How to choose a safety valve for a water heater

Supply valve for the water heater: recommendations for choosing and installing

The use of safety valves is regulated by national and industry standards, operating rules and technical instructions.

The following regulatory documents are used for blood vessels operating under pressure:

  • (PB 03-576-03). Safety rules for blood vessels and pressure installations.
  • Boiler Pressure Vessel Code American standard.
  • GOST 24570-81 National Standard for Safety valves.

Systems protected by emergency reinforcement, in the case of their emergency work or accident, pose a significant threat of production and public security. Therefore, their design, equipment, installation, operation are supervised by authorized bodies that monitor compliance with the requirements of the rules and standards at all stages of the life cycle of equipment. This is entrusted to Rostekhnadzor.

Why put a safety valve

The boiler descending valve is installed to ensure the safety of the operation of the device. Water is a liquid coolant that has a feature to increase in volume under the influence of high temperatures. Having warmed up to 80 90 ° C, the liquid expands by 3%. If, for example, in a boiler with a capacity of 50 liters, 1.5 liters of “extra” liquid appear, then the task of the device is to describe excess hot water.

Installation PC is a necessity without which the safe operation of the water heater is impossible. The lack of protection leads to a jump in pressure and remove excess fluid into the tap system, which is energetically ineffective and can lead to big troubles.

How the safety valve works in various situations

In order to finally verify the importance of the safety valve, it is best to consider the cases in which it works, as well as those situations that may develop if for some reason the valve is absent or faulty.

For clarity, once again. The simplest, but also the most understandable scheme of the binding of a boiler with a safety valve. The direction of the flows, respectively, cold and hot water, is shown by the blue and red arrows. The green arrow shows at the site of the safety valve installation.

Typical safety valve installation diagram

After the electric water heater is installed, completely “tied”, it should be filled out. To do this, it simply opens the supply of cold water and the hot tap on one of the mixers. Pressure in the water pipe is enough to open the check valve for unhindered flow passage. As the volume of the water heater is filled, air is removed. As soon as a stream of water comes from the mixer, the entire container is filled to the upper fence pipe, the feed can be turned off.

The pressure in the boiler in this MOMENT PR is equal to the pressure in the cold water line. It is, as it were, “props properly”. However, it can even be slightly higher. Due to the remaining compressed small volume of air in the upper part of the tank. Plus to this, when the power is turned on, water heat begins. And this also. Naturally leads to increased pressure.

Imagine the situation that the check valve is not installed. Or is in a faulty state. Then the balance that was achieved when filling out the boiler capacity is violated sooner or later, since the pressure becomes higher than the pressure in the pipe. “Hot” cranes on the faucets are closed, which means that the heated water will look for a way out in a different direction. This can lead to the fact that hot water suddenly begins to flow from the “cold” crane, or if it is filled with a drain tank on the toilet. Meanwhile, the boiler thermostat cannot figure out the situation and does not give a signal to turn off the heating. Expensive electric energy is spent absolutely wasted.

But this is not the saddest. It is no secret that the pressure in the water line, especially in multi.Storey buildings, often decreases to critical quantities (from the tap, as they say, barely flows), or even completely disappears. The reasons for this are a great many, for example, an accident on the highway, conducting preventive work, a planned reduction in pressure, for example, at night, etc.P. What will happen in the absence or fault of the check valve? Yes, nothing good. The boiler will simply be empty, since all the water will completely produce them into the feed pipes.

It’s good if the boiler provides for protection against “dry” heating, and it will work quickly! And if not? Powerful heating heating fees will warm the air in a closed volume. And this will end either with their burning or cracking enamel. In any case, there is nothing good in such a situation.

A reasonable question may arise. Is it possible to limit yourself only to the installation of this very check valve? Seemingly. Judging by the description, he is able to solve all problems.

Do not count with an exaggeration: such an installation is a bomb inherent in your house!

No, in no case is it. The installation of a comprehensive valve combining both in return and safety is a prerequisite for the safe operation of the water heater.

If a similar picture meets somewhere-only the check valve at the entrance, then he must understand that it is comparable to the laid powerful bomb, which is unknown when it is torn.

Another example of “suicidal creativity”

We are considering the situation in details. When the boiler is turned on, heating begins, and with an increase in temperature, according to the laws of thermodynamics, pressure begins to grow in a closed volume.

