Safety valve for heating. Pressure relief valve for water, air

The installation of the heating system may have an unexpected result: the first start-up of the system does not give the expected effect, the heat transfer is much lower than expected. The balancing valve for the heating system helps in the distribution of heat with air throughout the premises.

The heating system can be oversized, poorly balanced and lead to the following:

• heat radiators unevenly;
• make high noise
• uneconomical to use thermal energy;
• increase the cost of using the premises;
• feel uncomfortable in your own home.

Many experts argue that balancing the heating system should be carried out in large buildings, but this is not true, and smaller buildings require balancing.

What is needed for balancing:

• flow regulator;
• bypass valve;
• balancing valve;
• pressure regulator.

Each element is subject to excessive pressure drop. This can harm the thermostat and automation. At the same time, the elements allow you to determine what kind of shortcomings in the system, help to eliminate them in specific areas of the location.

The composition of the heating system determines what type of balancing shut-off and control equipment will be. A balancing valve is ideal for a single-pipe heating system. Automatic adjusting element better fit to two-pipe system. The installation of the adjusting device implies a certain length of the straight insert: in front and behind a valve of at least 5 pipeline diameters.

Installing a control device behind a circulation pump implies a straight pipe length of at least 10 diameters. If these standards are not adhered to, a vortex flow may occur. This will reduce both the quality and the adjustment accuracy. Therefore, depending on the diameter of the pipe, it is important to choose the appropriate size of the balancing valve.

Types of balancing valve

The balancing valve contribute to the achievement of hydraulic balance during the preparation of the heating system. There are two types of balancing element:

• static;
• dynamic.

A static balancing element is needed to create a constant resistance built into the system. All settings for such a balancing device must be elements that can affect the losses through all the others.

Dynamic balancing devices serve as cost limiters, regulating all losses. Adjustment of balancing elements is carried out at a certain level of costs, supported within the specified specific limits. As the pressure upstream of the valve increases, it opens slightly to increase the pressure through the balancing element. This allows you to maintain and control the flow within the desired limits. The outlet pressure for a dynamic balancing valve must be below a certain level to ensure correct operation (the resistance at the farthest valve cannot be near 0, unlike a static balancing valve).

Balancing elements are manual type and automatic regulating type. Even the highest quality calculation requires adjustments, including balancing devices. Adjustment of pressure, temperature is carried out with the help of control valves. The balancing device, like other elements, is very important and has its own tasks. Adjustment in the upper pressure threshold is an important point in the presence of a balancing control device.

The valve is also capable of performing a balancing role. But there are differences from the balancing element. It performs a fine regulatory task.

Balancing control element precisely distributes heat. Balancing elements have a functional range:

• pressure support;
• flow limit;
• pipeline blockage.

The balancing element on the automation is kept in balance with the flow in the range of 0-100%. For the automatic balancing device, it does not matter which supply: warm or cold.

The balancing element works without noise. Balancing valve setting is automatic, no complicated piping calculations are involved. Automatic balancing devices allow you to divide the pipeline area into independent parts. Apart from zone balancing, the balancing valve does not need to be statically adjusted.

bypass valve

The bypass valve in the heating system (Fig. 1) is one of the important components of the heating system, which is a section of a parallel pipeline.

There are two types of bypass: with and without a check valve. This control element is used for circulation pump. It can function if there is a need for it and at intervals. After starting the pump, the overpressure bypass valve opens, then the coolant passes through it. It is worth making sure that rust and scale do not get into the valve, as the system will fail.

If it is installed on a radiator, the bypass returns the coolant excess from the radiator. Control and shut-off valves receive parallel heat transport through the bypass.

If the heating system is in working condition, then without a bypass, repair of radiators will not be possible. This node can also help in faster filling or emptying of the entire system.

ball valve

On sale you can find a ball valve. A universal regulating element, which is based on spheres. The spherical element from the coolant flow rises to the branch pipe. In case of bad flow, its termination, this ball is lowered and the passage is blocked completely. This control device is reliable. This ball-shaped control mechanism does not break, as it does not have other auxiliary particles or mechanisms, in contrast to the balancing control element.

Bypass and gravity control valve

The bypass valve of the heating system is a device that is able to maintain pressure external environment at the desired level, passing the medium through the pipeline branch. The bypass valve for heating (Fig. 2) is also called an overflow valve. This element is installed on another circuit that allows flow to prevent pressure build-up on other circuits.

If there is noise during the heating process, it is worth installing a bypass element. For achievement optimal performance any circuit, the bypass element is very important.

The operation of the bypass element is similar to the fuse, but the difference is in the connection of the branch pipe with the return flow. The pressure increases, including the bypass element, the water is transferred in the opposite direction. To balance the pressure, in such cases, a gravity mount is added to the bypass valve.

