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Control valve for heating diagram. Thermostatic valve: types and installation methods

Among the huge variety of shut-off valves that are used on the heating system, there is a rather rarely used element - a three-way valve for heating with a thermostat. It is similar in shape to a tee, but it is designed for completely different functions. How a three-way valve with a servo drive works and why it is needed will be discussed in this article.

Operating principle of three-way valve

A three-way mixing valve is installed in those sections of the pipeline where it is necessary to divide the main coolant flow into 2 circuits:

with variable hydraulic mode;
with constant.

Often a constant flow is necessary for those who are supplied with high quality coolant and in established volumes. Its adjustment corresponds to quality indicators. Regarding the variable flow, it is used for objects where quality indicators are not key. Here important role plays the quantity coefficient indicator. In other words, the supply of warm fluid in this case is carried out according to the required quantity.

Note! One of the elements of shut-off valves is an analogue of the device that we are talking about in this article, which is called a two-way valve. What makes it different? It differs from the three-way one in the principle of its operation. The fact is that one of the elements of its design, the rod, cannot block the flow of liquid, which has constant hydraulic parameters.

The rod is constantly open, it is adjusted to a certain volume of liquid. Based on this, users have the opportunity to obtain the required volume, both in terms of quantity and quality. In general, this device cannot stop the flow of fluid for a network with a constant hydraulic flow. But it is capable of blocking a variable flow, which makes it possible to regulate the pressure/flow.

You can create one three-way valve by connecting a pair of two-way valves. But they must work in reverse mode, that is, when one opens, the other must close.

A three-way valve for underfloor heating or other purposes operates with the following sequence:

the collector, which is one of the elements of the heated floor, receives hot water;
the degree of heating of the liquid is determined as it passes through the thermomixing valve;
in the case when the temperature exceeds the set level, a passage opens from where the cooled liquid flows;
both streams mix internally;
Once the temperature drops to the set limit, the cold water passage is closed.

The disadvantages of three-way valves include the likelihood of sudden temperature jumps that can occur when heated water is turned on, which can have an impact negative impact on the condition of the pipeline during mixing.

The three-way thermostatic mixing valve is used to:

if necessary, redirect flows from different pipelines;
mix flows of diametrically different temperatures to obtain a flow of a set temperature;
dynamically control the direction of flows to obtain a flow with a constantly set temperature;
in a plumbing system, this is obtaining a flow with a given stable temperature;
in a heating system, this means obtaining a separate mixing unit with a consistently constant circulation temperature.

Using normal ball valve can be adjusted manually. In appearance, it is similar to a regular valve, but has such a feature as an additional output. This type of valve is used for forced manual control.

For automatic adjustment, a special three-way valve is used, which is equipped with an electromechanical device to change the position of the rod. It must be connected to a thermostat in order to be able to regulate the temperature in the room.

Types of valves for heating

Without further introduction, let's say that the device comes in two types, which differ in the principle of operation. It happens:

dividing;
mixing.

The principle of operation of the device is clear from its name. The design of the mixing device has two outputs and inputs. This is necessary in order to mix different flows of liquid to reduce its temperature. By the way, this is the best option for setting the required mode for a “warm floor”.

The adjustment process itself temperature regime simple enough. You only need to know what the current temperature of the incoming liquid streams is in order to accurately calculate the required proportions of each stream in such a way as to obtain the required output indicators. By the way, when correct installation This control device can also work to separate the flow.

A dividing valve divides one flow into two, so it has one inlet and two outlets. This device is used mainly for separating the hot flow in domestic hot water systems. Although quite often it can be found in the piping of air heaters.

In appearance, both options are quite similar to each other. But when examining the drawing, where the devices are shown in section, you can see the main differences. In the mixing device, the stem has one ball valve. It is located in the center and blocks the main passage.

The rod of the separating devices is equipped with two such valves installed at the outlets. They work as follows: one of them is pressed against the saddle, closing the passage, while the other opens the second passage.

Control method modern models It happens:

manual;
electric.

The most commonly used device is a manual control method; in appearance it is similar to a ball valve, but has three outlet pipes. But models with electrical control have automatic control, which is used mainly in private homes. Its job is to distribute heat. For example, the user can adjust the temperature regime in the rooms, and the coolant will flow according to how far the room is from the heating device. As an option, you can attach it to a warm floor.

Three way valves, just like other devices, are divided accordingly to the pressure in the system and the diameter of the inlet. All this is determined by the regulatory acts of GOST. And if these requirements are not met, this can be regarded as a gross violation, especially in cases where it concerns the pressure indicator inside the line.

Where is this device used?

The three-way valve, whose operating principle was discussed earlier, is used quite widely. For example, such variations as an electromagnetic device or a device with a thermal head can easily be found in modern pipelines, where proportions need to be adjusted when mixing two separated liquid streams, but the volume or power should not be reduced.

In everyday life, the most popular is the thermostatic mixing device, which, as mentioned earlier, helps regulate the temperature of the coolant. It can be supplied both to the underfloor heating pipeline and to heating radiators. And in the case when the valve is equipped automatic control, then temperature control will be carried out without any problems.

