Designing your own heating system is far from easy. Even if the installers “plan” it, you need to be aware of many nuances. Firstly, to monitor their work, and secondly, to assess the need and feasibility of their proposals. For example, in last years The hydraulic arrow for heating is being intensively promoted. This is a small addition, the installation of which costs a considerable amount. In some cases it is very useful, in others you can easily do without it.

What is a hydraulic arrow and where is it installed?

The correct name for this device is a hydraulic arrow or hydraulic separator. It is a piece of round or square pipe with welded pipes. There is usually nothing inside. In some cases there may be two grids. One (above) for better “discharge” of air bubbles, the second (bottom) for screening out contaminants.

In the heating system, the hydraulic arrow is placed between the boiler and consumers - heating circuits. It can be positioned both horizontally and vertically. Most often they are placed vertically. With this arrangement, an automatic air vent is installed at the top, and a shut-off valve at the bottom. Some of the water with accumulated dirt is periodically drained through the tap.

That is, it turns out that a vertically installed hydraulic separator, at the same time as its main functions, removes air and makes it possible to remove sludge.

Purpose and principle of operation

A hydraulic arrow is needed for branched systems in which several pumps are installed. It provides the required coolant flow for all pumps, regardless of their performance. That is, in other words, it serves for hydraulic decoupling of the heating system pumps. That’s why this device is also called a hydraulic separator or hydraulic separator.

A hydraulic arrow is installed if the system has several pumps: one on the boiler circuit, the rest on the heating circuits (radiators, water-heated floor, boiler indirect heating). For correct operation, their performance is selected so that the boiler pump can pump a little more coolant (10-20%) than is required for the rest of the system.

Why do you need a hydraulic arrow for heating? Let's look at an example. In a heating system with several pumps, they often have different capacities. It often turns out that one pump is many times more powerful. All pumps have to be installed nearby - in the manifold unit, where they are hydraulically connected. When the powerful pump turns on at full power, all other circuits are left without coolant. This happens all the time. To avoid similar situations and install a hydraulic arrow in the heating system. The second way is to spread the pumps over a long distance.

Operating modes

Theoretically, three modes of operation of a heating system with a hydraulic arrow are possible. They are shown in the figure below. The first is when the boiler pump pumps exactly the same amount of coolant as required by the entire heating system. This is an ideal situation in real life very rare. Let's explain why. Modern heating adjusts operation according to the temperature of the coolant or the temperature in the room. Let's imagine that everything was calculated perfectly, the valves were tightened, and after adjustment, equality was achieved. But after some time, the operating parameters of the boiler or one of the heating circuits will change. The equipment will adapt to the situation, and the equality of productivity will be violated. So this mode can last a matter of minutes (or even less).

The second mode of operation of the hydraulic switch is when the flow rate of the heating circuits is greater than the power of the boiler pump (middle picture). This situation is dangerous for the system and should not be allowed to happen. This is possible if the pumps are selected incorrectly. Or rather, the boiler pump has too low a capacity. In this case, to ensure the required flow rate, coolant from the return line will be supplied to the circuits along with the heated coolant from the boiler. That is, at the boiler outlet, for example, 80°C, in the circuit after mixing cold water goes, for example, 65°C (the actual temperature depends on the flow deficit). Walking through heating devices, the coolant temperature drops by 20-25°C. That is, the temperature of the coolant supplied to the boiler will be, at best, 45°C. If we compare it with the output temperature - 80°C, then the temperature delta is too high for a conventional boiler (not a condensing boiler). This mode of operation is not normal and the boiler will quickly fail.

The third operating mode is when the boiler pump supplies more heated coolant than the heating circuits require (right figure). In this case, part of the heated coolant is returned back to the boiler. As a result, the temperature of the incoming coolant rises, and it operates in a gentle mode. This is the normal operating mode of a heating system with a hydraulic arrow.

When is a hydraulic arrow needed?

