A safety valve for a water heater is a design element that allows you to relieve excess fluid pressure and prevent the occurrence of emergency situation. You can install it yourself or with the help of qualified specialists. The first option is much less expensive, but requires certain knowledge, as well as experience in carrying out similar work.
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General information
Before installing a safety valve on a water heater, it is necessary to study in detail its structure, principle of operation, advantages and disadvantages. All this information will help you complete the job as efficiently as possible and avoid any problems.
Device and principle of operation
The water heater is a fairly simple device that ensures the safe operation of the entire heating system. It includes 2 valves and several additional elements.
Safety valve! A MISTAKE Many Make. Everyone Should Know!
Full list of components:
The operating principle is distinguished by its simplicity. It can be easily understood not only by a highly qualified specialist, but also by a beginner.
Working mechanism:
Advantages and disadvantages
A safety valve, like any other device, has several advantages and disadvantages. They must be taken into account before purchasing the device and starting its installation. Otherwise, you may encounter serious problems that will reduce efficiency. heating system and will lead to emergency situations.
Installing a safety valve for a Thermex water heater
The positive characteristics of the device include:
Despite a large number of The safety valve also has several disadvantages. They create certain difficulties during operation.
Among the negative aspects the following stand out:
- frequent failure of individual structural parts;
- difficulty in adjusting spring stiffness;
- constant bleeding of liquid.
✅ REPLACEMENT OF THE CHECK VALVE WITH RELEASE ON THE WATER HEATER / Plumbing repair
Installation process
In order to decide where to install the check valve on the water heater, and where to install the main valve, it is necessary to take into account many factors. Based on them, a decision should be made that may affect the performance of the entire device.
The installation process must be carried out in strict accordance with safety rules and regulations. Only in this case can the safety valve function properly and avoid any malfunctions.
When choosing a design, you should pay attention to some factors that may affect the operation of the entire device. The best option will be the purchase of a safety valve that meets all the parameters of a direct or indirect heating boiler.
When purchasing you should consider:
The most significant factor is considered to be pressure. When purchasing a device designed for high performance, the efficiency will be minimal, and for low performance, the problem of constant coolant leakage will appear.
Installation rules
In order for the blast valve for the boiler to perform its intended functions, it must be installed correctly. For this purpose, experts have developed several simple rules, following which you can eliminate errors and complete the work in minimal amount time.
Basic installation rules:
Functionality check
After installation of the safety valve is completed, it must be tested in operation. In order to understand why this event is needed, you should be patient, as testing may take several hours. During this period, it is prohibited to open water taps and use heated liquid.
Sequence of procedure:
List of preventive measures:
- 1. Approximately once every few months should be washed protective device from the formed scale and clean from rust. To perform this operation, it is enough to manually reset the liquid using a special handle.
- 2. The coolant will definitely contain small particles, which will gradually settle to the bottom of the tank. When the container is emptied, foreign particles may get stuck in the release spring and block its operation. To prevent this from happening, it is not recommended to use a protective device to drain the coolant from the tank.
Various problems may arise during the operation of the water heater. To eliminate them, you can call specialists or carry out repairs yourself. The second option is cheaper, but requires certain knowledge and skills.
Problems and ways to solve them:
The safety valve for a water heater is a very important and useful mechanism. With its help, you can prevent sudden changes in pressure in the heating system, as well as reduce the likelihood of an emergency.
At correct installation and the implementation of all preventive measures can significantly extend the service life of the device. The result of this will be the possibility of constant access to hot water and reduction of financial costs.
It's hard to imagine our normal life without hot and cold water. If the house has a well or borehole, then it’s time to think about installing a boiler. You can install the water heater yourself.
The person who will install the water heater should know how important it is to install a safety check valve for a water heater. No matter how terrible the accidents associated with heaters may be, there are still people who believe that they do not need advice. They will consider this information unnecessary.
No matter how much we would like to, but still, there is very important details in installing a water heater.
The most popular question on a water heater search engine is “water heater check valve.” It would be more correct if we talk about a safety valve. These two devices have some similarities, but at the same time, they are different. The main task of the device is to make using the boiler safe.
The device of the simplest check valve.