Note! Using a three-pass heating system to balance temperature changes is beneficial not only in terms of creating convenience and comfortable conditions, but also saves your money.

The bottom line is that by regulating the temperature of the coolant at the “return” of the heating device, you can quite significantly reduce the volume of fuel consumed, and in addition, the efficiency of the system itself will increase. On some systems, installing a valve is simply necessary. For example, in a “warm floor” system, this device prevents the floor covering from overheating higher than necessary for comfortable conditions, thereby relieving users of unpleasant sensations.

Regulating devices of this kind are also used in water supply systems in order to obtain a permanent flow with required temperature. The most common example is a regular faucet, which allows you to regulate the water temperature by opening and closing valves.

Selection criteria when purchasing

You need to remember that when purchasing, be sure to pay attention to the technical characteristics of the device, which include the following:

Diameter of connection to the heating main. Most often, this parameter ranges from 2 to 4 centimeters, although most of it depends on the characteristics of the system. If you cannot find a device of the required diameter, then you need to use a special adapter.
Possibility of mounting a servo drive on the device to ensure its automatic operation. This is especially important when the valve is planned to be installed on a warm water floor system.
Finally this throughput pipeline. This concept refers to the volume of liquid that can pass through it in a certain time.

There are many manufacturers of three-way valves on the domestic market. The choice of one model or another depends, first of all, on:

type of mechanism (and let us remember, it can be mechanical or electrical);
areas of use (DHW, cold water, “warm floor”, heating).

The most popular device is rightfully considered Esbe - a Swedish valve from a company that has existed for more than a hundred years. This is a reliable, high-quality and durable product that has proven itself in many areas. A combination of European quality and modern technology.

Another popular model is the American Honeywell - a true brainchild of high technology. Simple operation, convenience and comfort, compactness and reliability - these are distinctive features these valves.

Finally, relatively “young” but promising devices are valves from the Valtec line - the result of joint cooperation between engineers from Italy and Russia. All products are of high quality and are sold with a seven-year warranty. They differ in that they have a very affordable price.

DIY valve installation

We present to your attention several schemes for installing a mixing valve.

A scheme that is used mainly in boiler rooms of heating systems that are connected to a hydraulic separator or to a free-flow collector. The pump, which is located in the second circuit, ensures the necessary circulation of the coolant.

Attention! In the case where the valve is planned to be directly connected to the coolant source on the bypass, which is connected to port B, then it will be necessary to install a valve with hydraulic resistance, which will be equivalent to the same resistance of this source.

If this is not done, then the coolant flow in the segment A-B will fluctuate depending on the movement of the rod. It is worth noting that this installation scheme provides for a possible interruption of coolant circulation through the source if the installation is made without a circulation pump or hydraulic separator in the main circuit.

If the return is overheated, it is allowed to get rid of excess pressure using a jumper, which is mounted parallel to the valve mixture in the circuit.

Carrying out quantitative adjustment by changing fluid flow rates is the main function performed by this three-way thermal valve. It is used where it is possible to bypass liquid to the “return”, but stopping circulation, on the contrary, is extremely undesirable. We also present a diagram for installing a three-way separating valve:

Important! A similar connection scheme has become quite popular in water and air heating units connected from individual boiler houses.

In order to link hydraulic circuits, it is necessary that the consumer's pressure losses be equal to the losses on the valve - balancer in the bypass. The diagram shown here should be used for installation on those pipelines in which there is excessive pressure. The movement of liquid is carried out due to strong pressure, which is formed using a circulation pump.

Simplified mixing elements with temperature lock

An autonomous three-way valve of a simplified type can be installed in simple heating systems country houses, where heat is obtained from a TT boiler. To function, it does not require a thermal head with a temperature sensor, and there is no rod there.

The thermostatic element, which is installed inside the housing, is adjusted to a certain temperature of the coolant at the outlet, for example. 50 or 60 °C (must be marked on the body).

The mixing valve of this sample always maintains the set temperature of the coolant at the outlet; this setting does not change. This gives rise to positive and negative aspects when using such fittings:

advantage - cheaper, unlike a unit with a thermal head. The difference is about 30%;
disadvantage - there is no possibility of adjusting the heating of the exiting coolant. If the factory settings are set to 55°C, then it will constantly supply water at this temperature ±2°C;
Before purchasing a valve of a simplified design, carefully study the documentation for the solid fuel boiler; it usually indicates the minimum return temperature.

Thermostatic three-way valve is quite useful thing in the heating system of a private home, which makes it possible to efficiently use the heated liquid and thereby save fuel. Moreover, this part allows you to increase the service life of solid fuel boilers, and also plays the role of a safety element. On the other hand, you should not sculpt the valve just anywhere; it is always better to consult with a specialist who is well versed in this.

Good day, dear reader! I don’t know for what reason, but our five-story house is heated so well that even in the cold it was too hot. The windows in my apartment were constantly open for ventilation, and I had to pay huge sums for heating. Something had to be done about this.

So I decided to install a separate heat meter and... Now my apartment is quite warm, and the amounts on my bills have dropped by almost half.

