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Steel water and gas pipes. Steel water and gas pipes Steel pipe GOST 3262 75 technical characteristics

GOST 3262-75 is a regulatory document in accordance with which steel water and gas pipes are produced. Using pipes that, unlike plastic products, can be successfully operated in open areas, and carry out installation of pipelines for transporting liquid and gaseous media. Such steel pipes are practically irreplaceable in the field of capital and private construction, housing and communal services, and agriculture.

VGP steel pipes

General information about VGP steel pipes

Water and gas steel pipes, the parameters of which are determined by GOST 3262-75, are classified as products intended purpose, as their name suggests. The differences between their types lie primarily in the method of production. However, no matter what type the steel pipes of the category under consideration belong to, all their parameters are specified by the provisions of a document such as GOST 3262 (75, 80, 85, 91).

So, according to this standard (3262-75, latest edition 91st year), water and gas pipes made by welding can belong to one of the following types:

non-galvanized;
galvanized;
originally made with threads at the ends, which can be obtained by cutting or rolling;
without thread.

Each type of steel pipe is produced using a specific technology

Areas of application and individual parameters

The main areas of application of water and gas pipes are geometric parameters And specifications which comply with standard 3262-75 - construction and repair. Pipes of this category are used for arranging gas and water communications and heating systems in cottages and multi-apartment buildings, administrative buildings, educational institutions, agricultural, industrial and any other facilities.

So, this type of rolled metal is used in:

communications of cold and hot water supply;
heating systems;
gas pipeline networks.

GOST 3262 (75, 80, 85, 91) assumes that welded pipes VGP can be produced in measured, multiple measured and unmeasured lengths. So, according to this gradation, they have the following dimensions (according to the length of the manufactured products):

measured – length from 4 to 12 m;
having a length that is a multiple of the measured value;
unmeasured with a length within the limits of the measured value.

The standard length of pipes produced according to GOST is limited to 12 meters

Wall size is the criterion by which water and gas pipes are distinguished:

Reinforced VGP pipes are products (sometimes galvanized), the wall thickness of which is increased (accordingly, such products have more weight). They are used for installation of pipelines through which liquid or gaseous media are transported under high pressure.

If the technical characteristics and basic geometric parameters of water and gas pipes are regulated by a regulatory document, then the design option and cutting length are determined by the customer. Thus, the most popular are pipes whose ends are threaded during the production process. The reason for their high popularity is that they do not require welding to install them.

The use of pipes with ready-made threads significantly reduces the installation time for communications

Threads on VGP pipes can be created during their production:

rolling (a technology that allows you to obtain threads with the most accurate parameters, while it is assumed that the internal diameter of the pipe will be 10% smaller);
slicing.

The thread on VGP pipes is cut or rolled at the request of the customer, and it can be either short or long.

When calculating the weight of water and gas pipes, it should be borne in mind that galvanized products weigh 3% more than those made of ferrous metal. The standard also imposes a limitation on deviations in batch weight: they should not exceed 8%.

Technical requirements

An assortment of pipes of each type is formed, which lists their geometric parameters and theoretical weight.

Pipes are manufactured according to size and weight

The steel from which pipes of the VGP category are made must also meet the requirements specified in GOST (380, 1050), while the mechanical properties, as well as chemical composition manufacturing materials are not standardized. Each type of pipe (welded, ferrous metal, galvanized, threaded) has special technical requirements, which should be discussed in more detail.

In accordance with the provisions of GOST, the following requirements are imposed on welded-type pipes of the VGP category.

If tubular products are connected using furnace welding technology, then in the area of the weld their outer diameter can be reduced by half a millimeter. If there is a gentle thickening on the inside of the seam, its size should not exceed 1 mm.
If using welding it is necessary to connect water and gas pipes whose wall thickness is more than 5 mm, then their ends must be chamfered at an angle of 35-40 degrees. In this case, the width of the end ring after chamfering should be in the range of 1–3 mm.
On the inside of the welded seam of water and gas pipes whose diameter exceeds 20 mm, excess metal must be cut or flattened so that its height does not exceed half a millimeter.
The customer can additionally specify the characteristics of products with an internal bore diameter of over 15 mm, produced using hot reduction (drawing) technology and joined by furnace welding. According to such requirements, a flat thickening may be present on the inside of the weld, the height of which is no more than 0.5 mm.

Straight seam welded pipes are produced by folding the sheet and then welding the side edges

Water and gas pipes, the threads at the ends of which are cut or rolled by the manufacturer, must have the following parameters.

The threads formed at the ends of water and gas pipes in the factory must correspond to accuracy category “B”. Its characteristics are specified by the provisions of GOST 6357. Thus, the thread must be clean, there cannot be any flaws or burrs on it.
At the joints and thread turns there may be blackness, and the height of the thread profile in such places should not be reduced by more than 15%. The customer has the right to set more stringent requirements, according to which the limit for reducing the height of the thread profile can be reduced to 10%.
The useful length of the thread (indicated in the assortment and measured without runoff) can be reduced to 15%, but the customer has the right to reduce the value of this deviation to 10%.

Thread requirements according to GOST

The zinc layer, which is applied to the entire surface of the water and gas pipe in the factory, must have a thickness of at least 30 microns. It is assumed that in areas with cut threads and at the ends there may be no zinc coating.
The zinc film must be applied with high quality; it must not contain bubbles, detachments from the base metal and foreign inclusions (oxides, sintered charge, zinc waste, etc.).
GOST allows the presence of flux stains, small deposits of zinc, roughness and marks on the surface of galvanized pipes that are left by elements of lifting devices.
If areas not coated with zinc are found on water and gas pipes, they can be re-treated, provided that the total area of such areas does not exceed 0.5% of the total surface area of the product.

VGP galvanized pipes

The customer can negotiate with the manufacturer the provision of GOST couplings (8944, 8954, 8965, 8966) - one coupling for each product.
On the surface of the pipes, defects such as swelling, sunsets, cracks, oxide film are excluded, and at the ends of the products - delamination.
There may be some defects on the surface of water and gas pipes that are caused by the production method (ripples, scratches, dents, traces of stripping). At the same time, such defects should not reduce the pipe wall thickness below the tolerance specified in the product range. A layer of scale may also be present, but it should not interfere with inspection of the product.
The ends of water and gas pipes supplied to consumers are cut at right angles. The bevel, if it occurs during pruning, should not exceed 2 degrees. The size of the burrs remaining after trimming should not exceed half a millimeter.

Pipes are checked for compliance with GOST selectively - at least two products from each batch are examined

The regulatory document also stipulates the control methods to which all pipes of the water and gas category must be subjected:

Test for hydraulic pressure, which the pipes must withstand:

Ordinary and light type - 25 kgf/cm2 (2.4 MPa);

Reinforced - 32 kgf/cm2 (3.1 MPa);

Meeting special requirements - 50 kgf/cm2 (4.9 MPa).

Bend tests carried out on mandrels with a radius of:

– 2.5 outer diameter sizes – products with diameter up to 40 mm;

– 3.5 outer diameter sizes – pipes with DN 50 mm.

Distribution test for water and gas pipes with remote control:

– 15–50 mm – not less than 7%;

Labeling and storage conditions

By marking water and gas pipes, which must also comply with GOST, you can find out almost all the necessary information about the product: geometric dimensions, method of manufacture and processing, quality of the material. The number must be indicated at the end of the marking normative document, in accordance with which the product was manufactured.

