A hydraulic arrow or hydraulic separator for a heating system is a device for equalizing temperatures and pressure in the system. Installed before and after the boiler to ensure smooth and gentle balancing of the heating system. Usually this device is bought ready-made, but you can make a hydraulic arrow for heating with your own hands. The Plumber Portal website provides a working diagram for the manufacture of a thermo-hydraulic distributor.

Hydraulic arrow - it is also a hydraulic separator, thermo-hydraulic distributor, hydraulic separator, bottle, hydraulic distributor, hydraulic arrow. All these are names of the same device for piping the boiler.

Before studying the diagram and making a hydraulic arrow, you need to find out why it is needed and what tasks it performs.

When designing an independent heating system, one of the main difficulties constantly becomes the precise balancing of its functioning. It is necessary to ensure that all equipment and areas work correctly. Each element fully coped with its tasks, but did not have a negative impact on other nodes.

This is very difficult to do, especially with a complex, branched system with several circuits, since usually each circuit has its own thermostatic control circuit, its own temperature gradient, its own throughput and the required level of coolant pressure.

To connect all the elements into a single system, a hydraulic arrow is used for heating systems. This device balances the functioning of all components.

As a rule, a thermohydraulic distributor works with a forced circulation system, where each circuit has its own circulation pump. In order for all circuits to work correctly, it is necessary to ensure precise coordination of all circulation pumps. The hydraulic separator copes with this task perfectly.

In addition, the thermohydraulic distributor is capable of performing several other useful functions:

• at the bottom of the hydraulic arrow there is a tap for periodically draining accumulated suspended matter and sediment from the system;
• ensuring maximum coolant flow, maintaining hydraulic and temperature balances;
• ensures minimal loss of pressure, productivity and thermal energy;
• protection of the boiler from differences in supply and return temperatures and thermal shock;
• equalizing the circulating volume of liquid in the primary and secondary circuits;
• increasing boiler efficiency;
• the possibility of secondary circulation of part of the coolant in the boiler circuit;
• saving electricity and fuel;
• maintaining a constant volume of boiler water thanks to admixture;
• compensation of flow deficit in the secondary circuit;
• reducing the influence of pumps with different kW power on secondary circuits and the boiler;
• creating conditions for the separation of dissolved gases and sludge.

Another important function is performed by the hydraulic arrow in systems with a boiler made of a cast iron heat exchanger. Cast iron does not withstand mechanical and thermal shocks well. As a result of a sharp temperature change, the heat exchanger may crack. To minimize temperature differences, a hydraulic separator is used.

Thermohydraulic distributor device

The structure of a standard hydraulic distributor is very simple. It is a medium-sized round or rectangular tank, plugged at the ends, into which pairs of pipes are embedded - for connection to the boiler and separately - to the boiler or manifold. There are usually four working pipes.

In fact, two completely independent circuits are formed. They are interconnected in terms of heat transfer, but each of them uses its own coolant circulation. In other words, both the flow rate (Q) of the coolant and the created pressure (N) in each circuit are different. Basically, the performance parameters in the circuit are stable (Qk) - the circulation pump operates in the specified appropriate mode.

The cross-section of the distributor itself guarantees minimal hydraulic resistance in the “small” circuit, which makes the circulation in it completely independent of the processes currently occurring in other parts of the heating system. A similar principle of operation of the boiler, without pressure drops, without multiple frequent start-up and stop cycles, is the key to its long-term trouble-free operation.

There are also special hydraulic separators for combining two or more boilers, but the operating principle is the same for all devices.

Operating principle of the hydraulic distributor

Without taking into account the various intermediate options, the principle of operation of the hydraulic arrow can be described by three main modes of its operation:

Mode one. The system operates almost in equilibrium. The flow rate of the “small” circuit is almost no different from the total flow rate of all circuits (Qк = Qо). The distilled liquid is not retained in the hydraulic needle, but passes through it horizontally, creating almost no vertical movement.

The water temperature at the supply pipes (T1 and T2) is the same. The same situation applies to the pipes that are connected to the “return” (T3 and T4). In this mode, the hydraulic distributor, by and large, does not affect the operation of the system in any way. However, in this mode, the circuits operate extremely rarely, since the system parameters always undergo changes during operation.

Mode two. The principle of operation is as follows: at the moment it happens that the total flow rate on the circuits exceeds the flow rate in the boiler circuit (Qk< Qо). Данная ситуация на практике случается очень часто, когда всем контурам в один момент времени требуется максимальный расход жидкости.