Thermal valve is a type pipeline fittings. It allows you to maintain a given temperature in the room by optimizing the heat transfer of a separate heating device.

Purpose and scope

The thermal valve is designed to be operated manually or via the radiator or distribution manifold.

In autonomous heating systems, where the medium is heated by a solid fuel boiler.
On hot water pipelines. Water for domestic needs may be supplied too hot (up to 95 ºС) and, in the absence of a mixing tap, causes burns to users.
In front of the plastic elements of the piping system. The thermal valve will protect the material from which the pipes are made from overheating.

Characteristics

For your reference, here are some of the main technical characteristics thermostatic valves:

The maximum operating pressure level is 1.0 MPa.
Pressure testing before commissioning is 1.5 MPa.
Maximum operating temperature - +110 ºС.
The maximum permissible ambient temperature is +50 ºС.
The valve capacity is from 1.6 to 2.5 m³/h.
Temperature control range - +20…+60 ºС.
Response time - 25 min.
MTBF with manual control - 8000 cycles.

What materials are they made from?

Corrosion-resistant metals are used to make the thermostatic valve body:

Brass.
Bronze.
Stainless steel.

Additionally, the surfaces of brass products are nickel-plated, and the bronze body is either also nickel-plated or coated with a layer of chrome.

Design and principle of operation

The thermal valve includes two main components:

Valve.
Thermostatic head.

The thermostatic valve is designed as a hollow body with a cover. Inside it there is a movable rod with a sealing surface that ensures a tight seal of the valve seat. The rod is spring-loaded with a return spring; a ring with washers is provided to secure it.

The threaded valve cover is equipped with a packing unit consisting of a packing ring and a nut. To ensure additional tightness of the connection, an O-ring is installed on the rod.

The radiator thermal valve is connected to the devices by means of a half-fitting, which has a lock nut with a Teflon liner. It is secured to the device body with a union nut through a sealing gasket.

In the cavity of the thermostatic head there is a bellows filled with a thermo-reactive substance and a rod. As the temperature rises, the filler in the bellows container expands and acts on the rod, which, in turn, transmits force through the extension to the thermostatic valve rod. When the valve stem lowers, it blocks the flow of coolant.

Circulation in the radiator slows down, heat transfer decreases. A spring mechanism is provided to return the rod. The thermostatic head is secured to the valve with a brass union nut.

Advantages and disadvantages

The advantages of installing thermostatic valves in the heating system include the following factors:

Energy independence of the device.
Compactness.
High precision temperature control.
Easy to operate and highly reliable.
Aesthetic appearance.
The optimal combination of price and functionality.

The disadvantages of using thermostatic valves are:

Difficulty setting up.
There is a danger of the thermal head malfunctioning under the influence of a draft or a nearby stove.

Kinds

Thermal valves are divided into types according to the following characteristics:

By installation method - straight, angular, axial.
Purpose: mixing, balancing.
By type of heating system - for a single-pipe or two-pipe system.
According to the type of filler in the bellows container of the thermoelement - paraffin, gaseous or liquid substance.
By type of thermostatic element - manual, mechanical or electronic regulation, with a remote sensor.

Manual

For manual thermostatic valves, the stem is activated to stop the movement of the coolant when the handle located outside the body is rotated manually. By turning the regulator, you can change the pressure in the thermostatic head, which will affect the sensing element and cause the stem to move. They come in straight or angular design.

Available in two passage diameters - ½" or ¾". They are distinguished by a simpler design and lower price. The main disadvantage of a thermostatic valve with manual adjustment is the low accuracy of temperature control and the need to control timely operation by a person.

Mechanical

These are devices with a more complex design that can automatically maintain a given temperature in the room. The basis of their thermostatic head is a bellows container filled with liquid with a high coefficient of thermal expansion.

When heated, the liquid in the bellows expands and moves the thermal head rod. Through an extension cord, it transmits force to the rod of the thermostatic valve, which blocks the flow of coolant. When the liquid cools, the process goes in the opposite direction.

Gas or liquid

The effectiveness of a thermostatic valve depends on the properties of the substance in the bellows. Gas-filled thermoelements are more accurate and reliable. They respond faster to temperature changes, but are more difficult to produce and therefore more expensive.

Liquid ones work a little slower, but are easier to manufacture. The advantages of liquid thermoelements also include the high accuracy of transfer of the internal pressure of the bellows to the thermostatic valve stem.

With remote sensor

Designed for installation in radiators with bottom connections or located in a niche. The thermostatic head is mounted on the valve using threaded connection, and the temperature sensor is attached to the wall in any convenient place. The head and sensor are connected to each other by a capillary tube.

Such models maintain temperature more accurately, but are more expensive than others.

Electronic

Electronic thermal valves have larger dimensions. An electronic microprocessor is built into the body of the device, which controls the movement of the rod; there is also an additional compartment for two batteries. One of the advantages of electronic models is wider functionality. With their help, for example, you can set different temperatures indoors in the morning or evening, for every day of the week.

Life time

Most manufacturers state that the design life (subject to proper operating instructions) of a thermostatic valve is at least 15 years.