Examples of symbols

Special requirements for the packaging of VGP pipes are imposed only if their outer diameter is from 6 to 20 mm. Such pipes, upon specific instructions from the customer, can be packaged in coils.

Depending on the type of water and gas pipes, their storage conditions may be as follows.

Galvanized products, which are characterized by increased resistance to the formation and development of corrosion, are securely fixed in storage areas and protected from direct moisture.
Water and gas pipes that are not coated with a protective layer of zinc must be stored in a fixed position in dry rooms with a minimum level of ambient humidity.

GOST 3262-75 Steel water and gas pipes: dimensions, characteristics

GOST 3262-75 and its requirements for steel water and gas pipes. Technical characteristics, scope and methods of quality control of VGP pipes.

Steel water and gas pipes technical specifications GOST 3262-75

STATE STANDARD OF THE USSR UNION

STEEL WATER AND GAS PIPES GOST

Specifications 3262-75

Water-supply and gas-supply steel pipes

Date of introduction 01.01.77

At customer's request light pipes series intended for thread rolling are manufactured according to the dimensions and weight given in table. 2.

b) of unmeasured length.

Pipe wall thickness

Weight of 1 m of pipes, kg

Steel water and gas pipes technical specifications GOST 3262-75 - Document - page

Document - This standard applies to non-galvanized and galvanized welded steel pipes with cut or rolled cylindrical thread and without thread, used for water and gas pipelines, heating systems, as well as for

STATE STANDARD OF THE USSR UNION

Specifications Water-supply and gas-supply Specifications

Date of introduction: 01.01.77

This standard applies to non-galvanized and galvanized steel welded pipes with cut or rolled cylindrical threads and without threads, used for water and gas pipelines, heating systems, as well as for parts of water and gas pipeline structures.

(Changed edition, Amendment No. 2, 3, 5).

1. ASSORTMENT

1.1. Pipes are manufactured according to the dimensions and weight given in table. 1.

At the consumer's request, light series pipes intended for thread rolling are manufactured according to the dimensions and weight given in Table 2.

1.2. The length of the pipe is made from 4 to 12 m:

a) measured or multiple measured length with an allowance for each cut of 5 mm and a maximum deviation for the entire length plus 10 mm;

b) of unmeasured length.

By agreement between the manufacturer and the consumer, up to 5% of pipes with a length of 1.5 to 4 m are allowed in a batch of unmeasured pipes.

(Changed edition, Amendment No. 3, 4).

1. For threads made by rolling on a pipe, its internal diameter is allowed to be reduced by up to 10% along the entire length of the thread.

2. The mass of 1 m of pipes is calculated at a steel density of 7.85 g/cm 3 . Galvanized pipes are 3% heavier than non-galvanized ones.

(Changed edition, Amendment No. 1, 3)

1.3. Maximum deviations in pipe sizes should not exceed those indicated in the table. 3.

1. The maximum deviation in the positive direction for wall thickness is limited by the maximum deviations for the mass of the pipes.

2. Pipes of standard manufacturing precision are used for water supply, gas pipelines and heating systems. Pipes with increased manufacturing precision are used for parts of water and gas pipeline structures.

1.4. Maximum deviations in the mass of pipes should not exceed + 8%.

At the request of the consumer, maximum deviations in mass should not exceed:

7.5% – for the party;

10% – for a separate pipe.

(Changed edition, Amendment No. 2, 5).

1.5. The curvature of pipes per 1 m length should not exceed:

2 mm – s conditional passage up to 20 mm inclusive;

1.5 mm – with a nominal bore over 20 mm.

1.6. Pipe threads can be long or short. The thread requirements must correspond to those indicated in the table. 4.

1.7. Pipes with a nominal bore of 6, 8, 10, 15 and 20 mm are wound into coils at the consumer’s request.

Examples of symbols

An ordinary pipe, non-galvanized, of normal manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling:

The same, measured length, with thread:

Pipe R-20×2.8 – 4000 GOST 3262-75

The same, with zinc coating, of unmeasured length, with thread:

The same, with zinc coating, custom length, with thread:

Pipe Ts-R-20×2.8 – 4000 GOST 3262-75

For pipes for thread rolling in symbol After the word “pipe” the letter N is indicated.

For pipes with long threads, the letter D is indicated after the word “pipe” in the symbol.

For pipes with increased manufacturing precision, the letter P is indicated in the symbol after the size of the nominal bore.

(Changed edition, Amendment No. 1).

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard and according to technological regulations, approved in in the prescribed manner, made of steel according to GOST 380-88 and GOST 1050-88 without standardization mechanical properties and chemical composition.

Pipes for parts of water supply and gas pipeline structures are made of steel in accordance with GOST 1050-88.

2.2. At the request of the consumer, the ends of pipes to be welded, with a wall thickness of 5 mm or more, must be chamfered at an angle of 35-40° to the end of the pipe. In this case, an end ring 1–3 mm wide should be left.

At the request of the consumer, on ordinary and reinforced pipes with a nominal bore of more than 10 mm, threads are applied to both ends of the pipe.

2.1; 2.2. (Changed edition, Amendment No. 3, 4).

2.3. At the consumer's request, pipes are equipped with couplings manufactured in accordance with GOST 8944-75, GOST 8954-75, GOST 8965-75 and GOST 8966-75 at the rate of one coupling for each pipe.

(Changed edition, Amendment No. 3).

2.4. Cracks, spots, swellings and declines are not allowed on the surface of the pipes.

Delamination is not allowed at the ends of the pipes.

Individual dents, rippling, scratches, traces of stripping and other defects caused by the production method are allowed, if they do not take the wall thickness beyond the minimum dimensions, as well as a layer of scale that does not interfere with inspection.

On pipes made by furnace welding, it is allowed to reduce the outer diameter to 0.5 mm at the seam if there is a gentle thickening in this place along internal diameter no more than 1.0 mm.

(Changed edition, Amendment No. 3, 4).

2.5. At the request of the consumer, on pipes with a nominal bore of 20 mm or more, the burr on the inner surface of the pipe seam must be cut off or flattened, and the height of the burr or its traces should not exceed 0.5 mm.

At the request of the consumer, on pipes with a nominal bore of more than 15 mm, manufactured by furnace welding and hot reduction, a gentle thickening with a height of no more than 0.5 mm is allowed on the inner surface of the pipes in the weld area.

(Changed edition, Amendment No. 2, 3, 4, 5, 6).

2.6. The ends of the pipes must be cut at right angles. The bevel of the end is allowed to be no more than 2°. The remaining burrs should not exceed 0.5 mm. When removing burrs, the formation of blunting (rounding) of the ends is allowed. It is allowed to cut pipes in the mill line.

By agreement between the manufacturer and the consumer, burrs up to 1 mm are allowed on pipes with a nominal bore of 6-25 mm, manufactured by furnace welding.

(Changed edition, Amendment No. 4, 6).

2.7. Galvanized pipes must have a continuous zinc coating over the entire surface with a thickness of at least 30 microns. The absence of zinc coating on the ends and threads of pipes is allowed.

On the surface of galvanized pipes, bubbles and foreign inclusions (hardzinc, oxides, sintered mixture), and peeling of the coating from the base metal are not allowed.

Individual flux spots and traces of pipes being caught by lifting devices, roughness and minor local deposits of zinc are allowed.

It is allowed to correct individual non-galvanized areas on 0.5% of the outer surface of the pipe in accordance with GOST 9.307-89.

(Changed edition, Amendment No. 3, 4).