The gravity valve for heating has the following scheme: water passes through the return element in one direction, locking in case of its possible movement back. The gravity device assists in the calculation of hydraulic resistance and pressure.

The work of the gravity element is to automatically switch the heating to the natural system from the forced system. Gravity heating occupies part of the return pipe in front of the boiler, where it is divided into small parallel parts. On one branch there is a pump, on the other - a gravity valve.

If there is electricity in the network and the operation of the circulation pump continues, then the gravity element is closed and is in the waiting phase. If the electrical voltage in the network disappears, the pump stops, then the gravity element automatically opens and starts natural circulation.

Relief valve

One of the safety devices is a reset control element (Fig. 4). The relief safety element is directly related to pipeline control valves. Having a relief type, the element is designed for a specific pressure. When the pressure is exceeded, the relief control device begins to remove excess coolant.

The system has a drain hole, which is provided in case of pressure increase. At normal pressure and conditions, it is closed, when the pressure rises, the relief control device drains excess fluid. The reset control device operates in automatic mode.

Solenoid control valve

The solenoid valve for heating is becoming more and more popular among consumers every year. Various energy efficient technologies, devices provide convenience in managing communications in a home, while also saving money. The electromagnetic control element is one of the popular new technologies. By using an electromagnetic control element mounted on a radiator, the owner receives reduced system performance, saves maintenance and use costs.

The essence of the operation of the electromagnetic control element is as follows: it provides opening or closing of the valve flow area, depending on the power supply or its shutdown. An electromagnetic device (Fig. 5) effectively controls water, air, steam and gas flows (densities).

The electromagnetic control device is divided into:

• direct action device;
• indirect device.

A direct-acting solenoid valve is able to open or close the section, as it has a direct effect on the radiator core. An indirect acting solenoid valve is used with major pipeline where the pressure is high enough. With its help, the action is enhanced, which uses the pressure of the most working environment.

The use of an electromagnetic element depends on the design of the devices. Feature of the two-way regulating electromagnetic device consists in a single-inlet or single-outlet pipe connection. It can be closed or open. As for the three-way regulating electromagnetic element, its feature is in the existing three connections, two flow sections. An electromagnetic control device of this type can be closed or open, as well as universal.

An electromagnetic control valve is an effective element for creating automatic control of liquids and gases.

Air and its descent from the heating system

A cork from the air is a fairly common occurrence, but unpleasant. Characteristics that indicate the presence of air in the radiator, venting is required:

• the presence of noise during operation;
• corrosion.

Pressure plays an important role in any system. There are a number of reasons that can affect the change in pressure. One of the most common reasons for an increase in pressure is the formation of an air lock.

Air can enter the system and require venting due to several factors:

• the presence of dissolved air in the water, which, when heated, accumulates in the upper part of the pipe;
• accidental release of air during installation;
• during the filling of the system with water, they did not adhere to certain rules: slow filling of pipes with coolant;
• air could be sucked in through poor tightness at the joints of the structure.

The air release valve of the heating system is an important and indispensable element in every design. Most The best way air removal is a multi-stage deaeration system. The air bleed elements are not installed in one place, but in several. When started correctly, the bleed stage will not be difficult.

The air bleeder is:

• manual;
• auto.

The presence of several drain valves does not imply their simultaneous opening. If this multi-storey building, then in this case all the air will accumulate in one place and, due to pressure, go to the neighbor. During the opening of the drain valve, a hiss is heard, which means that air is escaping from the radiator.

The drain valve must not be completely torn off and in turn. It is important to carry out the air descent slowly, gradually. After a hiss, water will start to drip from the drain tap. It is important to continue and open the drain element until the water does not drip, but flows in a trickle. This means the air is out.

Any boiler equipment installed in a private house or enterprise is a source of danger. The water jacket of the boiler is the same vessel under pressure, and therefore it is considered explosive. To minimize the danger, modern heat generators, as well as their piping schemes, provide for many protective devices and systems. One of the simplest and at the same time common devices - safety valve in the heating system. It will be discussed in this article.

Where is the safety valve installed?

To answer this question, we must first understand what it serves. The purpose of installing this simple device is to protect heating systems, to prevent increased coolant pressure in them. This can occur as a result of overheating of the water in the boiler, especially for units that burn solid fuels. When the coolant in the boiler tank boils and vaporization begins, this is followed by a pressure jump in the system. The consequences may be:

• leaks and breaks in heating pipelines, most often at joints;
• destruction of polymer pipes and fittings;
• explosion of the boiler tank, danger of electrical short circuit in the boiler room.