How to choose

Thermostat is selected according to operating characteristics heating system. The device must:

Withstand pressure in the range of 16–40 bar and temperatures up to 200 °C.
Be made of corrosion-resistant materials that are resistant to mechanical stress.
Match the diameter with the size of the pipeline.
Match the thread parameters on the pipe.

Popular manufacturers

Thermostats manufactured by the following companies are considered the most reliable and durable:

Danfoss (Denmark). Devices from this manufacturer, despite quite low price, have an improved design. They are equipped with a flow stabilizer, so they operate silently. They do not become clogged when working with any contaminated coolant, since their rod stroke is 1.5 times greater, and the performance adjustment window has a larger cross-section.

Oventrop (Germany). The variety of standard sizes of thermostatic fittings from Oventrop allows you to choose the ideal model for any engineering system. Excellent regulating qualities, high product reliability are combined with an aesthetic appearance.

Luxor (Italy). Luxor thermostats are suitable for heating systems where the coolant is hot water. They are equipped with a thermostatic spindle that allows pre-setting of the flow.

What does the cost and approximate price depend on?

The cost of thermostatic valves varies and depends on:

From the design.
Material of body parts.
Technical characteristics.
Features of production.

See the table for approximately how much different models of thermostatic valves cost.

Installation and operation rules

I install the thermostatic valve according to the following scheme:

I drain all the liquid from the heating system. In a private building this is easier to do, but to drain in an apartment building you will have to contact a service organization, since the valve is located in the basement.
I cut out a part of the pipe that matches the size of the purchased device.
I cut threads on the ends of the pipes.
I screw the product into the threads on the pipes and seal the joint with linen thread and heat-resistant paint.
I check the tightness of the connections and the immovability of the position of the valve body.
Setting up the thermocouple.

When using thermostatic valves, I try to:

The device was protected from direct sunlight.
The valve was closed while ventilating the room, since cold air will quickly cool the thermostat and it will increase the flow of hot coolant into the radiator.
If the device is configured to control the temperature in several rooms at the same time, then I make sure that the interior doors are closed.
Until the next heating season, all valves remained in the open position. Otherwise, the spool may stick to the valve seat and the device may fail.
In the summer, I remove the thermostatic head from the valve. This will increase its service life.

Adjusting the device

After installation, I adjust the device as follows:

I open the valve completely until the temperature in the room heats up and stabilizes.
Then I close it completely and wait until the room temperature becomes comfortable.
I remove the handle of the thermostatic head and reinstall it so that the desired temperature value on its scale is achieved when the valve is fully open.
After this, I begin to open it little by little until coolant begins to flow into the battery and the body of the thermostatic valve becomes warm to the touch.

Frequent errors and problems during installation

Since the thermostat head must be in free contact with air during operation, the following errors must not be made when installing the device:

Install the head in a vertical position. The thermostatic head will be exposed to air heated by the supply pipe, which will not allow it to correctly assess the room temperature.
Install the device without taking into account the direction of flow.
Block access to the main air mass valve with furniture, thick curtains, decorative screens, etc.
Place under a wide window sill or in a niche where there is a high heating zone.

Errors in the placement of the thermostatic head lead to the creation of a zone around it with warmer air than in the room. Therefore, the device will block the movement of the coolant too early and will not allow the optimal temperature regime to be created in the room.

A few tips from professionals will help the apartment owner install and configure the thermostatic valve with his own hands and in accordance with all the rules:

It is important to mount the device in such a way that the direction of water movement coincides with the direction shown by the arrow shown next to the marking on the body, otherwise the operation of the thermostatic valve will be incorrect.
For underfloor heating systems, it is better to choose thermostats with a side valve - this makes it easier to access settings.
In public areas, thermostatic valves with remote control or pre-setting to protect them from outside influence.
To seal the threaded connection, you should not use fum tape, but polymer or linen threads with heat-resistant paint. When heated and significant temperature changes occur, thermal expansion of the pipes occurs, the density of the tape may be disrupted, which will lead to the formation of a leak.
It is more appropriate to place the valve on the supply pipe.
The distance from the floor to the installation site of the thermostatic valve should be at least 40-60 cm. Initially, manufacturers configure them to capture temperature changes at this level. If it is necessary to change this parameter, then additional customization device.
The thermostatic head must be installed on the valve in a horizontal position and turned towards the inside of the room. If you install the thermal head vertically, then warm air from the riser will interfere with the normal operation of the sensor.
When installing a thermostatic valve in a one-pipe heating system, it is necessary to install an additional bypass section - a bypass. It should be located between the sections of pipelines entering the heating device and leaving it (as in the photo below).

Regardless of the selected circuit and circuit configuration. With the help of these simple devices, heat supply parameters are adjusted, ensuring the safety and stability of the system. This publication will discuss the main valves used in centralized and autonomous heating systems, their purpose, operating principle and design features.

Criterias of choice

The number and parameters of valves required for a specific CO are selected at the calculation and design stage. The main criteria that influence the selection of these elements are:

Type, circuit and configuration of CO.
Temperature conditions (nominal and maximum).
(working and maximum).
Pipeline cross-section and thread type.
Type of coolant (water, brines, antifreeze).