The designers of household appliances are laid in each water heater a certain operational resource that allows the apparatus to work to certain values ​​of pressure in the container. Usually this value is indicated in the technical documentation. Typically, all boilers are very balanced thermodynamic systems, in which the optimal ratios of permissible temperatures and pressure levels are very accurately calculated. However. Everything happens. And as soon as the pressure level, for some reason begins to approach the permissible upper mark, the spring is compressed on the safety valve, and the resulting excess fluid is discharged into the drainage pipe. As a result, the system is again entering a state of dynamic equilibrium.

Water protruding from the drainage pipe is a normal phenomenon

And now let’s try to imagine what can happen in a situation where there is no emergency valve, and everything is limited only to the reverse

Water heating should be limited to the thermostatic regulator, but quite often these electromechanical devices are far from perfection, and may simply fail. In this case, heating continues uncontrollably.

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The pressure inside the boiler tank is growing. But he does not have a way out. The faucets are closed, and the check valve reliably blocked the feeding line. It would seem that the temperature will only reach 100 degrees, to the boiling point? Nothing like this! With an increase in pressure in a closed volume, the fluid boiling temperature rises sharply. For example, the data is shown in the table:

Pressure in a closed volume, ATM (MPa) The temperature of boiling water, ° ċ
one.0 (0.One) 99.09
one.033 (0.One) 100.0
one.Fifty.Fifteen) 110.79
2.0 (0.2) 119.62
2.Fifty.25) 126.79
3.0 (3.0) 132.88
4.0 (0.4) 142.92
5.0 (0.5) 151.Eleven
6.0 (0.6) 158.08
7.0 (0.7) 164.17
eight.0 (0.Eight) 169.61
nine.0 (0.Nine) 174.53
ten.0 (1.0) 179.04
20.0 (2.0) 211.38
25.0 (2.5) 222.90
fifty.0 (5.0) 262.70
100.0 (10.0) 309.53

How the water heater emergency valve works

After the installation and strapping of EVN is filled: open a cold riser and a hot mixer. The pressure in the pipe is enough for moving the reverse shutter, the stream will pass freely into the container, the air is replaced, it leaves the open mixer, after the appearance of water from the parsing point. The tank is complete.

In the full tank, the number of atmospheres is approximately equal or slightly higher than the “supporting” of its value. If there is no protection against reverse leak and with closed cranes, hot liquid will find a way out through the same entrance. Into a cold crane, a toilet tank.

The pressure in the MKD water supply is often reduced (accidents, repair, planned work). Without a reverse tap, the tank is empty and you will need to wait again for heating. There are no reasons for the auto shutdown, electricity is wasted, and when the supply is stopped and if the protection against “dry” work is not used, the heater will overheat and block it.

Working boiler, this is the balance of permissible temperatures and loads, its maintenance is mandatory. There is a certain supply of capacity for the amount of MPa, which is indicated in the instructions.

The pressure drop valve is needed to reduce the onslaught in the tank, to ensure dynamic balance. When the amount of MPa approaches the critical mark, the spring is compressed, the excessive pressure of the water is discharged into the drainage pipe.

Not only it is impossible, but also dangerous to limit yourself to one reverse shutter, you need a knot combining it and the demolition, otherwise the tank will turn into a kind of bomb. Water at 90 ° C expands by 3%, and so on the increasing.

The thermostat stops heating, but can fail. There is no way out for an increasing onslaught. The faucets are blocked, and on the other hand, the return node closed the return path.

In a closed space, the temperature is sharply achieved above 150 ° C, the breakdown force up to 4. 8 bar and higher increases in parallel. Mpa growth will lead to excessive expansion of the walls and chips of enamel. But the danger is different: large pressure increases the boiling point, but at the same time the temperature grows.

A small crack or opening of the mixer is sufficiently enough. A sharp drop in MPa will lead to a decrease in the boiling mark to the standard 100 ° C, but the liquid is heated more (150 ° C and above). Instant boiling of a total volume of 50, 80, 100 l with the formation of steam, will occur at once, A strong explosion will follow.

On the other hand, the connection without a check valve is not desirable, but the permissible in extreme cases and safer. There is no risk of gap, and with a decrease/increase in MPa, the water will simply go back to the highway.

Is it possible to replace the safety valve in the inverting?