A hydraulic arrow for heating is 100% needed if the system will have several boilers operating in a cascade. Moreover, they must work simultaneously (at least most of the time). Here, for correct operation, a hydraulic separator is the best solution.

If there are two simultaneously operating boilers (in cascade), a hydraulic arrow is the best option

Another hydraulic arrow for heating can be useful for boilers with a cast iron heat exchanger. Warm and cold water are constantly mixed in the hydraulic separator tank. This reduces the temperature delta at the boiler outlet and inlet. This is a blessing for a cast iron heat exchanger. But a bypass with a three-way adjustable valve will cope with the same task and will cost much less. So even for cast iron boilers located in small heating systems, with approximately the same flow rate, it is quite possible to do without connecting a hydraulic arrow.

When can I deliver

If the heating system has only one pump - on the boiler, a hydraulic arrow is not needed at all. You can get by if one or two pumps are installed per circuit. Such a system can be balanced using control valves. When is the installation of a hydraulic arrow justified? When the following conditions exist:

• There are three or more circuits, all of very different power (different circuit volumes, different temperatures required). In this case, even with perfectly accurate selection of pumps and calculation of parameters, there is a possibility of unstable operation of the system. For example, a situation often occurs when when turning on the pump heated floors, the radiators are getting cold. In this case, hydraulic isolation of the pumps is needed and therefore a hydraulic arrow is installed.
• In addition to radiators, there is a water-heated floor that heats large areas. Yes, it can be connected via a manifold and mixing unit, but it can force the boiler pump to work in extreme mode. If your heating pumps often burn, you most likely need to install a hydraulic arrow.
• In a medium or large volume system (with two or more pumps), you are going to install automatic control equipment - based on coolant temperature or air temperature. At the same time, you don’t want/can’t adjust the system manually (with taps).

In the first case, a hydraulic decoupling is most likely needed, in the second, it is worth thinking about installing it. Why just think? Because these are significant expenses. And it’s not just the cost of the hydraulic gun. It costs about $300. I'll have to put more optional equipment. At a minimum, you need manifolds at the inlet and outlet, pumps for each circuit (with a small system, you can do without them), as well as a pump speed control unit, since they can no longer be controlled through the boiler. Combined with the installation fee for the equipment, this “add-on” amounts to approximately two thousand dollars. Quite a lot indeed.

Why then install this equipment? Because with a hydraulic arrow, heating works more stable and does not require constant adjustment of the coolant flow in the circuits. If you ask the owners of cottages whose heating is made without a hydraulic separator, they will tell you that they often have to reconfigure the system - turn the valves, adjusting the flow of coolant in the circuits. This is typical if used various elements heating. For example, there is a warm floor on the ground floor, radiators on two floors, heated utility rooms, in which it is necessary to maintain a minimum temperature (garage, for example). If you expect to have approximately the same system, but the prospect of “adjustment” does not suit you, you can install a hydraulic arrow for heating. If it is available, each circuit receives as much coolant as it requires in this moment and in no way depends on the operating parameters of nearby pumps of other circuits.

How to select parameters

The hydraulic separator is selected taking into account the maximum possible coolant flow rate. The fact is that at high speeds of liquid movement through the pipes, it begins to make noise. To avoid this effect, the maximum speed is assumed to be 0.2 m/s.

Parameters required for the hydraulic separator

By maximum coolant flow

To calculate the diameter of the hydraulic arrow using this method, the only thing you need to know is the maximum coolant flow that is possible in the system and the diameter of the pipes. With pipes everything is simple - you know which pipe you will use for wiring. We know the maximum flow that the boiler can provide (available in technical specifications), and the flow rate through the circuits depends on their size/volume and is determined when selecting circuit pumps. The flow rate for all circuits is added up and compared with the power of the boiler pump. A large value is substituted into the formula to calculate the volume of the hydraulic needle.