The operation of these devices stabilizes CO, making it effective and safe. Anyone who is independently installing a heating system in their home needs to know its purpose and operating principle. All valves can be divided according to their purpose into three categories: safety, control and regulation groups.

Everyone knows that any CO is an increased source of danger, since the system is under pressure. And the higher the temperature, the higher the pressure (in closed CO). Next, let's look at the devices that are responsible for the safety of CO operation.

Safety

In most models, manufacturers provide a security system, “ key figure» which is a safety valve included directly in the boiler heat exchanger or in its piping.

Purpose safety valve in the heating system is to prevent pressure in the system from increasing above the permissible limit, which can lead to: destruction of pipes and their connections; leaks; explosion of boiler equipment

The design of this type of fittings is simple and unpretentious. The device consists of a brass body containing a spring-loaded locking diaphragm connected to a stem. The elasticity of the spring is the main factor that keeps the membrane in the locked position. The adjustment handle adjusts the spring compression force.

When the pressure on the membrane is higher than the set one, the spring is compressed, it opens and the pressure is released through the side hole. When the pressure in the system cannot overcome the elasticity of the spring, the membrane will return to its original position.

Tip: Buy a safety device with pressure adjustment from 1.5 to 3.5 Bar. Most models of solid fuel boiler equipment fall into this range.

Air vent

Quite often, air pockets form in the CO. As a rule, there are several reasons for their appearance:

boiling of the coolant;
high air content in the coolant, automatically added directly from the water supply;
As a result of air leaks through leaky connections.

The result of air locks is uneven heating of radiators and oxidation of the internal surfaces of the metal elements of the CO. The air release valve from the heating system is designed to remove air from the system automatically.

Structurally, the air vent is a hollow cylinder made of non-ferrous metal, in which there is a float connected by a lever to a needle valve, which in the open position connects the vent chamber to the atmosphere.

In operating condition, the internal chamber of the device is filled with coolant, the float is raised, and the needle valve is closed. When air enters and rises to the upper point of the device, the coolant cannot rise in the chamber to the nominal level, and therefore the float is lowered and the device operates in exhaust mode. After the air escapes, the coolant rises in the chamber of this type of fitting to the nominal level, and the float takes its normal place.

Back

In gravity-flow CO, there are conditions under which the coolant can change direction of movement. This threatens to damage the heat exchanger of the heat generator due to its overheating. The same can happen in fairly complex systems with forced movement of the coolant, when water flows back into the boiler through the bypass pipe of the pumping unit. Mechanism of action check valve in the heating system is quite simple: it allows coolant to flow only in one direction, blocking it when moving back.

There are several types of this type of fittings, which are classified according to the design of the locking device:

disc-shaped;
ball;
petal;
bivalve.

As is already clear from the name, in the first type, a steel spring-loaded disk (plate) connected to a rod acts as a locking device. In a ball valve, a plastic ball acts as a shutter. Moving in the “right” direction, the coolant pushes the ball through a channel in the housing or under the cover of the device. As soon as the circulation of water stops or the direction of its movement changes, the ball, under the influence of gravity, takes its original position and blocks the movement of the coolant.

In the petal type, the locking device is a spring-loaded lid, which lowers when the direction of water in the CO changes under the influence of natural gravity. The double-leaf element is installed (usually) on pipes large diameter. The principle of their operation is no different from the petal one. Structurally, in such fittings, instead of one petal spring-loaded from above, two spring-loaded flaps are installed.

These devices are designed to regulate temperature, pressure, and also stabilize the operation of CO.

Balancing

Any CO requires hydraulic adjustment, in other words, balancing. It is being carried out different ways: correctly selected pipe diameters, washers, with different flow sections, etc. The most effective and at the same time simple element in setting up the operation of CO is considered balancing valve for heating system .

The purpose of this device is to supply each branch, circuit and radiator with the required volume of coolant and amount of heat.

The valve is a regular valve, but with two fittings installed in its brass body, which make it possible to connect measuring equipment (pressure gauges) or a capillary tube as part of an automatic pressure regulator.

Operating principle of a balancing valve for a heating system is as follows: By turning the adjustment handle it is necessary to achieve a strictly defined coolant flow rate. This is done by measuring the pressure at each fitting, after which the number of turns of the adjustment handle to achieve the required water flow for each CO circuit is determined using a diagram (usually supplied by the manufacturer to the device). For circuits with up to 5 radiators, manual balancing regulators are installed. On branches with a large number of heating devices - automatic.

Bypass

This is another CO element designed to equalize pressure in the system. Principle of operation heating system bypass valve similar to the safety element, but there is one difference: if the safety element bleeds excess coolant from the system, then the bypass element returns it to the return line past the heating circuit.

The design of this device is also identical to the safety elements: a spring with adjustable elasticity, a shut-off membrane with a rod in a bronze case. The flywheel adjusts the pressure at which this device is triggered, the membrane opens the passage for the coolant. When the pressure in CO stabilizes, the membrane returns to its original place.