In other words, the immediate demand for coolant is greater than what the boiler circuit can produce. In this case, if there is a hydraulic arrow, the system will not stand up and become unbalanced. In the hydraulic distributor, a vertically ascending flow is simply formed from the “return” pipe of the manifold to the supply pipe.

At the same time, hot liquid circulating along the “small” circuit will be added to this flow in the upper area of ​​the hydraulic needle. Temperature balance: T1 > T2, T3 = T4.

Mode three. The principle of operation of the hydraulic arrow in this mode is, in fact, the main one. In a competently designed and installed heating system it will be superior. The coolant flow in the “small” circuit is greater than the similar total indicator on the collector, that is, the “demand” for the required volume has become lower than the “supply”. (Qк > Qo).

There can be any number of reasons for this - from changing the parameters of thermostatic control equipment to turning off some radiators. None of these factors will have a negative impact on the overall operation of the heating system.

The excess liquid volume will simply go into the “return” of the small circuit in a vertical downward flow. In essence, the boiler will provide excess volume, and each of the circuits will take as much as is needed at the moment. Temperature balance under this operating mode: T1 = T2, T3 > T4.

How to choose a hydraulic gun?

As a rule, the thermohydraulic distributor is calculated and selected individually for each heating system. The most important characteristic is the horizontal speed of movement of the coolant inside the hydraulic structure. Some manufacturing companies average these parameters and mass produce a line of hydraulic separators.

Among the manufacturers there are developers of hydraulic separators who carry out the calculations and design of hydraulic structures specifically for specific needs. This helps to increase the efficiency of the heating system to maximum values. Basically, hydraulic switches are produced in pairs with a hydraulic manifold.

Devices can be manufactured in such a way that two or three pipes enter from the heat source. Then the hydraulic arrows are called combined. This model of hydraulic arrow is a convenient alternative to the cascade connection of several boilers and is very convenient - several sources are simultaneously introduced into the hydraulic separator, which saves space in boiler rooms.

D – diameter of the hydraulic arrow body, mm; d – pipe diameter, mm; P – maximum boiler power, kW; G – maximum flow through the hydraulic separator, m3/hour; π = 3.14; ω – maximum vertical velocity of the coolant through the separator (0.2), m/sec; ΔT – difference between flow and return temperatures, °C; C – heat capacity of water, W/(kg°C); V – coolant velocity through secondary circuits, m/s; Q – maximum flow rate in the consumer circuit, m3/h.

Attention! The approximate size for small devices is selected according to the diameter of the inlet pipes. The distance between the taps must be at least 10 diameters of the fitting. The height of the body should significantly exceed its diameter.

Schemes for self-manufacturing hydraulic arrows

When assembling a hydraulic arrow with your own hands, the main thing is to make the calculations correctly and have the skills to work with a welding machine.

First of all, it is necessary to find the optimal dimensions of the hydraulic separator:

• internal diameter: divide the sum of all heating boiler capacities in kW by the temperature difference between the supply and return, take the square root of the resulting parameter, and then multiply the last value by 49;
• height: multiply the inner diameter by six.
• spacing between pipes: multiply the internal diameter by two.

Based on the obtained parameters, you need to draw up a drawing or use one of the diagrams of the future hydraulic distributor presented by the Plumber Portal resource. After this, you need to prepare a steel tube of round or square cross-section, which corresponds to the calculated indicators, and weld the required number of pipes with threaded connections into it.

Despite the simplicity of the device, the characteristics of the hydraulic gun must still correspond to specific conditions. Also, when assembling it yourself, you need to understand what to start from.

Attention! All pipe diameters listed below are not external diameters, but internal ones, that is, nominal diameters!

The classic assembly of a typical hydraulic boom is based on the “three diameter rule”. That is, the diameter of the pipes is three times smaller than the diameter of the main cylinder of the separator. The pipes are diametrically opposite, and their height arrangement is also tied to the main diameter.

Classic hydraulic separator diagram:

Some change in the position of the pipes is also used - a kind of “ladder”. This modification is aimed mainly at more efficient removal of gas and insoluble suspended matter. When circulating through the supply pipe, a slight change in the direction of the liquid flow in a zigzag downward manner contributes to the best elimination of gas bubbles.