2.8. Pipes must withstand hydraulic pressure:

2.4 MPa (25 kgf/cm 2) – pipes, ordinary and light;

3.1 MPa (32 kgf/cm 2) – reinforced pipes.

At the request of the consumer, the pipes must withstand hydraulic pressure of 4.9 MPa (50 kgf/cm2)

(Changed edition, Amendment No. 2, 3, 5).

2.9. Pipes with a nominal bore up to 40 mm inclusive must withstand the bend test around a mandrel with a radius equal to 2.5 outer diameters, and with a nominal bore of 50 mm - on a mandrel with a radius equal to 3.5 outer diameters.

At the request of the consumer, pipes must withstand the distribution test:

for pipes with a nominal bore from 15 to 50 mm - no less than 7%;

for pipes with a nominal bore of 65 or more - no less than 4%.

At the request of the consumer, pipes must withstand the flattening test to a distance between the flattened surfaces equal to 2/3 of the outer diameter of the pipes.

(Changed edition, Amendment No. 2, 3, 5).

2.10. At the request of the consumer, the mechanical properties of pipes for parts of water supply and gas pipeline structures must comply with GOST 1050-88.

2.11. Pipe threads must be clean, without flaws or burrs and comply with GOST 6357-81, accuracy class B.

Pipes with cylindrical threads are used when assembling with seals.

2.10; 2.11. (Changed edition, Amendment No. 3, 4).

2.12. At the seam, blackness on the threads is allowed if the reduction in the normal height of the thread profile does not exceed 15%, and at the request of the consumer does not exceed 10%.

Threads with torn (for cut) or incomplete (for rolled) threads are allowed on threads, provided that their total length does not exceed 10% of the required thread length, and at the request of the consumer does not exceed 5%.

(Changed edition, Amendment No. 2, 3, 5).

2.13. On a thread, it is allowed to reduce the useful length of the thread (without running) up to 15% compared to that indicated in the table. 4, and at the consumer’s request up to 10%.

(Changed edition, Amendment No. 2, 3, 5).

2.14. Threading on galvanized pipes is carried out after galvanizing.

2.16. At the request of the consumer, pipe welds are subjected to testing using non-destructive methods.

(Changed edition, Amendment No. 5).

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, the same brand and be accompanied by one quality document in accordance with GOST 10692-80 with an addition for pipes intended for the manufacture of parts for water supply and gas pipeline structures, made of steel in accordance with GOST 1050-88: chemical composition and mechanical properties steel in accordance with the document on the quality of the billet manufacturer.

The batch weight is no more than 60 tons.

(Changed edition, Amendment No. 3, 4).

3.2. Each pipe in the batch is subjected to inspection of the surface, dimensions and curvature.

Allowed to use statistical methods control according to GOST 18242-72 with a normal level. Control plans are established by agreement between the manufacturer and the consumer.

The outer diameter of the pipes is checked at a distance of at least 15 mm from the end of the pipe.

(Changed edition, Amendment No. 3, 4, 5).

3.3. To control thread parameters, to test for expansion, flattening, bending, internal burr height, burr residues, right angle and chamfer angle (for pipes with beveled edges), mechanical properties, no more than 1%, but not less than two pipes from the batch are selected, and for pipes manufactured by continuous furnace welding - two pipes per batch.

(Changed edition, Amendment No. 3, 4).

3.4. All pipes are subject to weight control.

(Changed edition, Amendment No. 3).

3.5. Each pipe is subjected to hydraulic pressure testing. With 100% quality control of the weld using non-destructive methods, hydraulic pressure testing may not be carried out. At the same time, the ability of the pipes to withstand the test hydraulic pressure is guaranteed.

(Changed edition, Amendment No. 6).

3.6. To check the thickness of the zinc coating on the outer surface and in accessible places on the inner surface, two pipes from the batch are selected.

(Changed edition, Amendment No. 2).

3.7. If unsatisfactory test results are obtained for at least one of the indicators, a repeat test is carried out on a double sample.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test.

The tensile test is carried out according to GOST 10006-80. Instead of tensile testing, it is allowed to control mechanical properties using non-destructive methods.

4.2. The surface of the pipes is inspected visually.

4.3. Hydraulic testing is carried out in accordance with GOST 3845-75 with exposure under test pressure for at least 5 s.

4.4. The bend test is carried out according to GOST 3728-78. Galvanized pipes are tested before coating.

(Changed edition, Amendment No. 3).

4.4a. The expansion test is carried out according to GOST 8694-75 on a conical mandrel with a cone angle of 6°.

It is permissible to test on a mandrel with a taper angle of 30°.

(Changed edition, Amendment No. 3, 4).

4.4b. The flattening test is carried out according to GOST 8695-75.

(Changed edition, Amendment No. 3).

4.4v. Weld inspection is carried out using non-destructive methods according to regulatory and technical documentation.

(Introduced additionally, Amendment No. 3).

4.5. The thickness of the zinc coating on the outer surface and in accessible places on the inner surface is controlled according to GOST 9.301-86 and GOST 9.302-88, as well as with devices of the MT-41NTs, MTZON or Impulse type according to the normative and technical documentation.

4.6. The thread is checked using thread ring gauges in accordance with GOST 2533-88 (third accuracy class).

In this case, the screw-in of the no-go ring gauge onto the thread should be no more than three turns.

(Changed edition, Amendment No. 3, 4).

4.7. The curvature of the pipes is controlled using a straight edge in accordance with GOST 8026-92 and a set of probes in accordance with TU 2-034-225-87.

(Changed edition, Amendment No. 3, 5).

4.8. The right angle of the pipe ends is controlled with a 90° square measuring 160x100 mm, class 3 GOST 3749-77, plate probes set 4 TU 2-034-225-87 or an inclinometer GOST 5378-88. The bevel angle of the chamfer is controlled with a protractor according to GOST 5378-88.

(Changed edition, Amendment No. 3, 6).

4.9. The outer diameter is checked using smooth micrometers in accordance with GOST 6507-90, clamp gauges in accordance with GOST 2216-84 or GOST 18360-93.

The wall thickness, the height of the internal burr and the height of the burrs are measured with a micrometer according to GOST 6507-90 or a wall gauge according to GOST 11358-89 from both ends of the pipe.

The length of the pipes is measured with a tape measure according to GOST 7502-98. Threads are controlled with gauges in accordance with GOST 2533-88.

The mass of a batch of pipes is controlled on scales of no more than 10 tons with a division value of no more than 20 kg.

(Changed edition, Amendment No. 3, 4, 5, 6).

4.10. Weld inspection is carried out using non-destructive methods according to technical documentation.

(Introduced additionally, Amendment No. 4).

5. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Labeling, packaging, transportation and storage are carried out in accordance with GOST 10692-80 with addition.

5.1.1. Pipe threads must be protected from mechanical damage and corrosion with lubricant according to regulatory and technical documentation.

Sec. 5. (Changed edition, Amendment No. 3).

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Ferrous Metallurgy

V. I. Struzhok, Ph.D. tech. sciences, V. M. Vorona, Ph.D. tech. sciences, Yu. M. Mironov, Ph.D. tech. nook, A. I. Postolova

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Standards dated 09.11.75 No. 2379

3. Inspection frequency 5 years

4. INSTEAD GOST 3262-62

5. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

6. Reissue (May 1994) with Amendments No. 1, 2, 3, 4, 5, 6, approved in November 1977, December 1978, January 1987, May 1988, November 1989. , November 1991 (IUS 1-78, 2-79, 4-87, 8-88, 2-90, 2-92)

GOST 3262 75 applies to galvanized and non-galvanized welded steel pipes without threads and with rolled or cut cylindrical threads. Their scope of application is water and gas pipelines, heating systems, as well as the production of parts for water and gas pipeline structures.