Three-way

There is practice to achieve a certain coolant temperature in various branches and CO circuits by mixing or separating coolant flows. Three-way valve on a heating system plays the role of a device that regulates the temperature of the working fluid after the heat generator.

The design of the mixing fittings is simple: there are three holes in the device body, two inlets and one outlet. Separating type devices have one input and two outputs.

The main control device of this element is a thermal head, inside of which there is a reservoir with liquid (bellows). When the remote sensor heats up, the liquid in it expands and enters the bellows. The volume of this reservoir increases and affects the valve stem, which opens or closes the inlets for mixing or separating flows. In separating types of this CO element, the same principle is used, but the rod does not open a passage for flows, but divides one flow into two.

It is not only the thermostatic head that can control the device. Manually controlled devices are quite popular. The depth of pressing of the rod is determined by the rotation of the control handle. Today, these devices with electric and servo drives are widely represented on the climate control equipment market.

Automatic refill device

By virtue of different circumstances(natural evaporation, operation of a safety element, etc.), the volume of coolant in the CO may decrease. The less coolant, the more air in the system, which inevitably disrupts the circulation of water in the CO and overheats the boiler equipment. To prevent air from entering the system, it is necessary to replenish the amount of coolant in a timely manner. You can do this manually, or you can install heating system make-up valve , thereby organizing automatic replenishment of CO coolant.

The design of this type of valve is practically no different from safety valves, but the principle of operation is exactly the opposite: as long as there is the necessary pressure in the CO, which props up the membrane to the seat, the spring is in a compressed state. When the pressure drops below the minimum, the spring straightens and moves the membrane away from the seat, allowing water from the reserve tank or water supply network to enter the CO. In Fig. The design of this device is shown below.

As the CO fills, the pressure in it increases, the spring compresses, and the membrane sits in the seat on the body, cutting off the replenishment.

Important! Valve selection is complex and important process, which is best left to professionals.

Boiling of the coolant due to overheating is a common problem in the operation of solid fuel boilers. To maintain the required temperature and connect several circuits to heating equipment at once, a thermostatic valve for solid fuel boilers is used.

Why do you need a three-way valve for a solid fuel boiler?

In boilers operating on solid fuel, it is quite difficult to achieve a stable heating temperature of the coolant. It is even more difficult to ensure constant parameters on the supply and return of the water circuit.

The purpose of a three-way valve in a heating system with a solid fuel boiler is:

Prevent emergency situations and failure of the boiler due to a large difference in the temperature of the water flow at the supply and return of the heating system. Cast iron heat exchangers are especially sensitive to heating changes.
Ensure stable heating parameters when simultaneously connecting several water circuits. When connecting underfloor heating, a three-way valve is included in the mandatory piping scheme. If it is necessary to simultaneously heat several separate buildings, control valves of this type are also used.

You can replace a three-way valve in a heating system by installing two two-way devices. Wherein, prerequisite is the operation of the fittings in reverse. When one valve opens, the second must close, etc.

How does a three-way thermal valve work for a TT boiler?

The temperature safety valve for solid fuel boilers has several purposes. The type of device chosen affects the installation location and operating principle.

It is customary to classify two types of control valves, depending on the principle of operation of the valve:

A three-way thermostatic distribution valve for a solid fuel boiler is used to separate the flow of circulating liquid for two heating circuits operating at the same heating temperature. The fittings have one inlet and two outlets, and, depending on the design, operate at constant or variable pressure in the heating system.
A three-way mixing valve for a solid fuel boiler is needed when simultaneously connecting heated floors, with a maximum temperature limit of 55°C (optimum 45°C) and a radiator system operating at 80-90°C. The flow going to heated floors, diluted cold water, which allows you to reduce the heating intensity. The three-way valve device has two inputs (for connecting hot and cold water) and one output.

The principle of operation of the valve resembles a regular tee, only with a complex internal device. The coolant passes inside the housing from the inlet to the outlet until its temperature reaches the value set by the user. After this, the flow is partially blocked by the rod. At the same time, the second inlet pipe opens, connected to cold water, diluting the coolant.

Options for using a thermostatic mixing overheating safety valve in the piping depend on the heating circuit. But, basically, the device is installed:

For supply or return to heated floors.
To the supply pipeline coming from the boiler.

Installation is carried out according to the arrows and symbols indicated on the valve body. The instructions describe in detail the different strapping schemes.

How to choose a three-way valve for a boiler

To select a valve, you will need to consider several important characteristics, related both to the operation of the boiler itself and the control valves. The following parameters influence the choice:

Operating parameters of the coolant are indicated in technical documentation supplied with the boilers. As a rule, the return temperature is 45-50°C.
Bandwidth.
Drive type – non-volatile three-way mixing valve, has a mechanical regulator. Provides a stable coolant temperature, regardless of the intensity of heating of the room. Three-way thermostatic mixing valve for a solid fuel boiler, comes complete with a ball-mounted sensor that reacts exclusively to the temperature of the incoming coolant. Used in domestic conditions.
Electronically controlled devices allow you to set heating parameters by room. Such three-way thermostatic mixing valves for solid fuel boilers with a remote sensor are connected to a servo drive and room thermostats.