Let's give an example. Let the maximum flow rate in the system be 7.6 cubic meters/hour. The permissible maximum speed is taken as standard - 0.2 m/s, the diameter of the pipes is 6.3 cm (2.5 inch pipes). In this case we get: 18.9 * √ 7.6/0.2 = 18.9 * √38 = 18.9 * 6.16 = 116.424 mm. If we round, we find that the diameter of the hydraulic needle should be 116 mm.

According to the maximum boiler power

The second method is to select a hydraulic needle according to the boiler power. The estimate will be approximate, but it can be trusted. The boiler power and the difference in coolant temperatures in the supply and return pipelines will be needed.

The calculation is also simple. Let the maximum boiler power be 50 kW, the temperature delta be 10°C, the diameters of the pipes be the same - 6.3 cm. Substituting the numbers, we get - 18.9 * √ 50 / 0.2 * 10 = 18.9 * √ 25 = 18.9*5 = 94.5 mm. Rounding, we get the diameter of the hydraulic needle 95 mm.

How to find the length of the hydraulic arrow

We have decided on the diameter of the hydraulic separator for heating, but we also need to know the length. It is selected depending on the diameter of the connected pipes. There are two types of hydraulic arrows for heating - with taps located one opposite the other and with alternating pipes (located offset from one another).

Determining the length of the hydraulic arrow from a round pipe

It is easy to calculate the length in this case - in the first case it is 12d, in the second - 13d. For medium-sized systems, you can select the diameter depending on the pipes - 3*d. As you can see, nothing complicated. You can calculate it yourself.

Buy or make it yourself?

As they said, a ready-made hydraulic arrow for heating costs a lot - $200-300 depending on the manufacturer. To reduce costs, there is a natural desire to do it yourself. If you know how to cook, no problem - we bought the materials and did it. But the following points must be taken into account:

• The thread on the bends should be well cut and symmetrical.
• The walls of the outlets are of the same thickness.

Quality homemade product maybe "not very"

It seems like obvious things. But you will be surprised how difficult it is to find four normal fittings with normally made threads. Further, all welds must be of high quality - the system will work under pressure. The bends are welded strictly perpendicular to the surface, at the required distance. In general, this is not such an easy task.

If you don’t know how to do it yourself, you’ll have to look for a performer. It’s not at all easy to find: either they charge a lot for the services, or the quality of the work is, to put it mildly, “not very good.” In general, many people decide to buy a hydraulic gun, despite the considerable cost. Moreover, in Lately, domestic producers They do it just as well, but much cheaper.

In order to level hydraulic pressure in the heating system and to reduce the pressure on the boiler, a hydraulic separator or, more simply put, a hydraulic arrow is used. This device is a piece of pipe of round or square cross-section, with pipes welded to it. General form Such a device can be seen in the figure below.

What does a hydraulic arrow look like for a heating system?

As can be seen from the figure, on one and the other side there are pipes for connecting pipes from the boiler and from the heating system circuits. At the top there is usually an automatic valve for releasing air, and at the bottom there is a tap for discharging sediment from the heating system.

Usage

Typically, a hydraulic separator is installed in the following cases:

1. If the house has a large, powerful heating system with a large number of radiators, but at the same time with a small water circuit of the heating boiler. If such a system operates without a hydraulic valve, then, firstly, it is very difficult to balance, if at all possible, and secondly, a large load is created on the heating boiler pump, which quickly disables it.
2. If the heating system is combined from several circuits: radiators, heated floors, indirect heating boiler. In such heating systems without a hydraulic separator, when one circuit is turned off, an imbalance of the heating system may occur with a sharp increase in the temperature of the coolant. This also adversely affects the operation of the boiler.
3. When using two or more heating boilers in a heating system to link them into one heating system.

By installing a hydraulic arrow in the heating system, you can get the following positive changes:

1. Uniform heating of all radiators of the heating system. With good correct balancing, you can set the optimal thermal regime in the heating system.
2. Coordinated operation of water floor circuits, heating batteries and an indirect heating boiler.
3. The ability to remove accumulated dirt and excess air in the heating system. With a drain valve and automatic air valve on the hydraulic arrow you can remove various slag from the heating system.
4. It is possible to coordinate the operation of two boilers without using complex, bulky equipment.