Welded steel pipes are used for installation of water and gas pipelines

Range of water and gas pipes GOST 3262 75

In accordance with the requirements of this regulatory document, pipes are produced according to the weight and dimensions indicated in Table No. 1. The unit of measurement of geometric dimensions is millimeters.

Table 1

When calculating the mass of 1 meter of products, the steel density value was taken as 7.85 g/cm³. Non-galvanized pipes are 3% lighter than galvanized water and gas pipes GOST 3262 75.

The maximum mass deviation at the customer's request should not exceed:

for a separate pipe +10%,
for the party +7.5%.

The production of steel water and gas pipes of the above range in accordance with GOST 3262 75 is carried out from steels in accordance with GOST 1050 and GOST 380 without standardization of chemical composition and mechanical properties. Pipes for parts of gas and water supply structures are produced in accordance with GOST 1050.

Technical characteristics of water and gas steel pipes GOST 3262 75

The length of steel water and gas pipes according to GOST 3262 75 is produced in the range of 4m ≤ L ≤12m.

Steel pipes come in regular and irregular lengths

If we use this parameter as a criterion, these products are:

of unmeasured length. In a batch of pipes of this range, the presence of up to 5 percent of products with a length of 1.5 m ≤ L1 ≤ 4 m is allowed.
multiple of measured or measured length. The magnitude of the longitudinal deviation in accordance with the requirements of GOST 3262 75 for the entire length can exceed the nominal value by 10 centimeters with a cut allowance of up to 5 millimeters.

All tolerances are strictly regulated by GOST and if there are deviations exceeding the permissible ones, the product is considered defective.

Important! If the thread is made by rolling, a reduction in the internal diameter of the steel water and gas pipe GOST 3262 75 is allowed by no more than 10 percent along the length of the thread.

The range of maximum deviations of pipe sizes is indicated in table No. 2.

table 2

The indicator “Pipe curvature” per 1 meter of length according to GOST 3262 75 does not exceed:

2 mm at conditional passage up to 20 mm,
1.5 mm if the nominal diameter is more than 20 mm.

One of the most significant technical characteristics of a water and gas pipe according to GOST 3262 75 is pressure resistance. Depending on the type, a product of this type can withstand:

reinforced pipe – 3.1 MPa,
the pipe is ordinary and light - 2.4 MPa.

Requirements for galvanized steel water and gas pipes GOST 3262 75

The thickness of the zinc coating over the entire surface of pipes of this range must be at least 30 microns. Its absence is allowed on threads and ends of products. The galvanized surface should not have inclusions (sintered charge, oxides, hardzinc), bubbles or signs of peeling of the coating from the steel base.

Minor zinc deposits in some places and roughness, traces of products being caught by lifting equipment and local flux stains are allowed.

Individual sections of galvanized steel water and gas pipes GOST 3262 75 can be corrected if they lack a layer of zinc coating no more than 0.5% of total area surfaces. This operation must be carried out in accordance with the requirements of GOST 9.307.

If the nominal diameter does not exceed 40 millimeters, the galvanized pipe must withstand a bending test carried out around a mandrel whose diameter is 2.5 * Din, where Din. – outer diameter of the tested product.

Expansion testing of steel pipes is carried out using cone-shaped mandrels

In addition to this method, there is a more stringent technology for checking the technical characteristics of pipes. It is called the “Expansion Test”, it is expressed as a percentage and determines the ability of the pipe to expand until cracks appear when a cone-shaped body moves in its hole. With a nominal diameter of 15...50 millimeters, the value of this indicator should be at least 7 percent. For pipes whose nominal diameter exceeds 65 millimeters - at least 4 percent.

Helpful information! The above test methods are especially relevant for galvanized water and gas pipes GOST 3262 75. After all, the destruction of the coating layer will deprive the product of many attractive technical characteristics for which the consumer buys not just steel, but galvanized water and gas pipes.

Galvanized pipes manufactured in accordance with the requirements of GOST 3262-75 are a guarantee of the reliability and durability of pipelines for any purpose.

GOST 3262 75: welded steel water and gas pipes
GOST 3262 75 steel water and gas pipes. Product range. Technical characteristics of pipes according to GOST 3262 75. Requirements. Test methods.

Water and gas pipes

Steel water and gas pipe (GOST 3262-75)

This group includes non-galvanized and galvanized welded steel pipes, used for water and gas pipelines, as well as for heating systems and structural parts. By lenght water and gas pipes manufactured from 4 to 12 m:
a) measured or multiple measured length with an allowance for each cut of 5 mm and a longitudinal deviation over the entire length plus 10 mm,
b) of unmeasured length.

By agreement between the manufacturer and the consumer, in a batch of unmeasured water and gas pipes up to 5% of pipes with a length of 1.5 to 4 m are allowed.

For threads made by rolling on a pipe, it is allowed to reduce its internal diameter by up to 10% along the entire length of the thread. Weight 1 m water and gas pipe calculated at a steel density of 7.85 g/cm. Galvanized water and gas pipes heavier than non-galvanized ones by 3%.

Note: The maximum deviation in the positive direction in wall thickness is limited by the maximum deviations in mass water and gas pipes. Water and gas pipes of standard manufacturing precision are used for water supply, gas pipelines and heating systems.

Water and gas pipes with increased manufacturing precision are used for parts of water and gas pipeline structures.

Maximum deviations in the mass of pipes should not exceed +8%. At the request of the consumer, maximum deviations in mass should not exceed: + 7.5% for a batch, + 10% for an individual pipe.
The curvature of water and gas pipes per 1 m of length should not exceed: 2 mm – with a nominal bore up to 20 mm inclusive, 1.5 mm – with a nominal bore over 20 mm.

Water and gas pipes with a nominal diameter of 6, 8, 10, 15 and 20 mm are wound into coils at the request of the consumer. Examples of symbols:

An ordinary pipe, non-galvanized, of normal manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling: pipe 20x2.8 GOST 3262-75.
The same, with a coupling: pipe M-20x2.8 GOST 3262-75.
The same, measured length, with thread: pipe R-20x2, 8-4000 GOST 3262-75.

For water and gas pipes for rolling threads, the letter N is indicated in the symbol after the word “pipe”.

For water and gas pipes with long threads, the letter D is indicated in the symbol after the word “pipe”.

For water and gas pipes with increased manufacturing precision, the letter P is indicated in the symbol after the size of the nominal diameter.

Water and gas pipes
Pipes water and gas pipe water and gas steel pipes (GOST 3262-75) This group includes non-galvanized and galvanized welded steel pipes used for water supply and

Galvanized VGP pipe according to GOST 3262-75- This is a fairly well-known and in demand type of rolled pipe, which has a zinc coating, which gives the product decent anti-corrosion strength.

VGP pipe is manufactured according to GOST 3262-75 from the highest quality steel. The average length of products is 4-13 meters. At the request of the customer, it can be created longer than the established length.

Steel pipes VGP GOST 3262-75

Galvanized steel VGP pipe is a high-precision pipe product that is used mainly as gas and water supply structures.

GOST 3262-75 establishes the technical requirements and standards by which rolled VGP pipes are manufactured. But each standard provides for possible deviations from the norms. For example, the possible maximum deviation in mass cannot exceed 8%.