The electronic valve is sensitive to changes in temperature in living spaces. Installing a device with a servo drive connected to a temperature sensor saves 10-25% of heating costs.

What brand of thermomixing valve should be installed on the TT boiler?

Shut-off and control valves are manufactured by several foreign and domestic manufacturers. Using consumer reviews, the most popular valve models were selected. The products of the following manufacturers are in constant demand:

ESBE is a Swedish company that supplies shut-off and control valves almost all over the world. The company places the main emphasis on energy-saving technologies and control automation.
The consumer is offered a model range of thermal mixing and distribution valves, with built-in and remote sensors, and the ability to connect to a servo drive. ESBE products are distinguished by high quality, reliability and cost-effectiveness.
Watts is a US company that owns three large divisions. Shut-off and control valves are manufactured in Germany and fully comply with the requirements in force in EU countries.
A special feature of the product is the release of a separate series of valves designed for connection to heated floors and radiators. Under the Watts brand, the consumer is offered all the components and devices necessary for installation, including temperature sensors, servos, etc.
Caleffi is an Italian company known for producing control and shut-off valves for such concerns as Viessmann, Buderus, Vaillant, Grundfos. The company places a special emphasis on the production of valves and water distribution units for heated floors. The product range includes a fully equipped mixing unit.
The company manufactures equipment intended for household and industrial facilities. Caleffi thermostatic valves are designed taking into account the operating characteristics of solid fuel boilers.
Valtec is a joint Italian-Russian company that was created in 2002 with the aim of manufacturing shut-off and control valves for heating and water supply systems. The products are popular due to the optimal ratio of cost and quality of the plumbing equipment offered.
All thermomixing valves have a 10-year factory warranty. Risks are covered by compulsory insurance of all manufactured equipment. Valtec products are offered to domestic consumers at the most affordable price among analogues.
Herz is one of the oldest manufacturers of sanitary fittings in Europe. The Austrian company has been operating since 1896. Herz owns several patented innovations that have influenced the efficiency, appearance and duration of operation of the devices.
The company focuses on energy-saving technologies. An additional “bonus” is the beautiful appearance of the control valves produced under the DE LUXE brand.
Danfoss is a company that was created as a small family business, in Denmark, in 1933. On this moment, the company's staff includes more than 24 thousand people. Products are supplied to more than 100 countries around the world.
Danfoss products are intended for domestic and industrial heating systems. The range includes thermostatic valves with mechanical and electronic adjustment. The consumer is offered servos and temperature sensors.
Systemair is a Norwegian company established in 1974, whose assets are constantly increasing. In 2000, the concern's products became available to domestic consumers. Production workshops that manufacture products for Russia are located in Lithuania, Turkey, and since 2011 in the Russian Federation, which has reduced the cost of products.
All Systemair sanitary fittings pass mandatory certification. Constant quality control is carried out.
Barberi is an Italian company that produces simple control devices with high degree reliability. Mixing units with built-in heat-sensitive elements are especially popular.
Barberi mechanical thermomixing valves are designed for open and closed heating systems. L-comfort series, designed for connection to heated floors.

How and where to install the TT boiler thermostatic valve

To correctly connect a three-way thermal overheating protection valve to a solid fuel boiler, you need to determine the purpose for which the control valve will be used:

Boiler protection - the correct installation of the distribution valve is carried out for the coolant supply, with a non-closing hole towards the boiler. The mixing unit is installed exclusively on the return line. Immediately after turning on the boiler, the coolant circulates through a small circle of the heating system; after heating, the valve begins to let liquid into the water circuit.
Temperature regulation in heating circuits– hydraulic piping involves installing a manifold between the boiler and the valve. The mixing unit, in this case, is installed exclusively for supply. The connection diagram with a three-way thermomixing valve implies installation after the control unit. The distribution valve is placed on the return line.

To facilitate installation, the flow diagram of the coolant with a three-way thermal mixing or distribution valve is indicated on the valve body with arrows or letter designations. The unit can only be installed in the specified direction.

The thermostatic valve is a necessary piping device for solid fuel boiler equipment. Installation of the valve is also required when simultaneously connecting several heating circuits with different temperature characteristics.

The thermostatic heating valve is installed in the piping system that supplies heat.

The device is most in the best possible way can regulate heat transfer from heating radiators.

Device Features

Currently, the thermostatic valve that is installed for the heating system is the preliminary standard for reliable and modern equipment.

By including an Oventrop thermostatic mixing valve in your heating system circuit, you can not only achieve the optimal temperature in your living room, but also save on energy consumption.

Often, in addition to heating radiators, other alternative heat sources are installed for the premises.

These could be household electrical appliances, a working stove, and more. In addition, in sunny weather the room temperature rises quite noticeably.

The Danfoss valve facilitates constant control of optimal temperature in room.

Temperature adjustment is carried out automatically, based on temperature fluctuations in rooms at a height of 2 m.

The mixing valve used for radiators works to limit the level of coolant supply to each individual heating radiator.