On the reverse flow, on the contrary, the step is upward, and this simplifies the removal of solid sediment. In addition, this placement promotes optimal mixing of flows. The proportions are chosen in such a way as to create conditions for vertical flow speed in the range from 0.1 to 0.2 meters per second.

Exceeding this limit is prohibited. The lower the speed of the vertical flow, the more effective the separation of air and sludge will be. The slower the movement, the better the mixing of flows with different temperatures. As a result, a temperature gradient is formed along the height of the device.

Diagram of a hydraulic arrow with a stepped arrangement of pipes:

If the heating system contains circuits with different temperature conditions, then it is worth using a hydraulic distributor that acts as a collector, and different pairs of pipes will have their own temperature pressure. This will significantly reduce the load on thermostatic devices, making the entire system more manageable, efficient and economical.

The closer the pair of pipes is to the middle, the lower the temperature pressure in the supply tube, and the smaller the temperature difference in the supply and return. For example, for batteries the best mode is 75 degrees in supply with a difference Δt = 20 ºС, and for a heated floor system 40÷45 with Δt = 5 ºС is enough.

Diagram of a hydraulic separator with three outputs to the heating circuits:

Horizontal placement. In such variations, of course, there is no question of removing sediment and air. The placement of fittings varies significantly - to effectively move liquid, circuits are often used even in the opposite direction of the flow of the “small” and heating circuits.

Such a hydraulic arrow is made in order, for example, to place equipment more compactly in a boiler room, since the counter direction of flows makes it possible to slightly reduce the diameter of the tubes. However, the design must meet certain requirements:

• between the pipes of one circuit a gap of at least 4d must be maintained;
• if the inlet pipes have a diameter of less than 50 mm, then the distance between them should not be less than 200 mm.

Options for horizontal hydraulic separator circuits:

There are also completely “outlandish” designs. For example, one craftsman was able to build a hydraulic arrow from two sections of an ordinary cast-iron radiator. This device copes with hydraulic separation without problems. However, this method requires very reliable thermal insulation of the device, otherwise it will result in absolutely unproductive heat losses.

How to connect a hydraulic boom?

The thermohydraulic distributor has its own connection diagram, which is as simple as its design. The main part of the rules concerns not so much the connection as the calculation of bandwidth and pin placement. And yet, understanding the detailed information will make it possible to carry out the installation correctly, as well as verify the suitability of the selected hydraulic arrow for installation in a specific heating system.

The most important thing that needs to be clearly understood is that the hydraulic separator will function exclusively in heating systems with forced circulation. In this case, the system must have at least two pumps: one in the circuit of the generation part and one more in the consumer part. Under other circumstances, the hydraulic distributor will act as a shunt with zero resistance and, therefore, short-circuit the entire system.

The hydraulic arrow is connected to the direct and return pipelines of the boiler or several boilers. Of course, when connecting the device there should not be a hint of narrowing of the nominal passage. This condition forces the use of pipes with a very large nominal bore in the boiler piping and when connecting the manifold, which somewhat complicates the optimization of equipment placement and increases the amount of materials for piping.

Conclusion: the advantages of using a hydraulic gun

Let us once again emphasize the advantages of using a hydraulic arrow in a heating system with several circuits:

1. The functioning of the equipment is smoothed out. The coolant flow through its heat exchanger is always stable, without pressure and temperature surges. This only increases the wear resistance of the boiler.
2. A heating system with diverse circuits becomes easily manageable - it is easy to set individual parameters for each circuit, and this will not in any way affect the activity of other elements.
3. If the boiler has a cast iron heat exchanger, then installing a water gun will protect it from sudden “thermal shocks,” which will ultimately increase the service life of expensive equipment.
4. There are no problems with the choice of pumps. Each circuit is selected based on existing needs. In addition, there is no need to purchase a high-power circulation pump for installation in the boiler circuit.
5. Additional capabilities for removing accumulated gases and cleaning the coolant from insoluble contaminants can also become significant.

The need to install a hydraulic arrow in the heating system is considered individually and depends on a number of conditions - the power of the pumps, their interaction, the total power of the system, the presence of additional boilers used in conjunction.

Experts recommend installing this device only when the number of boilers is more than one and the number of pumps is more than three. Otherwise there is no need for it. It won't cause any damage, but there will be no benefit from complicating the entire structure.