The range of water and gas steel pipes with galvanized coating is divided into 2 categories.

Variety of VGP pipe lengths

Unmeasured length with coupling.

Advantages of galvanized VGP pipes according to GOST 3262-75:

High strength,
Heat resistance and resistance to mechanical stress,
Corrosion resistance,
Affordable price.

These products significantly exceed the strength metal products, and when compared with carbon metal pipes, they have high stability to corrosion.

The specialists of the Metal-Service company confidently guarantee the highest quality and durability of this pipe rolling.

Galvanizing methods

A galvanized VGP pipe in accordance with GOST 3262-75 is coated in two ways. At hot galvanized the rolled pipe is dipped into molten zinc, after which it is allowed to cool, as a result of which a film is formed. At electrochemical galvanizing a zinc solution is used. But the disadvantage of this method is that the toxic electrolyte used in this method needs to be destroyed.

Technical requirements according to GOST 3262-75

According to this standard, products are produced with a length of 4-13 meters and an outer diameter of 10.2-166 mm. At the request of the customer, pipes can be with a diameter of up to 20 mm and the required length.

The method is selected taking into account the wall thickness of the products. Products with a thickness of 5 mm or more are suitable for welding.

Lightweight and ordinary galvanized VGP pipes are used in areas with a pressure of 2.4 MPa, reinforced - 3.1 MPa.

The entire surface of the products is covered with a zinc coating with a thickness of at least 30 microns. It may be missing at the end. An “influx” of zinc in some places, roughness, and traces from lifting equipment are allowed.

Manufactured products are tested using various methods.

Test methods

If the product has a nominal bore of no more than 40 mm, it can withstand bending test (hot dipping method), passing around the mandrel with outer diameter 2.5 mm.

There is an even more serious test - this distribution test (immersion method), which is expressed as a percentage. It can be used to determine how much the pipe can expand before cracks appear. With a nominal passage of 15-50 mm, the value of this indicator is usually more than 7%, and with a passage of more than 65 mm - less than 4%.

“The described methods are only suitable for galvanized VGP pipes in accordance with GOST 3262-75. After all, the destruction of the galvanized coating layer of the pipe will deprive it of many quality characteristics.”

Range of water and gas steel pipes

All VGP pipes are manufactured according to the GOST standard. This table presents established dimensions for the production of water and gas products. Each manufacturer focuses specifically on them.

Now let's find out where this rolled metal is used.

Application of galvanized VGP pipes according to GOST 3262-75

Galvanized VGP pipe according to GOST 3262-75 used for laying internal communications in residential and production facilities, as well as their heating.

Such products are in demand in the aviation, shipbuilding industries, as well as in civil engineering.

Galvanized products, including VGP pipes in accordance with GOST 3262-75, will be popular for many years to come. This is due to the fact that metal has qualities such as:

Constant sizes,
Heat resistance,
Unique characteristics.

Compared to other types of pipe products, galvanized VGP pipe in accordance with GOST 3262-75 has a great advantage. The product is not subject to rust at all, and its walls are smooth. By quality characteristics, the product has high mechanical properties. It is impossible to accidentally damage it. At the same time, the product can be used in any weather conditions, as it is heat-resistant. For this type, the method of welding or threaded connection is usually used.

But the installation of galvanized VGP pipes in accordance with GOST 3262-75 must be carried out by a specialist. To obtain a leak-free connection requires knowledge and experience.

Buy galvanized VGP pipes

"Metal-Service" offers to buy galvanized VGP pipes High Quality from trusted suppliers. We guarantee that all products will fully comply with established GOST standards.

Our employees are distinguished by their special professionalism. Therefore, if you have any questions about rolled metal, call us! The company's managers will be happy to tell you what a galvanized VGP pipe is in accordance with GOST 3262 75 and where it is used.

Galvanized VGP pipe according to GOST 3262-75
Technical requirements required by galvanized VGP pipe according to GOST 3262-75. Test methods and methods for galvanizing VGP pipes.

INTERSTATE STANDARD

STEEL PIPES
WATER AND GAS

TECHNICAL CONDITIONS

Date of introduction 01/01/77

1. ASSORTMENT

1.1. Pipes are manufactured according to the dimensions and weight given in table. 1.

At the consumer's request, light series pipes intended for thread rolling are manufactured according to the dimensions and weight given in table. 2.

1.2. The length of the pipe is made from 4 to 12 m:

a) measured or multiple measured length with an allowance for each cut of 5 mm and a maximum deviation for the entire length plus 10 mm;

b) of unmeasured length.

By agreement between the manufacturer and the consumer, up to 5% of pipes with a length of 1.5 to 4 m are allowed in a batch of unmeasured pipes.

Table 1

Conditional pass	Outside diameter	Pipe wall thickness			Weight of 1 m of pipes, kg
Conditional pass	Outside diameter		ordinary	reinforced		ordinary	reinforced

table 2

Conditional pass	Outside diameter	Wall thickness	Weight of 1 m of pipes, kg








Notes: 1. For threads made by rolling on a pipe, its internal diameter is allowed to be reduced by up to 10% along the entire length of the thread. 2. The mass of 1 m of pipes is calculated at a steel density of 7.85 g/cm 3 . Galvanized pipes are 3% heavier than non-galvanized ones.

1.3. Maximum deviations in pipe sizes should not exceed those indicated in the table. 3.

Table 3

Pipe sizes		Pipe sizes	Limit deviations for manufacturing accuracy pipes
Pipe sizes	increased	Pipe sizes		increased
		Outer diameter with nominal bore:
		over 40 mm
up to 40 mm incl.		Wall thickness
Notes: 1. The maximum deviation in the positive direction for wall thickness is limited by the maximum deviations for the mass of the pipes. 2. Pipes of standard manufacturing precision are used for water supply, gas pipelines and heating systems.

Pipes with increased manufacturing precision are used for parts of water and gas pipeline structures.

1.4. Maximum deviations in the mass of pipes should not exceed +8%.

At the request of the consumer, maximum deviations in mass should not exceed:

7.5% - for the party;

(Changed edition, Amendment No. 2, 5).

1.5. The curvature of pipes per 1 m length should not exceed:

2 mm - with nominal bore up to 20 mm inclusive;

1.5 mm - with a nominal bore over 20 mm.

1.6. Pipe threads can be long or short. The thread requirements must correspond to those indicated in the table. 4.

Table 4

Conditional bore, mm	Thread length before run		Conditional bore, mm	Number of threads at nominal size	Thread length before run
Conditional bore, mm		short	Conditional bore, mm	Number of threads at nominal size		short

1.7. Pipes with a nominal bore of 6, 8, 10, 15 and 20 mm are wound into coils at the consumer’s request.

Examples of symbols

An ordinary pipe, non-galvanized, of normal manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling:

The same with the coupling:

The same, measured length, with thread:

The same, with zinc coating, of unmeasured length, with thread:

The same, with zinc coating, custom length, with thread:

For pipes for rolling threads, the letter N is indicated in the symbol after the word “pipe”.

For pipes with long threads, the letter D is indicated after the word “pipe” in the symbol.

For pipes with increased manufacturing precision, the letter P is indicated in the symbol after the size of the nominal bore.

(Changed edition, Amendment No. 1).

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard and according to technological regulations approved in the prescribed manner, from steels in accordance with GOST 380 and GOST 1050 without standardization of mechanical properties and chemical composition.