Disadvantages of using a hydraulic gun:

1. The need to work only on heating systems with forced circulation coolant;
2. It is necessary to install an additional circulation pump on each circuit.

The hydraulic arrow in the heating system is installed strictly vertically so that sediment collects at the bottom and air leaves the heating system at the top.

Design and principle of operation

The diagram of an industrial hydraulic separator is shown in the figure below.

Hydraulic separator device

In the figure, the movement of water from the boiler is shown by a red arrow. Water entering the hydraulic switch goes around the dividing plate (2) and enters through the air exhaust channel (3) to the flow straightener (4). To remove excess air from the water, the design provides an automatic air vent (1). To control the water temperature in the hydraulic arrow, a thermometer is installed in the sleeve (5). The further movement of water into the system is shown by the red arrow. The blue arrow shows the reverse movement of water from the system to the boiler. Through the separating plates (6) the water is mixed in the hydraulic arrow. At the bottom of the hydraulic arrow there is a dirt collector with plates (7). Dirt is drained from the hydraulic arrow using a tap (9).

As can be seen from the figure, the design is not so complicated, and therefore there are no special requirements for operation. You just need to monitor the operation of the automatic air vent and dump the accumulated dirt from the hydraulic arrow.

The connection diagram and operating modes of the hydraulic arrow are shown in the figure below.

Diagram of hydraulic gun operating modes

The figure shows three main options for the operation of the hydraulic arrow. As can be seen from the figure, in the first case, the heating system consumes less coolant than the heating boiler produces. At the same time, in the hydraulic arrow there is a downward movement of water, in the direction of water movement in the boiler circuit. This situation can occur if, for example, thermal valves operate in the heating system, which restrict the flow of water. In the second case, the coolant flow rates of the heating system and the boiler are the same, and the heating operates in optimal mode. In this case, no movement of water along the hydraulic arrow is observed. The third option is when the consumption heating system more than the boiler consumption. In this case, the water in the hydraulic arrow moves upward.

Manufacturing schemes

Industrially manufactured water guns are not cheap and many people make them with their own hands. In this case you need to do preliminary calculations. The main design dimensions are shown in the figure below.

Hydraulic switch diagram with main design dimensions

As can be seen from the figure, the diameter of the hydraulic needle itself is taken equal to three diameters of the inlet pipes, so the calculations come down mainly to determining the diameter of the hydraulic needle.

The figure shows two options for hydraulic arrows. Purpose of the second option better than the first the fact that when water passes through the supply pipeline, it is freed from air bubbles, and when it flows back, it better gets rid of sludge.

The calculation comes down mainly to determining the diameter of the hydraulic needle:

Where:

• D – diameter of the hydraulic needle in mm;
• d is the diameter of the inlet pipe in mm, usually taken equal to D/3;
• 1000 – conversion factor meters to mm;
• P – boiler power in kJ;
• π – pi number = 3.14;
• C – heat capacity of the coolant (water – 4.183 kJ/kg C°);
• W – maximum vertical speed of water movement in the hydraulic arrow, m/s, usually taken equal to 0.1 m/s;
• ΔT – difference in coolant temperatures at the inlet and outlet of the boiler, C°.

The calculation can also be performed using the following formula:

• Q – coolant flow, m³/s;
• V – speed of water movement in the hydraulic arrow, m/s;

There is also the following formula to calculate the diameter of the hydraulic needle:

• G – flow rate, m³/hour;
• W – water speed, m/s;

The height of the hydraulic arrow can be any and is limited only by the height of the ceiling in the room.

If you make the diameter of the hydraulic arrow large enough, you can get two in one: a hydraulic arrow and a heat accumulator, the so-called capacitive separator.

