What is a hydraulic arrow in a heating system? What is a hydraulic arrow: principle of operation, purpose and diameter calculations

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Simple heating systems consist of a minimum number of components - a small number of pipes, several radiators and a boiler. For small buildings and households this is enough. When it is necessary to provide heat to a large building, the task is complicated by the need to use additional equipment– a hydraulic arrow for heating will ensure uniform heat distribution, eliminate pressure drops, and balance the work heating system.

In this review we will look at:

Purpose of the hydraulic arrow in the heating system.
Structural features of hydraulic arrows.
Simple calculation schemes.

The material will contain diagrams, useful tips, detailed explanations - everything is extremely clear and understandable.

What is a hydraulic arrow

A hydraulic arrow is a hydraulic separator in a heating system, a device designed to properly distribute the coolant across several circuits and devices. This is a kind of buffer element between the heating boiler and the secondary circuits. The coolant flows from the boiler into the hydraulic valve, after which it is distributed in several directions.

The most simple system There is no need for heating in the hydraulic arrow. Here it is important to choose the right circulation pump and set its operating speed to ensure the required pressure. The coolant flows from the boiler into the batteries, releases the accumulated heat there, and then returns back to the heating device– nothing complicated or supernatural. But modern housing is built using several circuits and auxiliary equipment. Here are present:

Several secondary heating circuits (for example, per group of rooms or per floor).
Warm floors - one or more circuits.
Boilers indirect heating– used for preparing hot water.

And here we may encounter a situation where one circulation pump cannot push the coolant throughout the entire circuit. Water (or antifreeze) will flow along the path of least resistance, after which it will return along a similar path. For example, it will pass through a nearby boiler and partially penetrate into the radiators, but it may not be enough for warm floors.

The hydraulic arrow for heating systems is designed to ensure proper order in the distribution of heat throughout the circuits and auxiliary equipment. It is an extremely simple hydraulic separator, created from sections of pipes of one diameter or another.

Design features of the hydraulic arrow

The design of a hydraulic heating arrow is so simple that there are literally no moving parts, electronics or anything else. Take a look at its diagram - it is a round or rectangular pipe, sealed on both sides. It is located vertically or horizontally. On one side it has two pipes for connecting to the heating system, and on the other side there are two pipes for connecting to the boiler.

This is exactly what a hydraulic arrow looks like for a single-circuit heating system. There is nothing inside the pipe itself - absolutely, there is empty space, which is subsequently filled with coolant.

The hydraulic arrows are visible from the outside:

Connections for connection to the boiler and heating.
Tap for draining water.
Automatic air vent.

This is exactly how the simplest hydraulic guns are designed.

The hydraulic needle for heating systems with several circuits is no more complicated. It just has more pipes for connecting secondary circuits. Boilers and underfloor heating systems are also connected here. Circulation pumps are connected to each supply pipe through taps - one for each circuit. To control pressure and temperature, thermomanometers are installed here.

Hydroarrow and its purpose

It’s easy to assemble a hydraulic arrow for heating yourself using welding machine and pipe sections of the required length. To do this, you need to find a suitable drawing and select materials.

We looked at the principle of operation of a hydraulic heating arrow - it simply distributes the coolant over several circuits. Its main task is to create ideal conditions for the operation of the secondary and primary circuits. The primary circuit includes a heating boiler with pipes connected to a hydraulic arrow. Secondary circuits are everything else. With equal pressure throughout the entire circuit, the boiler operates in a gentle mode - part of the heated coolant enters the return pipe, which reduces the load on the heat source.

If the system has a low-power boiler, and the heating system has a high capacity, conditions are created for the coolant to be supplied from the return pipe to the supply pipe, bypassing the boiler (partially). In this case, the equipment is practically worn out - heat exchangers can become unusable in the shortest possible time.

Even heat distribution

Ideally balanced heating means uniform temperature throughout the entire house, equal pressure in the secondary circuits and balanced load on the boiler. In this case, the task of the hydraulic arrow is simple - it “distributes” the coolant to several circuits, each of which has a circulation pump installed. By adjusting its performance and coolant supply, you can achieve a uniform temperature throughout the house.

The most important thing is that thanks to this distribution there will be no cold circuits left in the house, since the coolant will flow into every pipe, and not just where it is easier.

Pressure balancing

An imbalance in the heating system can affect the stability of its operation. A long circuit requires one pressure, a shorter circuit another. The same applies to warm floors and boilers. If the system had one large pump for all circuits at once, there would be overloads in some places - the pipes or heat exchanger in the storage water heater could break. The hydraulic arrow will distribute the pressure and allow all circuits to be properly balanced.

Working with multiple boilers

There are heating systems with two or even three boilers (sometimes more). Such solutions allow you to heat a fairly large area or use one of the boilers as a reserve. If not sequential is used, but parallel connection equipment, this is done through a hydraulic switch. At the same time, this helps to neutralize the mutual influence of the secondary circuits on each other.

Hydroarrow allows you to achieve balance in heating systems of any complexity. Two or three boilers, five or seven circuits - the degree can be different. The potential for system expansion is also revealed. For example, in the future you can connect another boiler, heated towel rail, summer kitchen with a separate heating circuit. All this work can be performed even on the go, without stopping the boiler equipment while maintaining heating of the building.

How to install a hydraulic arrow

The best option for installing a hydraulic arrow is vertically. Typically, taps for draining water are located at the bottom. Any debris circulating through the heating settles in this part. Carefully open the tap and it drains. Hot coolant is supplied to top part, while the return pipe is located below. The same applies to pipes for connecting secondary circuits - they are mounted in the same way.

Purchased models

A typical example is the Sever-M5 collector. It works in heating systems with a power of up to 70 kW. The cost of the unit is about 9.5 thousand rubles.

A hydraulic arrow in a heating system is a hydraulic distribution device designed to distribute coolant over several circuits. Its installation is recommended in cases where the power of the boiler used is over 50 kW. The arrow is also used in complex branched systems with many secondary circuits - it is needed for balancing. You can buy it or assemble it yourself.

The easiest way is to buy a hydraulic gun in a ready-made factory version. The most simple model, for example, SINTEK ST-35 will cost 2,700 rubles if you buy it directly from the manufacturer. It can withstand pressure up to 6 bar and can be installed in heating systems with a heating power of up to 35 kW.

