelines D_y >= 900 mm - up to 5000 m while ensuring water drainage and filling a sectioned section of one pipeline in a time not exceeding that specified in 10.19.

Sectional valves may not be installed on steam and condensate heating networks.

c) in water and steam heating networks in nodes on branch pipelines D_y more than 100 mm.

10.18 At the lowest points of pipelines of water heating networks and condensate pipelines, as well as sectioned sections, it is necessary to provide fittings with shut-off valves for draining water (draining devices).

10.19 Discharge devices for water heating networks should be provided based on ensuring the duration of water discharge and filling of the sectioned section (one pipeline), h:

for pipelines D_у<= 300 мм - не более 2;

D_у= 350 - 500 same 4;

D_у >= 600 " 5.

If the drainage of water from pipelines at the lowest points is not ensured within the specified time frame, intermediate drainage devices must be additionally provided.

10.20 Sump traps in water heating networks should be provided on pipelines in front of pumps and in front of pressure regulators in cutting units. There is no need to provide mud traps in the installation units of sectional valves.

10.21 The installation of bypass pipelines around mud traps and control valves is not allowed.

10.22 At the highest points of heating network pipelines, including at each sectioned section, fittings with shut-off valves for air release (air vents) must be provided.

In pipeline assemblies on branches up to valves and in local bends of pipelines with a height of less than 1 m, air release devices may not be provided.

10.23 The drainage of water from pipelines at the lowest points of water heating networks when laid underground must be provided separately from each pipe with a break in the stream into discharge wells, followed by drainage of water by gravity or mobile pumps into the sewerage system. The temperature of the discharged water must be reduced to 40 °C.

Draining water directly into chambers of heating networks or onto the surface of the earth is not allowed. When laying pipelines above ground in an undeveloped area, water can be drained into concrete pits with water drained from them using ditches, trays or pipelines.

It is allowed to provide for the drainage of water from waste wells or pits into natural reservoirs and onto the terrain, subject to agreement with the supervisory authorities.

When discharging water into the domestic sewerage system, a gravity pipeline must be provided with check valve in case of possible reverse flow of water.

It is allowed to drain water directly from one section of the pipeline into the section adjacent to it, as well as from the supply pipeline to the return one.

10.24 At the lowest points of steam networks and before vertical rises, constant drainage of steam lines should be provided. In these same places, as well as on straight sections of steam pipelines, starting drainage of steam pipelines must be provided every 400 - 500 m with a downward slope and every 200 - 300 m with a counter slope.

10.25 For start-up drainage of steam networks, fittings with shut-off valves must be provided.

At each fitting with an operating steam pressure of 2.2 MPa or less, one valve or valve should be provided; at operating steam pressure above 2.2 MPa - two valves located in series.

10.26 For permanent drainage of steam networks or when combining permanent drainage with start-up drainage, fittings with plugs and condensate drains connected to the fitting through a drain pipeline must be provided.

When laying several steam pipelines, a separate condensate trap must be provided for each of them (including with the same steam parameters).

10.27 Condensate drainage from permanent drains of steam networks into a pressure condensate pipeline is permitted provided that at the point of connection, the condensate pressure in the drainage condensate pipeline exceeds the pressure in the pressure condensate pipeline by at least 0.1 MPa; in other cases, condensate is discharged outside. There are no special condensate pipelines for discharging condensate.

10.28 To compensate for thermal deformations of heating network pipelines, the following compensation methods and compensating devices should be used:

flexible expansion joints ( various shapes) from steel pipes and angles of rotation of pipelines - for any coolant parameters and installation methods;

bellows and lens compensators - for coolant parameters and installation methods in accordance with the technical documentation of the manufacturers;

Starting compensators designed to partially compensate for temperature deformations by changing the axial stress in the pinched pipe;

stuffing box steel compensators with coolant parameters R_y<= 2,5 МПа и t<= 300 °С для трубопроводов диаметром 100 мм и более при подземной прокладке и надземной на низких опорах.

It is allowed to use non-compensatory gaskets when compensation for temperature deformations is carried out fully or partially due to alternating changes in axial compression-tension stresses in the pipe. Checking for longitudinal bending is mandatory.

10.29 When laying above ground, metal casings should be provided to prevent access to the stuffing box expansion joints by unauthorized persons and protect them from precipitation.

10.30 It is not required to install displacement indicators to monitor thermal elongation of pipelines in heating networks, regardless of the coolant parameters and pipeline diameters.

10.31 For heating networks, as a rule, parts and elements of factory-made pipelines should be accepted.

For flexible expansion joints, bending angles and other bent pipeline elements, steeply curved factory-made bends with a bend radius of at least one pipe diameter must be accepted.

For pipelines of water heating networks with a working coolant pressure of up to 2.5 MPa and a temperature of up to 200 °C, as well as for steam heating networks with an operating pressure of up to 2.2 MPa and a temperature of up to 350 °C, welded sector bends are allowed.

Stamp-welded tees and bends can be used for coolants of all parameters.

Notes

1. Stamp-welded and welded sector bends are allowed to be accepted subject to 100% control of the welded joints of the bends by ultrasonic flaw detection or radiation scanning.

2. Welded sector bends are allowed to be accepted provided they are manufactured with internal welding of the welds.

3. It is not allowed to manufacture pipeline parts, including bends, from electric-welded pipes with a spiral seam.

4. Welded sector bends for pipelines made of ductile iron pipes may be accepted without internal welding of the welds, if the formation of a reverse bead is ensured, and the lack of penetration in depth does not exceed 0.8 mm over a length of no more than 10% of the length of the seam at each joint.

10.32 The distance between adjacent welds on straight sections of pipelines with a coolant with a pressure of up to 1.6 MPa and a temperature of up to 250 °C must be at least 50 mm, for coolants with higher parameters - at least 100 mm.

The distance from the transverse weld to the beginning of bending must be at least 100 mm.

10.33 Steeply curved bends may be welded together without a straight section. Steeply curved and welded bends are not allowed to be welded directly into a pipe without a fitting (pipe, pipe).

10.34 Movable pipe supports should be provided:

Sliding - regardless of the direction of horizontal movements of pipelines for all installation methods and for all pipe diameters;

roller - for pipes with a diameter of 200 mm or more during axial movement of pipes when laying in tunnels, on brackets, on free-standing supports and overpasses;

ball - for pipes with a diameter of 200 mm or more with horizontal movements of pipes at an angle to the axis of the route when laying in tunnels, on brackets, on free-standing supports and overpasses;

Spring supports or hangers - for pipes with a diameter of 150 mm or more in places where pipes move vertically;

Rigid suspensions - for above-ground laying of pipelines with flexible compensators and in self-compensation areas.

Note - On sections of pipelines with stuffing box and axial bellows expansion joints, it is not allowed to lay pipelines on suspended supports.

10.35 The length of rigid hangers should be taken for water and condensate heating networks to be at least ten times, and for steam networks - at least twenty times the thermal displacement of the pipe with the hanger furthest from the fixed support.

10.36 Axial bellows expansion joints (SC) are installed indoors, in passage channels. It is allowed to install the SK outdoors and in thermal chambers in a metal shell that protects the bellows from external influences and contamination.

Axial bellows compensating devices (SKU) (bellows compensators protected from contamination, external influences and lateral loads by a durable casing) can be used for all types of laying.

SKU and SKU can be placed anywhere in the heat pipeline between fixed supports or conditionally fixed sections of the pipe, unless there are restrictions from the manufacturer.

When choosing a location, it must be possible to move the compensator casing in any direction to its full length.

10.37 When using SC and SKU on heat pipelines for underground installation in channels, tunnels, chambers, for above-ground installation and in rooms, the installation of guide supports is mandatory.

When installing starting compensators, guide supports are not installed.

10.38 Guide supports should be used, as a rule, of the covering type (clamp, pipe-shaped, frame), forcibly limiting the possibility of transverse shift and not interfering with the axial movement of the pipe.

10.39 Requirements for the placement of pipelines when laying them in non-passable channels, tunnels, chambers, pavilions, for overhead installation and in heating points are given in Appendix B.

10.40 The technical characteristics of expansion joints must satisfy the strength calculations in cold and operating conditions of pipelines.

10.41 Heat pipes when laid without ducts should be checked for stability (longitudinal bending) in the following cases:

When the depth of installation of heat pipes is shallow (less than 1 m from the axis of the pipes to the surface of the earth);

if there is a possibility of flooding of the heating pipeline by ground, flood or other waters;

if there is a possibility of excavation work near the heating main.

11 THERMAL INSULATION

11.1 For heating networks, as a rule, thermal insulation materials and structures that have been tested by operational practice should be used. New materials and designs are allowed for use if the results of independent tests conducted by specialized laboratories are positive.

11.2 The materials of thermal insulation and the covering layer of heat pipelines must meet the requirements of SNiP 41-03, fire safety standards and are selected depending on the specific conditions and installation methods.

When jointly laying heat pipelines underground in tunnels (passage channels) with electrical or low-current cables, pipelines transporting flammable substances, it is not allowed to use a thermal insulating structure made of flammable materials. When laying heat pipes separately in tunnels (pass-through channels), the use of non-combustible materials (NG) is mandatory only for the covering layer of thermal insulation of heat pipes.

For underground channelless installation and in non-passable channels, it is allowed to use flammable materials for the heat-insulating and cover layers.

11.3 The tunnel (passage channel) should be divided into compartments every 200 m by type 1 fire partitions with type 2 fire doors.

11.4 When laying heat pipes in thermal insulation made of flammable materials, inserts made of non-combustible materials with a length of at least 3 m should be provided:

in each chamber of the heating network and at the entrance to the buildings;

for overhead installation - every 100 m, and for vertical sections every 10 m;

in places where heat pipes exit the ground.

When using heat pipeline structures in thermal insulation made of combustible materials in a non-combustible shell, it is allowed not to make inserts.

11.5 The fastening parts of heat pipelines must be made of corrosion-resistant materials or coated with anti-corrosion coatings.

11.6 The choice of thermal insulation material and heat pipeline design should be made according to the economic optimum of the total operating costs and capital investments in heating networks, related structures and structures. When choosing thermal insulation materials, the use of which requires changing the parameters of the coolant (design temperature, control modes, etc.), it is necessary to compare the options for centralized heating systems as a whole.

The choice of thermal insulation thickness should be made according to SNiP 41-03 for the given parameters, taking into account the climatological data of the construction site, the cost of the thermal insulation structure and heat.

11.7 When determining heat losses by pipelines, the calculated temperature of the coolant is accepted for the supply heat pipelines of water heating networks:

at a constant temperature of the network water and quantitative regulation - the maximum temperature of the coolant;

with variable supply water temperature and high-quality regulation - the average annual coolant temperature is 110 °C with a temperature control schedule of 180 - 70 °C, 90 °C at 150 - 70 °C, 65 °C at 130 - 70 °C and 55 °C at 95 - 70 °C. The average annual temperature for return heat pipes of water heating networks is assumed to be 50 °C.

11.8 When placing heat pipes in service rooms, technical undergrounds and basements of residential buildings, the internal air temperature is assumed to be 20 °C, and the temperature on the surface of the heat pipe structure is not higher than 45 °C.

11.9 When choosing the designs of heat pipes for overhead and duct installation, the requirements for heat pipes in the assembly should be observed:

When using structures with non-hermetic coatings, the covering layer of thermal insulation must be waterproof and not prevent the drying of the moistened thermal insulation;

when using structures with hermetic coatings, it is necessary to install a system for operational remote control (ORC) of thermal insulation humidification;

indicators of temperature resistance and insolation resistance must be within specified limits throughout the entire design service life for each element or structure;

11.10 When choosing designs for underground ductless installations of heating networks, two groups of heat pipeline designs should be considered:

group "a" - heat pipes in a sealed, vapor-tight waterproof shell. Representative design - factory-made heat pipes in polyurethane foam thermal insulation with a polyethylene shell in accordance with GOST 30732;

group "b" - heat pipes with a vapor-permeable waterproof coating or in monolithic thermal insulation, the outer compacted layer of which must be waterproof and at the same time vapor-permeable, and the inner layer adjacent to the pipe must protect the steel pipe from corrosion. Representative structures are factory-made heat pipes in poly-polymer-mineral foam or reinforced foam-concrete thermal insulation.

11.11 Mandatory requirements for heat pipes of group “a”:

uniform density of filling the structure with heat-insulating material;

the tightness of the shell and the presence of a UEC system, organizing the replacement of a wet area with a dry one;

the rate of external corrosion of pipes should not exceed 0.03 mm/year;

Abrasion resistance of the protective coating - more than 2 mm/25 years.

Mandatory requirements for the physical and technical characteristics of group “b” heat pipeline structures:

temperature resistance indicators must be within specified limits during the design service life;

the rate of external corrosion of steel pipes should not exceed 0.03 mm/year.

11.12 When calculating the thickness of the insulation and determining the annual heat losses of heat pipes laid without ducts at a depth of the heat pipe axis of more than 0.7 m, the annual average soil temperature at this depth is taken as the design ambient temperature.

When the depth of the heat pipeline from the top of the heat-insulating structure is less than 0.7 m, the same outside air temperature is taken as the calculated ambient temperature as for above-ground installation.

To determine the soil temperature in the temperature field of an underground heat pipeline, the temperature of the coolant must be taken:

for water heating networks - according to the temperature control schedule at the average monthly outside air temperature of the billing month;

For hot water supply networks - according to the maximum hot water temperature.

11.13 When choosing structures for above-ground heat pipelines, the following requirements for the physical and technical characteristics of heat pipeline structures should be taken into account:

temperature resistance indicators must be within specified limits during the design service life of the structure;

the rate of external corrosion of steel pipes should not exceed 0.03 mm/year.

11.14 When determining the thickness of thermal insulation of heat pipes laid in passage channels and tunnels, the air temperature in them should be taken to be no more than 40 °C.

11.15 When determining annual heat losses by heat pipes laid in channels and tunnels, the coolant parameters should be taken according to 11.7.

11.16 When laying heating networks in non-passing channels and without ducts, the thermal conductivity coefficient of thermal insulation must be taken taking into account possible moisture in the structure of heat pipelines.

12 BUILDING STRUCTURES

12.1 Frames, brackets and other steel structures for heating network pipelines must be protected from corrosion.

12.2 For the external surfaces of channels, tunnels, chambers and other structures when laying heating networks outside the groundwater level zone, coating insulation and adhesive waterproofing of the floors of these structures must be provided.

12.3 When laying heating networks in channels below the maximum groundwater level, associated drainage should be provided, and waterproof insulation should be provided for the external surfaces of building structures and embedded parts.

If it is impossible to use associated drainage, lining waterproofing must be provided to a height exceeding the maximum groundwater level by 0.5 m, or other effective waterproofing.

When laying heat pipes without ducts with a polyethylene covering layer, a associated drainage device is not required.

12.4 For associated drainage, pipes with prefabricated elements, as well as ready-made pipe filters, should be accepted. The diameter of the drainage pipes must be taken according to calculation.

12.5 At turning corners and on straight sections of associated drainages, inspection wells should be installed at least every 50 m. The bottom elevation of the well should be taken 0.3 m below the laying level of the adjacent drainage pipe.

12.6 A reservoir with a capacity of at least 30% of the maximum hourly amount of drainage water must be provided for collecting water.

Water removal from the associated drainage system should be provided by gravity or pumping into storm drains, reservoirs or ravines.

