Pressure relief valve for water and air. What can be the safety valve of the heating system

Safety valve for heating system

The water heating system includes several groups of elements. And some of them the inhabitants do not attach much importance. Take, for example, a safety group consisting of a heating system safety valve and an expansion tank. It may seem that both elements do not play the most important role. But you can't do without them. No wonder they were assigned to the security group, which means that their choice and correct installation need to pay special attention.

Consider each device separately and find out why it is needed and what functions are assigned to it.

Safety valve

The name of the device speaks for itself. Its main function is to relieve unforeseen loads that may arise under certain circumstances. Plus additional adjustment of the coolant flow.

By the way, it can be installed on any section of the pipeline. At the same time, it is not the place that is important, but the convenience of service, if such a need suddenly arises.

Types of safety valves

• The simplest option is brass sleeve fuses. Their design is simple - threads are cut on both sides, and the valve is a spring-loaded stem with an EPDM gasket. This is a direct-flow model, the valve of which opens under the pressure of the coolant flow. back pressure blocks the highway. This is one of the cheapest devices, but it lasts a very long time, which is time-tested.
• There is another brass version, but with more complex design where pipes are connected in perpendicular planes. It uses a stem and a spring from of stainless steel. Install it directly after circulation pump. The principle of operation of such a device is quite simple. The pressure of the coolant compresses the spring, which begins to put pressure on the rod. He opens the channel through which the coolant is squeezed out of the system, saving it from pipe ruptures and other elements. By the way, Maximum temperature that the valve can withstand is 120C.
• Exist a large number of types of check valves, which are also included in the group of safety valves. Their main function is to prevent the backflow of the coolant from occurring if the pressure suddenly drops in the system.

There are several main types - disk, ball, flag and others. But they are all divided into spring-loaded and springless. With the first, everything is clear - there the main emphasis is on the counteraction force of the spring. The second type is when the return of the locking element occurs under the action of its own mass.

• Three way valves. This kind stop valves It is installed in heating systems where low-temperature circuits are provided. For example, when there is a condensing boiler in the circuit. Currently, manufacturers produce this type of valve with manual or electric switching. In the second case, you need to connect the device to the network alternating current voltage of 220 volts.

Three way valves

Let's take a closer look at three-way valves, because consumers rarely encounter them, and they are simply unknown to many. There are three holes in their design - two outlets and one inlet. The coolant flow is regulated by a damper, which can be in the form of a rod or a ball. The rotational movement redistributes the flow of the moving fluid.

We have already mentioned condensing boilers, but three-way valves are not only used in these systems. Very often they are used when they work from one heating boiler different systems heating. For example, "warm floors" and conventional radiators. It is clear that for a warm floor it is not necessary to heat the coolant to a very high temperature. But what if there is only one boiler, and it heats hot water to the standard temperature for the entire system?

In this case three-way valve performs several functions at once:

• First, it separates the plots.
• Secondly, it delimits the flow density by branches.
• Thirdly, with its help, the heat carrier is mixed from the supply and return lines, before the latter is supplied to the “warm floor” heating system. That is, in floor heating water will flow at a lower temperature than radiators.

A few recommendations. Get a servo model. This will relieve you of the need for constant monitoring of the temperature of the coolant. Such a device is automatic and operates from a sensor mounted in a low-temperature circuit. A change in temperature entails the operation of a shut-off device that opens or closes the water supply from the return line. So everything is simple.

And the last. The servomotor may be included with the valve or sold as individual element. And the valves themselves are made of steel, cast iron or brass. The latter are used in residential heating systems.

Expansion tank

Boilers indirect heating with expansion tank

First, let's find out what it is. This is a small container that is built into the heating system and filled with air. It is designed to relieve the pressure of the coolant when it expands when heated.

There are two main systems that are directly connected to the expansion tank - open and closed. An open system is used if the coolant in the heating circulates naturally. That is, direct contact hot water with air. The point of contact is expansion tank.

In this case, the expansion tank performs two functions at once:

1. Hides the expanding volume of the heated coolant.
2. Allows you to remove the air that accumulates in the heating system. That's why in open circuit all lines are made at a slight angle.

The closed system is characterized by complete sealing of the joints. The tank in this case is no exception. It works for its intended purpose, that is, it contains an increasing volume of hot water. And what will happen if the pressure limit of the tank suddenly exceeds the maximum? The system from closed will become open, that is, somewhere there will be a break. It can be a pipe or the same tank.

Both designs have very serious differences. For example, it is a container with a lid. But the latter plays the role of a cover from debris and in no way provides sealing. In addition, this design does not save the coolant from evaporation, so it is periodically added. Closed variant It is a sealed container with a membrane inside. It is she who creates a barrier that does not let oxygen into the heating system of a private house.

As you can see, the selection expansion tank not as complicated as it might seem at first glance. Here it is important to consider the type of heating system and the volume of the coolant. After all, it is believed that the volume of the expansion tank should be about 10% of the total volume of the coolant.

Where to install the expansion tank

Where to install the tank for the system

This is not the most difficult question, but still there are some nuances in it. If your home has an open heating system with natural circulation coolant, then the expansion tank is installed above all other heating elements.