Thus, a hydraulic arrow for heating is suitable only for a large branched system, for example, in apartment buildings or large private houses with a large number of extensions. Despite the complex principle of operation and a large number of tasks, this mechanism is quite simple in design, so it can be done with your own hands. However, if there are only one or two pumps, this is simply a waste of money and an irrational use of funds.

Boiler room equipment is a separate, broad topic that we have already touched upon. One of the elements of the boiler room that is constantly heard is the hydraulic separator. In this article we will touch on the principle of operation of the hydro insole, why it is needed and its main purpose.

In pursuit of additional benefits, many sellers, managers and even production workers are ready to tell anything if it helps sell the product. So various miracle hoses, incredibly reliable boilers and so on appear.

But the real scope for scammers to operate is in goods about which the consumer knows little. I heard something about its benefits, but I don’t know what they are.

One of these devices, surrounded by a lot of legends and rumors, is a hydraulic gun. The device is necessary, but for a very specific task, everything else is marketing and profanity.

Hydraulic gun device

This is simply a small pipe with a cross-section in the form of a circle or rectangle, in which there are four pipes through which heat flows to the consumer in one direction and return to the boiler in the other.

The purpose of the hydraulic arrow is to separate the boiler circuit and the consumer circuit.

The hydraulic separator can be positioned both vertically and horizontally, it all depends on the characteristics of the room. Most often they are placed vertically, since in this position it is easier to install an air vent on top and a tap at the bottom to remove unnecessary substances.

Operating principle of the hydraulic arrow is such that it cannot work independently; a complex is needed. The entire system includes the following components:

• The hydraulic arrow itself
• Main manifold
• Pumping groups (one direct and two mixing)
• Harness
• Controller

Operating principle of the hydraulic arrow

Manufacturers and cunning marketers declare three possible modes of operation of the hydraulic gun. While experts say that there is only one way to use this device.

When a boiler provides more energy than the consumer’s entire heating system needs, then the excess heat is returned along the arrow to the boiler itself.

This protects our boiler from return flow, which at lower thermal values ​​can cause damage to the entire system and provides additional heating.

The main principle of operation of the hydraulic gun– not manipulations with heat redistribution between the main supply and return, but ensuring the operation of pumps in all circuits of the heating system.

Let us explain: if one powerful pump produces increased pressure on one of the circuits, then the second pump, weaker in its characteristics, ceases to perform its task and does not take away anything at all, which causes interruptions, temperature changes and other troubles.

The hydraulic separator creates an area of ​​zero resistance. Thanks to this, it is possible to distribute the load evenly across all circuits and pumps, and such problems will never occur. Uniformity also makes it possible to increase the stability and reliability of the entire system as a whole, since none of the sections are no longer subject to critical loads.

Alternative operating modes of the hydraulic gun

Despite the fact that the correct principle of operation of the hydraulic arrow is only the method described above, it must be taken into account that it is technically possible to use an alternative.

One of them is when the boiler operates in a balanced manner, giving off as much heat as it goes to the return. But this condition is similar to a spherical horse in a vacuum, since complete identity of the values ​​of Q1 (boiler circuit) and Q2 (consumer circuit) is achieved extremely rarely and for a very short period of time. So it is impossible to seriously build work on this regime.

The second operating mode of the hydraulic gun is dangerous and should be avoided at all costs.

It is based on the fact that the boiler gives off less heat than is required by the consumer, and in this case, part of the heat from the return flow through the hydraulic separator goes back into the consumption circuit, which does not benefit either the system or the consumers.

The disadvantages are obvious - the return to the boiler comes with reduced temperature values, that is, the boiler actually cools down when receiving the return coolant, which is prohibited by all standards, GOSTs and even common sense, since the final power supplied to the consumption circuit becomes less and the desired result is not is achieved.

Additional features and myths

There is an opinion that the design of the hydraulic gun also allows you to perform the following tasks:

• Boiler protection against thermal shock
• Increasing the durability of the heating system
• Increases the efficiency factor of the boiler

However, independent experts claim that these are just fairy tales to increase sales.

At the same time, there are still additional options, such as additional protection from dirt, air removal, and protection of the boiler from return flow with a low temperature.

But these functions can be provided by much cheaper devices.

When and under what conditions should you install a hydraulic arrow?

The limit of the need to include a device such as a hydraulic arrow in the heating system, in the boiler room, is considered individually and depends on a number of conditions - the power of the pumps, their interaction, the total power of the system, the presence of additional boilers used in conjunction with the main one.