12.7 To pump water from the associated drainage system, at least two pumps must be installed in the pumping room, one of which is a backup one. The supply (performance) of the working pump should be taken according to the maximum hourly amount of incoming water with a coefficient of 1.2, taking into account the removal of random water.

12.8 The slope of associated drainage pipes must be taken to be at least 0.003.

12.9 Designs of fixed panel supports should only be accepted with an air gap between the pipeline and the support and allow the possibility of replacing the pipeline without destroying the reinforced concrete body of the support. Panel supports must have openings to allow water drainage and, if necessary, openings for ventilation of channels.

12.10 The height of passage channels and tunnels must be at least 1.8 m. The width of passages between heat pipes must be equal to the outer diameter of the uninsulated pipe plus 100 mm, but not less than 700 mm. The clear height of the chambers from the floor level to the bottom of the protruding structures must be taken to be at least 2 m. A local reduction in the height of the chamber to 1.8 m is allowed.

12.11 For tunnels, entrances with stairs should be provided at a distance of no more than 300 m from each other, as well as emergency and entrance hatches at a distance of no more than 200 m for water heating networks.

Entrance hatches must be provided at all end points of dead-end sections of tunnels, at turns and at nodes where, due to the layout conditions, pipelines and fittings make passage difficult.

12.12 In tunnels, at least every 300 m, installation openings should be provided with a length of at least 4 m and a width of at least the largest diameter of the pipe being laid plus 0.1 m, but not less than 0.7 m.

12.13 The number of hatches for cells should be at least two, located diagonally.

12.14 From the pits of chambers and tunnels at the lowest points, provision must be made for gravity drainage of random water into discharge wells and the installation of shut-off valves at the entrance of the gravity pipeline to the well. Water drainage from the pits of other chambers (not at the lowest points) should be provided by mobile pumps or directly by gravity into the sewerage system with a hydraulic seal installed on the gravity pipeline, and if reverse flow of water is possible, additional shut-off valves.

12.15 Supply and exhaust ventilation must be provided in tunnels. Ventilation of tunnels should ensure that the air temperature in the tunnels is not higher than 40 °C both in winter and summer, and during repair work - not higher than 33 °C. The air temperature in tunnels can be reduced from 40 to 33 °C using mobile ventilation units.

The need for natural ventilation of channels is established in projects. When using materials for thermal insulation of pipes that emit harmful substances during operation in quantities exceeding the maximum permissible concentration in the air of the working area, a ventilation device is required.

12.16 Ventilation shafts for tunnels can be combined with their entrances. The distance between the supply and exhaust shafts should be determined by calculation.

12.17 When laying ductless heating networks, the heating pipes are laid on a sandy base with a bearing capacity of the soil of at least 0.15 MPa. In soft soils with a bearing capacity of less than 0.15 MPa, an artificial foundation is recommended.

12.18 Ductless installation of heating pipelines can be designed under impassable parts of streets and inside residential areas, under streets and roads of category V and local significance. The laying of heat pipes under the roadway of categories I - IV highways, main roads and streets is allowed in channels or cases.

12.19 When underground crossings of roads and streets, the requirements set out in Appendix B must be observed.

12.20 When compensating for temperature expansions due to the angles of rotation of the route, U-shaped, L-shaped, Z-shaped compensators for channelless laying of pipelines, shock-absorbing gaskets or channels (niches) should be provided.

Branches that are not located at fixed supports should also be provided with shock-absorbing pads.

13 PROTECTION OF PIPELINES FROM CORROSION

13.1 When choosing a method for protecting steel pipes of heating networks from internal corrosion and make-up water preparation schemes, the following main parameters of network water should be taken into account:

hardness of water;

Hydrogen pH;

13.2 Protection of pipes from internal corrosion should be carried out by:

reducing the oxygen content in network water;

coating the inner surface of steel pipes with anti-corrosion compounds or using corrosion-resistant steels;

application of a reagent-free electrochemical method of water treatment;

application of water treatment and deaeration of make-up water;

use of corrosion inhibitors.

13.3 To monitor internal corrosion on the supply and return pipelines of water heating networks, installation of corrosion indicators should be provided at the outlets from the heat source and in the most typical places.

14 THERMAL POINTS

14.1 Heating points are divided into:

individual heating points (IHP) - for connecting heating, ventilation, hot water supply and technological heat-using installations of one building or part of it;

Central heating points (CHS) - the same, two buildings or more.

14.2 Thermal points provide for the placement of equipment, fittings, monitoring, control and automation devices, through which the following is carried out:

transformation of the type of coolant or its parameters;

control of coolant parameters;

accounting for heat loads, coolant and condensate flow rates;

regulation of coolant flow and distribution across heat consumption systems (through distribution networks in central heating stations or directly to heating and heating systems);

Protection of local systems from emergency increases in coolant parameters;

filling and replenishing heat consumption systems;

Collection, cooling, return of condensate and quality control;

heat accumulation;

water treatment for hot water supply systems.

At a heating point, depending on its purpose and local conditions, all of the listed activities or only part of them can be carried out. Devices for monitoring coolant parameters and metering heat consumption should be provided at all heating points.

14.3 The installation of an ITP input is mandatory for each building, regardless of the presence of a central heating point, while the ITP provides only for those measures that are necessary for connecting a given building and are not provided for in the central heating point.

14.4 In closed and open heat supply systems, the need to install central heating stations for residential and public buildings must be justified by technical and economic calculations.

14.5 In the premises of heating points it is allowed to place equipment for sanitary systems of buildings and structures, including booster pumping units that supply water for domestic drinking and fire-fighting needs.

14.6 Basic requirements for the placement of pipelines, equipment and fittings in heating points should be taken according to Appendix B.

14.7 The connection of heat consumers to heating networks at heating points should be provided according to schemes that ensure minimum water consumption in heating networks, as well as heat savings through the use of heat flow regulators and limiters of the maximum flow of network water, correction pumps or elevators with automatic control that reduce the temperature water entering heating, ventilation and air conditioning systems.

14.8 The design temperature of water in the supply pipelines after the central heating point should be accepted:

when connecting heating systems of buildings according to a dependent scheme - equal, as a rule, to the calculated water temperature in the supply pipeline of the heating networks to the central heating point;

with an independent scheme - no more than 30 °C below the design temperature of water in the supply pipeline of the heating networks to the central heating point, but not higher than 150 °C and not lower than the design temperature accepted in the consumer’s system.

Independent pipelines from central heating stations for connecting ventilation systems with an independent connection scheme for heating systems are provided at a maximum thermal load for ventilation of more than 50% of the maximum thermal load for heating.

14.9 When calculating the heating surface of water-water heaters for hot water supply and heating systems, the water temperature in the supply pipeline of the heating network should be taken equal to the temperature at the break point of the water temperature graph or the minimum water temperature, if there is no break in the temperature graph, and for heating systems - also the temperature water corresponding to the calculated outside air temperature for heating design. The larger of the obtained values ​​of the heating surface should be taken as the calculated value.

14.10 When calculating the heating surface of hot water supply water heaters, the temperature of the heated water at the outlet from the water heater into the hot water supply system should be taken to be at least 60 °C.

14.11 For high-speed sectional water-to-water water heaters, a countercurrent flow pattern of coolant should be adopted, while heating water from the heating network should flow:

in water heaters of heating systems - in tubes;

The same goes for hot water supply - into the interpipe space.

In steam-water water heaters, steam must enter the inter-tube space.

For hot water supply systems with steam heating networks, it is allowed to use capacious water heaters, using them as hot water storage tanks, provided that their capacity corresponds to that required in the calculation for storage tanks.

In addition to high-speed water heaters, it is possible to use other types of water heaters that have high thermal and operational characteristics and small dimensions.

14.12 The minimum number of water-to-water heaters should be:

two, connected in parallel, each of which must be calculated for 100% of the heat load - for heating systems of buildings that do not allow interruptions in the heat supply;

two, designed for 75% of the heat load each, - for heating systems of buildings constructed in areas with a design outdoor temperature below minus 40 ° C;

one - for other heating systems;

Two, connected in parallel in each heating stage, designed for 50% of the heat load each - for hot water supply systems.

With a maximum heat load for hot water supply of up to 2 MW, it is allowed to provide one hot water supply heater in each heating stage, except for buildings that do not allow interruptions in the supply of heat to hot water supply.

When installing steam-water water heaters in heating, ventilation or hot water supply systems, their number must be at least two, connected in parallel; backup water heaters need not be provided.

For technological installations that do not allow interruptions in the heat supply, backup water heaters must be provided, designed for the heat load in accordance with the operating mode of the enterprise's technological installations.

14.13 Pipelines should be equipped with fittings with shut-off valves with a nominal bore of 15 mm for releasing air at the highest points of all pipelines and with a nominal bore of at least 25 mm for draining water at the lowest points of water and condensate pipelines.

It is permissible to install devices for draining water not in the central heating station pit, but outside the central heating station in special chambers.

14.14 Mud traps should be installed:

at the heating point on the supply pipelines at the inlet;

On the return pipeline in front of the control devices and water and heat flow metering devices - no more than one;

in ITP - regardless of their availability in the central heating center;

in thermal units of consumers of the 3rd category - on the supply pipeline at the inlet.

Filters should be installed in front of mechanical water meters (vane, turbine), plate heat exchangers and other equipment along the water flow (as required by the manufacturer).

14.15 At heating points, it is not allowed to install starting jumpers between the supply and return pipelines of heating networks, as well as bypass pipelines in addition to pumps (except for booster pumps), elevators, control valves, mud traps and devices for metering water and heat consumption.

Overflow regulators and steam traps must have bypass piping.

14.16 To protect pipelines and equipment of centralized hot water supply systems connected to heating networks through water heaters from internal corrosion and scale formation, water treatment should be provided, usually carried out in a central heating station. In ITP, only magnetic and silicate water treatment is allowed.

14.17 Treatment of drinking water should not worsen its sanitary and hygienic indicators. Reagents and materials used for water treatment that have direct contact with water entering the hot water supply system must be approved by the State Sanitary and Epidemiological Supervision authorities of Russia for use in domestic and drinking water supply practice.

14.18 When installing storage tanks for hot water supply systems in heating points with vacuum deaeration, it is necessary to protect the inner surface of the tanks from corrosion and the water in them from aeration by using sealing liquids. In the absence of vacuum deaeration, the internal surface of the tanks must be protected from corrosion through the use of protective coatings or cathodic protection. The design of the tank should include a device that prevents sealing liquid from entering the hot water supply system.

14.19 For heating points, supply and exhaust ventilation should be provided, designed for air exchange determined by heat release from pipelines and equipment. The calculated air temperature in the work area in the cold period of the year should be taken no higher than 28 °C, in the warm period of the year - 5 °C higher than the outside air temperature according to parameters A. When placing heating points in residential and public buildings, a verification calculation of heat inputs from heating point into adjacent rooms. If the permissible air temperature in these rooms exceeds the permissible air temperature, measures should be taken for additional thermal insulation of the enclosing structures of adjacent rooms.

14.20 A drain should be installed in the floor of the heating unit, and if gravity drainage of water is not possible, a drainage pit should be installed measuring at least 0.5 x 0.5 x 0.8 m. The pit is covered with a removable grate.

To pump water from the catchment pit into the sewerage system, drainage system or associated drainage, one drainage pump should be provided. A pump designed for pumping water from a catchment pit is not allowed to be used for flushing heat consumption systems.

14.21 At heating points, measures should be taken to prevent noise levels from exceeding those allowed for premises in residential and public buildings. Heating units equipped with pumps are not allowed to be placed adjacent to or above the premises of residential apartments, dormitories and playrooms of preschool institutions, sleeping quarters of boarding schools, hotels, hostels, sanatoriums, rest homes, boarding houses, wards and operating rooms of hospitals, premises with long stays patients, doctors' offices, auditoriums of entertainment enterprises.

14.22 The minimum clear distances from free-standing ground central heating centers to the external walls of the listed premises must be at least 25 m.

In particularly cramped conditions, it is permissible to reduce the distance to 15 m, provided that additional measures are taken to reduce noise to a level acceptable according to sanitary standards.

14.23 Based on their placement on the general plan, heating points are divided into free-standing, attached to buildings and structures, and built into buildings and structures.

14.24 Heating units built into buildings should be located in separate rooms near the outer walls of buildings.

14.25 The following exits must be provided from the heating point:

if the length of the heating point room is 12 m or less - one exit to the adjacent room, corridor or staircase;

if the length of the heating point room is more than 12 m, there are two exits, one of which must be directly outside, the second - into the adjacent room, staircase or corridor.

The premises of heating points for consumers of steam with a pressure of more than 0.07 MPa must have at least two exits, regardless of the dimensions of the room.

14.26 There is no need to provide openings for natural lighting of heating points. Doors and gates must open from the room or building of the heating point away from you.

14.27 In terms of explosion and fire hazards, the premises of heating points must comply with category D according to NPB 105.

14.28 Heating units located in industrial and warehouse buildings, as well as administrative buildings of industrial enterprises, residential and public buildings, must be separated from other premises by partitions or fences that prevent unauthorized persons from accessing the heating unit.

14.29 For installation of equipment whose dimensions exceed the dimensions of the doors, installation openings or gates in the walls should be provided in ground-based heating units.

In this case, the dimensions of the installation opening and gate should be 0.2 m larger than the overall dimensions of the largest equipment or pipeline block.

14.30 To move equipment and fittings or integral parts of equipment units, inventory lifting and transport devices should be provided.

If it is impossible to use inventory devices, it is allowed to provide stationary lifting and transport devices:

When the mass of the transported cargo is from 0.1 to 1.0 tons - monorails with manual hoists and crampons or single-girder manual overhead cranes;

the same, more than 1.0 to 2.0 t - single-girder manual overhead cranes;

the same, more than 2.0 t - single-girder electric overhead cranes.

It is allowed to provide for the possibility of using mobile lifting and transport equipment.

14.31 To service equipment and fittings located at a height of 1.5 to 2.5 m from the floor, mobile platforms or portable devices (stepladders) must be provided. If it is impossible to create passages for mobile platforms, as well as to maintain equipment and fittings located at a height of 2.5 m or more, it is necessary to provide stationary platforms with fencing and permanent stairs. The dimensions of platforms, stairs and fences should be taken in accordance with the requirements of GOST 23120.

The distance from the level of the stationary platform to the upper ceiling must be at least 2 m.

14.32 In central heating stations with permanent staff, a bathroom with a washbasin should be provided.

15 POWER SUPPLY AND CONTROL SYSTEM

15.1 Power supply to electrical receivers of heating networks should be carried out in accordance with the rules for the construction of electrical installations (PUE).

Electrical receivers of heating networks for reliability of power supply should include:

Category II - shut-off valves for remote control, booster, mixing and circulation pumps for heating networks with a pipe diameter of less than 500 mm and heating and ventilation systems in heating points, pumps for charging and discharging storage tanks for feeding heating networks in open heat supply systems, make-up pumps at the cutting nodes;

15.2 Control equipment for electrical installations in underground chambers must be located in rooms located above ground level.

15.3 Electric lighting should be provided in pumping stations, in heating points, pavilions, in tunnels and siphons, chambers equipped with electrical equipment, as well as on platforms of overpasses and free-standing high supports in places where electrically driven valves, regulators, and instrumentation are installed. Illumination must be taken according to current standards. Permanent emergency and evacuation lighting should be provided in the permanent premises of operating and maintenance personnel. In other rooms, emergency lighting is provided by portable battery-powered lamps.