In a closed system, the tank can be located in the area where the circulation pump is installed. Thus, the issue of the laminar pressure indicator is solved, since it is in this area that it is the largest. But in the case of air outlet, this tank does not play a role. Yes, and in a closed system it does not matter. But if problems still arise, they can be solved by installing Mayevsky cranes on radiators.

• It has been said more than once that the volume of the expansion tank should be equal to 1/10 of the volume of the coolant. Of course, sometimes it is difficult to accurately determine the last indicator, so an approximate calculation is carried out, to which a few percent of the stock is added.
• In closed tanks there is already a slight pressure that is created in the factory. It is equal to 1.5 kg / cm 2. The pressure in the heating system reaches two atmospheres (kg / cm 2). You can increase the pressure in the tank by pumping air into it through a special nipple, which is present in the design of the tank.
• On sale today you can find tanks different colors. The red ones are for heating, and the blue ones are for plumbing.
• Installation is carried out in such a way that the coolant enters it from above. In this way, air can be prevented from entering the piping system.
• If installed safety valve works very often, then you made a mistake with the volume of the tank down. But do not immediately dismantle it and change it to a new larger volume. You just need to install another smaller one next to it.
• In modern gas boilers, especially wall-mounted, expansion tanks are already included. Therefore, before purchasing the latter, make sure it is available or not.

Another question that is often heard on construction forums concerns the manufacture of do-it-yourself expansion tanks. There are no objections to this. It is only important to correctly observe the parameters of the tank. But remember that homemade containers can only be installed in an open heating system. They can be made from metal sheets or plastic containers with thick walls. The main thing - no leaks at the joints.

Expansion tank boiled

Heating system with pump circulation

This is already a serious matter. This sometimes happens if amateurs are engaged in the installation of the heating system.

There are two reasons:

1. Incorrectly selected diameter of the pipe of the main line. It must be at least 32 millimeters. It is optimal if the radiators crash without breaking the line, but are connected in parallel to it.
2. If there is no slope of the branches. Usually, a so-called accelerating collector is installed after the boiler. A vertical riser rises from it, on which an expansion tank is installed. All other highways are laid at a slight angle. If something is broken, the tank will surely boil.

What to do if this problem arose, and the alteration is too costly or does not want to be carried out? Option one - install a circulation pump on the return line near the boiler. He will feel great in an open heating system.

Conclusion on the topic

As you can see, the security group is necessary elements, which directly affect not only the operation of heating, but also the efficiency indicator. Eliminate one of them, and you will have a box of problems that cannot be solved in other ways. And if possible, it is very expensive.

Any boiler equipment, installed in a private house or at an 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 is a safety valve in a 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 fuel. 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, upon reaching set temperature coolant 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 polymer 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.

Because not all manufacturers heating equipment complete their products with a safety group, then often the choice of a safety valve for a heating system has to be done independently. For this, it is necessary to study specifications boiler plant, namely to know it thermal power and maximum coolant pressure.

For reference. Most solid fuel heat generators famous brands the maximum pressure is 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 pipeline section from the boiler to the place where the relief valve is installed overpressure It is strictly forbidden to install shut-off 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 of emergency situations. 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 there is an excess temperature regime. 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 of the hot water is withdrawn. 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 control valve must be installed in such a way that outgoing heat batteries did 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 installation shut-off valve heating will improve 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 two-pipe heating multi-apartment residential 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 on following areas systems:

• 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. This place is the most heat coolant, as well as the maximum pressure. 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, a check valve is mounted.

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 spring version is used check valve. 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.

The main purpose of the safety valve in heating systems is to protect the line and connections from sudden changes in the parameters of the coolant: pressure and temperature. Its installation prevents ruptures and deformation of pipes in case of malfunctions, reduces the risk of emergency situations. This type shut-off valves are part of the so-called safety group, recommended primarily as a component of the circuit individual heating. But in an apartment with district heating it will also be relevant, it all depends on the selection correct parameters safety valve.

The safety mechanism consists of a robust housing, an adjusting block and an outlet for discharging excess coolant (or an element for a return outlet). The flow acts on the valve gate, the position of which is changed by a spring or weight, when a certain pressure value is exceeded, the stem rises and water is ejected into the outlet pipe. After stabilization of the parameters, the safety type of the valve returns to its original state, the coolant begins to circulate inside the system again. In order to check the operability, a rod is used to manually retract the spring or another mechanism that changes the position of the shutter (performing forced opening). After installation and adjustment, the device functions fully automatically.

Valve types

The main difference concerns locking mechanism(regulating block). Allocate safety valves for heating of spring and lever-cargo type. The former consist of a spool with a seat, an elastic spring, a disk diaphragm for pressure measurement and a stem. This is the most common type of safety relief valve in individual systems heating. The advantages are: availability, reliability, small size and weight, safety and ease of use. The disadvantage is the frequent compression of the spring, which leads to a quick failure of the device, which is not recommended for systems with large volumes of coolant.

Lever-and-cargo, on the contrary, is suitable for pipes with a diameter of over 200 mm. In this safety mechanism, the spool is directly dependent on the position of the lever with the load. The latter controls the contact force of the spool to the seat, and, accordingly, the reliability of the coolant transmission. The main purpose of this safety valve is the heating of industrial facilities, its cost is not suitable for use in private construction.

Safety heating fittings are divided, depending on the lifting height of the locking mechanism, into low- and full-lift. The first has a low throughput, the second one opens in the process of draining excess water or ejecting steam at least a quarter of the saddle. Full-lift fittings are also suitable for gas-fired heating. The last classification concerns the type of reset: devices are divided into closed (reverse) and open.

When selecting a safety valve for heating, the following parameters are taken into account:

1. Maximum allowable temperature coolant (the more the better).
2. Pressure: working, connecting, opening and closing. The main (first) characteristic is determined by the difference between the value of the parameter at the moment of movement of the rod and at full passage. For heating in a private house, safety fittings with an operating pressure of more than 3 bar are rarely needed.
3. Nominal diameter (not less than that of the hot water supply pipe).
4. Future installation position: horizontal or vertical.
5. Availability additional features: built-in pressure gauge, check valve.

Also pay attention to the material of the case and the membrane. Modern high-quality safety fittings are made of brass with minimal thermal expansion, the internal control block is made of special heat-resistant plastic. You should not buy devices with a case made of cheap Chinese alloys, they are destroyed at the slightest excess of the working pressure. If you have any doubts about how to choose a valve, it is better to contact specialists.

Installation technology

The installation conditions depend on the boiler power and nominal pressure in the heating system. With large volumes of coolant, two are sequentially duplicated at once. safety devices. The recommended installation location is the section of the supply line at the outlet of the boiler (with extreme parameter values). The valve has internal thread for reliable fastening to pipes, you will need pliers and adjustable wrenches. There is a special arrow on the case, its purpose is to indicate the correct direction.

Also, during the installation process, a number of rules are observed:

• A discharge for the discharged coolant or steam into the sewer is provided, taking into account maximum safety for people. Drain hose should not have more than two bends and be too long.
• It is not allowed to narrow the pipeline between the valve and the main line by a size that exceeds the conditional diameter of the extra shut-off and control valves at the inlet or drain (an exception is not made even for filters).
• It is undesirable to install a fuse without other elements of the safety group (in particular, a pressure gauge), in this case it is impossible to fine-tune the set pressure.
• To minimize water hammer, the mounted valve sometimes has a slope only towards the boiler.
• The load on the control unit is not allowed.
• To strengthen the tightness at the joints, tow or silicone sealant is used.

Adjustment

Each safety valve of the heating system is adjusted to certain parameters by the manufacturer, but nothing prevents you from carrying out this procedure yourself. Usually, the adjustment is carried out downwards using a pressure gauge, the water flow is increased by an average of 25% of the nominal working pressure. When the desired value is reached, the spool is set in a new position (by turning a special cap for spring valves, moving cargo - for lever).

This process, as well as checking for full opening, is recommended to be repeated at least once a year in order to prevent accidents. Optimal time adjustment - before starting the heating at the beginning of the season.

In the article you will learn what a relief valve for heating is, types of blast valve and tips for installing and choosing a relief valve for water.

There are many factors that affect the stability of the heating system. Sudden temperature fluctuations can lead to leakage of connections. To prevent this from happening, it is necessary to provide for the installation of a protective device in the heating system.

Such a device is water pressure relief valve or relief valve. Its application is prerequisite during the installation of heating devices. What is a safety valve used for? When the heating system is started, the coolant begins to heat up. It begins to expand, increasing in volume. Accordingly, the pressure on inner surface walls of pipelines and heating devices.

When the pressure exceeds a certain value, depressurization of the joints occurs. This leads to disruption of the system and ultimately to the occurrence emergency. In order to timely discharge excess water, a safety valve is required. valve functions.

• Timely removal of excess coolant. This leads to a decrease in pressure in the system.
• The safety valve must be able to set the maximum pressure at which it opens. When choosing specific model It is necessary to take into account the characteristics of the heating system:
• Average and maximum pressure in the system.
• How far is the expansion tank.
• The length of the heating pipes.
• Type of heating system. When installing heating appliances, two types of valves are used, the operation of which is based on different principles.

The installation of a safety valve is required to protect the heating system from exceeding the pressure level above the limit allowable value. For this reason, the calculation this appliance should be reduced to the calculation of the maximum allowable increase in the volume of the coolant and the identification of possible sources of overpressure.

Sources of volume growth can be:

1. Overheating in a heat exchanger or boiler unit with subsequent vaporization. During vaporization, the liquid is able to increase its volume by 461 times, so this factor is predominant when choosing a valve.
2. Output of automatic control of make-up lines of boiler houses and independent heating systems out of service. This may also be the overriding factor in valve selection.
3. The coolant, heating up in a heat exchanger or boiler unit, increases in volume. When heated, the specific increase in volume is from 0 to 100 °C, which is only 4%, therefore, when selecting the device size of this type, it is not fundamental.

The selected equipment must ensure the discharge of the calculated amount of coolant, according to the most significant volume growth factor.

Water Pressure Relief Valve for Water Heater

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