In front of you you see a cylinder cast from metal; there are threads on both edges for “packing” into a straight section of pipe of the appropriate caliber.
Next we see the so-called poppet valve. It has the shape of a disk, along the edges of which there is rubber for sealing. The rod is located in the center. This valve design allows it to shut off the internal flow of water.
It is designed to prevent water from flowing in the opposite direction. The operating principle is as follows. If water flows in one direction, it puts pressure on the spring. The spring compresses and the valve allows water to pass through. If water flows in the opposite direction, the spring does not deform and the valve does not allow water to pass through. Since the mechanism is not visible from the outside, in order to know in which direction the water is moving, an arrow is depicted on the valve. Most often it is embossed.
Thus, water will flow into the boiler and will never run back into the water supply system. However, what happens if the pressure is too much? In this case, a check valve alone is not enough.
A boiler or electric water heater has a very fine tuning. If too much water enters it, it will break due to high pressure. Therefore, an additional check valve is needed. Considering that this combination is very popular, they were combined into one “ safety valve».
Its structure is as follows. There is a thread at the water inlet. It allows you to screw a water supply pipe or even a hose onto the valve. At the water outlet, which is connected directly to the boiler, there is a threaded coupling. This makes it easier to put the valve on the boiler tube.
Perpendicular to the direction of water in the valve, below the poppet valve there is a soldered metal cylinder. There is a hole on the side of the cylinder. And inside the cylinder there is a “stall” valve. The design of the “stall” valve is the same as that of the non-return valve. But the spring of the “stall” valve is much stronger, and allows water to pass through only when critical pressure is reached. In this case, the water will exit through the above-mentioned hole on the side of the cylinder.
The hole in the side of the cylinder or pipe often has a raised surface so that a hose can be put on it and lead to the sewer.
The outer top of the cylinder may have a sealed flat or a screw plug with an adjustable screw. But most often you can see a lever in this place. It is available for manual discharge of water through the pipe.
Often on safety valves it is written at what pressure the “breakdown” valve will open and release “excess” water.
How the boiler and safety valve work
1. After the electric water heater is installed, it can be operated. To do this, you first need to fill the tank with water. The pressure in the water supply system will be sufficient for the check valve leading to the boiler to allow water to pass through.
Next, air will be forced out of the boiler. Therefore, be prepared that water will not flow immediately from the faucet. The pressure will be created by backing up cold water from the water supply system. As soon as the water starts flowing, close the faucet and wait. Once the tank is full, the internal pump in the water heater will turn off and the water inside will be heated. By heating the water, steam will be generated, which will create sufficient pressure at the outlet when the hot water tap is opened on the mixer.
2. Let's imagine that the safety valve is not installed. If water under pressure does not come out through the faucet, it looks for another way. This path turns out to be a water supply pipe. There is much less pressure in it, so hot water will begin to flow in the opposite direction, and boiling water will flow from all taps, while cold water is installed on the mixer. The boiler will heat all the water in the pipes, because new water will constantly arrive. And the internal thermometer will show that the water needs to be heated. And the electricity bill will be sky-high.
3. It happens that water disappears. You have to wait for a plumber to come and fix everything. But while there is no water, it is very dangerous if the valve is faulty. If the valve is faulty or missing, all the water will leak out. It's good if the sensor turns off the heating. But this may not happen. Then the air will heat up. This will either burn out the heating element or crack the enamel.
4. A logical question arises: is it possible to install only a check valve?
No, that would be a disaster. If you see such a picture, know: a disaster can happen at any moment.
What could happen?
When the boiler is filled with water and heats up, steam is released. The pressure inside increases. Often the manufacturer provides the heating temperature and corresponding pressure.
If the pressure rises to a critical level, the valve will open and excess water will flow out through the “breakdown” valve. And the pressure in the boiler is equalized.
If the pressure increases and there is no way out, this promises another problem: as the internal pressure increases, the boiling point of water also increases.
If the pressure continues to increase, the water heater will become a real bomb and explode from internal pressure. The consequences in this case are devastating.
At 4-5 atmospheres the boiling point is already 150 degrees Celsius. After this, you can expect the boiler to swell. The walls will bend, causing the enamel or ceramic coating to crack.