16 ADDITIONAL REQUIREMENTS FOR THE DESIGN OF HEATING NETWORKS IN SPECIAL NATURAL AND CLIMATIC CONDITIONS OF CONSTRUCTION

16.1 When designing heating networks and structures on them in areas with seismicity 8 and 9 points, in mined areas, in areas with type II subsidence soils, saline, swelling, peat and permafrost, along with the requirements of these norms and rules, construction requirements for buildings and structures located in these areas.

Note - For type I subsidence soils, heating networks can be designed without taking into account the requirements of this section.

16.2 Shut-off, control and safety valves, regardless of pipe diameters and coolant parameters, should be made of steel.

16.3 The distance between sectional valves should be no more than 1000 m. When justified, it is allowed to increase the distance on transit pipelines to 3000 m.

16.4 Laying heating networks from non-metallic pipes is not allowed.

16.5 The joint installation of heating networks with gas pipelines in channels and tunnels, regardless of gas pressure, is not permitted.

It is allowed to provide for joint installation with natural gas pipelines only in intra-quarter tunnels and common trenches with a gas pressure of no more than 0.005 MPa.

Applications

APPENDIX A
(required)

Appendix A. LIST OF REGULATIVE DOCUMENTS REFERENCED IN THIS DOCUMENT

GOST 9238-83 Approach dimensions of buildings and rolling stock of 1520 (1524) mm gauge railways

GOST 9720-76 Approximation dimensions of buildings and rolling stock of 750 mm gauge railways

GOST 23120-78 Flight stairs, platforms and steel fences. Specifications

GOST 30494-96 Residential and public buildings. Indoor microclimate parameters

GOST 30732-2001 Steel pipes and fittings with thermal insulation made of polyurethane foam in a polyethylene shell. Specifications

SNiP 2.02.04-88 Foundations and foundations on permafrost soils

SNiP 2.04.01-85* Internal water supply and sewerage of buildings

SNiP 41-03-2003 Thermal insulation of equipment and pipelines

SanPiN 2.1.4.1074-01 Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control

NPB 105-03 Determination of categories of premises, buildings and outdoor installations for explosion and fire safety

PB 10-573-03 Rules for the design and safe operation of steam and hot water pipelines

PUE Rules for electrical installations

Rules for technical operation of power plants and networks

RD 10-249-98 Standards for strength calculations of stationary boilers and steam and hot water pipelines

RD 10-400-01 Standards for strength calculations of heating network pipelines

RD 153-34.0-20.518-2003 Standard instructions for the protection of heating network pipelines from external corrosion

APPENDIX B
(required)

Appendix B. DISTANCES FROM BUILDING STRUCTURES OF HEAT NETWORKS OR INSULATION SHELL OF PIPELINES DURING CHANNELLESS LAYING TO BUILDINGS, STRUCTURES AND ENGINEERING NETWORKS

Table B.1

Vertical distances

Structures and utility networks	Minimum vertical clear distances, m
To water supply, drainage, gas pipeline, sewerage	0,2
Up to armored communication cables	0,5
Up to power and control cables with voltages up to 35 kV	0.5 (0.25 in cramped conditions) - subject to the requirements of note 5
Up to oil-filled cables with a voltage of St. 110 kV	1.0 (0.5 in cramped conditions) - subject to the requirements of note 5
To a telephone sewer block or to an armored communication cable in pipes	0,15
To the base of the rails of industrial railways	1,0
The same, railways of the general network	2,0
" tram tracks	1,0
To the top of the road surface of public roads of categories I, II and III	1,0
To the bottom of a ditch or other drainage structures or to the base of a railway roadbed embankment (if heating networks are located under these structures)	0,5
To subway structures (if heating networks are located above these structures)	1,0
To the head of the railway rails
To the top of the roadway	5,0
To the top of the pedestrian roads	2,2
To parts of the tram contact network	0,3
Same thing, trolleybus	0,2
To overhead power lines with the greatest sag of wires at voltage, kV:
up to 1	1,0
St. 1 to 20	3,0
35-110	4,0
150	4,5
220	5,0
330	6,0
500	6,5

Notes

1 The depth of heating networks from the surface of the earth or road surface (except for highways of categories I, II and III) should be taken at least:

a) to the top of the ceilings of canals and tunnels - 0.5 m;

b) to the top of the chamber ceilings - 0.3 m;

c) to the top of the shell of the channelless laying 0.7 m. In the impassable part, ceilings of chambers and ventilation shafts for tunnels and channels protruding above the ground surface to a height of at least 0.4 m are allowed;

D) at the entrance of heating networks into the building, it is allowed to take depths from the ground surface to the top of the ceiling of channels or tunnels - 0.3 m and to the top of the shell of a channelless installation - 0.5 m;

e) if the groundwater level is high, it is permissible to reduce the depth of canals and tunnels and place the ceilings above the ground surface to a height of at least 0.4 m, if this does not interfere with the conditions of transport movement.

2 When laying heating networks above ground on low supports, the clear distance from the ground surface to the bottom of the thermal insulation of pipelines must be, m, not less than:

For pipe group widths up to 1.5 m - 0.35;

" " " " more than 1.5 m - 0.5.

3 When laid underground, heating networks at the intersection with power, control and communication cables can be located above or below them.

4 For channelless installation, the clear distance from the water heating networks of an open heating supply system or hot water supply networks to the heating networks of sewer pipes located below or above is taken to be at least 0.4 m.

5 The soil temperature at the intersection of heating networks with electrical cables at the depth of laying power and control cables with voltages up to 35 kV should not increase by more than 10 °C in relation to the highest average monthly summer soil temperature and by 15 °C - to the lowest average monthly winter soil temperature at a distance of up to 2 m from the outer cables, and the soil temperature at the depth of the oil-filled cable should not increase by more than 5 °C relative to the average monthly temperature at any time of the year at a distance of up to 3 m from the outer cables.

6 The depth of heating networks at underground intersections of railways of the general network in heaving soils is determined by calculation based on the conditions under which the influence of heat release on the uniformity of frost heaving of the soil is excluded. If it is impossible to ensure the specified temperature regime by deepening the heating networks, ventilation of tunnels (channels, casings), replacement of heaving soil at the intersection site, or overhead laying of heating networks are provided.

7 Distances to the telephone sewer block or to the armored communication cable in pipes should be specified according to special standards.

8 In places of underground intersections of heating networks with communication cables, telephone sewer units, power and control cables with voltage up to 35 kV, it is allowed, with appropriate justification, to reduce the vertical distance in the light when installing reinforced thermal insulation and observing the requirements of paragraphs 5, 6, 7 of these notes.

Table B.2

Horizontal distances from underground water heating networks of open heating systems and hot water supply networks to sources of possible pollution

Source of pollution	Minimum horizontal clear distances, m
1. Structures and pipelines for domestic and industrial sewerage:
when laying heating networks in channels and tunnels	1,0
for ductless installation of heating networks D_u<= 200 мм	1,5
The same, D_y > 200 mm	3,0
2. Cemeteries, landfills, cattle burial grounds, irrigation fields:
in the absence of groundwater	10,0
	50,0
3. Cesspools and garbage pits:
in the absence of groundwater	7,0
in the presence of groundwater and in filter soils with the movement of groundwater towards heating networks	20,0

Note - When sewerage networks are located below heating networks and parallel laying, the horizontal distances must be taken to be no less than the difference in the elevations of the networks; above heating networks, the distances indicated in the table must increase by the difference in the depth of installation.

Table B.3

Horizontal distances from building structures of heating networks or pipeline insulation shells for ductless installation to buildings, structures and utility networks

Buildings, structures and utility networks	Shortest clear distances, m
Underground laying of heating networks
To the foundations of buildings and structures:
a) when laying in channels and tunnels and non-subsidence soils (from the outer wall of the tunnel channel) with pipe diameter, mm:
D_u< 500	2,0
D_y = 500-800	5,0
D_y = 900 or more	8,0
D_u< 500	5,0
D_y >= 500	8,0
b) for channelless installation in non-subsidence soils (from the shell of the channelless installation) with pipe diameter, mm:
D_u< 500	5,0
D_y >= 500	7,0
The same in type I subsidence soils with:
D_u<= 100	5,0
D_y > 100 to D_y< 500	7,0
D_y >= 500	8,0
To the axis of the nearest track of the 1520 mm gauge railway	4.0 (but not less than the depth of the heating network trench to the base of the embankment)
The same, 750 mm gauge	2,8
To the nearest railway subgrade structure	3.0 (but not less than the depth of the heating network trench to the base of the outermost structure)
To the center line of the nearest electrified railway track	10,75
	2,8
To the side stone of the road street (edge ​​of the roadway, reinforced shoulder strip)	1,5
To the outer edge of the ditch or the bottom of the road embankment	1,0
To the foundations of fences and pipeline supports	1,5
To masts and poles of external lighting and communication networks	1,0
To the foundations of bridge supports and overpasses	2,0
To the foundations of railway contact network supports	3,0
The same, trams and trolleybuses	1,0
Up to power and control cables with voltages up to 35 kV and oil-filled cables (up to 220 kV)	2.0 (see note 1)
To the foundations of overhead power transmission line supports at voltage, kV (at approach and intersection):
up to 1	1,0
St. 1 to 35	2,0
St. 35	3,0
To the telephone sewerage block, armored communication cable in pipes and to radio broadcast cables	1,0
To the water pipes	1,5
The same, in type I subsidence soils	2,5
To drainage and storm drainage	1,0
To industrial and domestic sewerage (with a closed heating system)	1,0
Up to gas pipelines with a pressure of up to 0.6 MPa when laying heating networks in channels, tunnels, as well as when channelless laying with associated drainage	2,0
The same, more than 0.6 to 1.2 MPa	4,0
Up to gas pipelines with a pressure of up to 0.3 MPa with ductless installation of heating networks without associated drainage	1,0
The same, more than 0.3 to 0.6 MPa	1,5
The same, more than 0.6 to 1.2 MPa	2,0
To the tree trunks	2.01 (see note 10)
Up to the bushes	1.0 (see note 10)
To canals and tunnels for various purposes (including to the edge of irrigation network canals - ditches)	2,0
Up to subway structures when lining with external adhesive insulation	5.0 (but not less than the depth of the heating network trenches to the base of the structure)
The same, without adhesive waterproofing	8.0 (but not less than the depth of the heating network trenches to the base of the structure)
Before the fencing of the above-ground metro lines	5
To tanks of automobile filling stations (gas stations):
a) for channelless installation	10,0
b) for channel installation (provided that ventilation shafts are installed on the heating network channel)	15,0
Aboveground laying of heating networks
To the nearest railway subgrade structure	3
To the axis of the railway track from intermediate supports (when crossing railways)	Dimensions "S", "Sp", "Su" according to GOST 9238 and GOST 9720
To the center of the nearest tram track	2,8
To the side stone or to the outer edge of the road ditch	0,5
To the overhead power line with the greatest deviation of wires at voltage, kV:	(see note 8)
up to 1	1
St. 1 to 20	3
35-110	4
150	4,5
220	5
330	6
500	6,5
To the tree trunk	2,0
To residential and public buildings for water heating networks, steam pipelines under pressure Р_у<= 0,63 МПа, конденсатных тепловых сетей при диаметрах труб, мм:
D_u from 500 to 1400	25 (see note 9)
D_u from 200 to 500	20 (see note 9)
D_u< 200	10 (see note 9)
To hot water supply networks	5
The same for steam heating networks:
Р_у from 1.0 to 2.5 MPa	30
St. 2.5 to 6.3 MPa	40

Notes

1 It is allowed to reduce the distance given in Table B.3, provided that the condition is met that in the entire area of ​​proximity of heating networks with cables, the soil temperature (accepted according to climatic data) at the place where the cables pass at any time of the year will not increase compared to the average monthly temperature by more than 10 °C for power and control cables with voltages up to 10 kV and by 5 °C - for power control cables with voltages of 20 - 35 kV and oil-filled cables up to 220 kV.

2 When laying heating and other utility networks in common trenches (during their simultaneous construction), it is allowed to reduce the distance from heating networks to water supply and sewerage to 0.8 m when all networks are located at the same level or with a difference in elevations of no more than 0.4 m.

3 For heating networks laid below the base of the foundations of supports, buildings, structures, the difference in elevations must be additionally taken into account, taking into account the natural slope of the soil, or measures must be taken to strengthen the foundations.

4 When laying parallel underground heating and other utility networks at different laying depths, the distances given in Table B.3 must be increased and taken to be no less than the difference in network laying. In cramped installation conditions and the impossibility of increasing the distance, measures must be taken to protect utility networks from collapse during the repair and construction of heating networks.

5 When laying heating and other utility networks in parallel, it is allowed to reduce the distances given in Table B.3 to structures on the networks (wells, chambers, niches, etc.) to a value of at least 0.5 m, providing for measures to ensure the safety of structures during production of construction and installation works.

6 Distances to special communication cables must be specified in accordance with the relevant standards.

7 The distance from ground-based heating network pavilions for placing shut-off and control valves (if there are no pumps in them) to residential buildings is taken to be at least 15 m. In particularly cramped conditions, it can be reduced to 10 m.

8 When laying parallel overhead heating networks with overhead power lines with voltages over 1 to 500 kV outside populated areas, the horizontal distance from the outermost wire should be taken not less than the height of the support.

9 When laying temporary (up to 1 year of operation) water heating networks (bypasses) above ground, the distance to residential and public buildings can be reduced while ensuring measures for the safety of residents (100% inspection of welds, testing of pipelines at 1.5 of the maximum working pressure, but not less than 1.0 MPa, application

to the channel wallto the surface of the thermal insulation structure of the adjacent pipelineuntil the channel is blockedto the bottom of the channel 25-80 70 100 50 100 100-250 80 140 50 150 300-350 100 160 70 150 400 100 200 70 180 500-700 110 200 100 180 800 120 250 100 200 900-1400 120 250 100 300

Note - When reconstructing heating networks using existing channels, deviations from the dimensions indicated in this table are allowed.

Table B.2

Tunnels, overhead installation and heating points

In millimeters

Conditional diameter of pipelines	Distance from the surface of the heat-insulating structure of pipelines in the clear, not less
	to the tunnel wall	before the tunnel is closed	to the bottom of the tunnel	to the surface of the thermal insulation structure of the adjacent pipeline in tunnels, during above-ground installation and in heating points
				vertically	horizontally
25-80	150	100	150	100	100
100-250	170	100	200	140	140
300-350	200	120	200	160	160
400	200	120	200	160	200
500-700	200	120	200	200	200
800	250	150	250	200	250
900	250	150
up to 500	600
from 600 to 900	700
from 1000 or more	1000
From the wall to the flange of the stuffing box compensator housing (from the branch pipe side) with pipe diameters, mm:
up to 500	600 (along the pipe axis)
600 or more	800 (along the pipe axis)
From the floor or ceiling to the valve flange or to the axis of the gland seal bolts	400
The same, up to the surface of the heat-insulating structure of pipe branches	300
From the extended valve spindle (or steering wheel) to the wall or ceiling	200
For pipes with a diameter of 600 mm or more between the walls of adjacent pipes on the side of the gland compensator	500
From the wall or flange of the valve to the water or air outlet fittings	100
From the valve flange on the branch to the surface of the heat-insulating structures of the main pipes	100
Between the thermal insulation structures of adjacent bellows expansion joints with expansion joint diameters, mm:
up to 500	100
600 or more	150

B.2 The minimum distances from the edge of the movable supports to the edge of the supporting structures (traverses, brackets, support pads) must ensure the maximum possible lateral displacement of the support with a margin of at least 50 mm. In addition, the minimum distances from the edge of the traverse or bracket to the pipe axis without taking into account the displacement must be at least 0.5 D_y.