A heating manifold with a hydraulic arrow for 5 circuits is designed for the branched systems mentioned above. You can connect an indirect heating boiler to it, heated floors in the bathroom, kitchen and hallway, as well as three main circuits - on the ground floor, in the basement, and in the attic.

Other store equipment:

Hydraulic arrow WOODSTOKE 331 – for heating with a power of up to 70 kW for 7 circuits. The cost of the device is 11 thousand rubles.
Warme WGR 80 is a simple hydraulic valve with two pipes and two outlets for connecting an air vent and a tap. Cost – 4000 rubles. The model can operate in heating systems with a power of up to 80 kW.
Proxotherm GS 32-1 - hydraulic needle is made in a shiny case, as it is made of stainless steel. It is designed to work in heating systems with a power of up to 85 kW. Cost – about 7-8 thousand rubles.
Gidruss BM is a whole series of hydraulic arrows for heating systems with a power from 60 to 150 kW. They are made of high-quality structural steel and can withstand pressures of up to 6 bar at temperatures up to +110 degrees. The cost varies from 9 to 30 thousand rubles.

There are thousands of ready-made hydraulic guns, there is plenty to choose from.

The advantages of magazine-operated hydraulic shooters are quite obvious. First of all, they are characterized by impeccable build quality. The equipment must withstand significant pressure - up to 3-4 atmospheres for autonomous heating and up to 20-25 atmospheres for general house heating. It is made from proven grades of steel created for the construction of heating equipment and other systems.

Secondly, factory water guns are already designed for use in heating systems with one or another power. They have been verified many times, so their use will not cause any accidents. The stores will also offer auxiliary equipment for installation of heating systems. And then there will be no problems with the warranty on boilers and radiators.

Do-it-yourself hydraulic arrow assembly

Self-assembly is carried out in several steps:

Calculation of hydraulic arrows for heating.
Selection of materials.
Welding of prepared and calculated elements.

For calculations, it is best to use specialized calculators that take into account many parameters. In the simplest case, use our calculations.

Calculation formula

The internal diameter d depends on the boiler power P and the difference between flow and return ∆t. We divide the power in kilowatts by the temperature difference, take the square root of the resulting figure and multiply the resulting value by 49 - we get the diameter of the hydraulic needle. The height of the pipe is 6 diameters, and the distance between the pipes is double inner diameter pipes.

There are many drawings of hydraulic arrows on the Internet, both simple and combined with manifolds. They will allow you to collect what you need, and with minimal calculations. In any case, when assembling and installing a hydraulic distributor, experts advise obtaining at least some knowledge on balancing heating systems. As for heating systems for large buildings, the task of selecting a hydraulic arrow and balancing the heating should be entrusted to specialized specialists.

You can assemble a hydraulic arrow for heating with your own hands from polypropylene, but it is not recommended to do so - it may not withstand the load if it is used in large heating systems. Nevertheless, many masters practice this.

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Hydraulic arrow for heating - purpose, principle of operation and calculation

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In order for the heating system to work with maximum efficiency, it is necessary to achieve good balancing of all its components, and all elements cope well with their functions. This task is quite difficult, especially when we're talking about and about a branched mechanism with a large number of circuits.

Very often, such circuits have individual thermostatic control schemes, their own temperature gradient, differ in throughput, as well as the required level of coolant pressure. In order to combine all nodes into a single whole. A hydraulic heating arrow will help solve this problem. We will talk about what a hydraulic separator is and how it works in this article.

Hydraulic jib MEIBES MNK 32

Purpose of the hydraulic separator

If you plan to install a simple closed-type heating system in your home, where no more than two circulation pumps, then there is no need for a hydraulic separator.

When there are three circuits and pumps, and one of them is needed to work with an indirect heating boiler, then here too you don’t have to resort to installation hydraulic guns. It is advisable to install a hydraulic arrow in large houses where there are two or more heating circuits. The hydraulic arrow is needed in order to balance the pressure level in the entire boiler system when the indicators in the main circuit change. Such a unit is responsible for regulating the three-circuit version of the system, which simultaneously includes a water heater, a heating radiator, and a heated floor.

If all rules of hydrodynamics are observed, stable operation in normal mode will be ensured.

In addition, the hydraulic arrow acts as a kind of sump, in which various deposits are removed from the coolant: scale, corrosion. This can only be achieved with full compliance with all hydromechanical standards.

This function of the hydraulic arrow, made of both stainless steel and other materials, contributes to the long service life of many elements in the heating system. In addition, the device removes the air formed in the coolant, thereby reducing the oxidation process in mechanical parts.

The traditional version of the hydraulic separator provides for the presence of only one circuit. If several branches are disconnected, the heat consumption in the system is reduced. That is why the temperature of the coolant after traveling the entire path does not decrease much. The hydraulic arrow makes it possible to maintain a stable level of heat consumption, thereby ensuring stable circulation in the system.

In order to answer the question: what is the purpose of the hydraulic arrow, you need to understand how the heating system functions. The simplest version of a forced circulation system simplified consists of:

boiler (K), here the coolant is heated;
circulation pump(N1), due to the functioning of which the coolant moves through the supply (red lines) and return pipes (blue lines). The pump is mounted on a pipe or is included in the boiler design kit - this is especially typical for wall-mounted models;
heating radiators (HR), thanks to which heat exchange occurs - the thermal energy of the coolant is transferred to the rooms.

Having made the right choice of a circulation pump in terms of performance and generated pressure in a simple single-circuit system, one copy may be enough for you and you will not have to install auxiliary devices.

Circulation pump- an integral part of the heating system. Thanks to this device, the efficiency of the system increases.

For small houses, such a simple scheme may be quite sufficient. But in large rooms it is often necessary to resort to the use of several heating circuits. Let's complicate the scheme.

Hydraulic arrow in a system with several heating circuits

As can be seen in the figure, thanks to the pump, the coolant circulates through the Cl collector, from where it is disassembled into several different circuits. It can be:

One or more high temperature circuits with conventional radiators or convectors (RO).
Water heated floors (WHF), for which temperature regime coolant should be much lower. This means that you will have to use thermostatic devices specially designed for this. Most often, the sensory length of underfloor heating circuits is several times higher than conventional radiator wiring.
Home hot water supply system with installation (BKN). Here there are very special requirements for the circulation of the coolant, since usually by changing the flow rate of the coolant flowing through the boiler, the heating temperature of the hot water is also regulated.