Professional engineers recommend including a hydraulic arrow in the heating system when the number of boilers is more than one and the number of pumps is more than three. Otherwise there is no need for it. It won't cause any damage, but there will be no benefit from complicating the entire structure.

Thus, this device is only suitable for a large branched system, for example, in apartment buildings or large summer cottages with a large number of extensions, otherwise. Especially when there are only one or two pumps, this is simply a waste of money and an irrational use of funds.

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 operation of the 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 simplest heating system does not require a 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.
• Indirect heating boilers are used to prepare 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 bleeder.

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 a 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 heated 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 parallel rather than serial connection equipment is used, 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 may vary. 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 here. 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. The hot coolant is supplied to the upper 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 simplest 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 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 the 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 twice the internal diameter of the pipe.

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 of 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 doing so is not recommended - it may not withstand the load if it is used in large heating systems. Nevertheless, many masters practice this.

Video

A hydraulic separator is a device whose main purpose is to separate the heating and boiler circuits. This, in turn, allows you to smooth out pressure drops and coolant flow rates, as well as quickly respond to temperature changes. Most often it is used in systems that are characterized by medium or high power. A hydraulic separator for boilers with multiple circuits eliminates the need to balance system pump flows, because all elements function independently of one another. Among other things, one cannot fail to note another very important role. In this case, we are talking about protecting the boiler itself from exposure to very low temperatures (so-called “low-temperature corrosion”).

Operating principle

If we talk about such a concept as the principle of operation, then it is quite simple. The entire heating system consists of a large and a small circuit. When the boiler produces the required volume of coolant at a suitable temperature, the liquid filling the hydraulic separator begins to move horizontally in it. As soon as the balance in the system is disturbed (for example, the tap in any of the consumers is turned off), it will begin to move along a small circuit, and the temperature in front of the boiler itself will increase. The automation will respond by turning off the device for safety reasons. The coolant will move as usual until its temperature drops. Cold liquid will become a signal to the system about the need to turn on the boiler again.

Operating modes

The hydraulic separator can be operated in three main modes. The first of them is activated when the system’s need for heat corresponds to the amount that has already been produced. In the second mode, the heating system requires less heat than has already been generated. In this case, a certain proportion of the liquid returns to the boiler through the hydraulic separator and signals the automation to reduce its power or even temporarily shut down. The third mode of operation is when the system requires more heat. If this happens, part of the coolant flow is taken over by the pumps, after which the automation receives a signal to increase the boiler power.

Main advantages of using the device

As studies have shown, the use of a hydraulic separator makes it possible to increase the service life of the boiler by approximately thirty percent. First of all, this is achieved by ensuring its protection from low-temperature corrosion. In addition, the service life of the pump is also increased. An important advantage is considered to be an increased response to all kinds of changes in conditions. It is impossible not to emphasize the fact that the device avoids imbalance, because the heating system becomes more hydraulically stable.

conclusions

To summarize, it should be noted that the functioning of the hydraulic separator occurs automatically. In other words, there is no need to configure or adjust it. The boiler turns on under conditions of closed circuit flow, thereby providing itself with protection from low return water temperature. As for the cost of such a device as a hydraulic separator, the price for the cheapest model is about three thousand rubles.

Why do you need a hydraulic arrow?

In this article I would like to explain in a simple and accessible form the principle of operation of a hydraulic separator and dwell on the advantages of using this device. First, consider the following typical diagram (Figure 1.

If in your diagram the number of heating circuits (consumer pumps) is not as large as in Figure 1, do not rush to close the page; in schemes with floor-standing boilers made of cast iron heat exchangers, the hydraulic arrow can perform an important function - to protect the heat exchanger from “thermal shock”.

Hydraulic boom operation

The function of the hydraulic separator, as its name suggests, is to separate the primary (boiler) circuit from the secondary (heating) circuit. When using a hydraulic diverter, the pressure delta P between the supply and return manifolds is close to zero. The delta pressure P is determined by the hydraulic resistance of the separator, which is insignificant. In addition, this value is a constant value, independent of the number of simultaneously operating pumps in the secondary circuit.

Practical experience shows that the use of a hydraulic boom is strongly recommended if, without a separator, the pressure difference between the collectors is delta P > 0.4 meters of water column.

In addition, one of the most important functions of the hydraulic switch is to protect the cast iron heat exchanger of the boiler from thermal shock. When the boiler is turned on for the first time, the heat exchanger can heat up to a high temperature in a very short period of time, while even in the shortest heating loop the coolant does not yet have time to heat up to a similar temperature. Therefore, from the return pipeline of the heating system (for example, from the return manifold, Figure 1), the “cold” coolant enters the hot heat exchanger, which leads to its premature destruction and failure of the boiler.

The use of a hydraulic arrow makes it possible to reduce the heating circuit of the boiler and ensure that the temperature difference in the supply and return pipelines does not exceed 45 degrees. WITH.

Inside the hydraulic separator, mixing of incoming and return water can occur and it can operate in three modes.

In practice, the hydraulics of the circuit never correspond to the calculated parameters, and the use of a hydraulic separator can eliminate many shortcomings.
Dimensions and calculation of the hydraulic boom

When making a hydraulic separator yourself, two methods are usually used to determine the optimal dimensions - the method of three diameters (Figure 6) and the method of alternating pipes (Figure 7).

The only size that needs to be determined when selecting a separator is the diameter of the separator (or the diameter of the supply pipes).

The hydraulic separator is selected based on the maximum possible water flow in the system (cubic m/hour) and ensuring the minimum water speed in the separator and in the supply pipes. The recommended maximum speed of water movement through the cross-section of the hydraulic separator is approximately 0.2 m/sec.

Hydraulic separator dimensions

• D – diameter of the hydraulic separator, mm;
• d – diameter of supply pipes, mm;
• G – maximum water flow through the separator, cubic meters. m/hour;
• w – maximum speed of water movement through the cross-section of the hydraulic separator, m/sec (approximate value is approximately 0.2 m/sec);
• с – heat capacity of the coolant, in this example – heat capacity of water (constant);
• P – maximum power of installed boiler equipment, kW;
• ?T is the specified temperature difference between the supply and return of the heating system, °C (assumed to be approximately 10°C).

Omitting simple mathematical calculations, we obtain the following formulas:

1) Dependence of the diameter of the hydraulic separator on the maximum water flow in the system.

Example. According to the diagram in Figure 2, after selecting the pumps, the following values ​​for maximum modes were obtained. In the boiler circuit, the water flow through each of the boilers was 3.2 cubic meters. m/hour. The total water consumption in the boiler circuit is:

3.2+3.2=6.4 cubic meters m/hour.

In the heating circuit we have:
- first zone of the heating system – 1.9 cubic meters. m/hour;
- second zone of the heating system – 1.8 cubic meters. m/hour;
- low temperature zone – 1.4 cubic meters. m/hour;
- DHW boiler – 2.3 cubic meters. m/hour.
The total water flow through the heating circuit in peak mode is:

1.9+1.8+1.4+2.3=7.6 cubic meters m/hour.

The peak water flow in the heating circuit is higher than the water flow in the boiler circuit, therefore the size of the hydraulic separator is determined by the flow in the heating circuit.

The approximate diameter of the separator was 116 mm.

2) Dependence of the diameter of the hydraulic separator on the maximum power of the installed boiler equipment.

If the pumps have not yet been selected, then you can approximately estimate the size of the hydraulic separator based on the maximum power of the installed boiler equipment, setting the temperature difference between the supply and return of the heating system to approximately 10 ° C.

Example. According to the diagram in Figure 2, two boilers will be used with a maximum power of each - 49 kW.

The approximate diameter of the separator was 121 mm.
The main advantages of using hydraulic booms

1. The selection of pumps is greatly simplified.
2. The operating mode and durability of boiler equipment is improved.
3. Protection of cast iron heat exchanger from thermal shock.
4. Hydraulic stability of the system, no imbalance.
5. If a typical wall-mounted double-circuit boiler operates on a large heating system, then the built-in pump may not be enough. The ideal option is to use a hydraulic separator and small pumps for each zone.
6. Commercially available commercially available separators can be used as effective removers of sludge and air from the system.

Why is the coolant temperature after the arrow (hydraulic separator) less than at the inlet?

This is the most frequently asked question from people who have a hydraulic separator installed in their boiler room. This mode of operation of the hydraulic switch is described in Figure 4. The main reason is that the coolant flow rate of the boiler circuit is less than the flow rate of the heating circuits. If the temperature difference is small, you don’t have to think about this problem; if the difference is more than 10 degrees, then you need to see if the pumps are selected correctly, or try to adjust the pump flow rates using the speed switches (the pumps themselves).