B.3 The maximum clear distances from the thermal insulation structures of bellows expansion joints to the walls, ceilings and bottom of tunnels should be taken as follows:

at D_y<= 500 - 100 мм;

with D_у = 600 or more - 150 mm.

If it is impossible to maintain the specified distances, compensators should be installed staggered with a horizontal offset of at least 100 mm relative to each other.

B.4 The distance from the surface of the heat-insulating structure of the pipeline to building structures or to the surface of the heat-insulating structure of other pipelines after thermal movement of the pipelines must be at least 30 mm in clearance.

B.5 The clear passage width in tunnels should be taken equal to the diameter of the larger pipe plus 100 mm, but not less than 700 mm.

B.6 The supply pipeline of two-pipe water heating networks, when laid in the same row with the return pipeline, should be located to the right along the coolant flow from the heat source.

B.7 For pipelines with a coolant temperature not exceeding 300 °C, it is allowed to attach pipes of smaller diameters when laying above ground.

B.8 Gland compensators on the supply and return pipelines of water heating networks in chambers can be installed with an offset of 150 - 200 mm relative to each other in plan, and flange valves D_y<= 150 мм и сильфонные компенсаторы - в разбежку с расстоянием (по оси) в плане между ними не менее 100 мм.

B.9 In heating points, the clear width of passages, m, should be taken, not less than:

between pumps with electric motors with voltages up to 1000 V - 1.0;

the same, 1000 V and above - 1.2;

between the pumps and the wall - 1.0;

between the pumps and the distribution board or instrumentation panel - 2.0;

between protruding parts of equipment or between these parts and a wall - 0.8.

Pumps with electric motors with voltages up to 1000 V and a pressure pipe diameter of no more than 100 mm may be installed:

At the wall without a passage; in this case, the clear distance from the protruding parts of pumps and electric motors to the wall must be at least 0.3 m;

two pumps on the same foundation without a passage between them; in this case, the clear distance between the protruding parts of pumps with electric motors must be at least 0.3 m.

B.10 The central heating point should provide installation platforms, the dimensions of which are determined by the dimensions of the largest piece of equipment (except for a tank with a capacity of more than 3 m3) or a block of equipment and pipelines supplied for installation in assembled form, with a passage around them of at least 0.7 m.

The website "Zakonbase" presents "HEATING NETWORKS. BUILDING NORMS AND RULES. SNiP 41-02-2003" (approved by Resolution of the State Construction Committee of the Russian Federation dated June 24, 2003 N 110) in the latest edition. It is easy to comply with all legal requirements if you read the relevant sections, chapters and articles of this document for 2014. To find the necessary legislative acts on a topic of interest, you should use convenient navigation or advanced search.

On the Zakonbase website you will find "HEATING NETWORKS. BUILDING NORMS AND RULES. SNiP 41-02-2003" (approved by Resolution of the State Construction Committee of the Russian Federation dated June 24, 2003 N 110) in the latest and complete version, in which all changes and amendments have been made. This guarantees the relevance and reliability of the information.

Thermal insulation of flange connections, fittings, sections of pipelines subject to periodic inspection, and expansion joints must be removable.

3.24. The outer surface of pipelines and metal structures of heating networks must be protected with reliable anti-corrosion coatings. Work to protect heating networks from corrosion, corrosion measurements, and operation of corrosion protection equipment must be carried out in accordance with the Standard Instructions for the Protection of Heating Networks from External Corrosion and the Rules and Regulations for the Protection of Heating Networks from Electrochemical Corrosion. Commissioning of heating networks after completion of construction or major repairs without external anti-corrosion coating is not allowed.

When using heat-insulating materials or pipeline structures that exclude the possibility of corrosion of the pipe surface, a protective coating against corrosion may not be provided.

3.25. Discharge of water from associated drainage systems onto the ground surface and into absorption wells is not permitted. Water must be drained into storm drains, reservoirs or ravines by gravity or by pumping after approval in the prescribed manner.

3.26. Supply and exhaust ventilation must be provided in the passage ducts, ensuring an air temperature of no higher than 50 degrees during both the heating and inter-heating periods. C, and during repair work and inspections - no higher than 32 degrees. C. Decrease in air temperature to 32 degrees. C is allowed to be produced by mobile ventilation units.

3.27. The control equipment for electrical installations in underground chambers must be located outside the chambers.

3.28. Electric lighting should be provided in pumping stations, heating points, pavilions, tunnels and siphons, chambers equipped with electrical equipment, as well as on platforms of overpasses and free-standing high supports in places where electric drive fittings, regulators, and instrumentation are installed.

3.29. For centralized control and management of equipment of heating networks, heating points and pumping stations, telemechanization technical means must be used.

3.30. The following must be provided at the outlets of heating networks from heat sources:

Measurement of pressure, temperature and coolant flow in the supply and return pipelines of network water, steam, condensate, make-up water pipelines;

Alarm and warning signaling of limit values ​​of make-up water flow, pressure difference between the supply and return lines;

Heat energy and coolant metering unit.

Rules for the technical operation of thermal power plants Team of authors

6. HEATING NETWORKS

6. HEATING NETWORKS

6.1. Technical requirements

6.1.1. The method of laying new heating networks, building structures, and thermal insulation must comply with the requirements of current building codes and regulations and other regulatory and technical documents. The selection of pipeline diameters is carried out in accordance with the feasibility study.

6.1.2. Pipelines for heating networks and hot water supply with a 4-pipe installation should, as a rule, be placed in one channel with separate thermal insulation of each pipeline.

6.1.3. The slope of heating network pipelines should be at least 0.002, regardless of the direction of movement of the coolant and the method of laying the heating pipelines. The routing of pipelines should exclude the formation of stagnant zones and ensure the possibility of complete drainage.

The slope of heating networks to individual buildings during underground installation is taken from the building to the nearest chamber. In certain areas (when crossing communications, laying over bridges, etc.) it is allowed to lay heating networks without a slope.

6.1.4. At intersections of heating networks when they are laid underground in channels or tunnels with gas pipelines, leak sampling devices are provided on heating networks at a distance of no more than 15 m on both sides of the gas pipeline.

The passage of gas pipelines through the building structures of chambers, impassable channels and niches of heating networks is not allowed.

6.1.5. When heating networks cross existing water supply and sewerage networks located above the pipelines of heating networks, as well as when crossing gas pipelines, casings should be installed on the water supply, sewerage and gas pipelines at a length of 2 m on both sides of the intersection (in the clear).

6.1.6. At the inputs of heating network pipelines into buildings, it is necessary to provide devices that prevent the penetration of water and gas into the buildings.

6.1.7. At the intersection of overhead heating networks with high-voltage power lines, it is necessary to ground (with a resistance of grounding devices of no more than 10 ohms) all electrically conductive elements of heating networks located at a distance of 5 m in each direction from the axis of projection of the edge of the overhead power line structure onto the surface of the earth.

6.1.8. In areas where heat pipelines are laid, the construction of buildings, storage, and planting of trees and perennial shrubs are not allowed. The distance from the projection on the surface of the earth of the edge of the building structure of the heating network to the structures is determined in accordance with building codes and regulations.

6.1.9. The materials of pipes, fittings, supports, compensators and other elements of pipelines of heating networks, as well as methods of their manufacture, repair and control must comply with the requirements established by the Gosgortekhnadzor of Russia.

6.1.10. For pipelines of heating networks and heating points at a water temperature of 115 °C and below, at a pressure up to 1.6 MPa inclusive, it is allowed to use non-metallic pipes if their quality meets sanitary requirements and corresponds to the parameters of the coolant.

6.1.11. Welded connections of pipelines are subjected to testing using non-destructive testing methods in accordance with the volumes and requirements established by the State Technical Supervision Authority of Russia.

6.1.12. Non-destructive testing methods should be applied to 100% of welded joints of heating network pipelines laid in non-passable channels under roadways, in cases, tunnels or technical corridors together with other utilities, as well as at intersections:

railways and tram tracks - at a distance of at least 4 m, electrified railways - at least 11 m from the axis of the outermost track;

railways of the general network - at a distance of at least 3 m from the nearest roadbed structure;

roads - at a distance of at least 2 m from the edge of the roadway, reinforced shoulder strip or the bottom of the embankment;

metro - at a distance of at least 8 m from structures;

power, control and communication cables - at a distance of at least 2 m;

gas pipelines - at a distance of at least 4 m;

main gas and oil pipelines - at a distance of at least 9 m;

buildings and structures - at a distance of at least 5 m from walls and foundations.

6.1.13. When monitoring the quality of the welding joint of a pipeline with an existing main (if there is only one shut-off valve between them, as well as when monitoring no more than two connections made during repairs), testing for strength and density can be replaced by checking the welded joint with two types of control - radiation and ultrasonic For pipelines that are not subject to the requirements established by the Gosgortekhnadzor of Russia, it is sufficient to check the continuity of welded joints using magnetic testing.

6.1.14. For all pipelines of heating networks, except for heating points and hot water supply networks, the following fittings are not allowed:

from gray cast iron - in areas with a design outside air temperature for heating design below minus 10 °C;

made of malleable cast iron - in areas with a design outside air temperature for heating design below minus 30 °C;

from high-strength cast iron in areas with a design outdoor temperature for heating design below minus 40 °C;

made of gray cast iron on drainage, blow-off and drainage devices in all climatic zones.

6.1.15. It is not allowed to use shut-off valves as control valves.

6.1.16. On pipelines of heating networks, it is allowed to use fittings made of brass and bronze at a coolant temperature not exceeding 250 °C.

6.1.17. Steel reinforcement is installed at the outlets of heating networks from heat sources.

6.1.18. Installation of shut-off valves is provided for:

on all pipelines of heating networks outlets from heat sources, regardless of the coolant parameters;

on pipelines of water networks D y 100 mm or more at a distance of no more than 1,000 m (sectional valves) with a jumper between the supply and return pipelines;

in water and steam heating networks in nodes on branch pipelines D y more than 100 mm, as well as in nodes on branch pipelines to individual buildings, regardless of the diameter of the pipeline;

on condensate lines at the inlet to the condensate collecting tank.

6.1.19. On water heating networks with a diameter of 500 mm or more at a nominal pressure of 1.6 MPa (16 kgf/cm 2) or more, with a diameter of 300 mm or more at a nominal pressure of 2.5 MPa (25 kgf/cm 2) or more, on steam networks with a diameter of 200 mm or more at a nominal pressure of 1.6 MPa (16 kgf/cm 2) or more, valves and shutters are provided with bypass pipelines (bypasses) with shut-off valves.

6.1.20. Gate valves and shutters with a diameter of 500 mm and more are equipped with an electric drive. When laying heating networks above ground, valves with electric drives are installed indoors or enclosed in casings that protect the valves and electric drive from precipitation and prevent access to them by unauthorized persons.

6.1.21. At the lowest points of pipelines of water heating networks and condensate pipelines, as well as sectioned sections, fittings with shut-off valves for draining water (drainage devices) are installed.

6.1.22. From the steam pipelines of heating networks at the lowest points and before vertical rises, condensate must be continuously removed through condensate drains.

In these same places, as well as on straight sections of steam pipelines, a device for starting steam pipeline drainage is installed every 400–500 m with a downward slope and 200–300 m with a counter slope.

6.1.23. To drain water from pipelines of water heating networks, discharge wells are provided with water drainage into sewerage systems by gravity or mobile pumps.

When draining water into a domestic sewer, a water seal is installed on the gravity pipeline, and if reverse flow of water is possible, an additional shut-off (check) valve is installed.

When laying pipelines above ground in an undeveloped area, concrete pits should be provided for draining water with water drainage from them using ditches, trays or pipelines.

6.1.24. To remove condensate from permanent steam pipeline drains, it is possible to discharge condensate into a condensate collection and return system. It is allowed to be discharged into the pressure condensate pipeline if the pressure in the drainage condensate pipeline is at least 0.1 MPa (1 kgf/cm2) higher than in the pressure pipeline.

6.1.25. At the highest points of heating network pipelines, including at each sectional section, fittings with shut-off valves for air release (air vents) must be installed.

6.1.26. In heating networks, reliable compensation for thermal expansion of pipelines must be ensured. To compensate for thermal elongation, the following are used:

flexible pipe expansion joints (U-shaped) with pre-stretching during installation;

turning angles from 90 to 130 degrees (self-compensation); bellows, lens, stuffing box and lip seals.

Stuffing box steel compensators can be used at P y no more than 2.5 MPa and a temperature of no more than 300 °C for pipelines with a diameter of 100 mm or more for underground installation and overhead installation on low supports.

6.1.27. Stretching of the U-shaped compensator should be performed after completing the installation of the pipeline, quality control of the welded joints (except for the closing joints used for tension) and securing the structure of the fixed supports.

The compensator is stretched by the amount specified in the project, taking into account the correction for the outside air temperature when welding the closing joints.

Stretching of the compensator must be carried out simultaneously on both sides at joints located at a distance of no less than 20 and no more than 40 pipeline diameters from the axis of symmetry of the compensator, using tension devices, unless other requirements are justified by the design.

A report should be drawn up regarding the expansion of expansion joints.

6.1.28. To control the parameters of the coolant, the heating network is equipped with select devices for measuring:

temperatures in the supply and return pipelines in front of the sectional valves and in the return pipeline of branches with a diameter of 300 mm or more in front of the valve along the water flow;

water pressure in the supply and return pipelines before and after sectional valves and control devices, in the forward and return pipelines of branches in front of the valve;

steam pressure in branch pipelines upstream of the valve.

6.1.29. At control points of heating networks, local indicating instruments are installed to measure temperature and pressure in pipelines.

6.1.30. The outer surfaces of pipelines and metal structures of heating networks (beams, supports, trusses, overpasses, etc.) must be protected with durable anti-corrosion coatings.

Commissioning of heating networks after completion of construction or major repairs without external anti-corrosion coating of pipes and metal structures is not allowed.

6.1.31. For all heating network pipelines, fittings, flange connections, expansion joints and pipe supports, regardless of the coolant temperature and installation methods, thermal insulation should be installed in accordance with building codes and regulations that define the requirements for thermal insulation of equipment and pipelines.

The materials and thickness of thermal insulation structures must be determined during design based on the conditions for ensuring standard heat loss.

6.1.32. It is allowed in places inaccessible to personnel, during a feasibility study, not to provide thermal insulation:

when laying return pipelines of heating networks in premises D< 200 мм, если тепловой поток через неизолированные стенки трубопроводов учтен в проекте систем отопления этих помещений;

condensate pipelines when discharging condensate into the sewer system; condensate networks when they are laid together with steam networks in non-passable channels.

6.1.33. Fittings, flange connections, hatches, expansion joints should be insulated if equipment or pipelines are insulated.

Thermal insulation of flange connections, fittings, sections of pipelines subject to periodic inspection, as well as stuffing box, lens and bellows expansion joints is provided for removable.

Heating networks laid outdoors, regardless of the type of installation, must be protected from moisture.

6.1.34. The design of thermal insulation must prevent deformation and slipping of the thermal insulation layer during operation.