Now the question arises: can one pump cope with such a large load and such coolant flow? Unlikely. Undoubtedly, on the market you can find high-performance and high-power models that are distinguished by good indicators of the generated pressure, but here it is worth taking into account the capabilities of the boiler itself, which cannot be called unlimited. It and its pipes are designed for a certain performance and a certain pressure that occurs. If you exceed the specified parameters, you can simply end up with your heating device failing.

And if the pump always operates at the limit of its capabilities, providing coolant to all circuits of the branched system, then it will not last long. In addition, the work will be accompanied by loud noise, and electrical energy will be consumed in large quantities.

To solve this problem, it is necessary to divide the entire hydraulic system not only into end-use circuits through the manifold, but also to allocate a separate boiler circuit.

How to install a hydraulic arrow

This is precisely what the hydraulic arrow is designed for, which is mounted between the boiler and the collector.

Installing a hydraulic arrow in the heating system allows you to get rid of temperature surges.

What is a hydraulic separator and its design

A hydraulic separator is a vertical hollow vessel consisting of pipes large diameter(square profile) with elliptical plugs at the ends.

The dimensions of the separator are determined by the power of the boiler and depend on the number and volume of circuits.

The heavy metal casing is mounted on support posts so as not to create linear stress on the pipeline. Compact devices are attached to the wall and placed on brackets.

The connection pipe of the capacitive hydraulic separator and the heating pipeline are connected via flanges or threads.

Automatic valve air vent located in the uppermost part of the body. The sediment is disposed of using a valve or using a special valve that is cut into the bottom.

The material from which the hydraulic arrow is made is low-carbon stainless steel, copper, polypropylene. The body is treated with an anti-corrosion compound and covered with thermal insulation.

Hydraulic gun device

Principle of operation

Now that we know why a hydraulic arrow is needed for heating and have figured out its design, we can move on to the features of its functioning.

During its operation, there are three main modes.

Diagram of operation of the hydraulic separator

Mode one.

The system is practically in equilibrium. The flow rate of a “small” boiler circuit is practically no different from the total flow rate of all circuits connected to the manifold or directly to the hydraulic valve.

The coolant does not linger in the hydraulic arrow, but passes through it horizontally, creating virtually no vertical movement. The temperature of the coolant at the supply pipes (T1 and T2) is the same. Naturally, the same situation applies to the pipes connected to the “return” (T3 and T4). In this mode, the hydraulic gun, in fact, has no effect on the functioning of the system.

But such an equilibrium position is an extremely rare phenomenon that can be noticed only occasionally, since the initial parameters of the system always tend to change dynamically.

On sale you can find manifold models with built-in hydraulic separators. You can choose options for 2, 3, 4 or 5 circuits.

Mode two.

Currently, it is the case that the total flow rate on the heating circuits exceeds the flow rate in the boiler circuit.

We have to deal with this situation quite often, when all the circuits connected to the collector demand exactly at this moment maximum flow coolant. In ordinary words, the immediate demand for coolant exceeded what the boiler circuit could produce. The system will not stop or become unbalanced. It’s just that in the hydraulic arrow, a vertically ascending flow will form on its own from the “return” pipe of the manifold to the supply pipe. At the same time, this flow in the upper region of the hydraulic separator will be mixed with hot coolant circulating along the “small” circuit. Temperature balance: T1 > T2, T3 = T4.

A manifold with a hydraulic arrow for 3 circuits allows you to safely and correctly connect radiators, a boiler and heated floors. It is the most popular in its segment. The presence of 4 circuits allows you to additionally connect an air heater in the ventilation. To connect a backup boiler, you need 5 circuits.
Mode 3.

This mode of operation of the hydraulic separator is, in fact, the main one - in a well-planned and correctly installed heating system, it will be the one that will prevail.

The coolant flow rate in the “small” circuit exceeds the same total indicator on the collector, or, in other words, the “demand” for the required volume has become lower than the “supply”. There may be many reasons for this: - Thermostatic control equipment on the circuits has reduced or even temporarily stopped the flow of coolant from the supply manifold to the heat exchange devices.

The temperature in the indirect heating boiler has reached its maximum, and there has been no hot water intake for a long time - circulation through the boiler has stopped. Individual radiators or even circuits are turned off for some time or for a long period (need for maintenance or repair, there is no need to heat temporarily unused rooms and other reasons). The heating system is put into operation in stages, with the gradual inclusion of individual circuits.

None of the above reasons will have any negative impact on the overall functionality of the heating system. The excess coolant volume will simply go into the “return” of the small circuit in a vertical downward flow. In fact, the boiler will provide a slightly excess volume, and each of the circuits connected to the manifold or directly to the hydraulic arrow will take exactly as much as is currently required. Temperature balance under this operating mode: T1 = T2, T3 > T4.

When installing hydraulic arrows in individual heating systems, plastic models are most often used, which are cheaper and are installed using fittings.

In fact, the hydraulic arrow has one single principle of operation, it is presented at number three. It is impossible to achieve the ideal mode (shown in the first diagram), since the hydraulic resistance of the consumer branches is constantly changing due to the functioning of thermostats, and it will not be possible to select pumps so precisely. It is unacceptable to act according to the second scheme, since in this case most of the coolant will circulate in a circle from the consumers.

As a result you will receive reduced temperature in the heating system, because on the boiler side, a small amount of hot water will be mixed in the hydraulic arrow. To increase the temperature you will have to resort to the conclusion heat generator to the maximum mode, which will negatively affect the stability of the system as a whole. Thus, a third option remains, in which the optimal amount of water at the required temperature is supplied to the collectors. And three-way valves are responsible for reducing it in the circuits. Main function hydraulic arrows in the heating system - creating a zone with zero pressure, from where it will be possible to select coolant from any number of consumers.

Hydraulic arrow calculation

Many users ask the question: how to calculate a hydraulic arrow for heating? Since the devices that are on sale are designed for a certain power of the heating system.

Many people want to make the device themselves, and then it is very important to make correct and accurate calculations.

Let's imagine the calculation depending on the power of the heating system.

There is a universal formula that describes the dependence of coolant flow on the total need for thermal power, the heat capacity of the coolant and the temperature difference in the supply and return pipes.