But much worse is a sharp decrease in pressure. As stated above, pressure reduction and boiling point are closely related to each other. Once the pressure drops, the temperature will remain the same and will be more than enough to turn all the water inside the boiler into steam in a matter of seconds. What will cause the explosion?
It can occur because, while the pressure was growing, the seams along which the structure was soldered cracked and the rubber tore. A sharp decrease in pressure can also occur simply by opening a hot water tap.
Conclusions regarding the need for a valve:
1. Water from electric water heater does not flow back into the pipes if the pressure in the pipes is lower than in the boiler.
2. The valve protects the boiler from water hammer and pressure surges.
3. The safety valve ensures the safety of using the boiler if other safety systems do not work. It also maintains temperature-pressure balance.
4. If your specific valve model has a lever, you can drain the water manually if necessary.
How to choose and install the valve correctly
As a rule, the valve comes complete with the boiler itself. In this case, if the valve is faulty, you simply go to the store with the faulty model and ask for a new one. If the valve is not complete, you should look at the documentation. The documentation describes what pressure is limiting for the boiler.
You also cannot take valves “with a reserve”. If the valve is designed for a lower number of atmospheres than indicated in the documentation, the stall valve will open at operating pressure and water will flow out constantly. This may also affect your water bills.
If the safety valve shows large quantity atmospheres than the maximum permissible, this valve will not save you from a boiler explosion.
To install, connect the valve to the cold water pipe on the boiler. As a rule, the cold water pipe on the boiler is blue.
To seal the joint, use flax tow and sealing paste. If your wiring is bendable, it is enough rubber gasket
Alternatively, you can insert a drain valve between the valve and the water heater. This will make working with the boiler or just maintenance much easier.
The only thing you need to ensure is that:
1. The valve must not interrupt the flow between the boiler and the valve. Shut-off valves are not allowed in this location.
2. The valve must be installed at the outlet of the tee.
Installing a check valve on water
Boiler piping. Step by step.
There are two ways to piping a water heater. And both will be presented below. And in both options it is clearly visible that you cannot do without a safety valve.
1. Before choosing a boiler, you need to choose the space that you are willing to devote to it. This can be either a wall-mounted or a floor-mounted boiler. Measure the space that you are willing to allocate for the boiler, and with these measurements go to the store.
Please note that when the boiler is installed, it should not interfere with turning around in the bathroom.
Also note that there must be enough space for plumbing. You also need space for electrical wiring. Very often a separate power cable power supply and a separate machine.
2. Knowing the height of the water heater, you can calculate where its lower part will be.
3. There are fastenings on the back of the boiler. Most often this is a bracket. The bracket has two holes at the same level. Hooks are used to attach it to the wall. Sometimes other fastening methods are used. Often installation instructions are included with the water heater.
4. Make markings. We measure the distance from the bottom edge of the boiler to the bar. We transfer the distance to the wall. In this case, we use the mark mentioned in the second paragraph as a starting point.
5. Using a level, draw two horizontal lines at the level of the brackets.
6. You need to measure the distance between the hooks. Often this is 20 cm. But it is better to have some play in order to adjust the position of the boiler later.
7. Transfer the distance between the holes on the bracket to the wall. Namely, on the horizontal lines outlined in point 5. If possible, it is better to avoid joints between tiles for drilling holes for the hook. Otherwise, a crack may occur during drilling.
8. The following hooks are used for hanging: external diameter the dowel is 14 mm, and the hook in it is 8 mm. The length of the fastener is 8 cm. But often the hooks are included.
9. Holes are drilled in the designated places. Dowel plugs are inserted into the holes. Hooks are screwed into the dowel plugs.
10. It is necessary to tighten the hooks to such a depth that the boiler does not ride on them, but not point-blank either.
11. The boiler is hanging. Below we see two pipes: red - hot water outlet, blue - cold water inlet.
12. The master can install an additional tee valve to the pipe. It, as mentioned above, will allow preventive maintenance of the device. Before installation, a measurement is made: the number of revolutions is counted before the tee fits into its place.