On vertical sections of pipelines and equipment, support structures must be installed every 1–2 m in height.

6.1.35. For above-ground pipelines when using thermal insulation structures made of combustible materials, 3 m long inserts made of non-combustible materials should be provided every 100 m of the pipeline length.

6.1.36. In places where electrical equipment is installed (pumping stations, heating points, tunnels, chambers), as well as in places where electrically driven fittings, regulators and instrumentation are installed, electric lighting is provided that complies with the rules for electrical installations.

The passage channels of heating networks are equipped with supply and exhaust ventilation.

6.2. Exploitation

6.2.1. When operating heating network systems, reliability of heat supply to consumers, supply of coolant (water and steam) with flow rate and parameters must be ensured in accordance with the temperature schedule and pressure drop at the inlet.

The connection of new consumers to the heating networks of the energy supplying organization is allowed only if the heat source has a power reserve and a reserve capacity of the heating network mains.

6.2.2. The organization operating the heating networks monitors the consumer's compliance with the specified heat consumption regimes.

6.2.3. During the operation of heating networks, the access routes to network facilities, as well as road surfaces and the layout of surfaces above underground structures are maintained in proper condition, the serviceability of enclosing structures is ensured, preventing unauthorized persons from accessing the equipment and shut-off and control valves.

6.2.4. Excavation of the pipeline route of the heating network or work near them by outside organizations is permitted only with the permission of the organization operating the heating network, under the supervision of a person specially appointed by it.

6.2.5. The organization draws up and permanently stores: a heating network plan (large-scale);

operational and operational (calculation) schemes;

profiles of heating mains along each main line with a static pressure line;

list of gas hazardous chambers and passage channels.

The heating network plan includes adjacent underground communications (gas pipeline, sewerage, cables), rail tracks of electrified transport and traction substations in an area of ​​at least 15 m from the projection onto the ground surface of the edge of the building structure of the heating network or ductless pipeline on both sides of the route. On the plan of the heating network, the places and results of planned excavations, places of emergency damage, flooding of the route and shifted sections are systematically marked.

The plan, diagrams, profiles of heating mains and the list of gas-hazardous chambers and channels are adjusted annually in accordance with the actual state of heating networks.

All changes are made signed by the responsible person, indicating his position and the date of the change.

Information about changes in diagrams, drawings, lists and corresponding changes in instructions are brought to the attention of all employees (with an entry in the order log), for whom knowledge of these documents is mandatory.

6.2.6. The plans, diagrams and piezometric graphs indicate the operational numbers of all heating mains, chambers (branch nodes), pumping stations, automatic control units, fixed supports, compensators and other heating network structures.

On operational (calculation) diagrams, all consumer systems connected to the network are subject to numbering, and on operational diagrams, in addition, sectioning and shut-off valves.

The fittings installed on the supply pipeline (steam pipeline) are designated by an odd number, and the corresponding fittings on the return pipeline (condensate pipeline) are designated by the next even number.

6.2.7. All gas-dangerous chambers and passage channels are marked on the operational diagram of the heating network.

Gas-dangerous chambers must have special signs, painted hatches and be kept securely locked.

Supervision of gas hazardous chambers is carried out in accordance with safety rules in the gas industry.

6.2.8. The organization operating heating networks (heat supply organization) participates in the acceptance after installation and repair of heating networks, heating points and heat-consuming installations owned by the consumer.

Participation in the technical acceptance of consumer facilities consists of the presence of a representative of the heat supply organization when testing the strength and density of pipelines and equipment of heating points connected to the heating networks of the heat supply organization, as well as heat consumption systems connected according to a dependent circuit. The organization operating heating networks stores copies of test reports, as-built documentation indicating the main shut-off and control valves, vents and drains.

6.2.9. After completion of construction and installation work (during new construction, modernization, reconstruction), major or current repairs with replacement of pipeline sections, heating network pipelines are tested for strength and density.

Pipelines laid in non-through channels or channelless are also subject to preliminary tests for strength and density during the work process before installing gland (bellows) compensators, sectioning valves, closing channels and backfilling pipelines.

6.2.10. Preliminary and acceptance tests of pipelines are carried out with water. If necessary, in some cases it is possible to perform preliminary tests using a pneumatic method.

Pneumatic testing of above-ground pipelines, as well as pipelines laid in the same channel or in the same trench with existing utilities, is not allowed.

6.2.11. Hydraulic tests of pipelines of water heating networks in order to check strength and density should be carried out by test pressure and entered into the passport.

The minimum test pressure during hydraulic testing is 1.25 working pressure, but not less than 0.2 MPa (2 kgf/cm2).

The maximum value of the test pressure is established by strength calculations according to the normative and technical documentation agreed with the State Mining and Technical Supervision Authority of Russia.

The test pressure value is selected by the manufacturer (design organization) within the range between the minimum and maximum values.

All newly installed pipelines of heating networks controlled by Gosgortekhnadzor of Russia must be subjected to hydraulic testing for strength and density in accordance with the requirements established by Gosgortekhnadzor of Russia.

6.2.12. When conducting hydraulic tests for the strength and density of heating networks, it is necessary to disconnect the equipment of the heating networks (stuffing box, bellows compensators, etc.), as well as sections of pipelines and connected heat-consuming power plants not involved in the tests.

6.2.13. During operation, all heating networks must be tested for strength and density to identify defects no later than two weeks after the end of the heating season.

6.2.14. Strength and density tests are carried out in the following order:

disconnect the tested section of the pipeline from existing networks;

at the highest point of the section of the pipeline being tested (after filling it with water and bleeding air), set the test pressure;

the pressure in the pipeline should be increased gradually;

the rate of pressure rise must be indicated in the regulatory and technical documentation (hereinafter referred to as NTD) for the pipeline.

If there is a significant difference in geodetic elevations in the test area, the value of the maximum permissible pressure at its lowest point is agreed upon with the design organization to ensure the strength of the pipelines and the stability of the fixed supports. Otherwise, the site must be tested in parts.

6.2.15. Tests for strength and density should be carried out in compliance with the following basic requirements:

When performing tests, pressure measurements should be made using two certified spring pressure gauges (one is a control one) of class no lower than 1.5 with a body diameter of at least 160 mm. The pressure gauge must be selected from the condition that the measured pressure value is 2/3 of the scale of the device;

test pressure must be provided at the top point (mark) of the pipelines;

the water temperature must be no lower than 5 °C and no higher than 40 °C;

when filling with water, air must be completely removed from the pipelines;

the test pressure must be maintained for at least 10 minutes and then reduced to working pressure;

at operating pressure, a thorough inspection of pipelines is carried out along their entire length.

6.2.16. The test results are considered satisfactory if during the test there was no drop in pressure and no signs of rupture, leakage or fogging were found in the welds, as well as leaks in the base metal, in valve bodies and seals, in flange connections and other pipeline elements. In addition, there should be no signs of movement or deformation of pipelines and fixed supports.

It is necessary to draw up a report in the established form regarding the results of testing pipelines for strength and density.

6.2.17. Pipelines of heating networks, before they are put into operation after installation, major or routine repairs with the replacement of pipeline sections, are subject to cleaning:

steam pipelines – purging with steam discharge into the atmosphere;

water networks in closed heat supply systems and condensate pipelines - hydropneumatic flushing;

water networks in open heat supply systems and hot water supply networks - hydropneumatic washing and disinfection (in accordance with sanitary rules) followed by repeated flushing with drinking water. Repeated flushing after disinfection is carried out until the quality of the discharged water reaches the level that meets the sanitary standards for drinking water.

It is necessary to draw up a report on the flushing (purging) of pipelines.

6.2.18. To flush closed heating systems, it is allowed to use water from a drinking or technical water supply; after flushing, the water is removed from the pipelines.

6.2.19. Connection of heating networks and heat consumption systems after installation and reconstruction is carried out on the basis of a permit issued by state energy supervision authorities.

6.2.20. Filling pipelines of heating networks, their flushing, disinfection, turning on circulation, purging, warming up steam pipelines and other operations for starting up water and steam heating networks, as well as any testing of heating networks or their individual elements and structures are carried out according to a program approved by the technical manager of the organization and agreed upon with a heat source, and, if necessary, with environmental authorities.

6.2.21. The start-up of water heating networks consists of the following operations:

filling pipelines with network water; establishing circulation; network density checks;

switching on consumers and starting adjustment of the network.

The pipelines of heating networks are filled with water at a temperature of no higher than 70 °C when heat consumption systems are turned off.

Pipelines should be filled with water at a pressure not exceeding the static pressure of the filled part of the heating network by more than 0.2 MPa.

To avoid water hammer and to better remove air from pipelines, the maximum hourly water flow rate G b when filling heating network pipelines with a nominal diameter D y should not exceed the values ​​indicated below:

Filling of distribution networks should be done after filling the main pipelines with water, and branches to consumers - after filling the distribution networks.

6.2.22. During the start-up period, it is necessary to monitor the filling and heating of pipelines, the condition of shut-off valves, stuffing box expansion joints, and drainage devices.

The sequence and speed of starting operations are carried out in such a way as to exclude the possibility of significant thermal deformations of the pipelines.

The program for starting up heating networks takes into account the specifics of starting up a water heating network at negative outside temperatures (after a long emergency shutdown, major repairs or when starting up newly built networks).

Heating of network water when circulation is established should be done at a rate of no more than 30 °C per hour.

In the event of damage to the launch pipelines or associated equipment, measures are taken to eliminate this damage.

In the absence of coolant flow measuring devices, starting adjustment is made based on the temperature in the return pipelines (until the temperature from all consumers connected to the network is equalized).

6.2.23. Starting up steam networks consists of the following operations: warming up and purging steam lines;

filling and flushing condensate pipelines; connecting consumers.

6.2.24. Before heating begins, all valves on branches from the heated area are tightly closed. First, the main line is heated, and then its branches one by one. Small, lightly branched steam pipelines can be heated simultaneously throughout the entire network.

When hydraulic shocks occur, the steam supply is immediately reduced, and in the event of frequent and strong shocks, it is completely stopped until the condensate accumulated in it is completely removed from the heated section of the steam line.

The heating rate of the steam line is adjusted based on the appearance of light hydraulic shocks (clicks). When warming up, it is necessary to regulate its speed, while preventing the steam line from sliding off the movable supports.

6.2.25. During the current operation of heating networks, it is necessary to: maintain all equipment, building and other structures of heating networks in good condition, carrying out their timely inspection and repair;

monitor the operation of expansion joints, supports, fittings, drains, vents, instrumentation and other equipment elements, promptly eliminating identified defects and leaks;

identify and restore damaged thermal insulation and anti-corrosion coating;

remove water accumulating in channels and chambers and prevent groundwater and surface water from entering there;

disconnect idle sections of the network;

promptly remove air from heat pipelines through vents, prevent air from being sucked into heating networks, maintaining the constantly required excess pressure at all points of the network and heat consumption systems;

maintain cleanliness in the cells in the passage channels, do not allow unauthorized persons to stay in them;

take measures to prevent, localize and eliminate accidents and incidents in the operation of the heating network;

control corrosion.

6.2.26. To monitor the condition of heating network equipment and thermal insulation, and their operating modes, inspections of heating pipelines and heating points are carried out regularly according to schedule. The walk-through schedule provides for monitoring the condition of the equipment by both mechanics-inspectors and the foreman.

The frequency of inspections is set depending on the type of equipment and its condition, but at least once a week during the heating season and once a month during the non-heating period. Thermal chambers must be inspected at least once a month; chambers with drainage pumps - at least 2 times a week. Checking the functionality of drainage pumps and their automatic switching on is mandatory during each round.

The inspection results are recorded in the heating network defect log.

Defects that threaten an accident or incident are corrected immediately. Information about defects that do not pose a danger from the point of view of the reliability of operation of the heating network, but which cannot be eliminated without disconnecting the pipelines, is entered in the log of walk-through and inspection of heating networks, and in order to eliminate these defects during the next shutdown of pipelines or during repairs - in the log of current repairs . Control can be carried out by remote methods.

6.2.27. When inspecting the heating network and inspecting underground chambers, personnel are provided with a set of necessary tools, devices, lighting fixtures, and an explosion-proof gas analyzer.

6.2.28. To control the hydraulic and temperature conditions of heating networks and heat-consuming installations, it is necessary to check the pressure and temperature at network nodes using pressure gauges and thermometers during scheduled inspections.

6.2.29. When operating heating networks, coolant leakage should not exceed the norm, which is 0.25% of the average annual volume of water in the heating network and heat consumption systems connected to it per hour, regardless of their connection scheme, with the exception of hot water supply systems (hereinafter referred to as DHW) connected through water heater

When determining the rate of coolant leakage, the water consumption for filling heat pipelines and heat consumption systems during their planned repairs and connecting new sections of the network and consumers should not be taken into account.

6.2.30. To control the density of equipment of heat sources, heating networks and heat consumption systems, it is allowed in the prescribed manner to use coloring leakage indicators approved for use in heat supply systems.

6.2.31. At each heating network make-up node, the flow of make-up water corresponding to the standard leakage is determined, and instrumentation of the actual flow of make-up water is provided.

If a coolant leak exceeds the established standards, measures must be taken to detect the location of the leak and eliminate it.

6.2.32. In addition to tests for strength and density, organizations operating heating networks conduct tests for the maximum temperature of the coolant, to determine heat and hydraulic losses once every 5 years.

All tests of heating networks are carried out separately and in accordance with current guidelines.

6.2.33. For each section of the heating network that is newly put into operation (regardless of the parameters of the coolant and the diameter of the pipelines), a passport of the established form is drawn up (Appendix 5). The passport records the duration of operation of pipelines and heating network structures, records the results of all types of tests (except for annual tests for strength and tightness at the end of the heating season), and records information about repairs, reconstructions and technical examinations.

6.2.34. To monitor the condition of underground heating pipelines, thermal insulation and building structures, it is necessary to periodically carry out trenching on the heating network.

Scheduled excavations are carried out according to an annually drawn up plan, approved by the person responsible for the good condition and safe operation of thermal power plants and (or) heating networks (technical manager) of the organization.

The number of pittings carried out annually is established depending on the length of the network, methods of laying and thermal insulation structures, the number of previously identified corrosion damage to pipes, and the results of tests for the presence of stray current potential.

At least one pit is provided per 1 km of the route.

In new sections of the network, pitting begins from the third year of operation.

6.2.35. Testing is carried out first:

near places where corrosion damage to pipelines has been recorded;

at intersections with drains, sewers, and water pipes;

in areas located near open drains (ditches), passing under lawns or near sidewalk stones;

in places with unfavorable hydrogeological conditions;

in areas with the supposed unsatisfactory condition of thermal insulation structures (as evidenced, for example, by thawed spots along the heat pipeline route in winter);

in areas of channelless installation, as well as channel installation with thermal insulation without an air gap.

6.2.36. The dimensions of the hole are selected based on the convenience of inspecting the pipeline being opened from all sides. In channelless gaskets, the dimensions of the hole at the bottom are at least 1.5x1.5 m; in channel laying, the minimum dimensions ensure the removal of floor slabs to a length of at least 1.5 m.

6.2.37. During pit inspection, the insulation, the pipeline under the insulation and building structures are inspected. If there are noticeable traces of corrosion, it is necessary to clean the surface of the pipe and measure the thickness of the pipeline wall using an ultrasonic thickness gauge or flaw detector.