Formula for calculating coolant flow Q = W / (s × Δt)

Q – flow rate, l/hour;
W – heating system power, kW
c – heat capacity of the coolant (for water – 4.19 kJ/kg×°C or 1.164 Wh/kg×°C or 1.16 kW/m³×°C)
Δt – temperature difference between supply and return, °C.

At the same time, the flow rate when liquid moves through the pipe is equal to: Q = S × V
S – cross-sectional area of the pipe, m²;
V - flow velocity, m/s.

S = Q / V= W / (s × Δt × V)

It has been experimentally proven that for optimal mixing in a hydraulic separator, high-quality air separation and sludge precipitation, the speed in it should be no higher than 0.1 - 0.2 m/s.

Since the unit of measurement is hour, we multiply by 3600 seconds. It turns out 360 - 720 m/hour.

You can take the average value - 540 m/hour.

If the calculation is made for water, then you can enter several initial values to simplify the formula:
S = W / (1.16 × Δt × 540) = W / (626 × Δt).

Having determined the cross-section, using the formula for the area of a circle it is easy to determine the required diameter:
D = √ (4×S/π) = 2 × √ (S/π).

Substitute the values:
D = 2 × √ (W / (626 × Δt × π)) = 2 × √ (W / (1966 × Δt)) = 2 × 0.02255 × √(W/Δt) = 0.0451 × √(W /Δt).

Since the value will be obtained in meters, which is not entirely convenient, you can convert it directly to millimeters by multiplying by 1000.

As a result, the formula will take the following form:
D = 45.1 √(W/Δt) – for a flow speed in the hydraulic arrow pipe of 0.15 m/s.

Having determined the diameter of the hydraulic needle, it is easy to calculate the diameters of the inlet and outlet pipes.

Therefore, a hydraulic arrow for heating solves important problems. If necessary, it must be installed.

Ecology of knowledge. Manor: The hydraulic separator is a device surrounded by many myths. To understand which tasks the hydraulic gun is really capable of coping with, and which of its properties are just unsubstantiated claims by marketers, we suggest taking a detailed look at the principle of operation of this unit and its purpose.

The hydraulic arrow is a flask with an automatic air vent installed in the upper part. Nozzles are cut into the side surface of the housing to connect the main heating pipes. The inside of the hydraulic arrow is completely hollow; a threaded pipe for installation can be embedded in the lower part ball valve, the purpose of which is to drain the settled sludge from the bottom of the separator.

How does a hydraulic arrow work?

In essence hydraulic arrow- This is a shunt that short-circuits the supply and return flows. The purpose of such a shunt is to equalize the temperature of the coolant, as well as its flow in the generating and distribution parts hydraulic system heating. To obtain a real effect from a hydraulic separator, a careful calculation of its internal volume and the insertion points of the pipes is required. However, most of the devices on the market are mass-produced without adaptation to a specific heating system.

You can often come across the opinion that additional elements must be present in the cavity of the flask, such as flow dividers or meshes for filtering mechanical impurities or separating dissolved oxygen. In reality, such modernization methods do not demonstrate any significant effectiveness and even vice versa: for example, if the mesh is clogged, the hydraulic arrow completely stops working, and with it the entire heating system.

What capabilities are attributed to the hydraulic separator?

Among heating engineers, there are diametrically opposed opinions regarding the need to install hydraulic switches in heating systems. Adding fuel to the fire are statements from manufacturers of hydraulic equipment, promising increased flexibility in setting operating modes, increased efficiency and heat transfer efficiency. To separate the wheat from the chaff, let's first look at the completely baseless claims about the "outstanding" capabilities of hydraulic separators.

The efficiency of the boiler installation does not depend in any way on the devices installed after the boiler connecting pipes. Useful action The boiler is entirely contained in the conversion ability, that is, in the percentage of heat generated by the generator to the heat absorbed by the coolant. No special piping methods can increase efficiency; it depends only on the surface area of the heat exchanger and the correct choice of coolant circulation rate.

Multi-mode, which is supposedly ensured by installing a hydraulic gun, is also an absolute myth.

The essence of the promises boils down to the fact that if you have a hydraulic switch, you can implement three options for flow ratios in the generator and consumer parts.

The first is absolute equalization of flow, which in practice is only possible if there is no shunting and there is only one circuit in the system. The second option, in which the flow rate in the circuits is greater than through the boiler, supposedly provides increased savings, but in this mode, supercooled coolant inevitably flows through the return to the heat exchanger, which gives rise to a number of negative effects: fogging of the internal surfaces of the combustion chamber or temperature shock.

There are also a number of arguments, each of which represents an incoherent set of terms, but in essence does not reflect anything concrete. These include increasing hydrodynamic stability, increasing the service life of equipment, controlling temperature distribution and others like them.

You can also come across the statement that the hydraulic separator allows you to stabilize the balancing of the hydraulic system, which in practice turns out to be exactly the opposite. If in the absence of a hydraulic switch the system’s reaction to a change in the flow in any part of it is inevitable, then in the presence of a separator it is also completely unpredictable.

Real Application Area

However, the thermal hydraulic separator is far from a useless device. This is a hydraulic device and the principle of its operation is described in sufficient detail in specialized literature. The hydraulic arrow has a well-defined, albeit rather narrow, area of application.

The most important benefit of a hydraulic separator is the ability to coordinate the operation of several circulation pumps in the generator and consumer parts of the system. It often happens that circuits connected to a common collector unit are supplied with pumps whose performance differs by 2 or more times.

In this case, the most powerful pump creates a pressure difference so high that the intake of coolant by other circulation devices is impossible. Several decades ago, this problem was solved by so-called washering - artificially lowering the flow in consumer circuits by welding into the pipe metal plates With different diameters holes.

The hydraulic arrow shunts the supply and return lines, due to which the vacuum and overpressure they are leveled out.

The second special case is the excess productivity of the boiler in relation to the consumption of the distribution circuits. This situation is typical for systems in which a number of consumers do not work on a permanent basis. For example, an indirect heating boiler, a swimming pool heat exchanger and heating circuits of buildings that are heated only from time to time can be linked to the general hydraulics.