Diagram of a capacitive separator in a heating system

As can be seen from the figure, a hydraulic arrow of this type has a large volume, about 300 liters or more, therefore, in addition to performing its main task, it is also capable of accumulating heat. The use of a hydraulic arrow of this type is especially justified when heating with a solid fuel boiler, as it can smooth out temperature fluctuations in the heating boiler and maintain thermal energy boiler after the end of combustion for quite a long time.

You need to know some nuances when using this type of hydraulic arrow:

1. Firstly, such a hydraulic arrow must be insulated, since otherwise it will heat the boiler room and not transfer heat to the heating system.
2. The boiler will produce less power. This is explained by the fact that a high coolant temperature is required, and the boilers are equipped with automatic equipment that will automatically reduce its power to reduce the outlet temperature.

Hydraulic arrow for several circuits

For heating multiple circuits there are different designs hydraulic separators.

Scheme of using a hydraulic arrow in a heating system with several circuits

As can be seen from the figure, in this design, water flows from the boiler to the hydraulic switch and returns to it through two pipes, and is discharged into the system through several. This connection diagram allows you to separate the heating circuits and supply water with a different temperature gradient to each circuit.

If you make a device according to this principle, then during its operation the following will happen:

1. Hot water from the pipe (T1) will be absorbed by the pipe (T2), at a flow rate of Q1=Q2.
2. If Q1=Q2 the water entering the pipe (T3) becomes equal in temperature to the temperature of the pipes (T6), (T7), (T8), and the temperature difference between (T3) and (T4) is not significant.
3. If Q1=Q2+Q3 0.5, the following happens: temperature T1=T2, T3=(T1+T5)/2, T4=T5.
4. If Q1=Q2+Q3+Q4, then T1=T2=T3=T4.

As you can see, this connection scheme has a number of disadvantages and cannot separate the heating circuits qualitatively with the required temperature gradient.

In order to correctly distribute the temperature along the circuits, use the following connection diagram:

Hydraulic arrow diagram for correct temperature distribution along the circuits

When powered according to this scheme, it is necessary to observe certain conditions for proper operation devices:

1. The pipeline (T1) must be located above the pipeline (T2).
2. Pipe (T9) must be located exactly in the middle between pipes (T3) and (T4).
3. The pipeline (T10) and (T5) must be located at a distance of at least 20 cm from each other.
4. The pipe (T5) must be located above the pipes (T6), (T7) and (T8) so that the water coming from these pipes is mixed before entering the pipe (T5).
5. The distance between pipes (T2), (T3) and (T4) should be as equal as possible.

With this operating scheme, the temperature in the circuits can be equalized using balancing valves on pipelines (T1), (T9) and (T10). This is especially good for a boiler that needs to supply the most high temperature coolant for heated floors with the lowest temperature.

Instead of balancing valves, since they are too expensive, conventional valves with modulating control can be used.

You can also connect the circuits using the following collector circuit:

Collector diagram for connecting a hydraulic arrow

With this connection scheme, the temperature pressure is also regulated balancing valves, but not to the same extent as in the previous scheme. In this case, the diameter of the collectors must be large enough to distribute the coolant evenly.

Hydraulic gun designs

If, when using a water gun, the goal is not to remove sludge and air from the heating system, then you can position it horizontally according to the following scheme:

Diagram of the horizontal arrangement of the hydraulic arrow

As can be seen from the figure, here the hydraulic arrow is located horizontally, and the pipes, accordingly, can be either from below or from the side. In this case, the length of the hydraulic needle and the distance between the pipelines can be anything, it is only desirable that the supply and discharge pipes be located at a distance of at least 20 cm from each other.

Typically, a hydraulic separator is made of metal, but if you don’t want rust to get into the system, you can make it from polypropylene yourself. Moreover, if there are no polypropylene pipes of a suitable diameter, then the structure can be given the following form:

Hydraulic arrow made of plastic pipes

It can be made even easier if you install a heating radiator instead of this design. At the same time, it needs to be insulated so that it does not transfer heat to the boiler room. Otherwise, heat loss will occur.