One small valve of a simple design can protect against all these troubles. Based on the fact that an increase in pressure to a critical limit occurs in the boiler, the safety valve must be placed as close as possible to it, on the supply pipeline. Some manufacturers of boiler equipment complete their products with a so-called safety group, which includes relief valve, pressure gauge and automatic air vent. The group is mounted directly into the water jacket of the unit.

It should be noted that safety valves for heating are not always used in circuits. For example, when the source of heat in the house is a gas or electric boiler, then a relief device is not required. The reason is the presence of safety automation in these types of heat generators and the absence of any inertia. That is, when the set coolant temperature is reached gas-burner or electrical element turn off and the heating stops almost immediately.

Another thing is a solid fuel boiler or a furnace with a water circuit, here the installation of a safety valve is mandatory. When the firewood in the firebox flared up and the water in the network reached the required temperature, it is necessary to reduce its heating. The access of air to the combustion chamber is closed and the flame dies out, but the red-hot firebox by inertia continues to raise the temperature. If the process goes near the limit values ​​​​(temperature 90-95 ºС), then vaporization at such moments is inevitable.

As mentioned above, boiling is followed by an increase in pressure, which can be prevented by the safety valve of the heating system. It will automatically open the way to the outside for the formed steam and release it, thereby lowering the pressure to normal. Then the device will automatically close and will be in standby mode again.

The device and principle of operation of the valve

The design of the valve is extremely simple. The body is made of high-quality plumbing brass using hot stamping technology from two cast parts in a semi-solid state. General device safety valve shown in the figure:

The main working element of the valve is a spring. Its elasticity determines the force of pressure that must act on the membrane that closes the passage to the outside. The latter in the normal position is in the seat with a seal, preloaded by a spring. The upper stop for the spring is a metal washer attached to the rod, whose end is screwed to the plastic handle. It is used to adjust the valve. The membrane and sealing elements are made of polymeric materials, the spring is made of steel.

This whole simple mechanism works like this. In the normal (standby) mode, while the coolant parameters are within the specified limits, the membrane closes the entrance to the inner chamber. As soon as a situation close to an emergency arises and the pressure in the heating system of a private house increases, the steam-water mixture begins to support the membrane. AT certain moment the pressure force of the coolant overcomes the elasticity of the spring, opens the membrane, enters the chamber, and out of it through the side hole.

When some water leaves the system, the pressure will decrease so much that it cannot resist the spring and the membrane will close the passage again. It happens that the operation of the mechanism occurs cyclically, especially if the thermal unit operates at the limit and the temperature of the coolant is close to the maximum (90-95 ºС). In practice, when the blast valve for the boiler is activated very often, it loses its tightness and starts to leak.

If you find fresh traces of drips from the safety mechanism, then this clear sign the operation of the heat generator in extreme mode or the presence of malfunctions in the heating system, for example, in the expansion tank.

Since far from all manufacturers of heating equipment complete their products with a safety group, you often have to make the choice of a safety valve for a heating system yourself. To do this, it is necessary to study the technical characteristics of the boiler plant, namely to know it thermal power and maximum coolant pressure.

For reference. Most well-known brands of solid fuel heat generators have a maximum pressure of 3 bar. Exception - boilers long burning STROPUVA, whose limit is 2 bar.

The best option is to purchase a pressure-controlled valve covering a certain range. The control limits must include the value for your boiler. Then you need to choose a product according to the power of the thermal installation, but it is difficult to make a mistake here. The instructions from the manufacturer always indicate the limits of the thermal power of the units, with which a valve of one or another diameter can work.

On the section of the pipeline from the boiler to the place where the overpressure relief valve is installed, it is strictly forbidden to install shutoff valves. In addition, you can not put the device after the circulation pump, do not forget that the latter is not able to pump the steam-water mixture.

To prevent splashing of water around the furnace room, it is recommended to connect a pipe to the outlet of the valve, which leads the discharge into the sewer. If you want to visually control the process, then a special drain funnel with a visible jet break can be placed on the vertical section of the tube.

Conclusion

The pressure relief safety device is considered to be very reliable due to its simple design. When making a choice, you should pay attention to the quality of the material and not chase a cheap product. No less important is correct setting valve according to the maximum pressure of the boiler plant.

The package of any heating system must include elements of regulation and safety. With their help, there is a change in the parameters of heat supply - stabilization of work, automatic adjustment. For these purposes, valves for heating systems are used: balancing, check, three-way.

Purpose of valves for heating

Autonomous or district heating must adapt to the current values ​​of the parameters - pressure and temperature in the system. To perform this task, a bypass valve is needed in the heating system, mixing, safety and others.

Unlike shut-off valves, they operate in automatic or semi-automatic mode. All must comply with the parameters of a particular heat supply.