Installing a hydraulic valve in such systems allows you to maintain the rated power of the boiler and the circulation speed all the time, while the excess heated coolant flows back into the boiler. When an additional consumer is turned on, the difference in costs is reduced and the excess is no longer sent to the heat exchanger, but to an open circuit.

The hydraulic arrow can also serve as a collector for the generator part when coordinating the operation of two boilers, especially if their power differs significantly.

An additional effect from the operation of the water gun can be called protection of the boiler from temperature shock, but for this, the flow rate in the generator part must exceed the flow rate in the consumer network by at least 20%. The latter is achieved by installing pumps of appropriate capacity.

Connection diagram and installation

The hydraulic arrow has a connection diagram that is as simple as its own device. Most of the rules relate not so much to the connection, but to the calculation of bandwidth and the location of pins. However, knowledge complete information will allow installation to be carried out correctly, as well as to verify the suitability of the selected hydraulic arrow for its installation in a specific heating system.

The first thing you need to clearly understand is that the hydraulic arrow will only work in heating systems with forced circulation. In this case, there must be at least two pumps in the system: one in the circuit of the generation part, and at least one in the consumer part. Under other conditions, the hydraulic separator will play the role of a shunt with zero resistance and, accordingly, will short-circuit the entire system.

An example of a hydraulic switch connection diagram: 1 - heating boiler; 2 - boiler safety group; 3 - expansion tank; 4 - circulation pump; 5 - hydraulic separator; 6 - automatic air vent; 7 - shut-off valves; 8 - drain valve; 9 - circuit No. 1 indirect heating boiler; 10 - circuit No. 2 heating radiators; 11 - three-way valve with electric drive; 12 - circuit No. 3 heated floor

The next aspect is the dimensions of the hydraulic needle, diameter and location of the leads. In general, the diameter of the flask is determined based on the largest calculated flow in the line. The maximum can be taken as the coolant flow rate either in the generation or in the consumer part of the heating system according to the hydraulic calculation data.

The dependence of the diameter of the separator flask on the flow is described by the ratio of the flow rate to the flow rate of the coolant through the flask. The last parameter is fixed and, depending on the power of the boiler installation, can vary from 0.1 to 0.25 m/s. The quotient obtained when calculating the specified ratio must be multiplied by a correction factor of 18.8.

The diameter of the connection pipes should be 1/3 of the diameter of the flask. In this case, the inlet pipes are located from the top and bottom of the flask, as well as from each other at a distance equal to the diameter of the flask. In turn, the outlet pipes are located so that their axes are offset relative to the axes of the inputs by two of their own diameters. The described patterns determine the total height of the hydraulic gun body.

The hydraulic arrow is connected to direct and return main pipelines boiler or several boilers. Of course, when connecting the hydraulic arrow there should not be a hint of narrowing of the nominal passage. This rule forces the use of very significant pipes in the boiler piping and when connecting the manifold. conditional passage, which somewhat complicates the issue of optimizing the layout of boiler room equipment and increases the material consumption of the piping.

About separation collectors

Finally, let’s briefly touch on the topic of multi-terminal hydraulic switches, also known as sepcalls. Essentially, this is a collector group in which the supply and return splitters are combined by a separator. This type of device is extremely useful in coordinating the operation of several heating circuits with different flow rates and coolant temperatures.

A vertically mounted separation manifold allows for a temperature gradient in the outlet pipes by mixing portions of the coolant. This makes it possible to directly connect, for example, an indirect heating boiler, a radiator group and underfloor heating loops without a mixing group: the temperature difference between adjacent sepcoll terminals will naturally be maintained within 10–15 °C, depending on the circulation mode. However, it is worth remembering that this effect is only possible if the return pipe of the generator part is located above the return taps of the consumers.

As a result we give important recommendation. For most domestic heating systems up to 100 kW, installation of a hydraulic separator is not required.

Much more the right decision will select the performance of the circulation pumps and coordinate their operation, and to protect the boiler from temperature shock, connect the lines with a bypass tube.

If the design or installation organization insists on installing a hydraulic switch, this decision must be justified technologically. published If you have any questions on this topic, ask them to the experts and readers of our project.

The classic method of connecting a boiler to a heating system has a number of serious disadvantages. For example, it may not produce the rated power and, if adjustment is necessary, loses balance. There are significant temperature fluctuations inside the boiler, and choosing pumps for such a model is a real problem. Currently, these shortcomings are corrected using a hydraulic arrow for the heating system.

What is a hydraulic arrow in a heating system

Hydroarrow(hydraulic separator, hydraulic arrow) - part of the heating system, with the help of which the heating circuits are connected. It provides the smallest pressure difference between them, which makes it possible to turn off one without losing pressure in the others. In other words, the hydraulic arrow for the heating system removes the influence of the heat consumer pumps on the circulation pumps of the heat source and in the reverse order.

In addition, the hydraulic arrow is used for hydrodynamic balancing of heat supply. This simple device plays an important role in the entire heating system of a home. The hydraulic separator prevents the formation of thermal shock in cast iron heat exchangers and boilers.

Some boiler manufacturers include in the document about maintenance clause on the installation of a hydraulic arrow for heating. Without its use, the buyer loses the warranty on the device (for example, on a floor-standing gas boiler).

The hydraulic arrow for heating systems is balanced by the hydrodynamic parameters of the system. Thus, the mutual influence of various thermal circuits on each other is completely eliminated, which leads them to operate without failures and maintain the specified parameters and modes.

In addition to the above-described capabilities, a hydraulic gun for heating systems can also clean the coolant from impurities, for example, sand or rust (for this it is necessary to correctly calculate the parameters). In addition, the hydraulic separator also removes air from it, and this, in turn, extends the service life of metal parts, since their oxidation slows down. Increasing the service life of shut-off valves, pumps, sensors, radiators and heat exchangers directly affects the reliability and durability of the entire heating system.

The hydraulic boom performs the following functions:

Function for maintaining hydrobalance in the heating system. Elimination of the influence of one circuit on the hydraulic characteristics of the others when turned on and off.

Preservation function for cast iron boiler heat exchangers. The operation of a hydraulic arrow for heating systems protects heat exchangers from sudden temperature changes that may occur when the boiler is first started or when repair work oh, when the circulation pump is turned off. It is well known that such differences have a negative impact on cast iron devices.