13. The tee is secured with tow and Unipac paste.
14. The tee is “packed”.
15. Tow is wound onto the perpendicularly located outlet, paste is spread and the tap is screwed in. For reliability, when twisting, it is necessary to make at least 3 turns. The handle must ultimately be accessible for use.
16. When installing the safety valve, pay attention: the arrow on the valve should point in the direction of the boiler during installation.
17. The safety valve is screwed directly to the bottom of the installed tee. In this case, the water flow is not interrupted, and the rule about the absence of shut-off devices between the valve and the boiler is observed.
18. It is desirable that the harness be dismountable. This will allow right moment turn off the device and remove it. To do this, there are ball bearings on both inputs. shut-off valves“American” (flare nuts).
19. Attach a tap with a union nut to the inlet of the safety valve. In turn, a fitting will be adjacent to the fitting in order to put a pipe on it. It will also be quite easy to disconnect it later.
20. The fitting that is adjacent to the valve can be angled 90 degrees. This way, the pipe can be directly adjacent to the wall. Naturally, if you use one 90-degree fitting, you need to buy a second one so that the pipe is located along the wall.
21. A regular fitting is installed on the hot water outlet pipe with a transition to polypropylene pipe. This was done for the sake of aesthetics - so that the pipes “bend” at the same level. Therefore, two fittings with an angle of 90 degrees will also be installed below.
22. Conducted welding work. The pipes are connected to pipes that will drain hot and cold water, distributing it throughout the house.
23. You can connect the boiler to an outlet, it will heat the water. If possible, a PVC tube is connected to the branch pipe on the safety valve, the other end of which is lowered into the sewer, toilet, etc., so as not to wet the floor.
Installation of a check valve. Second option
The second installation option is installation with a flexible liner.
1. Sometimes pipes are hidden in the wall for the sake of aesthetics, and only two pipes are visible from it, to which the boiler needs to be connected. Ordinary ball shut-off valves are installed on the nozzles.
2. For fastening, the pipes are wrapped with flax tow and coated with Unipac paste.
3. The tap itself is put on the pipe by hand, and then tightened with a wrench. In this case, the lamb should be located on top.
4. There is a winding on the inlet pipe of the boiler.
5. Installation of a safety valve with a lever. Yes, you can do without the tee, which was considered in the first option. Although it will take much longer to dry the boiler for prevention. But it's cheaper.
6. The valve is screwed onto the tow and tightened with a wrench. Watch the lever - it should be conveniently located. More flax tow we won't need it.
7. Connecting flexible wiring. Corrugated stainless steel hoses are considered to last forever. Rubber ones are often counterfeited, which is why tire rubber particles end up in the water. However, to avoid this, do not be afraid to bend the tube all the way in the store. If it is of high quality, it will not break.
A storage water heater (boiler) or simply a water heater is a device designed to heat water used in everyday life. Storage water heaters can have different design features, but in the overwhelming majority these are metal containers completely filled with water, inside of which heating elements are located.
The water heater is designed in such a way that it constantly contains the same volume of water: when hot water is drawn in, the vacated volume is filled cold water from the water supply, which allows you to use the device continuously.
In the case when there is no hot water intake, and water heating continues, excess pressure may arise in the water heater tank, which can render it unusable.
Why in storage water heater Is there excess pressure?
When heated, water expands by approximately 3% of the total volume occupied by the liquid. This means that in a boiler with a volume of 100 liters, when heating water from 20 to 80 degrees, almost 3 liters of water are “extra”. If we remember that the liquid is practically not compressible, then it is easy to simulate a situation in which the metal tank of the boiler leaks and fails.
To prevent a possible emergency, water heaters are equipped with safety valves through which excess water is discharged outside.
In other words, a safety valve is pipeline accessories, designed to protect devices from destruction when overpressure by automatically releasing excess liquid into the environment.
The safety valve is activated under the direct influence of the working environment and is a device direct action. When the environmental parameters are normalized, the valve returns to its original position. This means that while there is no excess pressure in the water heater, the valve is in its original position and does not allow water to flow out. When the pressure increases above the maximum permissible value, the valve opens and releases excess fluid until the pressure drops below the set value.
How does a water heater safety valve work?
The water heater safety valve consists of two parts
A check valve that prevents hot water from flowing back into the water supply
Direct acting spring valve
How a safety valve works can be seen using the example of a typical spring valve direct acting, set to a certain maximum permissible pressure. In the closed state, two forces simultaneously act on the sensitive element of the valve: one from the side of the liquid pressure in the boiler, and the other from the side of the set pointer or spring, which prevents the valve from operating and opening.
If the fluid pressure exceeds the spring force, the valve opens and water is discharged. When the pressure of the working medium decreases, the valve closes and the water discharge stops.
Using the adjuster you can change the settings of the safety valve.
As you can see, the design of the safety valve is extremely simple, but a properly functioning valve is a guarantee safe work water heater and reliably protects against such troubles as overheating of the device and possible boiling of water in it, which can happen if the thermostat is not working.
How to check whether the valve is working or not?
It is not difficult to check the operation of the safety valve: you just need to turn on the water heater and do not open the hot water tap until the water is heated to the maximum permissible temperature. In this case, excess water should be discharged (dripped) through the safety valve.
If the water in the boiler heats up, but the valve does not work, it means that it is faulty, and it needs to be replaced with a new, working valve, and after installation, check its functionality.
But before starting repairs, you need to make sure that the hot water intake tap is working properly and is not leaking. If it is faulty, then “excess” water from the boiler will flow out through it and a situation in which the valve can operate will simply not arise.
Also, the valve will not work if the thermostat of the device is set to incomplete heating of water (30-40 C) or hot water is drawn from the water heater, which also reduces the pressure level in it.
Precautionary measures
To summarize the above, it should be noted that a safety valve is a mandatory device for installation in pressure devices, especially if they are used at home.
The water heater should not be operated without it. It is especially dangerous to independently improve the device and replace the safety valve with a non-return valve.
User Questions:
- Hello, when preliminary checking the connections between the tees, pressure gauge, safety valve, reducer and valves before connecting to the boiler, it turned out that the safety valve allows water to flow in the opposite direction, i.e. not through but
- Is it necessary to unscrew the screw on the lever to open the drain hole after installing the water heater?
- I have a valve without a lever, and there is water leaking from under the thread. How to set it up
- Hello! Please tell me, everyone and everywhere says that the safety valve serves to prevent excess pressure from entering the EWH tank and releasing excess pressure (when water is heated to the maximum permissible temperature) from the EWH tank. Question: how
- I have a hightag water heater 50 liters for how many atmospheres should I buy a valve. sometimes he beeps at me
- Why does the valve operate when the heater is turned off and water flows from it?
- Hello! I have water flowing from under the nut of the flexible line, which is screwed to the safety valve, which is screwed directly to the EWH. Water flows through the center of the nut, through the hole into which the liner enters the nut. What's wrong?
Ignoring the need to install a safety valve may result in an explosion of the electric boiler. Some people try to simplify the circuit and remove a much-needed device from the connection.
The cause of a boiler explosion may be an uncorrected water heater safety valve.
Why are safety valves important for water heaters?
Let's understand the design of the safety device for the water heater and the principle of operation.
Device
The device itself is very simple. The design consists of two cylinders. One is large and the other is smaller. The cylinders are located perpendicular to each other.
- Big cylinder. It contains a poppet valve, which is pressed by a spring. It ensures water flows in one direction. A poppet valve is essentially a check valve. On both sides the cylinder has a thread for connecting to a pipe and a heater.
- Small cylinder. It is placed perpendicular to the first and has a smaller diameter. The cylinder is equipped with a drainage pipe with a poppet valve inside. It works in the opposite direction.
Principle of operation
There is nothing complicated about the operation of a water heater safety valve.
To clarify the operation of the device, we will simulate several situations.
- Let there be no valve at the heater inlet, which would block the return flow of cold water supplied to the tank. Even with stable pressure in the water supply, such a unit will not be able to work. The fact is that as the water in the tank heats up, the pressure increases. At some point, the pressure in the tank may exceed the pressure in the water supply, and hot water will begin to flow into the water supply system. So, hot water can flow from a cold water tap or from a toilet cistern.
- There are times when the pressure in the water supply system drops.(this often happens at night, when the load at the water pumping station decreases). In this case, the water from the tank is drained into water pipes. Heating elements idle heat an empty tank, which leads to inevitable burnout. Of course, in theory, the automation should prevent the process of overheating. However, not all models are equipped with this function. And automation can simply fail at the most difficult moment.
Having considered both situations, someone will say that this can be avoided by installing a simple check valve. There are craftsmen who do just that. But they don’t even suspect that they are setting a time bomb in their home.
It’s terrible to think what consequences can be expected if the thermostat fails.
There is no way out of the tank for boiling water. The pressure rises, and with it the boiling point of water rises. If you open the tap, the pressure may drop, and the boiling point also drops. This will cause the water to boil instantly, as a result, a huge amount of steam is formed, which can cause a huge explosion.
Dangerous situations can be avoided by installing a properly functioning water heater valve.
The main advantages of a safety device for a water heater.
- Blocks the reverse flow of water from the heater into the water pipe.
- Prevents sudden changes in pressure in the water supply system.
- When pressure increases, it releases excess water from the boiler.
- By equipping the safety device with a lever, water can be drained for maintenance work.
Installation on a water heater
Selecting the right model
Typically, boilers are sold with a safety valve of a certain parameter. If the valve is missing, then you have to purchase it yourself. approximate price for a safety device - 250–450 rubles.
When purchasing a valve for a water heater, pay attention to the threaded part. If everything is in order with it, then you should pay attention to what operating pressure the valve is designed for. This value can be found by looking at the technical data sheet for the equipment. If it is below the required pressure level, then water will constantly flow from the safety device. A valve with a pressure level higher than required in a critical situation may not prevent the boiler from overheating.
Correct installation
Some users try to hide the water heater safety valve and place it as far away from the heater as possible.
This approach is not prohibited if two conditions are met:
- It is prohibited to install locking devices any kind between the boiler inlet and the safety device.
- It is prohibited to carry the boiler and valve at a distance of more than two meters.
If water leaks abundantly through the drainage pipe before the water becomes very hot, this indicates too high pressure in the water supply system. This rarely happens. In this case, it is worth installing a gearbox.
At the same time, it doesn’t hurt to check whether the purchased the valve has a low pressure indicator and does not match the heater model. If it is normal, then it is worth checking the spring - perhaps it has become slightly “hooked” and needs to be replaced.
You should be wary if the valve remains dry at maximum heating levels. In this case with a large share We can confidently say that it is faulty. You shouldn’t play Russian roulette; it’s better to buy a new device.
Conclusion
The safety of property and personal safety depend on the operation of the safety device for the water heater. When purchasing this device, be sure to:
Safety devices for water heaters designed for lower parameters cannot be installed. Also, you cannot install valves whose threaded connections do not fit the installation site.
If you doubt that you can install a safety valve for a water heater yourself, it is better to entrust the work to qualified specialists.
When using any thermal equipment It is very important to follow all recommended safety precautions. This applies not only to large installations that are used in construction or production, but also to compact devices, such as household water heaters.
If you ignore safety rules, the consequences can be extremely serious - after all, we're talking about not only about your life, but also about the lives of people around you. A safety valve is a very important thing in equipping a home water heater, which, unfortunately, many people forget about. In this article we will tell you what this device is for, how it works, and how to use it correctly.
Purpose
To understand the purpose of the safety valve, first let’s remember the basic things from school course physics. It is known that water tends to increase in volume when heated. If you heat water to 80 degrees (the approximate maximum temperature of hot water from the tap), its volume will increase by 2 or 3% - this depends on what the temperature was at the beginning of heating.
Since the container in which the water is heated in the boiler is sealed, the pressure inside this container inevitably increases with strong heating. An uncontrolled increase in pressure may result in an explosion of the device. This is where the safety valve comes to our aid. It performs the following functions:
- prevents hot water from flowing back into water pipes;
- normalizes the pressure inside the water heater, minimizing the likelihood of water hammer;
- gets rid of excess water by dumping it as soon as normal pressure and temperature are exceeded;
- makes it possible to safely drain the water from the boiler for maintenance.
If you are faced with the question of whether to install a safety valve on a boiler, we bring to your attention a video by Gennady Myagkov, in which he explains why and when it is necessary to install a valve and how it works.
Design and principle of operation
Despite its rather wide functionality, the safety valve has a very simple structure: its main elements are two cylinders - large and small.
- Big cylinder is a kind of “check valve”. There is a flap inside it called a “poppet valve”. This valve is activated by a small spring. At both ends of the large cylinder there are threaded parts that are needed to connect the safety valve to other elements of the boiler.
- Small cylinder fixed perpendicular to the large one. Both ends are plugged with plugs, and there is a drainage tube on the body. There is also a check valve inside the small cylinder, which operates in the opposite direction to the first.
How does a safety valve work? An increase in water pressure inside the boiler activates the check valve spring. It opens, allowing water to fill the tank. As soon as the water reaches the desired level, the pressure inside the water heater increases and the check valve slams shut. As the water in the tank is consumed, its reserves will be replenished automatically.
Check valve inside a small cylinder designed to hold more high pressure. As soon as this indicator becomes critical, a spring is activated, opening the valve. Thus, excess water will be discharged.
Kinds
There are several different modifications of check valves for boilers. They differ in certain key parameters. For example, according to the installation method, check valves are divided into:
- non-returnable;
- reception rooms;
- steel;
- ball
Depending on the principle of operation, the following types of check valves can be distinguished:
- straight;
- indirect;
- designed for two positions;
- proportional.
Finally, there are several more types of check valves for boilers based on the height of the constipation:
- full lift;
- mid-lift;
- low-lift.
With release handle
One of the most common types of check valves that are equipped with water heaters is a valve with a release handle.
Let's talk briefly about its structure and principle of operation.
The design of a check valve with a release handle has the following elements: a body, a water release fitting, a forced pressure release handle, a safety valve spring and a check valve spring.
Under the influence of water pressure, the spring of the check valve is compressed, as a result of which the poppet valve rotates and allows water access to the tank. Once enough water has been collected, the check valve returns to its original position.
The release handle is needed to, if necessary, forcefully relieve pressure inside the system. As soon as the pressure exceeds the permissible maximum, a safety valve is activated, through which excess water is discharged, thereby normalizing the pressure.
For indirect heating boiler Many apartments have indirect water heaters. Indirect heating does not occur in the boiler itself, but in another device, most often in a heating boiler. Thus, the operation of the indirect boiler and the boiler is closely interrelated.
All the characteristics we need are indicated in the technical data sheet of the device, so be sure to study this document before purchasing. It is important to know the permissible operating pressure of the device - you need to focus on it, and not on the pressure in the water pipes.
Can a safety valve be replaced with a non-return valve?
Users of household water heaters often ask the question: “Is it possible to install a non-return valve instead of a safety valve?” Technically this is possible, but under no circumstances should you do this. If such a replacement is made, the boiler will turn into balloon, which can burst at any moment.
For example, when water is heated to 150 degrees, the boiler can easily withstand the rapidly increasing pressure. However, if at this moment you open the tap with hot water, the pressure inside the water tank will begin to drop quickly. Next, the boiling point will drop to 100 degrees, but it will not have time to cool down 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.
When choosing a safety valve for a household water heater, use the recommendations that experts have compiled for you.
- Among the variety of designs, the spring mechanism is the most reliable, as it is able to withstand water pressure well.
- We must not forget about such a factor as throughput valve We advise you to choose a low or full lift device.
- Consider the installation of plumbing and sewer systems at your home. If excess liquid will be discharged into the atmosphere, choose an open safety valve, and if into a specially equipped pipeline, then choose a closed one.
- When choosing a safety valve, you should remember the maximum allowable pressure in the water heater system. If it is higher than indicated in the device data sheet, the valve will not be able to function normally.
Checking for serviceability
At home, you can quite easily find out whether the safety valve installed on the water heater is working properly. To do this, you just need to set the temperature regulator to the maximum value and open the hot water tap. If, after the water in the boiler has heated to the required temperature, excess liquid begins to flow out through the safety valve, then it is quite suitable for operation. If water does not flow through the valve, it is most likely faulty.