The main criteria are:

• Temperature regime of the system. The shut-off valve for heating must function normally even with critical thermal exposure;
• Pressure - nominal and maximum. Each pressure reducing valve of the heating system has certain operating limits, which should be 5-10% lower than the maximum;
• Type of coolant - water or antifreeze. In the latter case, malfunctions are possible, since the air valve for heating is not designed for liquid with greater density than water.

A suitable valve for bleeding air from the heating system is selected at the design stage. The operation of this device and similar components should stabilize the state of the system in the event of a risk emergencies. Therefore, it is necessary to know the principle of operation and types of valves for heat supply.

Some performance characteristics indicated directly on the housing of the heating bypass valve. If this is not the case, professional advice is required.

Bypass heating valves

Often, during the operation of heat supply, the temperature regime is exceeded. This provokes an increase in pressure and, as a result, the destruction of the components of the system. For the timely removal of part of the coolant, a bypass valve for heating is required.

The principle of operation of this component is simple - the pressure of the coolant constantly acts on the seat of the bypass valve in the heating system. When the spring force is less than the external pressure, the stem is displaced and some part is withdrawn hot water. After the pressure has stabilized, the seat returns to its original position.

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

The pressure valve for heating has the following functions:

• Reduces hydraulic load to 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 element is set only for closed systems. In gravitational heating, a pressure valve for heat supply is not needed. In case of exceeding the temperature regime, the expansion of the coolant is compensated by 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.

Types of control valves for heating

Normal operation of heat supply is impossible without a minimum set of control valves. They are designed to stabilize the heating parameters and change their values ​​depending on the settings.

The principle of operation of the pressure reducing valves of the heating system is based on limiting the flow of coolant by changing the cross section of the pipeline. To do this, the design has an adjusting head and shutoff valves. Bypass valves for heat supply are divided into the following types:

• With manual flow control;
• With mechanical thermostat. When the thermal element is exposed to temperature, it expands and pressure on the valve seat. As a result of this, the rod lowers, limiting the flow of coolant;
• With servo. To operate this type of heat supply control valve, the control element is connected to a control unit (programmer) or a temperature sensor. When a control command is received with the help of a servomechanism, the position of the rod changes and, as a result, the volume of coolant inflow is regulated.

These types of pressure reducing valves of heat supply systems allow you to change the main parameter - the temperature regime of operation. Installation of regulators is carried out in the piping of radiators, batteries, in collector nodes warm floor.

The installation of the control valve must be carried out in such a way that the outgoing heat from the batteries does not affect the thermocouple.

The purpose of the balancing valve in heating

Another type of control valve is the balancing valve in the heating system. Structurally, it is similar to the adjusting one, but has a number of features of operation and installation.

The purpose of the balancing valve for heating is to regulate the volume of the coolant depending on the value of its temperature. Their installation is optional for systems with a small extent or without problems with thermal distribution. They are mounted on each heating circuit.

After installing a shut-off valve for heating, the the following indicators heat supply:

• Uniform heat distribution for all heating circuits;
• Ensuring hydraulic stabilization of the system, no sudden pressure drop;
• Reduced heating costs– fuel consumption is optimized, the thermal mode of operation is stabilized;
• After installing a balancing valve in the heating system, it becomes possible to partially or completely disconnect individual circuits from the general heat supply.

To control the current readings of temperature pressure, fittings are provided in the design of the valve for installation with a thermometer or pressure gauges. Depending on the design, the coolant flows are adjusted manually or automatically.

Balancing valves are mounted in the collector systems of private houses or in the two-pipe heating of an apartment building.

Safety heating valves

In addition to the heating bypass valve for normal operation system requires the installation of other types of control and protective fittings. During the operation of the heat supply, an excess of air may appear, the reverse movement of the coolant will occur. To prevent these phenomena, it is necessary to foresee the installation of an air valve for heating and reverse.

Depending on the functional purpose, there are two types of safety valves - to remove air from the system and prevent the reverse movement of water in the pipes. Without these elements, the operation of the system may be unstable, which will lead to a violation of the temperature regime, destabilization of pressure and the creation of emergency situations.

Safety valves are installed in the following areas of the system:

• In places with the highest probability of overpressure - after boilers, circulation pumps, on collectors;
• On the return pipe to without fail mounted or its petal counterpart. It is also necessary to install this component in the piping of the circulation pump;
• At the highest point of the circuit - to remove air from the system. A Mayevsky crane is installed on radiators and batteries.

Safety valves must not impair the performance of the heating system. First of all, they eliminate possible failures in the heat supply. In the "inactive" state, these components of the system should not worsen the speed of the coolant, affect the temperature regime.