If the measurement results are questionable and if a wall thinning of 10% or more is detected, it is necessary to carry out control drilling and determine the actual wall thickness.

If local thinning of the wall is detected at 10% of the design (initial) value, these sections are subjected to re-inspection during the repair campaign of the next year.

Sections with a pipeline wall thinning by 20% or more must be replaced.

Based on the results of the inspection, a report is drawn up.

6.2.38. Work to protect heating networks from electrochemical corrosion is carried out by specialized organizations (divisions).

The operation of corrosion protection equipment and corrosion measurements are carried out in accordance with current regulatory and technical documents.

6.2.39. To determine the corrosive aggressiveness of soils and the dangerous effects of stray currents, systematic inspections of pipelines of underground heating networks and electrical measurements of the potential of stray currents are carried out.

6.2.40. Electrical measurements on the routes of newly constructed and reconstructed heating networks are carried out by organizations that developed the design of heating networks, or by specialized organizations that develop technical solutions for protecting heating networks from external corrosion.

Measurements of the electrical resistivity of soils are carried out as necessary to identify sections of the route of ductless heating networks in soils with high corrosive aggressiveness.

Corrosion measurements to determine the dangerous effect of stray currents on steel pipelines of underground heating networks should be carried out in areas influenced by stray currents once every 6 months, as well as after each significant change in the operating mode of power supply systems of electrified transport (changes in the operating schedule of electric transport, changes in the location of traction substations, suction points, etc.) and conditions associated with the development of a network of underground structures and sources of stray currents, the introduction of electrochemical protection equipment at adjacent structures.

In other cases, measurements are made once every 2 years.

6.2.41. Electrochemical protection installations are subject to periodic technical inspection, verification of their operating efficiency and scheduled preventive maintenance.

Electrical protection installations are always kept in a state of full functionality.

Preventive maintenance of electrochemical protection installations is carried out according to the schedule of technical inspections and scheduled preventive maintenance approved by the technical manager of the organization. The schedule provides a list of types and volumes of technical inspections and repair work, the timing of their implementation, instructions for organizing accounting and reporting on work performed.

6.2.42. Technical inspections and scheduled preventative repairs are carried out within the following periods:

technical inspection of cathode installations - 2 times a month, drainage installations - 4 times a month;

technical inspection with efficiency check – once every 6 months;

current repairs – once a year; major repairs – once every 5 years.

All malfunctions in the operation of the electrochemical protection installation are eliminated within 24 hours after their detection.

6.2.43. The effectiveness of drainage and cathode installations is checked 2 times a year, as well as with each change in the operating mode of electrochemical protection installations and with changes associated with the development of a network of underground structures and sources of stray currents.

6.2.44. The resistance to current spreading from the anode grounding conductor of the cathode station is measured in all cases when the operating mode of the cathode station changes sharply, but at least once a year.

6.2.45. The total duration of interruptions in the operation of electrochemical protection installations on heating networks cannot exceed 7 days during the year.

6.2.46. When operating electrically insulating flange connections, their technical inspections are carried out periodically, but at least once a year.

6.2.47. In water heating networks and condensate pipelines, systematic monitoring of internal corrosion of pipelines is carried out by analyzing network water and condensate, as well as using internal corrosion indicators installed at the most characteristic points of heating networks (at the outlets from the heat source, at the end sections, at several intermediate nodes ). Internal corrosion indicators are checked during the repair period.

6.2.48. Every year, before the start of the heating season, all pumping stations must be subjected to comprehensive testing to determine the quality of repairs, correct operation and interaction of all thermal-mechanical and electrical equipment, control equipment, automation, telemechanics, protection of heat supply system equipment and determine the degree of readiness of pumping stations for the heating season.

6.2.49. Routine inspection of the equipment of automated pumping stations should be carried out every shift, checking the load of electrical equipment, the temperature of the bearings, the presence of lubricant, the condition of the seals, the operation of the cooling system, and the presence of chart tapes in recording devices.

6.2.50. At non-automated pumping stations, equipment is serviced on a daily basis.

6.2.51. Before starting the pumps, and when they are running once per shift, it is necessary to check the condition of the pumping and associated equipment.

In drainage pumping stations, the effect of the level regulator on the automatic pump switching device should be monitored at least 2 times a week.

6.2.52. When operating automatic regulators, periodic inspections of their condition, checking operation, cleaning and lubrication of moving parts, adjustment and adjustment of the regulators to maintain the specified parameters are carried out. Automation and technological protection devices for heating networks can be taken out of operation only by order of the technical manager of the organization, except in cases of disabling individual protections when starting up equipment, as provided for in local instructions.

6.2.53. The heating network is fed with softened, deaerated water, the quality of which meets the quality requirements for network and make-up water for hot water boilers, depending on the type of heat source and heat supply system.

6.2.54. Heat consumption systems connected according to an independent circuit are fed with water from the heating network.

6.2.55. The water pressure at any point in the supply line of water heating networks, heating points and at the upper points of directly connected heat consumption systems when network pumps are operating must be higher than the saturated vapor pressure of water at its maximum temperature by no less than 0.5 kgf/cm 2 .

6.2.56. Excess water pressure in the return line of water heating networks during operation of network pumps must be at least 0.5 kgf/cm 2 . The water pressure in the return line should not be higher than permissible for heating networks, heating points and for directly connected heat consumption systems.

6.2.57. An idle heating network is filled only with deaerated water and must be under excess pressure of at least 0.5 kgf/cm 2 at the upper points of the pipelines.

6.2.58. For two-pipe water heating networks, the heat supply regime is based on a central quality control schedule.

If there is a hot water supply load, the minimum water temperature in the supply pipeline of the network is provided for closed heat supply systems at least 70 °C; for open heating systems of hot water supply – not lower than 60 °C.

6.2.59. The water temperature in the supply line of the water heating network, in accordance with the schedule approved for the heating supply system, is set according to the average outside air temperature over a period of time within 12–24 hours, determined by the heating network dispatcher depending on the length of the networks, climatic conditions and other factors.

Deviations from the specified mode at the heat source are provided for no more than:

according to the temperature of the water entering the heating network ±3%;

by pressure in the supply pipeline ±5%;

by pressure in the return pipeline ±0.2 kgf/cm 2.

The deviation of the actual average daily return water temperature from the heating network may exceed that specified by the schedule by no more than +5%. The decrease in the actual return water temperature compared to the schedule is not limited.

6.2.60. Hydraulic modes of water heating networks are developed annually for the heating and summer periods; for open heat supply systems during the heating period, modes are developed with maximum water withdrawal from the supply and return pipelines and in the absence of water withdrawal.

Measures to regulate water consumption among consumers are drawn up for each heating season.

The order of construction of new mains and pumping stations provided for by the heat supply scheme is determined taking into account the real growth of the connected heat load, for which purpose the organization operating the heating network is developing hydraulic modes of the heat supply system for the next 3–5 years.

6.2.61. For each control point of the heating network and at the make-up nodes, permissible values ​​of flow rates and water pressures in the supply, return (and make-up) pipelines are established in the form of a regime map, corresponding to normal hydraulic conditions for the heating and summer periods.

6.2.62. In the event of an emergency interruption of power supply to network and transfer pumps, the organization operating the heating network ensures pressure in heating networks and heat consumption systems within acceptable levels. If this level can be exceeded, it is necessary to install special devices that protect the heat supply system from water hammer.

6.2.63. Repair of heating networks is carried out in accordance with the approved schedule (plan) based on the results of the analysis of identified defects, damage, periodic inspections, tests, diagnostics and annual tests for strength and density.

The schedule of repair work is drawn up based on the condition of simultaneous repair of pipelines of the heating network and heating points.

Before repairing heating networks, pipelines are freed from network water, and the channels must be drained. The temperature of water pumped from waste wells should not exceed 40 °C. Draining water from the heating network chamber to the surface of the earth is not allowed.

6.2.64. Each organization operating heating networks (in each operational area, section) draws up instructions, approved by the technical manager of the organization, with a clearly developed operational action plan in the event of an accident on any of the heating mains or pumping stations in relation to local conditions and network communications.

The instructions must provide for the procedure for disconnecting highways, distribution networks and branches to consumers, the procedure for bypassing chambers and heating points, possible switches for supplying heat to consumers from other highways, and have diagrams of possible emergency switching between highways.

Plans for eliminating technological violations in heating networks of cities and large settlements are coordinated with local authorities.

6.2.65. According to the developed switching schemes, operational and operational-repair personnel of heating networks regularly conduct training according to the approved schedule (but at least once a quarter) to practice the clarity, consistency and speed of emergency operations with their reflection on the operational diagram.

6.2.66. To quickly carry out work to limit the spread of accidents in heating networks and eliminate damage, each operational area of ​​the heating network provides the necessary supply of fittings and materials. The fittings installed on pipelines are of the same type in length and flanges.

The emergency supply of materials is stored in two places: the main part is stored in the pantry, and a certain amount of the emergency supply (consumables) is in a special cabinet at the disposal of the responsible person from the operational staff. Consumables used by operational personnel are replenished within 24 hours from the bulk of the stock.

The supply of fittings and materials for each operational area of ​​the heating network is determined depending on the length of the pipelines and the number of installed fittings in accordance with emergency stock standards; a list of necessary fittings and materials is compiled, which is approved by the person responsible for the good condition and safe operation of the organization's heating networks.

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BUILDING REGULATIONS

HEATING NETWORK

SNiP 3.05.03-85

INTRODUCED by the USSR Ministry of Energy.

PREPARED FOR APPROVAL BY Glavtekhnormirovanie Gosstroy USSR (N. A. Shishov).

With the entry into force of SNiP 3.05.03-85 “Heating networks”, SNiP III-30-74 “Water supply, sewerage and heat supply. External networks and structures” becomes invalid.

When using a regulatory document, you should take into account approved changes to building codes and regulations and state standards.

These rules apply to the construction of new, expansion and reconstruction of existing heating networks transporting hot water at t≤ 200 °C and pressure P y ≤ 2.5 MPa (25 kgf/cm 2) and steam temperature t≤ 440 °C and pressure R y ≤ 6.4 MPa (64 kgf/cm 2) from the source of thermal energy to heat consumers (buildings, structures).

1. GENERAL PROVISIONS

1.1. When constructing new, expanding and reconstructing existing heating networks, in addition to the requirements of working drawings, work plans (WPP) and these rules, the requirements of SNiP 3.01.01-85, SNiP 3.01.03-84, SNiP III-4-80 and standards must also be observed .

1.2. Work on the manufacture and installation of pipelines, which are subject to the requirements of the Rules for the Construction and Safe Operation of Steam and Hot Water Pipelines of the USSR Gosgortekhnadzor (hereinafter referred to as the USSR Gosgortekhnadzor Rules), must be carried out in accordance with the specified Rules and the requirements of these rules and regulations.

1.3. Completed heating networks should be put into operation in accordance with the requirements of SNiP III-3-81.

2. EXCAVATION

2.1. Excavation and foundation work must be carried out in accordance with the requirements of SNiP III-8-76. SNiP 3.02.01-83, SN 536-81 and this section.

2.2. The smallest width of the trench bottom for channelless pipe laying should be equal to the distance between the outer side edges of the insulation of the outermost thermal pipelines

networks (associated drainage) with the addition on each side for pipelines with a nominal diameter D y up to 250 mm - 0.30 m, over 250 to 500 mm - 0.40 m, over 500 to 1000 mm - 0.50 m; The width of the pits in the trench for welding and insulation of pipe joints during channelless laying of pipelines should be taken equal to the distance between the outer side edges of the insulation of the outermost pipelines with the addition of 0.6 m on each side, the length of the pits is 1.0 m and the depth from the bottom edge of the pipeline insulation is 0 .7 m, unless other requirements are justified by working drawings.

2.3. The smallest width of the bottom of the trench during channel laying of heating networks should be equal to the width of the channel, taking into account formwork (in monolithic sections), waterproofing, associated drainage and drainage devices, trench fastening structure with the addition of 0.2 m. In this case, the width of the trench should be at least 1 .0 m.

If it is necessary for people to work between the outer edges of the canal structure and the walls or slopes of the trench, the clear width between the outer edges of the canal structure and the walls or slopes of the trench must be at least: 0.70 m for trenches with vertical walls and 0.30 m for trenches with slopes.

2.4. Backfilling of trenches during channelless and channel laying of pipelines should be carried out after preliminary tests of pipelines for strength and tightness, complete completion of insulation and construction and installation work.

Backfilling must be done in the specified technological sequence:

tamping of sinuses between pipelines of channelless laying and the base;

simultaneous uniform filling of the sinuses between the walls of trenches and pipelines during channelless installation, as well as between the walls of the trench and channel, chambers during channel installation to a height of at least 0.20 m above pipelines, channels, chambers;

backfilling the trench to the design marks.

Backfilling of trenches (pits) to which additional external loads are not transferred (except for the own weight of the soil), as well as trenches (pits) at intersections with existing underground communications, streets, roads, driveways, squares and other structures of settlements and industrial sites should be carried out in accordance with the requirements of SNiP III-8-76.

2.5. After turning off the temporary dewatering devices, the channels and chambers must be visually inspected for the absence of groundwater in them.

3. STRUCTURES AND INSTALLATION OF BUILDING STRUCTURES

3.1. Work on the construction and installation of building structures should be carried out in accordance with the requirements of this section and the requirements of:

SNiP III-15-76 - for the construction of monolithic concrete and reinforced concrete structures of foundations, supports for pipelines, chambers and other structures, as well as for grouting joints;

SNiP III-16-80 - for installation of prefabricated concrete and reinforced concrete structures;

SNiP III-18-75 - when installing metal structures of supports, spans for pipelines and other structures;

SNiP III-20-74 - for waterproofing channels (chambers) and other building structures (structures);

SNiP III-23-76 - for the protection of building structures from corrosion.

3.2. The outer surfaces of channel and chamber elements supplied to the route must be covered with a coating coating or adhesive waterproofing in accordance with the working drawings.

The installation of channel elements (chambers) in the design position should be carried out in a technological sequence linked to the project for the installation and preliminary testing of pipelines for strength and tightness.

Support pads for sliding supports of pipelines must be installed at the distances specified in SNiP II-G.10-73* (II-36-73*).

3.3. Monolithic fixed panel supports must be made after installation of pipelines in the panel support area.

3.4. In places where channelless pipelines are inserted into channels, chambers and buildings (structures), the cases of bushings must be put on the pipes during their installation.

At the entrances of underground pipelines into buildings, devices must be installed (in accordance with the working drawings) to prevent gas from penetrating into the buildings.

3.5. Before installing the upper trays (plates), the channels must be cleared of soil, debris and snow.

3.6. Deviation of the slopes of the bottom of the heating network channel and drainage pipelines from the design is allowed by ± 0.0005, while the actual slope must be no less than the minimum allowable according to SNiP II-G.10-73* (II-36-73*).

Deviation of installation parameters of other building structures from the design ones must comply with the requirements of SNiP III-15-76. SNiP III-16-80 and SNiP III-18-75.

3.7. The construction organization project and the work execution project must provide for the advanced construction of drainage pumping stations and water release devices in accordance with the working drawings.

3.8. Before laying in a trench, drainage pipes must be inspected and cleared of soil and debris.

3.9. Layer-by-layer filtering of drainage pipelines (except for pipe filters) with gravel and sand must be performed using inventory separation forms.