Pipes for parts of water supply and gas pipeline structures are made of steel in accordance with GOST 1050.

2.2. At the request of the consumer, the ends of pipes to be welded, with a wall thickness of 5 mm or more, must be chamfered at an angle of 35 - 40° to the end of the pipe. In this case, an end ring 1 - 3 mm wide should be left.

At the request of the consumer, on ordinary and reinforced pipes with a nominal bore of more than 10 mm, threads are applied to both ends of the pipe.

2.1; 2.2.

2.3. At the request of the consumer, pipes are equipped with couplings manufactured in accordance with GOST 8944, GOST 8954, GOST 8965 and GOST 8966 at the rate of one coupling for each pipe.

(Changed edition, Amendment No. 3).

2.4. Cracks, spots, swellings and declines are not allowed on the surface of the pipes.

Delamination is not allowed at the ends of the pipes.

On pipes made by furnace welding, it is allowed to reduce the outer diameter to 0.5 mm at the seam if there is a gentle thickening in this place along the inner diameter of no more than 1.0 mm.

(Changed edition, Amendment No. 3, 4).

(Changed edition, Amendment No. 2, 3, 4, 5, 6).

By agreement between the manufacturer and the consumer, burrs up to 1 mm are allowed on pipes with a nominal bore of 6 - 25 mm, manufactured by furnace welding.

(Changed edition, Amendment No. 4, 6).

2.7. Galvanized pipes must have a continuous zinc coating over the entire surface with a thickness of at least 30 microns. The absence of zinc coating on the ends and threads of pipes is allowed.

On the surface of galvanized pipes, bubbles and foreign inclusions (hardzinc, oxides, sintered mixture), and peeling of the coating from the base metal are not allowed.

Individual flux spots and traces of pipes being caught by lifting devices, roughness and minor local deposits of zinc are allowed.

It is allowed to correct individual non-galvanized areas on 0.5% of the outer surface of the pipe in accordance with GOST 9.307.

(Changed edition, Amendment No. 3, 4).

2.8. Pipes must withstand hydraulic pressure:

2.4 MPa (25 kgf/cm 2) - pipes, ordinary and light;

3.1 MPa (32 kgf/cm 2) - reinforced pipes.

At the request of the consumer, the pipes must withstand hydraulic pressure of 4.9 MPa (50 kgf/cm2)

(Changed edition, Amendment No. 2, 3, 5).

At the request of the consumer, pipes must withstand the distribution test:

for pipes with a nominal bore from 15 to 50 mm - no less than 7%;

for pipes with a nominal bore of 65 or more - no less than 4%.

At the request of the consumer, pipes must withstand the flattening test to a distance between the flattened surfaces equal to 2/3 of the outer diameter of the pipes.

(Changed edition, Amendment No. 2, 3, 5).

2.10. At the request of the consumer, the mechanical properties of pipes for parts of water supply and gas pipeline structures must comply with GOST 1050.

2.11. Pipe threads must be clean, without flaws or burrs and comply with GOST 6357, accuracy class B.

Pipes with cylindrical threads are used when assembling with seals.

2.10; 2.11. (Changed edition, Amendment No. 3, 4).

2.12. At the seam, blackness on the threads is allowed if the reduction in the normal height of the thread profile does not exceed 15%, and at the request of the consumer does not exceed 10%.

(Changed edition, Amendment No. 2, 3, 5).

2.13. On a thread, it is allowed to reduce the useful length of the thread (without running) up to 15% compared to that indicated in the table. 4, and at the consumer’s request up to 10%.

(Changed edition, Amendment No. 2, 3, 5).

2.14. Threading on galvanized pipes is carried out after galvanizing.

2.15. (Deleted, Amendment No. 3).

2.16. At the request of the consumer, pipe welds are subjected to testing using non-destructive methods.

(Changed edition, Amendment No. 5).

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, the same grade and be accompanied by one quality document in accordance with GOST 10692 with an addition for pipes intended for the manufacture of parts for water supply and gas pipeline structures, made of steel in accordance with GOST 1050: chemical composition and mechanical properties of steel in accordance with document on the quality of the workpiece manufacturer.

The batch weight is no more than 60 tons.

(Changed edition, Amendment No. 3, 4).

3.2. Each pipe in the batch is subjected to inspection of the surface, dimensions and curvature.

It is allowed to use statistical control methods in accordance with GOST 18242 * with a normal level. Control plans are established by agreement between the manufacturer and the consumer.

* GOST R 50779.71-99 is in force on the territory of the Russian Federation.

The outer diameter of the pipes is checked at a distance of at least 15 mm from the end of the pipe.

(Changed edition, Amendment No. 3, 4, 5).

(Changed edition, Amendment No. 3, 4).

3.4. All pipes are subject to weight control.

(Changed edition, Amendment No. 3).

(Changed edition, Amendment No. 6).

3.6. To check the thickness of the zinc coating on the outer surface and in accessible places on the inner surface, two pipes from the batch are selected.

(Changed edition, Amendment No. 2).

3.7. If unsatisfactory test results are obtained for at least one of the indicators, a repeat test is carried out on a double sample.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test.

The tensile test is carried out according to GOST 10006. Instead of tensile testing, it is allowed to control mechanical properties using non-destructive methods.

(Changed edition, Amendment No. 3, 6).

4.2. The surface of the pipes is inspected visually.

4.3. Hydraulic testing is carried out in accordance with GOST 3845 with exposure to test pressure for at least 5 s.

4.4. The bend test is carried out according to GOST 3728. Galvanized pipes are tested before coating.

(Changed edition, Amendment No. 3).

4.4a. The expansion test is carried out according to GOST 8694 on a conical mandrel with a cone angle of 6°.

Testing on a mandrel with a taper angle of 30° is allowed.

(Changed edition, Amendment No. 3, 4).

4.4b. The flattening test is carried out according to GOST 8695.

(Changed edition, Amendment No. 3).

4.4v. Weld inspection is carried out using non-destructive methods according to regulatory and technical documentation.

(Introducedadditionally, Rev. No. 3).

4.5. The thickness of the zinc coating on the outer surface and in accessible places on the inner surface is controlled according to GOST 9.301 and GOST 9.302, as well as with devices of the MT-41NTs, MTZON or Impulse types according to the normative and technical documentation.

4.6. The thread is checked using thread ring gauges in accordance with GOST 2533 (third accuracy class).

In this case, the screw-in of the no-go ring gauge onto the thread should be no more than three turns.

(Changed edition, Amendment No. 3, 4).

4.7. The curvature of the pipes is controlled using a straight edge in accordance with GOST 8026 and a set of probes in accordance with NTD.

(Changed edition, Amendment No. 3, 5).

4.8. The right angle of the pipe ends is controlled with a 90° square measuring 160´100 mm class 3 GOST 3749, plate probes set 4 according to NTD or an inclinometer

Water and gas pipe for a long time will be made of steel. Alternative options– metal-plastic water conduits, ceramic ones, can be used only in certain areas: local water supply systems, free-flow sewerage, communications inside the building. However, when installed above ground, the pipeline is exposed to too much weather. This eliminates the use of plastic or other products.

Characteristics of VGP

Water and gas pipes are made from steel blanks - strips, using the molding method. The edges of the workpiece are welded. The seam used is reinforced. Examination of the seam is the first task of quality control, since it represents a high-risk area. According to GOST 3262-75, radiography is used to determine quality.

Water and gas pipes, as a rule, are made straight-seam, since for these products the more important quality is resistance to internal pressure rather than resistance to external loads. On the picture - gas pipeline.