Users of household water heaters often ask the question: “Is it possible to install the reverse instead of the safety valve?””. This is technically possible, but it is by no means worth doing. If you make a similar replacement, then the boiler will turn into a balloon, which at any time can burst.

For example, when water is heated to 150 degrees, the boiler will calmly withstand rapidly increased pressure. However, if at this moment open a tap with hot water, the pressure inside the tank with water will begin to fall quickly. Further, the boiling temperature will drop to 100 degrees, but it will not have time to cool so quickly. As a result, the water will instantly boil, a huge amount of steam will be released, the pressure will jump up and a rather strong explosion will occur.

Problems and ways to solve them

The reason for the improper operation of the water heater should begin to be sought immediately, as soon as the first signs appeared. It is advisable to check all the elements of the household appliance, starting with a thermostat, a safety valve and a heating element. Most often, it is these details of the boiler.

When damaged the valve, the masters are advised not to save, engaged in the repair of the details, but immediately purchase a new analogue. The model is selected according to the pressure level for which the valve indicated on the case of the product is designed. This information is also indicated in the safety valve operating manual.

How To Replace Pressure Relief Valve On A Water Heater (T&P)

There are situations when the valve does not function due to a hidden marriage, which is not possible to identify. It is not worth spending time searching for marriage in the design of the part, since the boiler must be operated as intended.

Therefore, the defective valve is replaced with a new device. If the resource of the installed safety valve is exhausted, then it is also dismantled and put by a new device. By changing the valve, you can not worry about how the water heater works.

The set part will ensure reliable and safe operation of water heating equipment.

The safety valve in disassembled form allows you to see a screw, which using a screwdriver regulates the degree of stiffness of the spring

Install a water heater and perform it correctly by its binding can be possible for any novice master. After reading the article and watching the videos, you can do everything with your own hands, saving on payment of installation work done by third.Party organizations.

If you think that everyone should do their work at a professional level, then invite specialists. Experienced craftsmen will help you choose a suitable safety valve model, will write the missing fittings, connect the boiler to cold and hot water in accordance with the norms of construction work.

choose, safety, valve, water, heater

Do not listen only to those grief-masters who consider safety valves to unnecessary links in the warehouse of the water heater connected to the water supply. Never save on your safety!

After graduation in 2008. Engineering. The Faculty of Construction of St. Petersburg State Polytechnic University works with a degree in the “Engineer Engineer”. It has patents for inventions in the field of engineering plumbing equipment that are introduced into production. The author of the unique course of continuing qualifications of locksmiths. Invited Russian.Speaking teacher of the International University “Ontario College Certificate” with a degree in engineering of plumbing equipment.

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Safety valve for a water heater

The constant presence of hot water in a house or apartment. For most people, this has long become a familiar norm, without which it is difficult to imagine a normal, comfortable life. If an autonomous uninterrupted water supply is extended to housing, for example, from a well or well, then there is nothing to think. You need to install a water heater.

Found valve for a water heater

Probably, the leading position of the pularity among the devices of heating of water for household needs are electric boilers. They are extremely easy to operate, their installation will not require any additional approval procedures or compilations of individual projects. The installation of such a boiler is quite feasible for independent conduct. That is why the information that will be set out in this publication is necessary. Each of the home masters should clearly understand how important the safety valve is for the water heater is important.

No matter how warned housing and communal services, emergency and rescue services that control the bodies of the Gostekhnadzor, no matter what plots with the consequences of accidents they show on television, are still “wise men” with frightening regularity, to which all these technical recommendations and just kind tips- Not a decree. They themselves “know how easier and better”. Alas, ignoring very small in size, inexpensive, easy to install, and at the same time. An extremely important object of the strapping of an electric water heater can turn into very great troubles, and it is possible that even a tragedy.

Device and principle of valve operation

First of all, it is necessary to immediately make a very important reservation. Despite the fact that very often, in order to obtain information, the search query “check valve for the water heater” is driven by those who are interested in, much more precisely. It will be more correct to talk about the safety valve, which combines several functions. These devices have a certain similarity, but there is a huge difference, which determines the main task. Ensuring the safety of the operation of an electric heater.

For comparison. Consider the device of the usual check valve:

So the usual check valve is arranged. But for his boiler. Not enough!