3.10. The straightness of sections of drainage pipelines between adjacent wells should be checked by inspection “to the light” using a mirror before and after backfilling the trench. The pipe circumference reflected in the mirror must have the correct shape. The permissible horizontal deviation from the circle should be no more than 0.25 of the pipe diameter, but not more than 50 mm in each direction.

Vertical deviation from the correct circle shape is not allowed.

4. PIPELINE INSTALLATION

4.1. The installation of pipelines must be carried out by specialized installation organizations, and the installation technology must ensure high operational reliability of the pipelines.

4.2. Parts and elements of pipelines (compensators, mud traps, insulated pipes, as well as pipeline units and other products) must be manufactured centrally (in factories, workshops, workshops) in accordance with standards, technical specifications and design documentation.

4.3. The laying of pipelines in a trench, channel or on above-ground structures should be carried out using the technology provided for by the work project and excluding the occurrence of residual deformations in the pipelines, violation of the integrity of the anti-corrosion coating and thermal insulation by using appropriate installation devices, correct placement of simultaneously operating lifting machines and mechanisms.

The design of fastening mounting devices to pipes must ensure the safety of the coating and insulation of pipelines.

4.4. The laying of pipelines within the panel support must be carried out using pipes of the maximum delivery length. In this case, the welded transverse seams of pipelines should, as a rule, be located symmetrically relative to the panel support.

4.5. Laying of pipes with a diameter of over 100 mm with a longitudinal or spiral seam should be carried out with an offset of these seams by at least 100 mm. When laying pipes with a diameter of less than 100 mm, the displacement of the seams must be at least three times the thickness of the pipe wall.

Longitudinal seams must be within the upper half of the circumference of the pipes being laid.

Steeply curved and stamped pipeline bends are allowed to be welded together without a straight section.

Welding of pipes and bends into welded joints and bent elements is not allowed.

4.6. When installing pipelines, the movable supports and hangers must be shifted relative to the design position by the distance specified in the working drawings, in the direction opposite to the movement of the pipeline in working condition.

In the absence of data in the working drawings, the movable supports and hangers of horizontal pipelines must be shifted taking into account the correction for the outside air temperature during installation by the following values:

sliding supports and elements for fastening hangers to the pipe - by half the thermal elongation of the pipeline at the attachment point;

roller bearing rollers - by a quarter of thermal elongation.

4.7. When installing pipelines, spring hangers must be tightened in accordance with the working drawings.

When performing hydraulic tests of steam pipelines with a diameter of 400 mm or more, an unloading device should be installed in spring suspensions.

4.8. Pipe fittings must be installed in a closed state. Flange and welded connections of fittings must be made without tension in the pipelines.

The deviation from the perpendicularity of the plane of the flange welded to the pipe relative to the pipe axis should not exceed 1% of the outer diameter of the flange, but be no more than 2 mm at the top of the flange.

4.9. Bellows (wavy) and stuffing box expansion joints should be installed assembled.

When laying heating networks underground, installation of compensators in the design position is allowed only after preliminary testing of pipelines for strength and tightness, backfilling of channelless pipelines, channels, chambers and panel supports.

4.10. Axial bellows and stuffing box expansion joints should be installed on pipelines without breaking the axes of the expansion joints and the axes of the pipelines.

Permissible deviations from the design position of the connecting pipes of compensators during their installation and welding should be no more than those specified in the technical specifications for the manufacture and supply of compensators.

4 .11. When installing bellows expansion joints, they are not allowed to twist relative to the longitudinal axis and sag under the influence of their own weight and the weight of adjacent pipelines. Slinging of expansion joints should be done only by the pipes.

4.12. The installation length of bellows and stuffing box expansion joints must be taken according to the working drawings, taking into account corrections for the outside air temperature during installation.

Stretching of expansion joints to the installation length should be done using devices provided for in the design of expansion joints, or tensioning mounting devices.

4.13. Stretching of the U-shaped compensator should be performed after completion of pipeline installation, quality control of welded joints (except for closing joints used for tension) and fastening of fixed support structures.

The compensator should be stretched by the amount indicated in the working drawings, taking into account the correction for the outside air temperature when welding the closing joints.

Stretching of the compensator must be carried out simultaneously on both sides at joints located at a distance of no less than 20 and no more than 40 pipeline diameters from the axis of symmetry of the compensator, using tension devices, unless other requirements are justified by the design.

On the section of the pipeline between the joints used for stretching the compensator, there should be no preliminary displacement of supports and hangers in comparison with the design (detailed design).

4.14. Immediately before assembling and welding pipes, it is necessary to visually inspect each section to ensure that there are no foreign objects or debris in the pipeline.

4.15. The deviation of the pipeline slope from the design one is allowed by ± 0.0005. In this case, the actual slope must be no less than the minimum allowable according to SNiP II-G.10-73* (II-36-73*).

The movable supports of pipelines must be adjacent to the supporting surfaces of the structures without gaps or distortion.

4.16. When performing installation work, the following types of hidden work are subject to acceptance with drawing up inspection reports in the form given in SNiP 3.01.01-85: preparation of the surface of pipes and welded joints for anti-corrosion coating; performing anti-corrosion coating of pipes and welded joints.

A report on the stretching of compensators should be drawn up in the form given in the mandatory Appendix 1.

4.17. Protection of heating networks from electrochemical corrosion must be carried out in accordance with the Instructions for the protection of heating networks from electrochemical corrosion, approved by the USSR Ministry of Energy and the Ministry of Housing and Utilities of the RSFSR and agreed with the USSR State Construction Committee.

5. ASSEMBLY, WELDING AND QUALITY CONTROL

WELDED JOINTS

GENERAL PROVISIONS

5.1. Welders are allowed to tack and weld pipelines if they have documents authorizing them to carry out welding work in accordance with the Rules for Certification of Welders approved by the USSR State Mining and Technical Supervision.

5.2. Before being allowed to work on welding pipeline joints, the welder must weld the permitted joint under production conditions in the following cases:

with a break in work for more than 6 months;

when welding pipelines with changes in the steel group, welding materials, technology or welding equipment.

On pipes with a diameter of 529 mm or more, it is allowed to weld half the perimeter of the permissible joint; Moreover, if the permissible joint is vertical and non-rotating, the ceiling and vertical sections of the seam must be welded.

The permissible joint must be of the same type as the production joint (the definition of a joint of the same type is given in the Rules for Certification of Welders of the USSR State Mining and Technical Supervision).

The permissible joint is subject to the same types of control that production welded joints are subjected to in accordance with the requirements of this section.

MANUFACTURING JOBS

5.3. The welder is obliged to knock out or fuse the mark at a distance of 30-50 mm from the joint on the side accessible for inspection.

5.4. Before assembly and welding, it is necessary to remove the end caps, clean the edges and the adjacent inner and outer surfaces of the pipes to a width of at least 10 mm to bare metal.

5.5. Welding methods, as well as types, structural elements and dimensions of welded joints of steel pipelines must comply with GOST 16037-80.

5.6. Pipeline joints with a diameter of 920 mm or more, welded without a remaining backing ring, must be made with welding of the root of the seam inside the pipe. When welding inside a pipeline, the responsible person must be issued a work permit for high-risk work. The issuance procedure and form of the permit must comply with the requirements of SNiP III-4-80.

5.7. When assembling and welding pipe joints without a backing ring, the displacement of the edges inside the pipe should not exceed:

for pipelines that are subject to the requirements of the USSR State Mining and Technical Supervision Rules - in accordance with these requirements;

for other pipelines - 20% of the pipe wall thickness, but not more than 3 mm.

At pipe joints assembled and welded on the remaining backing ring, the gap between the ring and the inner surface of the pipe should not exceed 1 mm.

5.8. The assembly of pipe joints for welding should be done using mounting centering devices.

Correction of smooth dents at the ends of pipes for pipelines that are not subject to the requirements of the USSR Gosgortekhnadzor Rules is allowed if their depth does not exceed 3.5% of the pipe diameter. Sections of pipes with deeper dents or tears should be cut out. The ends of pipes with nicks or chamfers with a depth of 5 to 10 mm should be cut off or corrected by surfacing.

5.9. When assembling a joint using tacks, their number should be 1-2 for pipes with a diameter of up to 100 mm, and 3-4 for pipes with a diameter of over 100 to 426 mm. For pipes with a diameter over 426 mm, tacks should be placed every 300-400 mm around the circumference.

The tacks should be evenly spaced around the perimeter of the joint. The length of one tack for pipes with a diameter of up to 100 mm is 10-20 mm, with a diameter over 100 to 426 mm - 20-40, with a diameter over 426 mm - 30-40 mm. The height of the tack should be equal to the wall thickness S up to 10 mm - (0.6-0.7) S, but not less than 3 mm, with a larger wall thickness - 5-8 mm.

The electrodes or welding wire used for tack welding must be of the same grade as that used for welding the main seam.

5.10. Welding of pipelines that are not subject to the requirements of the USSR State Mining and Technical Supervision Rules may be carried out without heating the welded joints:

at outside air temperatures down to minus 20 °C - when using pipes made of carbon steel with a carbon content of no more than 0.24% (regardless of the wall thickness of the pipes), as well as pipes made of low-alloy steel with a wall thickness of no more than 10 mm;

at outside air temperatures down to minus 10 °C - when using pipes made of carbon steel with a carbon content of over 0.24%, as well as pipes made of low-alloy steel with a wall thickness of over 10 mm.

When the outside air temperature is very low, welding should be carried out in special booths, in which the air temperature in the area of ​​​​the joints being welded should be maintained not lower than the specified one.

It is allowed to carry out welding work in the open air when the pipe ends to be welded are heated at a length of at least 200 mm from the joint to a temperature of at least 200 °C. After welding is completed, a gradual decrease in the temperature of the joint and the adjacent pipe area must be ensured by covering them with asbestos sheets or using another method.

Welding (at negative temperatures) of pipelines that are subject to the requirements of the USSR State Technical Supervision Rules must be carried out in compliance with the requirements of these Rules.

In rain, wind and snow, welding work can only be carried out if the welder and the welding site are protected.

5.11. Welding of galvanized pipes should be carried out in accordance with SNiP 3.05.01-85.

5.12. Before welding pipelines, each batch of welding materials (electrodes, welding wire, fluxes, shielding gases) and pipes must be subjected to incoming inspection:

for the presence of a certificate with verification of the completeness of the data contained in it and their compliance with the requirements of state standards or technical specifications;

to ensure that each box or other package contains a corresponding label or tag with verification of the data on it;

for the absence of damage (damage) to the packaging or the materials themselves. If damage is detected, the question of the possibility of using these welding materials must be resolved by the organization performing the welding;

on the technological properties of electrodes in accordance with GOST 9466-75 or departmental regulatory documents approved in accordance with SNiP 1.01.02-83.

5.13. When applying the main seam, it is necessary to completely overlap and weld the tacks.

QUALITY CONTROL

5.14. Quality control of welding work and welded joints of pipelines should be carried out by:

checking the serviceability of welding equipment and measuring instruments, the quality of the materials used;

operational control during the assembly and welding of pipelines;

external inspection of welded joints and measurements of seam sizes;

checking the continuity of joints using non-destructive testing methods - radiographic (X-ray or gamma rays) or ultrasonic flaw detection in accordance with the requirements of the USSR State Mining and Technical Supervision Rules, GOST 7512-82, GOST 14782-76 and other standards approved in the prescribed manner. For pipelines that are not subject to the Rules of the State Mining and Technical Supervision of the USSR, it is allowed to use magnetographic testing instead of radiographic or ultrasonic testing;

mechanical tests and metallographic studies of control welded joints of pipelines, which are subject to the requirements of the USSR State Mining and Technical Supervision Rules, in accordance with these Rules;

tests for strength and tightness.

5.15. During operational quality control of welded joints of steel pipelines, it is necessary to check compliance with the standards of structural elements and dimensions of welded joints (blunting and cleaning of edges, the size of gaps between edges, width and reinforcement of the weld), as well as the technology and welding mode, the quality of welding materials, tacks and weld seam

5.16. All welded joints are subject to external inspection and measurement.

Pipeline joints welded without a backing ring with weld root welding are subject to external inspection and measurement of the dimensions of the seam outside and inside the pipe, in other cases - only from the outside. Before inspection, the weld seam and the adjacent surfaces of the pipes must be cleaned of slag, splashes of molten metal, scale and other contaminants to a width of at least 20 mm (on both sides of the seam).

The results of external inspection and measurement of dimensions of welded joints are considered satisfactory if:

there are no cracks of any size and direction in the seam and the adjacent area, as well as undercuts, sagging, burns, unsealed craters and fistulas;

the dimensions and number of volumetric inclusions and depressions between the rollers do not exceed the values ​​​​given in table. 1;

the dimensions of lack of penetration, concavity and excess penetration at the root of the weld of butt joints made without a remaining backing ring (if it is possible to inspect the joint from inside the pipe) do not exceed the values ​​​​given in table. 2.

Joints that do not meet the listed requirements must be corrected or removed.

Table 1

	Maximum permissible linear size of a defect, mm	The maximum permissible number of defects for any 100 mm of seam length
Volumetric inclusion of a round or elongated shape with a nominal wall thickness of welded pipes in butt joints or a smaller weld leg in corner joints, mm:
over 5.0 to 7.5
Recession (deepening) between the rollers and scaly structure of the weld surface with the nominal wall thickness of the pipes being welded in butt joints or with a smaller weld leg in corner joints, mm:
		Not limited

table 2

5.17. Welded joints are subjected to continuity testing using non-destructive testing methods:

pipelines that are subject to the requirements of the Rules of the State Mining and Technical Supervision of the USSR, with an outer diameter of up to 465 mm - in the volume provided for by these Rules, with a diameter of over 465 to 900 mm - in a volume of at least 10% (but not less than four joints), with a diameter of over 900 mm - in a volume of at least 15% (but not less than four joints) of the total number of similar joints made by each welder;

pipelines that are not subject to the requirements of the USSR State Mining and Technical Supervision Rules, with an outer diameter of up to 465 mm - in a volume of at least 3% (but not less than two joints), with a diameter over 465 mm - in a volume of 6% (but not less than three joints) of the total number of similar joints performed by each welder; in case of checking the continuity of welded joints using magnetic testing, 10% of the total number of joints subjected to control must also be checked using the radiographic method.

5.18. Non-destructive testing methods should be applied to 100% of welded joints of heating network pipelines laid in non-passable channels under roadways, in cases, tunnels or technical corridors together with other utilities. and also at intersections:

railways and tram tracks - at a distance of at least 4 m, electrified railways - at least 11 m from the axis of the outermost track;

railways of the general network - at a distance of at least 3 m from the nearest roadbed structure;

highways - at a distance of at least 2 m from the edge of the roadway, reinforced shoulder strip or the bottom of the embankment;

metro - at a distance of at least 8 m from structures;

power, control and communication cables - at a distance of at least 2 m;

gas pipelines - at a distance of at least 4 m;

main gas and oil pipelines - at a distance of at least 9 m;

buildings and structures - at a distance of at least 5 m from walls and foundations.

5.19. Welds should be rejected if, when tested by non-destructive testing methods, cracks, unwelded craters, burns, fistulas, as well as lack of penetration at the root of the weld made on the backing ring are detected.

5.20. When checking by radiographic method the welded seams of pipelines, which are subject to the requirements of the USSR State Mining and Technical Supervision Rules, acceptable defects are considered to be pores and inclusions, the dimensions of which do not exceed the values ​​​​specified in Table. 3.