Air vent function. The hydraulic arrow is also needed to remove air from the heating system. For these purposes, a pipe is mounted on it in its upper part, intended for mounting an automatic air vent.

Coolant filling and draining function. The overwhelming majority of hydraulic arrows, both industrial and self-made equipped with drain taps, which are used to fill or drain coolant from the heating system.

Heating system cleaning function. In the hydraulic arrow, the coolant moves at a reduced speed. Thus, this installation collects various types of dirt: scale, rust, sand, scale, and so on. These solid fractions accumulate in the lower part, which allows their removal through the drain valve. There are models of hydraulic arrows that are equipped with magnetic catchers for collecting metal debris.

Why is a hydraulic arrow needed in the heating system of a private house?

To the question: “Why do you need a hydraulic arrow in a heating system?” You can answer the following. The main goal installation of this device in a heating system is to separate the fluid flows inside it, as well as to protect boilers and associated equipment. Below are the main situations in which it may be necessary to install a hydraulic arrow in the heating system:

Typically, a hydraulic arrow is installed in rooms with an area of more than 200 m2.

In case it is necessary to create more than two circuits in the heating system with different coolant flow rates. For example, a docked element consumes more substance, transmitting thermal energy than the one that comes from the boiler. In this situation, it is necessary either to increase the power and circulation in the main circuit, which will not be economically feasible, as it will increase the load on the equipment, or to install a hydraulic valve to regulate the flow.

In those heating schemes that include heated floors, boilers and several circuits, the hydraulic arrow will remove any negative impact of these elements on top of each other. You can freely disconnect and connect any part of the structure without fear of disturbing the balance of the entire system.

If several circuits depart from one boiler, each of which has a circulation pump. Under such circumstances, the hydraulic gun will not allow counteraction from these components. The devices will operate softly, evenly distributing the coolant, which will be sufficient for each element.

A hydraulic arrow is indispensable when combining several boilers into one heating system.

In a situation where it is necessary to leave the entire system in working order, with the exception of one circuit. The hydraulic arrow provides this opportunity and, therefore, increases the maintainability of the entire heating system.

In cases where the equipment is subject to temperature changes. When exposed to cold liquid, having more than high temperature device, the latter may crack and fail. The greatest sensitivity to such effects is shown by cast iron batteries, heat exchangers and so on. This situation can happen when emergency shutdown, starting the heating system, during repair work. The hydraulic arrow will prevent thermal shock and save important parts of the entire heating system.

In addition to the above main functions of the hydraulic gun, it also has the ability to clean the heating system from decay products - scale, dirt, rust, sand, etc. For this purpose, the hydraulic separator is equipped with a valve in its lower part. In addition, the hydraulic valve can act as an air vent, thanks to a special valve in its upper part. Consequently, these capabilities of the hydraulic arrow directly have a positive impact on the reliability and safety of the entire heating system.

What types of hydraulic arrows can there be in the heating system of a private house?

Depending on the number of pipes, the following designs of hydraulic arrows can be determined:

A hydraulic arrow with 4 pipes provides 2 circuits.

KV series hydraulic arrow with 2 pipes on one side and 8 or 10 pipes on the other.

The manifold hydraulic arrow has many pipes for the possibility of connecting its own heating branch to each of them, as well as for connecting its own circulation pump to such branches.

The location of the pipes relative to each other is:

On one axis.

Offset in the form of alternating pipes (the outlet is located below the inlet).

In the latter case, the coolant will move more slowly, which will lead to better cleaning of it from air and impurities. When the pipes are located on the same axis, the coolant speed is higher, as a result of which parts of the debris can enter the second circuit.

Devices may differ in power and volume. If you know the characteristics of the boiler, then choosing the right one will not be difficult. By volume they are:

Small, up to 20 l.

Medium, up to 150 l.

Large, up to 300 l.

What are the advantages and disadvantages of a hydraulic arrow in the heating system of a private house?

Let us highlight the positive properties of the hydraulic arrow:

Creating a uniform direction of heat energy between the return and supply pipelines;

Possibility to use pumps with relatively low power, which has a beneficial effect on installation and maintenance costs;

Reducing hydraulic loads in the heating system pipeline;

Increasing the service life of thermal installations;

Removing air from the coolant.

The hydraulic separator has no obvious disadvantages. To the question: “Is a hydraulic arrow needed in a heating system?” the answer is mostly positive. But it is worth noting that this polypropylene device still has certain disadvantages.

The disadvantages of the hydraulic gun are:

Impossibility of use with a solid fuel boiler;

If the boiler has high power, then the period of use of the hydraulic arrow will be significantly reduced.

What is the principle of operation of a hydraulic arrow in a heating system

The hydraulic arrow can be designated as an intermediary between the boiler or stove and the entire heating system. The operation of the hydraulic separator is as follows:

The coolant enters the hydraulic separator, changing direction and speed. This is necessary to create a movement in which the hot flow goes up and the cold flow goes down. In turn, this process creates a thermal separation within the water gun for all circuits connected to it. For example, boilers have a high temperature, heated floors have a low temperature, and boilers are characterized by average values of this indicator.

A high-temperature coolant entering the hydraulic arrow reduces the rate of heat distribution. Which leads to the release of air, which must be removed from the heating system using special valve located at the top of the device. It can be either manual or automatic. A Mayevsky tap is usually used as a manual valve (it is also called a mechanical valve). In some models the hydraulic gun for complex systems The heating valve is installed at the bottom to remove dirt and debris.

The hydraulic arrow has three operating modes:

Mode 1

In this mode, the heating system works flawlessly. The coolant pressure generated by the pump in the smaller circuit is equal to the total pressure in the remaining circuits of the system. The inlet and outlet temperatures have the same values. The working fluid either does not move vertically at all, or this movement is minimal.

However, as practice shows, ideal work situations are extremely rare. As noted above, the functioning of heating circuits is prone to fluctuations and changes.

Mode 2

In a smaller circuit, the fluid flow is not as high as in the heating circuit. In this case, demand exceeds supply, which leads to the formation of a vertical flow from the return pipe to the supply pipe. During its rise, this flow mixes with hot liquid coming from the heating device.

Mode 3

Absolutely the opposite situation to mode 2. B in this case in heating circuits, the coolant flow rate is less than this figure in a small circuit. This happens for several reasons:

A short shutdown of one or more circuits due to the lack of need for heating any room;

During the heating process of the boiler, when all circuits are connected in turn;

Repair of one of the circuits in which this element is disabled.