As a result, the cost associated with paying for heating services is significantly reduced. Thermostatic valves installed on heating devices reduce the consumption of thermal energy providing heating by 15-20%.

This occurs due to reduced overheating. Thus, the mixing thermostatic valve of an air conditioner or heating radiator significantly helps to save on thermal energy consumption during temperature changes.

This device also ensures that the temperature is maintained at an optimally comfortable temperature. In order for the thermostatic valve (TRV) to automatically regulate the temperature conditions correctly, it is necessary to install two important elements.

To do this, you will need a thermostatic valve and a thermostatic head. The thermostatic mixing valve provides precise control of the coolant supply to the heating system devices.

As a result, the temperature of the radiator and the level of coolant flow change. The Danfoss mixing thermostatic valve (TV) allows you to change the temperature of the heating device in manual or automatic mode.

The thermostatic valve handle moves the stem. This in turn changes the working diameter of the seat bore.

It is worth noting that manual adjustment is not the most correct way to change heating parameters.

The protective cap installed on the valve is not designed for continuous temperature control; its purpose is rather decorative.

The angle thermostatic valve can change the temperature automatically with the assistance of the thermostatic head.

It is installed on top of the thermostatic valve, and works together with it. Based on the ambient temperature of the room, the thermal cylinder is able to change its volume.

It's full special liquid or gaseous substance. The operating principle of a thermostatic valve (TRV) is quite simple.

At the moment when the temperature around the thermostatic head cylinder increases, it expands and exerts an effect on the rod.

As a result, the valve stem produces translational movements. Next, the passage hole is closed or opened. Through it, coolant is supplied to the cavity of the heating radiator. A valve with a thermostatic head (tv) has such an operating principle that when it heats up, the inlet hole of the seat closes.

Therefore, the coolant consumption is significantly reduced and the heating device is gradually cooled.

The working diameter of the passage opening increases, which initiates the supply of more coolant to the heating system.

There is a significant increase in temperature in the system, and as a result in the room. The thermostatic direct valve (TDV), equipped with a stem, almost constantly changes its position.

Therefore it is extremely important high quality materials in the production of this product. The following factors can lead to incorrect operation of the device and its failure:

Stem jamming;
Corrosion processes;
Rupture of sealing materials.

If the thermostatic valve (TRV) 2m fails for one of the reasons described above, then its service life can be extended by replacing the thermostatic element.

Types, pros and cons

Thermostatic valves with thermal heads are classified based on the shape and type of supply to the pipe of the heating system. A valve with a thermal head can be:

Angular. To be used when supplying pipes to the battery from under the floor;
Straight. To be used when connecting pipes to the battery along the wall surface;
Axial. To be used when connecting pipes to the battery from the wall.

For those batteries connected to the side, a special kit is required, with valves and thermostatic heads.

In most cases, those batteries that are connected from below are pre-equipped with valve-type inserts.

Thermostatic valve for underfloor heating, corner type, is designed to regulate the thermal regime of the heating device.

This occurs due to a change in the amount of coolant from zero to the value that will be determined by the valve.

This valve can be equipped with a thermostatic head or an electrothermal servo drive with a thread diameter of 30×1.5.

The body of the device is made using hot stamped brass, and the outer coating is nickel plated.

Valve connection sizes: 3/8 – ½ – ¾”;
Maximum temperature of the working environment: +110°C.

Thermostatic mixing valve (TRV) direct type can also be adjusted manually or automatically.

This is possible if the package includes a thermal head and a servo drive. Using this shut-off valve as a thermostatic valve helps maintain the desired (preset) indoor temperature with an accuracy reaching 1°C.

This product is a direct design, dismountable, and, if necessary, can be subject to replacement of spare parts and repair. The price of a direct type thermostatic valve depends largely on the manufacturer.

Type of connecting thread: external, internal;
Control device connection size: 30×1.5 mm.

The axial type thermostatic valve is designed for use and installation on batteries in closed two-pipe systems.

Such systems are supplied circulation pumps. The mixing valve (mv) can be adjusted hydraulically using a special wrench.

Most models are plated with nickel alloy. To universal models, using a special coupling, you can connect a threaded or calibrated pipe using fittings.

Maximum temperature of the working environment: +110°C;
Permissible pressure inside the system: 10 bar;
Pipes with a diameter of 10, 12, 14, 16 and 18 mm can be connected.

These devices have a number of undoubted advantages. This:

Automatic temperature control, which is ideal for ;
Possibility of fine tuning of the unit;
Significant reduction in energy consumption with regular use.

Almost no serious shortcomings have been identified in such valves. Although, if the device is made using low-quality materials, it can quickly fail. The main criterion here is the price of the thermostatic valve.

How to choose?

When choosing thermostatic valves, it is important to take into account its main feature - this is a device that carries out adjustment.

It is worth choosing those products that are made using bronze - they are the most durable. You should avoid those modifications that are equipped with a rubber seal.

During low activity (summer), the rubber may dry out and interfere with the correct operation of the unit.

Also consider the suitability of the valve performance and water flow rates. They must be optimal. The price of these devices varies and depends on the design features and technical characteristics.

Thermostatic valve Vertex, angular: