Heating system valves. What is each one for?

Three way heating valve

Typically, boiler automation cannot meet the need for water at different temperatures for several circuits of the heating system. A three-way thermostatic mixing valve of the heating system comes to the rescue, which maintains the necessary thermal parameters of the coolant in the circuits of the heating system, as well as in the small circuit of the system. The valve looks like a simple tee, the metal is bronze or brass. An adjusting washer is installed at the top of this tee, under which there is material sensitive to temperature changes. And if necessary, it presses on the working rod coming out of the housing. The main task of the valve is based on maintaining the temperature of the coolant at the outlet within specified limits by adding cold or hot water . During unsuitable temperature changes, the external valve actuator presses on the stem. Next, the cone leaves the saddle and a passage opens between all channels. During operation, the three-way valve is controlled according to temperature by an external actuator.

Heating check valve

A complex heating system contains a fairly large number of auxiliary elements, the task of which is to ensure reliability and uninterrupted operation. One of these elements is the heating system check valve. A check valve is installed to prevent flow in the opposite direction . Its elements have very high hydraulic resistance. Due to this circumstance, there are restrictions on the use of check valves in a heating system with natural circulation. There is too little pressure in such a system. At minimum pressure, it is necessary to install gravity valves with a butterfly valve; some of them can operate at a pressure of 0.001 bar. The main part of the check valve is the spring, used in almost all models. It is the spring that closes the shutter when normal parameters change. This is the principle of operation of a check valve.

It is necessary to take into account the operating parameters in a particular heating system. Therefore, select a heating system valve that has the required spring elasticity. Shut-off valves used in heating systems are usually made of the following materials: steel; brass; stainless steel; gray cast iron. Check valves are divided into the following types: disc valves; petal; ball; bivalve. These types of valves are distinguished by a locking device.

Shut-off valves

In heating systems, shut-off valves for heating are used to control the supply of coolant, as well as to open the circuit. It allows you to control the heating process, making it more efficient and rational. In most cases, the shut-off valve on the heating radiator is installed in the radiator piping areas. In addition to functional advantages, this solution also has practical benefits - by closing the shut-off valve for the heating radiator, the homeowner will be able to repair the heating device without stopping the operation of the entire heating system. At the moment, shut-off valves for heating are represented by a wide range of devices.

The following types of devices are often used in heating systems:

• shut-off valves;
• Ball Valves;
• needle valve;
• valves

These elements are made of durable metals that are resistant to corrosion and high temperatures. Shut-off valves protect the circuit from critical emergencies and increase the reliability of the heating system, helping to minimize the negative consequences of failure of an individual heating device.

Ball Valves

A ball valve is a shut-off valve for heating radiators, which is installed to regulate the flow of coolant. The design of the fittings includes a union nut, an internal thread, a plug and an air release device designed to bleed air from the system.

When choosing this type of fittings, you need to pay attention to the material from which the valve is made and the presence of o-rings, which increase the service life of the element in the circuit. Brass taps have proven themselves well, as they are characterized by increased wear resistance and corrosion resistance.

Shut-off valves

This type of fittings is used to make it possible to replace radiators without draining the coolant from the circuit. Based on their design features, there are angle and straight shut-off valves. Moreover, some models can be equipped with a release mechanism to smoothly reduce the pressure in the circuit. Shut-off valves are characterized by a hose nozzle - it allows installation of the device as quickly and simply as possible.

Needle tap

The functions performed by a needle tap for heating can be different. Depending on the design, this device can perform locking, regulating and balancing functions. In heating systems, a shut-off needle valve for the heating radiator is most often used, which allows you to smoothly shut off the flow and avoid the occurrence of water hammer, which is detrimental to the system. Unlike a ball valve, which has two operating positions, a needle valve can operate in three positions:

1. "closed";
2. "open";
3. "partially closed".

Valves

This type of valve performs exclusively a shut-off function. Due to its design features, it can operate in two modes - the mechanism is equipped with a locking element located perpendicular to the coolant flow. In the open position, the valve supplies coolant to the circuit, and in the closed position it prevents its circulation. Among the features of the valve, it is worth noting the low hydraulic resistance created in the circuit, the optimal diameter of the internal section, which coincides with the diameter of the pipeline, simple installation and high reliability.

Heating control (shut-off and control) valves

Regulating and shut-off and control heating valves systematically change the flow of coolant, from maximum to minimum , with the valve open and closed. Shut-off or shut-off valves control the coolant discretely when the valve is in the fully open or fully closed position. A control valve consists of three main blocks: the body, the throttle assembly, and the valve actuator. The closing and regulating element of the valve is the throttle assembly. When choosing a sleeve, seat, or plunger, you should pay attention to the operating conditions of the valve. The medium and its temperature, the presence of impurities, and throughput are taken into account. The main and important importance in the operation of the valve is the correct direction of supply of the working medium. It is usually marked with an arrow on the working surface of the case.

Thermostatic valve

In modern realities, a thermostatic valve is a prerequisite for modern and reliable equipment in a heating system. The valve temperature is automatically adjusted. The operation of a heating system mixing valve for radiators is to limit the supply level to an individual heating radiator. The valve stem makes movements to open and close the hole. Through this hole, coolant enters the radiator. When the valve with a thermostatic head heats up, the inlet opening is closed, as a result of which the coolant flow rate decreases. The thermostatic valve constantly changes its position. And an important factor is the quality of the materials on which this product is made. The product may fail due to sticking of the rod, as well as significant corrosion and breakthrough of sealing materials. But even if the thermostatic valve fails, you can extend its service life by replacing the thermostatic element.

Heating system valves with thermal heads differ depending on the shape and type of supply to the heating system. They can be angular when connected to radiators from the floor, or they can be straight, which connect the pipes to the battery relative to the wall surface. Axial, mainly when connecting pipes from the wall to the battery. When connecting batteries sideways, a special kit is required. It uses thermostatic heads and valves. Batteries that come with a bottom connection are obviously equipped with valve-type inserts.

Pressure regulator

The operation of the batteries and the pump is disrupted due to high or low pressure levels. Correct control of the heating system will help to avoid this negative factor. The pressure in the system plays a significant role, it ensures that water gets into the pipes and radiators. Heat loss will be reduced if the pressure is standard and maintained. This is where water pressure regulators come to the rescue. Their mission is primarily to protect the system from too much pressure . The operating principle of this device is based on the fact that the heating system valve located in the regulator works as a force equalizer. Depending on the type of pressure, regulators are classified into: statistical, dynamic. It is necessary to select a pressure regulator based on throughput. This is the ability to pass the required volume of coolant, in the presence of the required constant pressure drop.

Heating bypass valves

Often during heating operation the temperature regime is exceeded. This provokes an increase in pressure and, as a result, destruction of system components. To remove part of the coolant in a timely manner, a heating bypass valve is required.

Heating bypass valve design

The operating principle of this component is simple - the seat of the bypass valve in the heating system is constantly exposed to coolant pressure. When the spring force is less than the external pressure, the rod moves and some of the hot water is released. After the pressure stabilizes, the saddle returns to its original position.

There are two types of heating control valves - with a constant response pressure and the ability to manually set this parameter. For autonomous heat supply systems, installation of the second type is recommended, since they can be adapted to any parameters.

The heating pressure valve has the following functions:

• Reduces the hydraulic load on the circulation pump ;
• Prevents rust . When the temperature is exceeded, oxygen is released. It is the main cause of oxidation of metal heating components;
• Reduces the noise level of heat supply . Without a pressure valve for heating, water circulation may increase and, as a result, vibration and noise will increase.

This item is installed only for closed systems. In gravity heating, a pressure valve for heat supply is not needed. If the temperature is exceeded, the expansion of the coolant is compensated by using an open expansion tank.

The bypass valve in the heating system is included in the mandatory safety group. It is also installed at the highest point of the circuit and in critical areas.

Heating bypass valve

To relieve the working medium, use the bypass valve of the heating system thermostat, which operates in the return direction when the pressure increases significantly . As a rule, the pressure increases due to the achievement of the maximum temperature set manually, the supply of coolant to the radiator decreases, as a result of which the pressure increases. Heating system bypass valves are basically designed to ensure a stable difference between the return and supply pipes. When the heat load decreases, the thermostatic valves close, resulting in a pressure difference between the pipelines. As a result of using a bypass valve, the load on the pump is reduced, the return temperature increases, and the boiler is protected from corrosion. The scope of application of the heating system bypass valve is quite wide; it is also used to prevent noise generation of thermostats. Bypass valves are installed not only on an unregulated pump, but also on riser jumpers.

Why are cranes needed?

First of all, it should be said that people commonly call a faucet any device for controlling the flow of liquid that has a handle. Technically, it is more correct to call taps shut-off valves.

Moreover, the latter only allows you to completely shut off or open the coolant flow, but not to regulate its flow. Valves and valves are used for regulation.

As a rule, control valves are installed at the entrance to the radiator, which performs the following functions:

• Allows you to disconnect the battery, which may be necessary for various reasons.
• Allows you to shut off the coolant for washing the device or inspection.
• In manual or automatic mode, it regulates the flow of coolant and thereby the temperature of the radiator.

It should be taken into account that different types of fittings may have different functions. Below we will get acquainted with the features and design of all types of taps that are used in conjunction with radiators of the heating system.

Safety valves

Any boiler equipment is a source of danger. Boilers are considered explosive because they have a water jacket, i.e. pressure vessel. One of the most reliable and widespread safety devices that reduces the danger to a minimum is the safety valve of the heating system. The installation of this device is due to the protection of heating systems from excess pressure . Often this pressure occurs as a result of boiling water in the boiler. The safety valve is installed on the supply pipe, as close to the boiler as possible. The valve has a fairly simple design. The body is made of good quality brass. The main working element of the valve is the spring. The spring, in turn, acts on the membrane, which closes the passage to the outside. The membrane is made of polymer materials, the spring is made of steel. When choosing a safety valve, it should be taken into account that full opening occurs when the pressure in the heating system increases above the value by 10%, and full closure occurs when the pressure drops below the response value by 20%. Due to these characteristics, it is necessary to select a valve with a response pressure higher than 20-30% of the actual one.

Balancing valve

The balancing valve of the heating system is intended to regulate the coolant passing through . Liquid consumption depends on pressure. The higher the pressure, the more fluid is consumed. This device is installed on risers. A balanced system ensures continuous operation. The manual valve is used as a diaphragm, and the automatic valve maintains pressure and consumption in the risers. A manual balancing valve can shut off the system. The design is a valve type device. Manual valves can be installed in conjunction with shut-off valves.

Design and principle of operation

Ball valve

Its bolt is a chrome plated brass ball with a high quality surface finish. To reduce friction when turning the shutter and to seal its connection with the body, a pair of saddles is used - rings made of heat-resistant plastic with a low coefficient of friction. The rod is equipped with a handle and sealed with a ring made of the same plastic or heat-resistant rubber.

This is how a ball valve works.

Throttle

A control valve for radiators is, in essence, a type of screw valve: a threaded rod, when screwed in, gradually closes the hole in the seat. The device dictates the requirements for installing the throttle: the coolant must flow to the seat from below; the direction of its movement is indicated by an arrow on the body.

The radiator angle valve is used to throttle the supply line.

Useful: chokes can be used both for adjusting heat transfer depending on weather conditions, and for one-time balancing of heating devices (for example, in two-pipe heating systems, where in order to uniformly heat the radiators, the passage of the connections of the devices closest to the boiler must be artificially limited).

Thermostatic valve

This is a type of throttle whose design involves changing the working position of the rod with an additional device - a thermal head.

Thermal head

The device works in conjunction with a thermostatic valve.

There are two types of thermostatic heads on sale:

• Bellows uses an extension of a bellows filled with a liquid or gas with a high coefficient of thermal expansion to change the position of the rod. The low price (from 400 rubles) is accompanied by limited functionality: a thermal head of this type is only capable of maintaining the set temperature around the clock. To make adjustments, use a scale with the degree of air heating indicated on it.

Bellows head in section.

• An electronic thermal head for temperature monitoring uses a thermocouple - conductors connected in series from two different metals; When there is a temperature difference between sections of such a circuit, a weak current arises. The signal from the thermocouple is processed by a microcontroller and used to control a miniature servo drive.

A small operating current (no more than 100 mA) allows you to use a pair of AA batteries as power sources.

The cost of an electronic thermal head varies from 2 to 4 thousand rubles. The device allows you to program daily and weekly operating cycles.

Programmable electronic thermal head.

Please note: when installing it yourself, the thermal head is installed in such a way that it is located outside the upward flow from the radiator or liner. The instruction, as you might guess, is due to the fact that additional heating will disrupt its calibration and force it to maintain a lower temperature in the room.

Mayevsky crane

This needle butterfly valve is typically made of brass (sometimes with plastic parts). When the stem is unscrewed, the air escapes along the threaded channel into a small hole on the side of the tap.

Flow regulator

Having installed energy metering devices, the question naturally arises of how you can regulate and control the supply of coolant, limit or add its flow. For this purpose, there are all kinds of automatic regulators, the use of which allows you to save money; they operate from outside air temperature sensors and return pipeline sensors. Another advantage of temperature controllers is that they control the temperature directly at the radiator installation site, unlike other devices. This advantage gives priority in obtaining a uniform temperature background for a comfortable stay in the room. The regulator will prevent overheating of the air in the room, which sensors on centralized automation cannot always track. It is possible to adjust the temperature for each room separately. Sometimes, when solving the adjustment issue, ordinary taps are installed. Of course, this solution reduces financial costs, but deprives a number of useful advantages. The faucet has limited functionality to open and close. There is a danger of stopping or airing the riser. By adjusting the heating using taps it is impossible to achieve the required temperature. Using automatic regulators, you can adjust the system accurately and efficiently.

How to adjust the balancing valve in a heating system

Setting up a mechanical balancer
Before setting up the balance of the radiator network, you need to study the instructions for the valve, which are included when purchasing it. It indicates an adjustment scheme; if the user installs everything correctly, he can actually reduce the cost of thermal energy. The valve can be adjusted in two ways.

The first way to adjust the valve

This is the simplest and most proven adjustment option, which is recommended by experienced thermal regulators in water heating networks. To do this, you will need to divide the number of valve revolutions by the number of batteries installed in the heating circuit around the perimeter of the room. This technique makes it possible to correctly determine the step of the tuning algorithm. The method consists of closing all the valves in the reverse order - from the outermost to the first battery in relation to the heating source.

For example, for a dead-end circuit with 4 radiators equipped with mechanical balancing valves and a 4.5-turn spindle adjustment:

4.5:4 = 1.1 turns

Opening diagram:

1. The first balancing valve is 1.1 turns.
2. Second balancing valve – 2.2 turns.
3. Third balancing valve – 3.3 turns.
4. The fourth balancing valve is 4.5 turns.

The second way to configure the balancer

There is another, very high-quality method of balancing. It runs much faster, and contains the ability to take into account some of the specific location of the battery. The only thing you need to do this is a contact thermometer.

The complete process goes like this:

1. Open all the valves and allow the network to enter temperature equilibrium with the operating temperature, for example, 80 C.
2. Measure the temperature of all heating devices.
3. Eliminate the difference by shutting off the first and middle taps. The end valves are not adjustable.
4. Typically, the first valve turns no more than 1.5 revs, and the middle ones - 2.5 revs.
5. Allow the system to reach temperature equilibrium for 20 minutes
6. Temperatures are measured and valves are adjusted further if necessary.