Advantages:

high strength, which allows the product to be used with any installation method and in any area;
oxygen and gas impermeability are precisely those properties due to which gas pipelines are and will be constructed only from steel products;
low coefficient of expansion - temperature and moisture changes do not affect the material. The pipeline does not expand, which allows the use of rigid fastening and does not require the installation of compensation devices;
durability - with proper maintenance it is 50 years;
affordable price.

Flaws:

quite heavy, which makes installation difficult and requires large quantity fasteners;
the need for preventive maintenance - metal accumulates electricity;
the need for thermal insulation when laying in the ground - the freezing liquid expands, while the parameters of the water pipeline remain unchanged. This leads to damage and ruptures.

VGP parameters

Dimensions and possible deviations are regulated by GOST 3262-75.

Outer diameter – from 33 to 165 mm.
Wall thickness – from 1 to 5.5 mm.
Length – unmeasured ranges from 4 to 12 m, measured 4–8 or 8–12 m.

Because we're talking about O water pipes, then instead of the internal diameter, an indicator such as nominal diameter is used. It is given in both inches and mm.

Product varieties

Different way pipeline laying and different conditions operation require different technical characteristics from each other. The rental company produces several modifications.

Classification by material

The raw material for the manufacture of water and gas pipes is carbon steel of various grades. At the same time, GOST 3262-75 regulates two types of products:

water pipelines made of steel of ordinary precision - only the mechanical qualities of the product are controlled. The chemical composition of steel is not studied. The products are used for household communication systems;
pipeline made of high-precision steel - galvanized steel is used in manufacturing, mechanical properties are standardized by GOST 3262-75. The products are used in the construction of large highways, where high pressure resistance is important.

In fact, both types of water and gas pipes are made of steel, but pass different levels control. As a result you get:

black – without galvanizing, more often used when laying gas lines;
galvanized – finished products undergoes galvanizing - immersion in molten zinc. A protective layer is formed on the internal and external surfaces of the product, protecting against corrosion. Large water mains are constructed from galvanized VGP.

Release form

Water and gas pipes GOST 3262-75 are produced:

with threads at the ends (knurling or cutting) - it is worth noting that the protective layer is damaged during welding, and therefore galvanized products are mounted only by the threaded method;
without thread - a welded connection is assumed.

Resistance to hydraulic pressure

The thickness of the walls of the water and gas pipeline determines the strength and resistance to a certain hydraulic pressure. The classification is:

lungs - operating pressure liquid should not exceed 25 kg/kV. cm;
conventional - assumes the same pressure, but allows water hammer;
reinforced - pressure can reach 32 kg/kV. cm.

GOST 3262-75

PUBLISHING HOUSE OF STANDARDS

STATE STANDARD OF THE USSR UNION

OKP 138500, OKP 138501

Date of introduction 01/01/77

1. ASSORTMENT

1.1. Pipes are manufactured according to the dimensions and weight given in table. 1.

At the consumer's request, light series pipes intended for thread rolling are manufactured according to the dimensions and weight given in table. 2.

1.2. The length of the pipe is made from 4 to 12 m:

a) measured or multiple measured length with an allowance for each cut of 5 mm and a maximum deviation for the entire length plus 10 mm;

b) of unmeasured length.

By agreement between the manufacturer and the consumer, up to 5% of pipes with a length of 1.5 to 4 m are allowed in a batch of unmeasured pipes.

Table 1

Conditional pass	Outside diameter	Pipe wall thickness			Weight of 1 m of pipes, kg
		lungs	ordinary	reinforced	lungs	ordinary	reinforced
	10,2				0,37	0,40	0,47
	13,5				0,57	0,61	0,74
	17,0				0,74	0,80	0,98
	21,3	2,35			1,10
	21,3				1,16	1,28	1,43
	26,8	2,35			1,42
	26,8					1,66	1,86
	33,5				2,12	2,39	2,91
	42,3				2,73	3,09	3,78
	48,0				3,33	3,84	4,34
	60,0				4,22	4,88	6,16
	75,5				5,71	7,05	7,88
	88,5				7,34	8,34	9,32
	101,3				8,44	9,60	10,74
	114,0				10,85	12,15	13,44
	140,0				13,42	15,04	18,24
	165,0				15,88	17,81	21,63

table 2

Conditional pass	Outside diameter	Wall thickness	Weight of 1 m of pipes, kg
			0,69
			1,08
			1,45
			2,02
			2,64
			3,26
			4,14
			5,59

Notes:

1. For threads made by rolling on a pipe, its internal diameter is allowed to be reduced by up to 10% along the entire length of the thread.

2. The mass of 1 m of pipes is calculated at a steel density of 7.85 g/cm 3 . Galvanized pipes are 3% heavier than non-galvanized ones.

(Changed edition, Amendment No. 1, 3)

1.3. Maximum deviations in pipe sizes should not exceed those indicated in the table. 3.

Table 3

Pipe sizes	Limit deviations for manufacturing precision pipes
	ordinary	increased
Outer diameter with nominal bore:
up to 40 mm incl.	0.4 mm	0.4 mm
	0.5 mm	0.4 mm
Over 40 mm	0,8 %	0,8 %
	1,0 %	0,8 %
Wall thickness	15 %	10 %

Notes:

1. The maximum deviation in the positive direction for wall thickness is limited by the maximum deviations for the mass of the pipes.

1.4. Maximum deviations in the mass of pipes should not exceed + 8%.

At the request of the consumer, maximum deviations in mass should not exceed:

7.5% - for the party;

(Changed edition, Amendment No. 2, 5).

1.5. The curvature of pipes per 1 m length should not exceed:

2 mm - with nominal bore up to 20 mm inclusive;

1.5 mm - with a nominal bore over 20 mm.

1.6. Pipe threads can be long or short. The thread requirements must correspond to those indicated in the table. 4.

Table 4

Conditional bore, mm	Thread length before running away		Conditional bore, mm	Number of threads at nominal size	Thread length before running away
	long	short			long	short
						17,0
						19,5
						22,0
						26,0
		10,5				30,0
		11,0				33,0
		13,0				36,0
		15,0

1.7. Pipes with a nominal bore of 6, 8, 10, 15 and 20 mm are wound into coils at the consumer’s request.

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard and according to technological regulations approved in the prescribed manner, from steels in accordance with GOST 380-88 and GOST 1050-88 without standardization of mechanical properties and chemical composition.

Pipes for parts of water supply and gas pipeline structures are made of steel in accordance with GOST 1050-88.

At the request of the consumer, on ordinary and reinforced pipes with a nominal bore of more than 10 mm, threads are applied to both ends of the pipe.

2.1; 2.2. (Changed edition, Amendment No. 3, 4).

2.3. At the request of the consumer, pipes are equipped with couplings manufactured in accordance with GOST 8944-75, GOST 8954-75, GOST 8965-75 and GOST 8966-75 at the rate of one coupling for each pipe.

(Changed edition, Amendment No. 3).

2.4. Cracks, spots, swellings and declines are not allowed on the surface of the pipes.

Delamination is not allowed at the ends of the pipes.

On pipes made by furnace welding, it is allowed to reduce the outer diameter to 0.5 mm at the seam if there is a gentle thickening in this place along the inner diameter of no more than 1.0 mm.

(Changed edition, Amendment No. 3, 4).

(Changed edition, Amendment No. 2, 3, 4, 5, 6).