To prevent a sharp pressure drop in the make-up unit, a heating drain valve must be installed. It will prevent a sharp jump in pressure.

Heating air valve

During operation of the heat supply, air pockets can form in pipes and radiators. The reason for this is the high content of oxygen in the water, the temperature of the coolant is over +100°C. As a result, the metal components are oxidized and the temperature distribution changes. To avoid these situations, it is necessary to install valves to bleed air from the heating system.

First of all, the air valve for heat supply is mounted in the safety group together with the drain and pressure gauge. In the heating circuit, they are located on a straight branch leading from the boiler. In this place, the highest temperature of the coolant, as well as the maximum pressure indicators. In the collector scheme, it is mandatory to install heat supply drain valves on each comb.

Air vents are divided into two types, each of which is designed for installation in certain parts of the system:

• Mayevsky crane. It is installed in the radiator (battery) and is needed to remove air pockets;
• Automatic air vent. It is mounted at the highest point of the system, as well as in security groups. Through it, air exits the heating system.

For the latest model, it is important to comply with the operating conditions. After a long period of inactivity, there is a high probability that some moving components will “stick” and then the air vent will not work. To avoid this, the structure should be regularly inspected and, if necessary, replaced with a new one.

Most models of the valve for bleeding air from the heating system are designed for pressures from 0.5 to 7 bar.

Heating check valve

Without a circulation pump, there is always the possibility of a change in the direction of water movement. In this case, damage to the boiler heat exchanger due to overheating, as well as failure of other components, is possible. To prevent such situations, it is mounted check valve.

AT big schemes heating install a heat supply ball valve. Under the action of the reverse flow of water, a polymer ball closes the pipeline, thereby preventing the movement of the coolant. As soon as the direction changes, it falls down under the influence of gravity. The solenoid valve for the heating system works on the same principle. The difference lies in the control element - a solenoid or an electromagnetic coil is used for this.

The advantages of installing a solenoid valve in a heating system are as follows:

• Ability to connect to the programmer;
• Setting the operation mode of the device depending on external factors– temperature or pressure;
• Work reliability.

To disadvantages solenoid valves in heat supply is their dependence on the supply of electricity. AT autonomous heating a spring-loaded version of the check valve is used. The pressure of water constantly acts on the saddle, squeezing the spring. As soon as the direction changes, the coolant movement will be automatically blocked.

Due to improper operation, temperature fluctuations and pressure surges, autonomous heating systems may malfunction. The negative consequences in such situations are critical: from the breakdown of individual components, ending with the destruction of buildings and a serious threat to life.

A safety valve in the heating system will help eliminate dangerous risks.

Heating systems are filled with water, the temperature of which is approximately 15 degrees. Circulating in a closed circuit, the coolant heats up, significantly increasing in volume. At this time, the pressure exerted on the inner surface pipes and devices installed in the system.

Exceeding the permissible norm, in most cases more than 3.5 bar, turns into:

• leakage at the junction of pipeline parts;
• damage or breaks connecting elements and pipes made of polymers;
• boiler tank explosion;
• short circuit electrical equipment in the boiler room.

The highest risk of accidents is characteristic solid fuel boilers in which it is difficult to control the heat transfer power. The performance of the electrical and gas equipment quickly adjusted from starting to maximum performance and vice versa.

Often they have safety automatics that turn off work items when the temperature rises excessively.

The intensity of burning wood, coal and other types of fuel in a solid fuel boiler is adjusted by opening / closing the damper. In this case, the force of heat transfer does not change immediately, but gradually. Due to the inertia of the heat generator, the heat transfer fluid can overheat greatly.

Together with a pressure gauge that calculates pressure and an air vent that removes air from the system, a safety valve is often included in the safety group.

When the firewood in the chamber warms up well, bringing the water in the network to the required temperature marks, air access is blocked, and the active flame begins to die out.

However, in a hot state, the firebox continues to release the accumulated heat. Reaching 90-95 degrees, the coolant boils and starts the inevitable intense vaporization. As a result, a sharp jump in pressure is provoked.

It is in such circumstances that the safety valve comes into operation. When the limiting pressure parameter is reached, it opens the shutter, freeing the way out for the resulting steam. After the values ​​stabilize, the valve closes automatically and goes back to sleep mode.

Its installation is mandatory not only for solid fuel, but also for steam boilers, as well as furnaces equipped with a water circuit. Many modifications of heating equipment are equipped with these devices at the production stage. Usually the device is cut directly into the heat exchanger or installed in the pipeline near the boiler.

Varieties and principle of operation

The design of the drain valve includes two mandatory components: a shut-off part, consisting of a seat and a shutter, and a force generator. There are several types of equipment with their own characteristics. They are classified according to certain characteristics.