When using a hydraulic arrow in a heating system, the following improvements in operation can be achieved:

1. The durability of the boiler increases. When working without a hydraulic valve, you can often observe temperature jumps in the system, which has a bad effect on the operation of the boiler.
2. Ability to adjust the temperature on each individual circuit.

Purpose of the hydraulic gun. Video

The video below tells about the device, purpose and operating principle of the hydraulic gun.

The hydraulic separator is considered one of the most good decisions to regulate the heating system. Despite its disadvantages, such as, for example, the need to use additional pumps and the inability to operate in free-flow mode, the use of a hydraulic arrow in a heating system has a number of advantages. It copes best with the distribution of hydraulic resistance and temperature gradient in the heating network, and it can be made with your own hands from available materials. This cannot be said, for example, about three way valve, for the production of which you need at least lathe. And subsequent operating costs are kept to a minimum. So the hydraulic separator can be considered one of the best means to regulate the heating system according to the price/functionality ratio.

In contact with

Owners individual houses When organizing, the concept of imbalance after connecting the circuits to the boiler is familiar. To equalize the pressure and reduce it, a hydraulic arrow is installed. We will discuss the principle of operation, purpose and calculations in today's review.

The hydraulic separator can be round or rectangular. The principle of operation is practically the same. Rectangular shape looks better. Round - more suitable from the point of view of organizing hydraulics. But basically, the form has virtually no effect on the organization of the functioning of the system.

Additionally, the hydraulic gun may include:

• filters;
• air separators with removal of air masses;
• taps;
• with thermal control elements that prevent cold water from entering the return of the boiler circuit;
• additional ;
• sludge trap;
• pressure gauge

The hydraulic separator housing can be made of low carbon, of stainless steel or copper. They also produce hydraulic arrows made of polypropylene. Additionally, it is treated with special anti-corrosion compounds and thermally insulated if necessary.

You should know this! Polymer water separators can be used for the heating system that is served by boiler equipment power 13-35 kW. They cannot be used for equipment operating on solid fuels.

Features of installation of hydraulic arrows

The hydraulic arrow is installed behind the boiler, and if there is a manifold, in front of it. The pipes are connected using flanges or threads in the following order: on one side of the separator they are connected to the outputs in the order 1, 2, 3, on the opposite side in the mirror order 3, 2, 1. This is not a dogma, depending on the conditions, the location of the pipe junction may change.

The most commonly used is a vertical distributor. This is the most favorable location for sifting water flows from suspended matter. If conditions require, it can be placed horizontally.

Brackets can be used to mount small models. Hydraulic guns with a large weight will be placed on the floor or stand so as not to overload the pipeline system.

Conclusion

So now you know what it is: a hydraulic boom. In summing up, we can note its main advantages. It reliably protects the cast iron heat exchanger from thermal and water shocks, simplifies the selection of pumping equipment, and all equipment operates as normal. The heating system is balanced, the operation of the circuits does not affect each other.

And finally, watch video reviews of the device, purpose and operation of the hydraulic gun:

Often, on the pages of Internet resources, you can find a very concise description, written only in technical terms. hydraulic guns. In this article we will try to reveal what is a hydraulic arrow and why is it needed?.

Hydroarrow— used for hydraulic separation of flows. Thus, a hydraulic separator is a kind of channel between the circuits, which allows you to create dynamically independent circuits for transmitting movement from the coolant. Most often used on the Internet official name: hydraulic arrow —hydraulic separator.

Why do you need a hydraulic arrow in a heating system?

In the heating system, the hydraulic arrow is connecting link between two separate heat transfer circuits and it completely neutralizes the dynamic influence between the circuits. She has two purposes:

• first, it eliminates the hydrodynamic influence, when turning off and turning on some circuits in the heating system, on the entire hydrodynamic balance. For example, when using radiator heating, underfloor heating and boiler heating, it makes sense to separate each flow into a separate circuit to eliminate influence on each other.()
• second - with a small coolant flow - it should receive high consumption for the second, artificially created circuit. For example, when using a boiler with a flow rate of 40 l/min, the heating system produces a flow rate 2-3 times greater (consumes 120 l/min). In this case, it is advisable to install the first circuit as the boiler circuit and install the heating decoupling system as the second circuit. In general, it is not economically feasible to accelerate the boiler more than provided by the boiler manufacturer; in this case, the hydraulic resistance also increases, it either does not provide the required flow rate, or increases the load of fluid movement, which leads to increased energy consumption of the pump.