These situations are not critical, since a downward vertical flow is formed in the hydraulic arrow.

What parameters are used to select a hydraulic arrow in the heating system of a private house?

There are only two parameters by which you can select a hydraulic gun:

Power. To determine this parameter, it is necessary to add up the thermal power of the heating system circuits. The power of the hydraulic switch must be equal to the total power of the boilers included in this system. It will not be a problem if this indicator of the hydraulic separator is higher, but a device with a lower power is unacceptable. For example, a device with a parameter of 100 kW is suitable for a system of 85, 90 or 95 kW. But if the total boiler rating is 105 kW, then you need to choose another hydraulic pump with greater productivity.

The total volume of coolant passed through.

Why is low vertical speed important in a hydraulic gun?

Reason #1

The main reason is that a low vertical velocity allows more debris to settle. Dirt, sand, and rust will accumulate in the hydraulic arrow after some time. Consequently, this element of the heating system is also used as a sludge storage tank.

Reason #2

Creation of natural convection of coolant in the heating system. In other words, the cold flow will go down, and the hot flow will go up. This process is necessary when using a hydraulic arrow to obtain the required pressure from the temperature gradient. For example, you can make a secondary circuit for a heated floor, the temperature in which will be lower than the main one. Or get a higher temperature for an indirect heating boiler, which will intercept the greatest temperature difference, which will allow you to heat the water faster.

Reason #3

Reduction of hydraulic resistance in the hydraulic arrow. This resistance in itself is close to zero, but if you remove the first reasons, then it becomes possible to make a hydraulic separator as a mixing unit. The diameter of the hydraulic needle will be reduced, and the vertical speed in it will be increased. This method provides significant savings on materials and can be used when a temperature gradient is not needed. Thus, only one heating circuit will be installed.

Reason #4

Removing air from the heating system through an air vent.

How to calculate the hydraulic arrow of a heating system using the formula

The hydraulic arrow for any heating system is selected or manufactured taking into account two parameters:

Number of pipes (calculated based on the number of circuits);

The diameter (or area) of the cross-section of the housing.

S = G / 3600 ʋ, where:

S – pipe cross-sectional area, m2;

G – coolant flow, m 3 /h;

ʋ – flow velocity, taken equal to 0.1 m/s.

Such a low flow rate of the coolant is explained by the need to ensure a zone of zero pressure. As the speed increases, the pressure will also increase.

Coolant consumption can be determined based on the required thermal power consumption of the heating system. If you plan to use an element with a round cross-section, then calculating the diameter of the hydraulic arrow will not be difficult. To do this, you need to take the formula for the area of a circle and determine the size of the pipe:

D = √ 4S/ π

If you decide to assemble the hydraulic arrow yourself, then you need to pay attention to the location of the pipes on it. In order not to place them haphazardly, you need to calculate the distance between the taps based on the diameter of the pipes being mounted. To do this, you can use one of the following methods:

Three diameter method;

Alternating pipe method.

Hydraulic arrow in the heating system of a private house and its step-by-step do-it-yourself installation

To make a hydraulic arrow you can use metal pipe or container. This will reduce costs, especially if you can do the welding work yourself (semi-automatically). You can also contact an experienced specialist. After making the hydraulic arrow, it needs to be insulated.

Step 1. Take necessary tools and spare parts

You will need:

Welding machine (argon);

Profiled pipe of the required diameter;

Air release plug;

Plug for sludge removal;

Branch pipes (at least 4).

Step 2. Weld the top and bottom bottom

Since the hydraulic arrow is made from a pipe or tank, the pipes and the bottom must be welded on both sides using argon welding. It is important to take into account that the quality of work must be at a high level. It is also advisable to use a drawing, even if made by hand, but indicating the necessary parameters.

Step 3. Divide the hydraulic separator capacity

The container for the hydraulic arrow must be divided into several components:

From the bottom bottom to the lower pipes the distance should be 10-20 cm. This is where rust, scale, sand and other debris will collect.

The distance from the top of the device to the upper nozzle should be approximately 10 cm.

The upper inlet and outlet pipes must be at a distance regulated by the temperature gradient. They can be either at the same level or with a shift. The higher the outlet pipe is located, the higher the operating temperature in it.

If the outlet pipe is located below the inlet pipe, then the hot flow will enter it after the entire volume has been completely heated. With this arrangement, you will get a smooth heating system. If the upper nozzles are located on the same axis, this will lead to the formation of a direct flow with weak air separation, which may lead to the occurrence of air jams.

It is important to pay attention to the location of the upper inlet pipe. It should not be at the highest point, as this prevents the movement of the hot flow. Thus, there will be no mixing of cold and hot water, which will make the installation of a hydraulic arrow pointless.

Step 4. Checking the device

The device is checked upon completion of welding work. To check, all holes are hermetically sealed, except one, through which water is drawn into the hydraulic arrow. After filling, the last hole is also sealed hermetically, and the hydraulic arrow is left for a day. This method allows you to detect the absence of leaks.

Installing a hydraulic arrow in a heating system: 5 general rules

It doesn’t matter at all how the hydraulic arrow will be fixed - it can be fixed both vertically and horizontally. The angle of inclination is also not important. It is only necessary to take into account the direction of the end pipes. The operation of the air vent and the ability to clean sludge depend on their location.

The hydraulic arrow is mounted immediately after the shut-off valves of the boiler.

The installation location is selected depending on the heating system layout. However, it is important to remember that the hydraulic separator must be installed as close to the boiler as possible. For a collector circuit, the hydraulic arrow is installed in front of the boiler.

If it is necessary to connect an additional pump, then the hydraulic arrow is installed between the pump and the outlet pipe leading to the heating device.

When using a solid fuel boiler, the hydraulic arrow is connected to the output-input. This method helps to select the optimal and individual temperature for each component of the system.

Unusual solutions regarding the hydraulic valve in the heating system of a private house

As a rule, hydraulic arrows are made of iron pipes or steel. However, not everyone wants to use iron devices in their heating system, which clog the entire system with rust. On top of that, finding large-diameter pipes made of plastic or stainless steel is not so easy.

In such conditions, a lattice-like structure made of small-diameter pipes can help. Such a design can actually be made from pipes and pipes of a similar diameter, using tees for connections. For example, a 32mm camera would be suitable. metal-plastic pipe. It can also be done from copper pipe, but polypropylene is only suitable if the operating temperature is low, up to 70 degrees.

An easier and cheaper way would be to install a radiator. However, this will lead to heat loss if thermal insulation is not performed.

How much will a hydraulic arrow cost in the heating system of a private house?

Due to the fact that the vast majority of industrially manufactured hydraulic arrows are equipped with a sludge separator, an air vent and thermal insulation, their cost is largely determined by the place of manufacture and additional capabilities.

The price of a device made in Germany, depending on additional elements, can be in the range of 17-156 thousand rubles.

Water guns for heating systems made in Italy have an average price range from 17 to 40 thousand.

Prices for hydraulic separators domestic producers start from 3,200 rubles and rarely exceed 40 thousand.

The SantekhStandard company offers a wide selection of devices for heating systems, and also delivers to your city. For more than 10 years, SantechStandard has been successfully operating in the plumbing equipment market. The products offered by the company are distinguished by high-tech performance and meet international quality standards. The company's consultants will select the most optimal option for you, and will also tell you in detail about the delivery of the selected equipment. You just need to contact us by phone:

A hydraulic arrow is a simple device that affects the balancing of the heating system and increases its reliability. There are several types of hydraulic arrows, and some of them may have completely different names that reflect the functional purpose of a particular device. This article will discuss the hydraulic arrow for heating, its purpose and features.

The purpose of the hydraulic arrow - what is it for?

The hydraulic arrow in heating systems performs the following functions:

One of the main functions of the hydraulic separator is hydrodynamic balancing in the heating circuit. The device in question is embedded in the system as an additional element and provides protection for the cast iron heat exchanger located in the boiler from thermal shock. This is why hydraulic separators are required to be installed when using boilers with cast iron heat exchangers. In addition, the hydraulic arrow provides heating protection from damage in the event of spontaneous shutdown of one of its elements (for example, hot water supply or heated floors).
When installing multi-circuit heating, a hydraulic separator is simply necessary. The thing is that the circuits during operation can conflict and interfere with each other - and the installed separator will prevent their pairing, due to which the system can function normally.
If the heating system was designed correctly, then the hydraulic arrow can be used as a sump that retains various solid mechanical impurities contained in the coolant.
The hydraulic separator located in the heating system allows air to be removed from the circuit, eliminating the need to use other methods of bleeding air and preventing oxidation of the internal surfaces of the heating system elements.

Knowing why a hydraulic arrow is needed in a heating system will allow you to correctly select and install such a device.

Operating principle of the hydraulic separator

The first thing you need to understand is what a hydraulic arrow is in a heating system as a separate element. Structurally, the hydraulic arrow is a hollow device in the form of a pipe with a square cross-section of the profile (read: “The principle of operation and design of the heating hydraulic arrow, purpose”). The simplicity of the design suggests that the operating principle of such a device is quite simple. Thanks to the hydraulic arrow, air is first released and removed from the system, for which an automatic air vent is used.

The heating system is divided into two circuits - large and small. The small circle includes the hydraulic needle itself and the boiler, and in the large circle the consumer is also added to these elements. When the boiler produces the optimal amount of heat, which is completely consumed for heating, the coolant in the hydraulic arrow moves only in the horizontal plane. If the balance of heat and its consumption is disturbed, the coolant remains within the small circuit, and the temperature in front of the boiler rises.

All these actions lead to automatic shutdown of the system, but the coolant continues to move quietly in the small circuit - and so on until its temperature drops to the required value. Upon reaching the set point, the boiler resumes operation in normal mode. All this answers the question of why a hydraulic arrow is needed for heating - it ensures the independent operation of all circuits.

The hydraulic separator can also be used in combination with solid fuel boilers. The principle of operation of heating with a hydraulic arrow is preserved, but the device itself is connected to the input and output of the heating equipment - this design makes it possible to fine-tune the temperature in the system.

Selecting a hydraulic distributor for a heating system

Knowing what a hydraulic separator is in a heating system, you can begin to select a suitable device. When choosing a hydraulic needle, you need to take into account only one indicator - the needle diameter, i.e. diameters of pipes that can be connected to the device. For maximum efficiency, you need to choose a device in such a way that the flow of coolant in the heating circuit is not limited, but in the hydraulic arrow itself and the pipes it should move at a minimum speed (the recommended value is about 0.2 m/sec.).

D – hydraulic needle diameter, mm;
d – diameters of supply pipes, mm;
G – limit value of the fluid flow speed along the hydraulic arrow;
w – maximum speed of water flow along the cross section of the hydraulic arrow;
c – heat capacity of the coolant;
P – maximum boiler power, kW;
t2-t1 – difference in coolant temperatures at the supply and return (the standard value is about 10 degrees).

To calculate the dependence of the diameter of the hydraulic separator on the maximum pressure value of the system, it is necessary to take the value of the diameter of the supply pipe and multiply it by 3, or use a formula in which the number 18.8 is multiplied by the square root maximum speed movement of the fluid divided by the maximum speed of fluid flow across the cross section of the device.

Before calculating the hydraulic arrow for heating, it is also worth learning about the dependence of its diameter on the power of the boiler. The formula has the same form, but in this case the square root is taken from the boiler power divided by the product of the fluid velocity along the cross-section of the separator multiplied by the temperature difference.

Advantages of hydraulic guns

Hydraulic separators used in heating systems have a number of advantages that make the installation of these devices justified:

The ability to avoid problems when selecting the size of a circulation pump installed in the secondary circuit and heating equipment;
Elimination of conflicts that arise between the boiler circuit and heating circuits;
Uniform distribution of coolant flows between heating equipment and consumers;
Providing the most good work all heating elements;
Possibility of insertion into the system expansion tank and automatic air vent;
Possibility of seamless connection of additional elements to the system.

In addition, the arrow used for heating allows significant savings on energy resources: gas consumption is reduced by about a quarter, and electricity consumption by almost half.

Conclusion

The hydraulic distributor for heating is very useful device, allowing you to optimize the operation of the heating system. Thanks to their qualities, the devices in question make it possible to achieve the most efficient heat distribution in the heating system with minimal initial costs and significant savings in the future.

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