The difference in the clamping mechanism

AT heating systems private houses, apartments and industrial installations of small power, preference is given to the spring type of the product.

The main working element of the device is a spring. It supports the membrane that covers the saddle. A washer is placed on the rod connected to the handle, against which it rests top part springs. The position of the washer and the pressing effect on the membrane is regulated by the handle

The device is characterized by a simple and reliable structure, compact dimensions, the ability to combine with other elements of the security unit, affordable price. The compression force of the spring mechanism depends on the pressure parameter at which the valve operates. The setting range is affected by the elasticity of the spring itself.

The principle of operation of spring fuses is as follows:

• the shutter of the device is affected by the flow of water;
• the movement of the coolant is limited by the force of the spring;
• critical pressure exceeds the compression force, lifting the valve stem up;
• liquid is sent to the outlet pipe;
• the internal volume of water is stabilized;
• the spring closes the shutter, returning it to its original position.

The body of the springy device is made of high-quality high-strength brass using hot stamping technologies and techniques. Steel is used in the production of the spring. The membrane, seals and handle are made of polymers.

Some brands produce equipment with factory settings already set. Also in the range there are models that are customizable at the installation site during commissioning.

Valves are open and closed. In the first version of the design, the coolant is discharged into the atmosphere, in the second it goes down into the return pipeline

Lever-load fuses are not so widespread. In private autonomous systems with a boiler, they are rarely mounted. Operation is concentrated in the industrial sector on large industries where the diameter of the pipelines is at least 200 mm.

The force on the rod in such mechanisms is not given by a spring, but by a load hung on the lever. It moves along the length of the lever, adjusting the force with which the stem will be pressed against the seat.

The lever-weight valve opens when the pressure of the medium from the bottom of the spool exceeds the values ​​emanating from the lever. After that, the water leaves through a special discharge hole.

The adjustment of the lever-load fuses is carried out by moving the rod along the lever. In order to prevent its unauthorized or accidental change, the load is bolted, covered with a special casing and locked with a lock.

The set pressure, as well as the setting range, is determined by the length of the lever and the mass of the load. Lever fuses are not inferior to spring devices in terms of reliability, but they are more expensive. Devices are installed on flange fittings of pipes with a nominal diameter of 50 or more.

Shutter height views

In low-lift safety valves, the valve lifts no more than 0.05 of the seat diameter. The opening mechanism in such equipment is proportional.

It is characterized by low bandwidth and the most primitive design. Low-lift equipment is used on vessels with a liquid medium.

Full-lift devices are equipped with a two-position opening mechanism. They equip not only vessels with liquids, but also systems in which compressible media circulate (compressed air, steam, gas)

Full lift instruments have a higher bolt lift. This means that their throughput is much better than the previous version, so they are able to discharge larger volumes of excess coolant.

Response speed classification

The shutter cover of the proportional relief valves opens gradually. As a rule, the amount of opening is proportional to the increase in pressure exerted on the inner surface. Simultaneously with the lifting of the mechanism, the volumes of the discharged coolant gradually increase.

The design of the devices does not limit the possibility of their use in a compressible medium, but still they prevail in systems with water and other liquids.

Some of the benefits of proportional speed relief valves include: low price, simplicity of design, absence of self-oscillations, portioned opening at the level of values ​​necessary to maintain specific operating parameters

A feature of on-off valves is instantaneous operation with full opening after reaching the boundary pressure marks in the system, at which the safety lock opens.

When installing a two-position valve in a heating system with a liquid heat carrier, it should be taken into account that during a sudden opening of the shutter, a reset will occur. a large number water.

This will cause the pressure to drop too quickly. The valve will instantly close, causing water hammer. Proportional devices do not cause such risks.

Three-way emergency valves

Separately, it is worth talking about a device not so well known to consumers - a three-way valve with a manual or electric switch. It is used in heating systems with low temperature circuits.

The design of the fuses is equipped with three holes, one of which is inlet, two are outlets. The flow of the medium is controlled by a damper made in the form of a ball or a rod. The moving fluid is redistributed by rotations.

Three-way fuses are appropriate for condensing boilers and in cases where several different systems operate from one heating equipment

Let's imagine a situation: a heating scheme with a system of conventional radiators and underfloor heating is implemented in a house. Technical requirements for the operation of the second option, not too high coolant temperatures are provided.

The boiler heats water at the same temperature for all systems. In such conditions, there is a need for a redistribution device, with the tasks of which the three-way valve does an excellent job.

It is responsible for the following functions:

• delimitation of areas;
• flow density distribution by zones;
• facilitating the mixing of the heat carrier from the supply / return main branches for sending to the underfloor heating pipeline more cold water than in radiators.