This is a metal cylinder. On both sides of which there are threaded areas for “pacing” in a straight section of the pipe of the corresponding diameter. Inside, a plate valve was stopped. A disk with a rubber seal in a circle, on the central axis. A rod (show in the figure with a green arrow). The disk is constantly in a spring.Loaded state, overlapping the internal channel for water passage.

When water is supplied in the direction of the arrow (the direction of the acceptable fluid current is always indicated on the valve body. In the figure this mark is indicated by the red arrow), the pressure in the pipe through the “plate” squeezes the spring and reveals the passage and reveals the passage. As soon as the pressure decreases, the valve again crosses the closed state on its own.

Such a precaution, of course, is necessary that in the water heater constantly, under any circumstances, the tank is filled. However, such a measure is clearly not enough to ensure security. This is described a little below.

The safety valve is a little more complicated:

Safety valve device for a water heater

choose, safety, valve, water, heater

In fact, these are two valves in one case located perpendicular to one another.

To b largest cylinder (pos. 1), which goes along the course of water, is installed the same valve that prevents the reverse current of water. From the supply side. The threaded section “Dad” (pos. 2) for inserting into the tap system (in particular, it will be convenient to connect a flexible water water hose here). On the opposite side. The threaded coupling “Mom” (pos. 3), which in some cases is wound directly on a standard cold water supply pipe in an electric heater.

The “plate” of the check valve is very clearly visible in the figure (pos. 4) with a sealing ring around the circle, and the spring (pos. 5) that holds the valve in a closed state.

choose, safety, valve, water, heater

And now. The main difference. Perpendicular to the check valve cylinder is located, slightly smaller in size (pos. 7). In fact, it contains the same plate valve, but its spring is much more powerful. This is the same safety “disruption” valve. The usual and even slightly increased pressure in the water supply system will not be able to compress the spring and open it. For this you need much more serious efforts.

In the cylinder cavity behind the “plate” of the safety valve, there is a hole with a pipe (pos. 8), where when the valve is triggered, the fluid is discharged.

Tsilin DR with an ejection “breakdown” valve can be completely drowned out. And sometimes it ends with a threaded plug (plug), behind which there is an adjusting screw (usually under the “internal” hexagon). But the most common safety valves with an additional lever:

choose, safety, valve, water, heater

Many valve models are equipped with a lever to possess manual fluid sipping

In the figure, the features of such a device are clearly visible. Lever (pos. 9) intended for manual opening of the safety valve from the discharge of water through the pipe (pos. Eight). Please note that the pipe may have a special embossed performance that allows you to wear thin hoses for it to drain water into drainage (sewage). The function of manual control of the valve is convenient, for example, for draining the contents of the boiler during repair or preventive work. However. The use of such manual control should not be “carried away”. This may be even dangerous in some cases (this will be described somewhat lower).

A check valve device

The check valve for the water heater serves to prevent water leakage from the boiler, if the pressure falls in the water supply or the water is completely turned off. With the initial filling of the tank capacity, the pressure of the water opens the spring of the locking element, and the water enters the case. When filling, the pressure inside the boiler grows, and as soon as it relates to the tap, a plate, shut.Off element blocks the access of water from the water supply. After that, the heating elements produce water to a given temperature. As soon as you open the hot tap on the sink or in the shower, the pressure inside the boiler will fall and the water will again begin to go into the boiler.

The tightness of the reverse hydroclapan is important for ensuring the safety of the operation of the water heater. In residential buildings, there are frequent cases when the pressure in the network drops or stops water supply. With a malfunction, water can leak out of the body of the water heater and the heater will heat the air inside.

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If the water heater does not provide automation of the disconnecting heating element with dry heating, this will lead to burning and failure of expensive equipment. This is especially dangerous if at this moment the supply of water begins, which falls on the hot heating elements, will cause intensive vaporization, which can even lead to explosion.

Found valve for a water heater: a detailed description why a check valve is needed

The constant presence of hot water in a house or apartment. For most people, this has long become a familiar norm, without which it is difficult to imagine a normal, comfortable life. If an autonomous uninterrupted water supply is extended to housing, for example, from a well or well, then there is nothing to think. You need to install a water heater.

Probably a leading position in popularity among water heating devices for household needs are electric boilers. They are extremely easy to operate, their installation will not require any additional approval procedures or compilations of individual projects. The installation of such a boiler is quite feasible for independent conduct. That is why the information that will be set out in this publication is necessary. Each of the home masters should clearly understand how important the safety valve is for the water heater is important.

No matter how warned housing and communal services, emergency and rescue services that control the bodies of the Gostekhnadzor, no matter what plots with the consequences of accidents they show on television, are still “wise men” with frightening regularity, to which all these technical recommendations and just kind tips- Not a decree, they themselves “know how easier and better”. Alas, ignoring very small in size, inexpensive, easy to install, and at the same time. An extremely important object of the strapping of an electric water heater can turn into very great troubles, and it is possible that even a tragedy.

Device and principle of valve operation

First of all, it is necessary to immediately make a very important reservation. Despite the fact that very often, in order to obtain information, the “check valve for the water heater” is driven by those who are interested in, it will be much more accurately more correct, it will be more correct about the safety valve, which combines several functions. These devices have a certain similarity, but there is a huge difference, which determines the main task. Ensuring the safety of the operation of an electric heater.

For comparison. Consider the device of the usual check valve:

So the usual check valve is arranged. But for his boiler. Not enough!

This is a metal cylinder, on both sides of which there are threaded areas for “pacing” in a straight section of the pipe of the corresponding diameter. Inside, a ramily valve was stopped. A disk with a rubber seal around the circle, on the central axis. The rod (shown in the figure with a green arrow). The disk is constantly in a spring.Loaded state, overlapping the internal channel for water passage.

When water is supplied in the direction of the arrow (the direction of the acceptable fluid current is always indicated on the valve body. In the figure this mark is indicated by the red arrow), the pressure in the pipe through the “plate” squeezes the spring and reveals the passage and reveals the passage. As soon as the pressure decreases, the valve again crosses the closed state on its own.

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Such a precaution, of course, is necessary that in the water heater constantly, under any circumstances, the tank is filled. However, such a measure is clearly not enough to ensure security. This is described a little below.

The safety valve is a little more complicated:

Safety valve device for a water heater

In fact, these are two valves in one case located perpendicular to one another.

To b largest cylinder (pos. 1), which goes along the course of water, is installed the same valve that prevents the reverse current of water. From the supply side. The threaded section “Dad” (pos. 2) for inserting into the tap system (in particular, it will be convenient to connect a flexible water water hose here). On the opposite side. The threaded coupling “Mom” (pos. 3), which in some cases is wound directly on a standard cold water supply pipe in an electric heater.

The “plate” of the check valve is very clearly visible in the figure (pos. 4) with a sealing ring around the circle, and the spring (pos. 5) that holds the valve in a closed state.

And now. The main difference. Perpendicular to the check valve cylinder is located, slightly smaller in size (pos. 7). In fact, it contains the same plate valve, but its spring is much more powerful. This is the same safety “disruption” valve. The usual and even slightly increased pressure in the water supply system will not be able to compress the spring and open it. For this you need much more serious efforts.

In the cylinder cavity behind the “plate” of the safety valve, there is a hole with a pipe (pos. 8), where when the valve is triggered, the fluid is discharged.

The cylinder with a safety “breakdown” valve can be completely drowned out, and sometimes it ends with a threaded cork (plug), behind which there is an adjusting screw (usually under the “internal” hexagon). But the most common safety valves with an additional lever:

Many valve models are equipped with a lever to possess manual fluid sipping

In the figure, the features of such a device are clearly visible. Lever (pos. 9) intended for manual opening of the safety valve from the discharge of water through the pipe (pos. Eight). Please note that the pipe may have a special embossed performance that allows you to wear thin hoses for it to drain water into drainage (sewage). The function of manual control of the valve is convenient, for example, for draining the contents of the boiler during repair or preventive work. Nevertheless, it should not be “carried away” by using such manual control. This may be even dangerous in some cases (this will be described somewhat lower).

On any safety valve there is always an arrow indicating the direction of the flow of cold water towards the electric water heater. (on the diagram. Red arrow). Very often on the housing, the limiting pressure of the “breakdown” valve is indicated. In this case it is 0.7 MPa or 7 atmospheres (yellow circle in the figure).

How the safety valve works in various situations

In order to finally verify the importance of the safety valve, it is best to consider the cases in which it works, as well as those situations that may develop if for some reason the valve is absent or faulty.

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