On what principle does the hydraulic arrow work?

Coolant circulation in the primary circuit is created using the first pump. The second pump creates circulation through the hydraulic valve in the second circuit. Thus, the coolant is mixed in the hydraulic arrow. If the flow rate in both circuits is the same, then the coolant freely penetrates from circuit to circuit, creating, as it were, a single, general outline. In this case, no vertical movement is created in the hydraulic arrow or this movement is close to zero. If the flow rate in the second circuit is greater than in the first circuit, then the coolant moves from bottom to top in the hydraulic arrow and, with increased flow in the first circuit, from top to bottom.

And when adjusting the hydraulic needle, you need to achieve minimal vertical movement. Economic calculation shows that this movement should not exceed 0.1 m/s.

Why reduce the vertical speed in the hydraulic gun?

The hydraulic arrow also serves as a waste settler in the system; at low vertical speeds, the garbage gradually settles in the hydraulic arrow, being removed from the heating system.

Creating natural convection of the coolant in the hydraulic arrow, so the cold coolant goes down, and the hot one rushes up. This creates the required temperature pressure. When using a heated floor, you can get reduced temperature coolant, and higher for the boiler, ensuring rapid heating of the water.

Reducing hydraulic resistance in the hydraulic arrow,

The release of microscopic air bubbles from the coolant, thereby removing it from the heating system through the auto-ventilator.

How do you know when you need a hydraulic gun?

As a rule, a water gun is installed in houses with an area of ​​more than 200 sq.m., in those houses where a complex system heating. Where distribution of coolant into several circuits is used. It is advisable to make such circuits independent of others in common system heating. Hydrostrelka allows you to create a perfectly stable heating system and distribute heat throughout the house in the right proportions. When using such a system, heat distribution along the circuits becomes precise and deviations from the configured parameters are eliminated.

Advantages of using hydraulic arrows.

Protection cast iron heat exchangers excluding heatstroke. IN normal system, without using a hydraulic switch, a sharp increase in temperature is created when some branches are disconnected and the subsequent arrival of already cold coolant. Hydraulic arrow gives constant flow boiler, reducing the temperature difference between supply and return.

The durability and reliability of boiler equipment increases due to stable operation without temperature changes.

Lack of imbalance and creation of hydraulic stability of the heating system. It is the hydraulic arrow that allows you to increase the additional coolant flow, which is very difficult to achieve by installing additional pumps.

Operating principle of a hydraulic boom video

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?

Essentially, a hydraulic needle 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 of the hydraulic heating system. 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 devices on the market are mass-produced without adaptation to specific system heating.

You can often come across the opinion that the flask cavity must contain additional elements, 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. The beneficial effect of the boiler lies entirely in its conversion ability, that is, in the percentage of heat generated by the generator to the heat absorbed by the coolant. None special methods piping cannot 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, however, in this mode, supercooled coolant inevitably flows through the return to the heat exchanger, which gives rise to a number of negative effects: fogging internal surfaces combustion chambers 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 reducing the flow in consumer circuits by welding 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.

Second special case- excess boiler productivity in relation to the consumption of 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; eleven - three way valve with electric drive; 12 - circuit No. 3 warm 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 indicated ratio must be multiplied by correction factor 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 the direct and return main pipelines of a 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 pipes with a very significant nominal bore in the boiler piping and when connecting the manifold, which somewhat complicates the issue of optimizing the layout of the 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.

Separation manifold vertical installation allows you to provide 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 will give an 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 insist on installing a hydraulic arrow, 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.