In order not to constantly control the temperature of the medium yourself, you need to pay attention to valve models equipped with a servo drive.

This device is powered by a sensor installed in the low temperature circuit. When the temperature marks change, a locking mechanism is activated that opens or closes the flow of liquid from the return.

How to choose the optimal model

Before dwelling on specific safety equipment, it is necessary to familiarize yourself in detail with technical specifications boiler plant.

The operation of the safety valve is negatively affected sub-zero temperatures. Therefore, a rather important characteristic for the device is the presence of frost protection.

Do not neglect the study of the manufacturer's instructions, which indicate all the limit values. decisive role In choosing a device for heating, there are several criteria:

1. Boiler performance.
2. Maximum allowable pressure environment for the thermal power of heating equipment.
3. Safety valve diameter.

It should be checked that the pressure regulator in the device has a range within which the parameters of a particular boiler are included. The set pressure should be 25-30% greater than the operating pressure required for stable operation of the system.

The higher the operating pressure, the less time the device should spend on operation. The gap between the pressure at the start of movement and when the valve is fully opened should be 15% for a nominal value of less than 2.5 atm, 10% for higher parameters

The diameter of the safety valve cannot be smaller than the inlet connection. Otherwise, constant hydraulic resistance will not allow the fuse to fully perform its immediate tasks.

The optimal material for the manufacture of equipment is brass. It has a low coefficient of thermal expansion, which excludes the destruction of the body from the effects of strong pressure.

The control block is made from heat-resistant plastic materials, maintaining the desired rigidity even when in contact with a boiling liquid.

Installation and setup rules

Having planned an independent installation of a safety valve for heating, you should prepare a set of tools in advance. In work, you can not do without adjustable wrenches and wrenches, Phillips screwdriver, pliers, tape measure, silicone sealant.

Before starting work, you need to determine a suitable place for installation. The safety valve is recommended to be mounted on the supply pipeline near the boiler outlet. Optimal distance between elements - 200-300 mm.

All compact household fuses are threaded. To achieve complete tightness when winding, it is necessary to seal the pipe with tow or silicone. It is undesirable to use FUM tape, as it does not always withstand critically high temperatures.

In the regulatory documentation that comes with each device, the installation process is usually described step by step. Some key installation rules are the same for all valve types:

• if the fuse is not mounted as part of a safety group, a pressure gauge is placed next to it;
• in spring valves the axis of the spring must have a strictly vertical position and be located under the body of the device;
• in lever-loading equipment, the lever is placed horizontally;
• on the section of the pipeline between the heating equipment and the fuse, it is not allowed to install check valves, taps, gate valves, a circulation pump;
• to prevent damage to the body during valve rotation, it is necessary to select with a key from the side where the screwing is carried out;
• a drain pipe that discharges the coolant into the sewer network or return pipe is connected to the outlet pipe of the valve;
• the outlet pipe is not connected directly to the sewer, but with the inclusion of a funnel or pit;
• in systems where the fluid circulates naturally, the safety valve is placed at the highest point.

The conditional diameter of the device is selected on the basis of methods developed and approved by Gostekhnadzor. In resolving this issue, it is wiser to seek help from professionals.

If this is not possible, you can try using specialized online calculation programs.

To reduce hydraulic losses during medium pressure on the valve disc, emergency equipment is installed with a slope towards the boiler plant

The type of clamping structure affects the adjustment of the valve. The spring fixtures have a cap. Spring preload is adjusted by rotating it. The adjustment accuracy of these products is high: +/- 0.2 atm.

AT lever devices adjustments are made by increasing the mass or moving the load.

After 7-8 operations in the installed emergency device, the spring and the plate wear out, as a result of which the tightness may be broken. In this case, it is advisable to replace the valve with a new one.

Conclusions and useful video on the topic

How the safety valve is arranged and what it consists of:

Emergency valve as part of the safety group:

More about choosing and installing the optimal device:

Safety valve - simple and reliable equipment, which will protect housing from unforeseen emergencies that occur in heating systems. To do this, it is enough to choose a high-quality device with suitable parameters, and then perform its competent configuration and installation.

High-quality shut-off and control valves for heating are mounted in the circuit to ensure the highest possible energy efficiency and heating efficiency. It is used as part of the creation of autonomous heating systems in private homes, when distributing heating appliances in apartment buildings, as well as in the design central systems heat supply.

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 stopcock on the heating battery is installed in the areas of piping the radiator with a pipeline. In addition to functional advantages, this solution also has practical benefits - by closing the shut-off valve for the heating battery, the homeowner will be able to repair the heater 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:

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

Ball Valves

A ball valve is a shut-off valve for, which is installed to regulate the supply of coolant. The design of the fittings provides for the presence of a union nut, an internal thread, a plug and an air outlet designed to bleed air from the system.