2.6. The ends of the pipes must be cut at right angles. The allowed end bevel is no more than 2°. The remaining burrs should not exceed 0.5 mm. When removing burrs, the formation of blunting (rounding) of the ends is allowed. It is allowed to cut pipes in the mill line.

By agreement between the manufacturer and the consumer, burrs up to 1 mm are allowed on pipes with a nominal bore of 6-25 mm, manufactured by furnace welding.

(Changed edition, Amendment No. 4, 6).

2.7. Galvanized pipes must have a continuous zinc coating over the entire surface with a thickness of at least 30 microns. The absence of zinc coating on the ends and threads of pipes is allowed.

On the surface of galvanized pipes, bubbles and foreign inclusions (hardzinc, oxides, sintered mixture), and peeling of the coating from the base metal are not allowed.

Individual flux spots and traces of pipes being caught by lifting devices, roughness and minor local deposits of zinc are allowed.

It is allowed to correct individual non-galvanized areas on 0.5% of the outer surface of the pipe in accordance with GOST 9.307-89.

(Changed edition, Amendment No. 3, 4).

2.8. Pipes must withstand hydraulic pressure:

2.4 MPa (25 kgf/cm 2) - pipes, ordinary and light;

3.1 MPa (32 kgf/cm 2) - reinforced pipes.

At the request of the consumer, the pipes must withstand hydraulic pressure of 4.9 MPa (50 kgf/cm2)

(Changed edition, Amendment No. 2, 3, 5).

At the request of the consumer, pipes must withstand the distribution test:

for pipes with a nominal bore from 15 to 50 mm - no less than 7%;

for pipes with a nominal bore of 65 or more - no less than 4%.

At the request of the consumer, pipes must withstand the flattening test to a distance between the flattened surfaces equal to 2/3 of the outer diameter of the pipes.

(Changed edition, Amendment No. 2, 3, 5).

2.10. At the request of the consumer, the mechanical properties of pipes for parts of water supply and gas pipeline structures must comply with GOST 1050-88.

2.11. Pipe threads must be clean, without flaws or burrs and comply with GOST 6357-81, accuracy class B.

Pipes with cylindrical threads are used when assembling with seals.

2.10; 2.11. (Changed edition, Amendment No. 3, 4).

2.12. At the seam, blackness on the threads is allowed if the reduction in the normal height of the thread profile does not exceed 15%, and at the request of the consumer does not exceed 10%.

(Changed edition, Amendment No. 2, 3, 5).

2.13. On a thread, it is allowed to reduce the useful length of the thread (without running) up to 15% compared to that indicated in the table. 4, and at the consumer’s request up to 10%.

(Changed edition, Amendment No. 2, 3, 5).

2.14. Threading on galvanized pipes is carried out after galvanizing.

2.15. (Deleted, Amendment No. 3).

2.16. At the request of the consumer, pipe welds are subjected to testing using non-destructive methods.

(Changed edition, Amendment No. 5).

3. ACCEPTANCE RULES

The batch weight is no more than 60 tons.

(Changed edition, Amendment No. 3, 4).

3.2. Each pipe in the batch is subjected to inspection of the surface, dimensions and curvature.

It is allowed to use statistical control methods in accordance with GOST 18242-72 with a normal level. Control plans are established by agreement between the manufacturer and the consumer.

The outer diameter of the pipes is checked at a distance of at least 15 mm from the end of the pipe.

(Changed edition, Amendment No. 3, 4, 5).

(Changed edition, Amendment No. 3, 4).

3.4. All pipes are subject to weight control.

(Changed edition, Amendment No. 3).

(Changed edition, Amendment No. 6).

3.6. To check the thickness of the zinc coating on the outer surface and in accessible places on the inner surface, two pipes from the batch are selected.

(Changed edition, Amendment No. 2).

3.7. If unsatisfactory test results are obtained for at least one of the indicators, a repeat test is carried out on a double sample.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test.

The tensile test is carried out according to GOST 10006-80. Instead of tensile testing, it is allowed to control mechanical properties using non-destructive methods.

4.2. The surface of the pipes is inspected visually.

4.3. Hydraulic testing is carried out in accordance with GOST 3845-75 with exposure under test pressure for at least 5 s.

4.4. The bend test is carried out according to GOST 3728-78. Galvanized pipes are tested before coating.

(Changed edition, Amendment No. 3).

4.4a. The expansion test is carried out according to GOST 8694-75 on a conical mandrel with a cone angle of 6°.

It is permissible to test on a mandrel with a taper angle of 30°.

(Changed edition, Amendment No. 3, 4).

4.4b. The flattening test is carried out according to GOST 8695-75.

(Changed edition, Amendment No. 3).

4.4v. Weld inspection is carried out using non-destructive methods according to regulatory and technical documentation.

(Introduced additionally, Amendment No. 3).

4.6. The thread is checked using thread ring gauges in accordance with GOST 2533-88 (third accuracy class).

In this case, the screw-in of the no-go ring gauge onto the thread should be no more than three turns.

(Changed edition, Amendment No. 3, 4).

4.7. The curvature of the pipes is controlled using a straight edge in accordance with GOST 8026-92 and a set of probes in accordance with TU 2-034-225-87.

(Changed edition, Amendment No. 3, 5).

(Changed edition, Amendment No. 3, 6).

4.9. The outer diameter is checked using smooth micrometers in accordance with GOST 6507-90, clamp gauges in accordance with GOST 2216-84 or GOST 18362-73.

The length of the pipes is measured with a tape measure according to GOST 7502-89. Threads are controlled with gauges in accordance with GOST 2533-88.

The mass of a batch of pipes is controlled on scales of no more than 10 tons with a division value of no more than 20 kg.

(Changed edition, Amendment No. 3, 4, 5, 6).

4.10. Weld inspection is carried out using non-destructive methods according to technical documentation.

(Introduced additionally, Amendment No. 4).

5. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Labeling, packaging, transportation and storage are carried out in accordance with GOST 10692-80 with addition.

5.1.1. Pipe threads must be protected from mechanical damage and corrosion by lubricant according to the regulatory and technical documentation.

Sec. 5. (Changed edition, Amendment No. 3).

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Ferrous Metallurgy

DEVELOPERS

V. I. Struzhok, Ph.D. tech. sciences, V. M. Vorona, Ph.D. tech. sciences, Yu. M. Mironov, Ph.D. tech. nook, A. I. Postolova

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Standards dated 09.11.75 No. 2379

3. Inspection frequency 5 years

4. INSTEAD GOST 3262-62

5. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

	Item number
GOST 9.301-86
GOST 9.302-88
GOST 9.307-89
GOST 380-88
GOST 1050-88	2.1, 2.10, 3.1
GOST 2216-84
GOST 2533-88	4.6, 4.9
GOST 3728-78
GOST 3749-77
GOST 3845-75
GOST 5378-88
GOST 6357-81	2.11
GOST 6507-90
GOST 7502-89
GOST 8026-92
GOST 8694-75	4.4a
GOST 8695-75	4.4b
GOST 8944-75
GOST 8954-75
GOST 8965-75
GOST 8966-75
GOST 10006-80
GOST 10692-80
GOST 11358-89
GOST 18242-72
GOST 18363-73
TU 2-034-225-88	4.7, 4.8

6. Reissue (May 1994) with Amendments No. 1, 2, 3, 4, 5, 6, approved in November 1977, December 1978, January 1987, May 1988, November 1989. , November 1991 (IUS 1-78, 2-79, 4-87, 8-88, 2-90, 2-92)

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