Table 3

The height (depth) of lack of penetration, concavity and excess penetration at the root of the weld of a joint made by one-sided welding without a backing ring should not exceed the values ​​​​specified in table. 2.

Acceptable defects in welds according to the results of ultrasonic testing are considered to be defects, measured characteristics, the number of which does not exceed those indicated in the table. 4.

Table 4

Notes: 1. A defect is considered large if its nominal length exceeds 5.0 mm for a wall thickness of up to 5.5 mm and 10 mm for a wall thickness of over 5.5 mm. If the conditional length of the defect does not exceed the specified values, it is considered minor.

2. When performing electric arc welding without a backing ring with one-sided access to the seam, the total conditional length of defects located at the root of the seam is allowed up to 1/3 of the pipe perimeter.

3. The amplitude level of the echo signal from the defect being measured should not exceed the amplitude level of the echo signal from the corresponding artificial corner reflector (“notch”) or equivalent segmental reflector.

5.21 . For pipelines that are not subject to the requirements of the USSR Gosgortekhnadzor Rules, acceptable defects in the radiographic inspection method are considered to be pores and inclusions, the dimensions of which do not exceed the maximum permissible according to GOST 23055-78 for class 7 welded joints, as well as lack of penetration, concavity and excess penetration at the root of a seam made by one-sided electric arc welding without a backing ring, the height (depth) of which should not exceed the values ​​​​specified in table. 2.

5 .22. When non-destructive testing methods are used to identify unacceptable defects in pipeline welds that are subject to the requirements of the USSR Gosgortekhnadzor Rules, repeated quality control of the seams established by these Rules must be carried out, and in pipeline welds that are not subject to the requirements of the Rules - in double the number of joints according to compared to that specified in clause 5.17.

If unacceptable defects are identified during re-inspection, all joints made by this welder must be inspected.

5.23. Sections of the weld with unacceptable defects are subject to correction by local sampling and subsequent welding (without re-welding the entire joint), if the sample size after removing the defective section does not exceed the values ​​​​indicated in the table. 5.

Welded joints, in the seams of which, in order to correct the defective area, it is necessary to make a sample with the dimensions of pain allowed according to the table. 5 must be completely removed.

Table 5

Note. When correcting several sections in one connection, their total length may exceed that indicated in the table. 5 no more than 1.5 times at the same depth standards.

5.24. Undercuts should be corrected by surfacing thread beads with a width of no more than 2.0 - 3.0 mm. Cracks must be drilled at the ends, cut out, thoroughly cleaned and welded in several layers.

5.25. All corrected areas of welded joints must be checked by external inspection, radiographic or ultrasonic flaw detection.

5.26. On the as-built drawing of the pipeline, drawn up in accordance with SNiP 3.01.03-84, the distances between welded joints, as well as from wells, chambers and user inputs to the nearest welded joints, should be indicated.

6. THERMAL INSULATION OF PIPELINES

6.1. Installation of thermal insulation structures and protective coatings must be carried out in accordance with the requirements of SNiP III-20-74 and this section.

6.2. Welded and flanged connections should not be insulated to a width of 150 mm on both sides of the connections before testing the pipelines for strength and tightness.

6.3. The possibility of carrying out insulation work on pipelines subject to registration in accordance with the Rules of the USSR Gosgortekhnadzor must be agreed with the local body of the USSR Gosgortekhnadzor before performing tests for strength and tightness.

6.4. When performing flooded and backfill insulation during channelless laying of pipelines, the work design must include temporary devices to prevent the pipeline from floating up, as well as soil from getting into the insulation.

7. TRANSITIONS OF HEATING NETWORKS THROUGH DRIVEWAYS AND ROADS

7.1. Work at underground (aboveground) intersections of heating networks with railways and tramways, roads, city passages should be carried out in accordance with the requirements of these rules, as well as SNiP III-8-76.

7.2. When piercing, punching, horizontal drilling or other methods of trenchless laying of casings, assembly and tack of casing links (pipes) must be performed using a centralizer. The ends of the welded links (pipes) must be perpendicular to their axes. Fractures of the axes of the links (pipes) of the cases are not allowed.

7.3. Reinforced shotcrete anti-corrosion coating of cases during trenchless installation should be made in accordance with the requirements of SNiP III-15-76.

7.4. Pipelines within the casing should be made from pipes of the maximum supplied length.

7.5. The deviation of the axis of the transition cases from the design position for gravity condensate pipelines should not exceed:

vertically - 0.6% of the length of the casing, provided that the design slope of the condensate pipelines is ensured;

horizontally - 1% of the length of the case.

The deviation of the axis of the transition casings from the design position for the remaining pipelines should not exceed 1% of the casing length.

8. TESTING AND WASHING (BLOWING) OF PIPELINES

GENERAL PROVISIONS

8.1. After completion of construction and installation work, pipelines must be subjected to final (acceptance) tests for strength and tightness. In addition, condensate pipelines and pipelines of water heating networks must be washed, steam pipelines must be purged with steam, and pipelines of water heating networks with an open heating supply system and hot water supply network must be washed and disinfected.

Pipelines laid without channels and in non-passable channels are also subject to preliminary tests for strength and tightness during construction and installation work.

8.2. Preliminary tests of pipelines should be carried out before installing gland (bellows) compensators, sectional valves, closing channels and backfilling of channelless pipelines and channels.

Preliminary tests of pipelines for strength and tightness should be performed, as a rule, hydraulically.

At negative outside temperatures and the impossibility of heating water, as well as in the absence of water, it is allowed, in accordance with the work plan, to perform preliminary tests using a pneumatic method.

It is not allowed to carry out pneumatic tests of above-ground pipelines, as well as pipelines laid in the same channel (section) or in the same trench with existing utilities.

8.3. Pipelines of water heating networks should be tested at a pressure equal to 1.25 working, but not less than 1.6 MPa (16 kgf/cm 2), steam pipelines, condensate pipelines and hot water supply networks - at a pressure equal to 1.25 working, unless other requirements are justified project (working project).

8.4. Before performing strength and tightness tests, you must:

carry out quality control of welded joints of pipelines and correction of detected defects in accordance with the requirements of Section. 5;

disconnect the tested pipelines with plugs from the existing ones and from the first shut-off valves installed in the building (structure);

install plugs at the ends of the tested pipelines and instead of stuffing box (bellows) compensators, sectional valves during preliminary tests;

provide access along the entire length of the tested pipelines for their external inspection and inspection of welds during the tests;

open the valves and bypass lines completely.

The use of shut-off valves to disconnect the pipelines under test is not permitted.

Simultaneous preliminary tests of several pipelines for strength and tightness may be carried out in cases justified by the work design.

8.5. Pressure measurements when testing pipelines for strength and tightness should be made using two duly certified (one control) spring pressure gauges of class not lower than 1.5 with a body diameter of at least 160 mm and a scale with a nominal pressure of 4/3 of the measured pressure.

8.6. Testing of pipelines for strength and tightness (density), their purging, washing, disinfection must be carried out according to technological schemes (agreed with operating organizations), regulating the technology and safety precautions for carrying out work (including the boundaries of security zones).

8.7. Reports on the results of tests of pipelines for strength and tightness, as well as on their flushing (purging) should be drawn up in the forms given in mandatory appendices 2 and 3.

HYDRAULIC TESTS

8.8. Pipeline testing should be carried out in compliance with the following basic requirements:

test pressure must be provided at the top point (mark) of the pipelines;

the water temperature during testing must be no lower than 5 °C;

if the outside air temperature is negative, the pipeline must be filled with water at a temperature not exceeding 70 °C and it must be possible to fill and empty it within 1 hour;

when gradually filling with water, air must be completely removed from the pipelines;

the test pressure must be maintained for 10 minutes and then reduced to operating pressure;

at operating pressure, the pipeline must be inspected along its entire length.

8.9. The results of hydraulic tests for the strength and tightness of the pipeline are considered satisfactory if during the tests there was no pressure drop, no signs of rupture, leakage or fogging were found in the welds, as well as leaks in the base metal, flange connections, fittings, compensators and other pipeline elements , there are no signs of shifting or deformation of pipelines and fixed supports.

PNEUMATIC TESTS

8.10. Pneumatic tests should be carried out for steel pipelines with a working pressure not higher than 1.6 MPa (16 kgf/cm 2) and a temperature of up to 250 ° C, mounted from pipes and parts tested for strength and tightness (density) by manufacturers in accordance with with GOST 3845-75 (in this case, the factory test pressure for pipes, fittings, equipment and other products and parts of the pipeline must be 20% higher than the test pressure accepted for the installed pipeline).

The installation of cast iron fittings (except for valves made of ductile cast iron) is not allowed during testing.

8.11. Filling the pipeline with air and raising the pressure should be done smoothly at a speed of no more than 0.3 MPa (3 kgf/cm2) per 1 hour. Visual inspection of the route [entry into the security (dangerous) zone, but without descending into the trench] is allowed at the pressure level , equal to 0.3 test, but not more than 0.3 MPa (3 kgf/cm 2).

During the inspection of the route, the pressure rise must be stopped.

When the test pressure value is reached, the pipeline must be maintained to equalize the air temperature along the length of the pipeline. After equalizing the air temperature, the test pressure is maintained for 30 minutes and then smoothly decreases to 0.3 MPa (3 kgf/cm2), but not higher than the operating pressure of the coolant; At this pressure, pipelines are inspected and defective areas are marked.

Leak locations are determined by the sound of leaking air, bubbles when covering welded joints and other places with soap emulsion and the use of other methods.

Defects are eliminated only when the excess pressure is reduced to zero and the compressor is turned off.

8.12. The results of preliminary pneumatic tests are considered satisfactory if during their conduct there is no drop in pressure on the pressure gauge, no defects are found in welds, flange connections, pipes, equipment and other elements and products of the pipeline, and there are no signs of shift or deformation of the pipeline and fixed supports.

8.13. Pipelines of water networks in closed heat supply systems and condensate pipelines should, as a rule, be subjected to hydropneumatic flushing.

Hydraulic flushing with reuse of flushing water by passing it through temporary mud traps installed along the flow of water at the ends of the supply and return pipelines is allowed.

Washing, as a rule, should be done with technical water. Washing with household and drinking water is allowed with justification in the work project.

8.14. Pipelines of water networks of open heating systems and hot water supply networks must be flushed hydropneumatically with potable water until the flushing water is completely clarified. After flushing, the pipelines must be disinfected by filling them with water containing active chlorine at a dose of 75-100 mg/l with a contact time of at least 6 hours. Pipelines with a diameter of up to 200 mm and a length of up to 1 km are permitted, in agreement with local sanitary authorities. epidemiological service, do not chlorinate and limit yourself to washing with water that meets the requirements of GOST 2874-82.

After washing, the results of laboratory analysis of wash water samples must comply with the requirements of GOST 2874-82. The sanitary and epidemiological service draws up a conclusion on the results of washing (disinfection).

8.15. The pressure in the pipeline during flushing should not be higher than the working pressure. The air pressure during hydropneumatic flushing should not exceed the working pressure of the coolant and be no higher than 0.6 MPa (6 kgf/cm2).

Water velocities during hydraulic flushing must be no lower than the calculated coolant velocities indicated in the working drawings, and during hydropneumatic flushing - exceed the calculated ones by at least 0.5 m/s.

8.16. Steam lines must be purged with steam and discharged into the atmosphere through specially installed purge pipes with shut-off valves. To warm up the steam line before purging, all start-up drains must be open. The heating rate should ensure that there are no hydraulic shocks in the pipeline.

The steam velocities when blowing each section must be no less than the operating velocities at the design parameters of the coolant.

9. ENVIRONMENTAL PROTECTION

9.1. When constructing new, expanding and reconstructing existing heating networks, environmental protection measures should be taken in accordance with the requirements of SNiP 3.01.01-85 and this section.

9.2. It is not allowed without agreement with the relevant service: to carry out excavation work at a distance of less than 2 m to tree trunks and less than 1 m to bushes; moving loads at a distance of less than 0.5 m to tree crowns or trunks; storing pipes and other materials at a distance of less than 2 m from tree trunks without installing temporary enclosing (protective) structures around them.

9.3. Hydraulic flushing of pipelines should be carried out by reusing water. Emptying of pipelines after washing and disinfection should be carried out in places specified in the work project and agreed upon with the relevant services.

9.4. The construction site area must be cleared of debris after completion of construction and installation work.

ANNEX 1

Mandatory

ABOUT STRETCHING COMPENSATORS

_______________________ « _____»_________________19_____

Commission consisting of:

______________________________________________________________________________

(last name, first name, patronymic, position)

______________________________________________________________________________

1. The extension of expansion joints listed in the table in the area from chamber (picket, shaft) No.______ to chamber (picket, shaft) No. ______ was presented for inspection and acceptance.

______________________________________________________________________________

______________________________________________________________________________

COMMISSION DECISION

The work was carried out in accordance with design and estimate documentation, state standards, building codes and regulations and meets the requirements for their acceptance.

(signature)

(signature)

APPENDIX 2

Mandatory

ABOUT TESTING PIPELINES

FOR STRENGTH AND TIGHTNESS

_______________________ "_____"____________19____

Commission consisting of:

representative of the construction and installation organization _________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

representative of the customer’s technical supervision ____________________________ ______ ____

______________________________________________________________________________

(last name, first name, patronymic, position)

______________________________________________________________________________

(last name, first name, patronymic, position)

inspected the work performed by _____________________________________________________

______________________________________________________________________________

(name of construction and installation organization)

and drew up this act as follows:

1. ___________________________________ are presented for inspection and acceptance

_______________________________________________________________________________

(hydraulic or pneumatic)

pipelines tested for strength and tightness and listed in the table, in the section from the chamber (picket, shaft) No. _______________________________________ to the chamber

(picket, mine) No. ______________________________ route _________________________

Length ______________ m.

(name of pipeline)

2. The work was carried out according to design estimates ____________________________

______________________________________________________________________________

______________________________________________________________________________

(name of the design organization, drawing numbers and date of their preparation)

COMMISSION DECISION

Representative of the construction and installation organization ________________

(signature)

Representative of the customer's technical supervision ___________ __________

(signature)

(signature)

APPENDIX 3

Mandatory

ABOUT CARRYING OUT WASHING (BLOWING) OF PIPELINES

_______________"_____"_______________19_____

Commission consisting of:

representative of the construction and installation organization _________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

representative of the customer’s technical supervision _____________________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

representative of the operating organization ______________________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

inspected the work performed by _____________________________________________

______________________________________________________________________________

(name of construction and installation organization)

and drew up this act as follows:

1. The flushing (blow-out) of pipelines in the area from the chamber (picket, shaft) No. ________________________________________ to the chamber is submitted for inspection and acceptance

(picket, mine) No.______________ route__________________________________________

______________________________________________________________________________

(name of pipeline)

length ____________________ m.

Washing (purging) has been completed_________________________________________________

______________________________________________________________________________

(name of medium, pressure, flow)

2. The work was carried out according to design estimates ____________________________

______________________________________________________________________________

______________________________________________________________________________

(name of the design organization, drawing numbers and date of their preparation)

COMMISSION DECISION

The work was carried out in accordance with design and estimate documentation, standards, building codes and regulations and meets the requirements for their acceptance.

Representative of the construction and installation organization ________________

(signature)

Representative of the customer's technical supervision _____________________

(signature)

Representative of the operating organization _____________________