When choosing this type of fitting, it is necessary to pay attention to the material from which the valve is made and the presence of sealing rings that increase the life of the element in the circuit. Brass faucets have proven themselves well, which are characterized by increased wear resistance and corrosion resistance.

Shut-off valves

This type of fitting is used to ensure the possibility of replacing radiators without draining the coolant from the circuit. According to the design features, angle and straight shut-off valves are distinguished. Moreover, some models can be equipped with a release mechanism for a smooth decrease in pressure in the circuit. Shut-off valves are characterized by a hose nozzle - it allows you to install the device as quickly and easily as possible.

Needle faucet

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

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

gate valves

This type of fitting performs an exclusively locking function. Due to the 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 the 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.

Shut-off and control valves

In addition to locking functions that prevent emergency situations on the circuit, valves can be used to control the supply of coolant. A separate range of shut-off and control valves is distinguished, when used in the circuit, it is possible to smoothly adjust the temperature of the coolant, stabilize the pressure in the circuit, and also control the direction of water circulation in the system.

Shut-off and control valves are represented by the following elements:

balancing valve

Installers use a balancing valve for a heating system in order to balance several hydraulic circuits. This mechanism allows you to increase the efficiency of the heating system, as it helps to clearly control the allowable flow rate of the coolant. A properly connected balancing valve, for the principle of operation of which is to evenly distribute the coolant over all parts of the system using a special valve, can fully function in difficult conditions. In particular, the valve withstands strong pressure surges in the circuit and the high speed of circulation of the coolant through the pipes.

By design, a balancing valve for a heating system, which costs about $ 150 for a direct-acting model, consists of several key elements:

check valve

This type of control valve helps to prevent water hammer and increases the reliability of the system. As can be understood from the name of the valve, the valve does not allow the return flow of the coolant in the system. For an optimal combination with the circuit, it is necessary to select a valve with an appropriate internal section diameter. The design of the device is quite simple - the main element of the valve is a spring that holds the stem and closes it in the event of an accident on the circuit. You can read more about the check valve in our article.

make-up valve

In order for the circulation of the coolant to be efficient, the optimal amount of water or antifreeze must be present in the circuit. Therefore, the make-up valve for the heating system is obligatory element any circuit. This type of armature allows to compensate possible losses coolant, due to the use of Mayevsky taps, release valves or the presence of leaks in heating appliances.

The function that the heating system make-up valve performs is to control the amount of coolant in the circuit and, if necessary, replenish it.

It is best to use an automatic heating system feed valve in the circuit, which is equipped with a reduction mechanism and a special membrane under coolant pressure.

When the pressure in the circuit decreases, the coolant does not exert pressure on the membrane, the rod pushed by the spring falls and opens the gap in the seat. As a result, the circuit is fed from the water supply until the pressure in the system returns to normal.

Thermal valve

The control thermostatic valve for a heating radiator is one of the most effective types fittings. The valve allows you to increase the functionality of the circuit and make the heating process simple, comfortable and rational. It can be automatic and mechanical. The mechanical thermal valve for heating consists of two main parts. This is a thermal head and a valve. The automatic analogue has a more complex design.

The automatic thermal valve is characterized by the presence of the following elements:

The automatic thermal valve regulates the temperature in the circuit according to the settings previously set by the user. This device has a rather high cost and allows you to optimize the system as much as possible.

Relief valve

If the pressure in the system exceeds the norm, then the risk of accidents, damage to the circuit and even an explosion of the boiler is inevitable. In view of this, installers use a pressure relief valve in the heating system, which in case of an accident or overheating of the coolant will not allow pressure surges. Choosing a place to install fittings of this type, it should be borne in mind that the highest probability of an increase in coolant pressure occurs in the boiler as a result of coolant overheating.

Even modern models of boilers, in which a gas valve for the boiler is installed, are not one hundred percent immune from emergency situations.

When choosing a model, you should pay attention to valves equipped with additional options in the form of pressure gauges and air vents. Such valves are more reliable and practical.

bypass valve

This type of fitting is used to normalize the pressure difference between supply and return. It is mandatory to use a bypass valve in the heating system in circuits with connected thermal valves. These devices contribute to the creation of pressure drops on certain branches of the circuit and lead to a decrease in the efficiency of the heating system. Bypass valves normalize pressure differences and return the circuit to performance and efficiency.

Shut-off valves for the heating system are represented by a wide range of devices for various purposes. However, the choice of a particular type of fitting must be made in accordance with the heating project developed for a particular building. Such measures are due to the fact that each house has different types pipelines and heating appliances, based on the specification of which, and should be made individual selection fittings.