A safety valve for a water heater, boiler or check valve device is one of the main elements responsible for safe operation device under conditions of pressure drops when heating water.

Purpose

During the process of heating water in storage tank water heating equipment, the volume of liquid increases by approximately 2-3%. In accordance with the law of thermodynamics, even with a slight increase in temperature, a closed system is characterized by an increase in pressure.

Temperature control devices and thermostats installed in boilers make it easy and effective to control temperature regime liquids, but when they fail, the pressure increase inside the system becomes critical.

Safety valve for Ariston water heaters

The result of an avalanche-like increase in pressure level is a rupture of the boiler casing and an explosion of water heating equipment.

In order to prevent exceeding permissible pressure limits, a safety valve is installed that is capable of releasing part of the liquid to the outside in a critical situation.

However functional purpose relief valve overpressure water for a water heater in water heating equipment is not limited solely to boiler protection, but also includes:

• preventing the return of heated liquid from the storage tank to the water supply system;
• smoothing out surges in water pressure or so-called water hammer at the entrance to water heating equipment;
• dumping an excessive amount of heated water from the tank under conditions of a critical increase in temperature and pressure levels;
• the ability to drain liquid from the water heating tank in order to carry out preventive maintenance and repair measures.

The absence of a valve does not prevent the outflow of heated water from the boiler in an emergency, so exposed heating elements burn out in a short time.

The safety valve will prevent water from backflowing into the water pipeline, will prevent pressure surges and water hammer, and will also allow excess fluid to be drained for maintenance purposes.

Flooring The bathroom is usually tiled, but the tiles are cold. To create comfort and coziness in the bathroom, lay. The article describes a guide to setting up the system.

The procedure for installing a bidet is described in detail.

Installation of a Jacuzzi must be carried out according to certain rules. everything from preparation for installation to connection to communications.

Principle of operation

The safety valve is represented by a main body structure and several elements that are located in a brass or nickel shell. Usually, this device has an inverted T-shape. A check valve is fixed at the bottom of the water heating tank, preventing water from leaking out due to a drop in pressure level in the pipeline.

On the perpendicular branch there is a valve device that is activated when the pressure increases and is also responsible for draining excess liquid through the fitting. Right installed device works in stages.

Check valve in the diagram

When the pressure level in the tank is lower than that occurring in the pipeline, the filling process causes the poppet plate in the valve to be pressed out under the influence of water pressure.

Normalization of pressure is accompanied by closing the plate and limiting the flow of water into the system. The active heating mode is characterized by a slow increase in water temperature and an increase in pressure, which can reach maximum values. In this case, the defense mechanism is activated.

Periodic drainage of liquid through the fitting channel should not cause concern, as it indicates that the safety valve of the water heating boiler is functioning normally.

Varieties

The safety valve device installed on household water heating equipment is most often represented by three main groups:

1. Safety devices for water heaters with a volume of no more than 50 liters. in the form of disposable valves. A special feature is the presence of a non-demountable design, low cost and sufficient short term operation. However, some very well-known manufacturers equip boilers with valves of higher quality characteristics.
2. Devices for water heaters with a volume of no more than 200 liters, characterized by a 7 bar safety valve, a check valve and a shut-off ball valve, as well as a special nozzle for connecting to the sewer system.
3. The safety device for water heating equipment with a volume of more than 200 liters is represented by mandatory elements in the form of a pressure reducer, a tap, a check valve and a safety valve with a drain fitting.

Fully dismountable safety valves are equipped with special test points that facilitate diagnostics and maintenance of water heating equipment.

Many American manufacturers, as a rule, install valve devices on their water heating equipment closed type with a lack of visual control of work.

Don’t want to create complex designs for finishing the ceiling in the bathroom? You can just whitewash the ceiling. and what is needed for this, we will tell you in detail.

A bidet is rather exotic these days, and not everyone has the opportunity to install one due to a cramped bathroom. Bidet lid - purpose, advantages and disadvantages, read.

Choice

Most often, all modern water heating devices are sold with already installed system protection in the form of a safety valve with certain parameters. When purchasing a device yourself, you should pay close attention to the features of the threaded part, as well as the maximum operating pressure.

Installed valve

Each valve is designed to a certain level pressure, which must be indicated in technical passport equipment. The total volume of the tank must also be taken into account. Produced protective systems

can have a response threshold from 6 to 10 Bar. At wrong choice

or incorrect installation of the safety valve, constant leakage of liquid or very strong overheating of the water heating equipment may occur.

Installation Installing the device yourself is usually not difficult. Before proceeding with installation, it is necessary to disconnect the water heating equipment from electrical network

• and drain all the water from the tank, then perform the installation, adhering to the following simple recommendations:
• the safety element is installed at the cold water supply inlet to the boiler;
• during installation it is necessary to use FUM sealing tape or traditional tow;
• the other side of the fuse is connected to the cold water supply system;

If there are pressure differences in the water supply system, a reducer is installed in front of the valve.

Valve installation diagram To connect the drainage pipe to A flexible and transparent hose is used. It should be noted that sometimes a special safety valve is replaced with a blasting device designed to discharge liquid in emergency mode.

Despite the similarity of functions, the operating principle of such devices is noticeably different, so you should not count on the correct operation of such a device.

It is prohibited to mount devices locking type in the area from the entrance to the water heating equipment to the safety valve, and also remove the protective element more than two meters from the boiler tank.

Possible breakdowns and causes

There are several most common problems that may arise during the operation of the safety valve of water heating equipment:

• When the boiler is disconnected from the network and the water supply is turned on, liquid leaks out of the drainage hole. The reason is a breakdown of the safety element or increased level pressure in the water supply system.
• When the boiler is connected to the network, there is minimal water intake, prolonged heating of water and constant leakage of liquid from the drainage hole. The reason is a malfunction of the safety valve.

All failures associated with the safety valve are usually accompanied by frequent leakage of water or a complete absence of fluid flow.

In both cases, it is advisable to replace the device with a serviceable safety valve configured for similar operating pressures.

It is very important to be sure to attach a flexible and transparent hose to the drain outlet of the device, which allows you to easily visually monitor the operation of the safety valve installed on the water heating equipment.

Correct operation of the safety valve installed on water heating equipment is a guarantee of property safety and personal safety, therefore, when choosing and purchasing such a device, you must ensure full compliance with the operating parameters and design power, as well as organize proper installation into the system.

Video on the topic Service life depends on correct strapping storage boiler , as well as the safety of using the device. One of important nodes

is a safety valve for a water heater installed on the incoming cold water pipe. To understand why a valve is installed on a water heater, it’s worth remembering. According to the law of physics, water expands when heated. The liquid is inside a sealed container. If there is no water supply, the pressure rises and the tank may burst. A safety valve for the boiler, which bleeds excess liquid from the tank, will help prevent an accident.

On the forums you can find information where they advise simply not to install a check valve. Then there is no need to install an excess water pressure relief valve. In their opinion, when excess pressure appears, some of the water will go back into the pipeline. The advice is partly correct, but the system will work as long as the water supply system functions stably. The advice is wrong for three reasons:

• there are no stable operating water pipelines without breakdowns;
• without check valve all the water from the tank will go into the empty pipeline;
• a bare heating element will heat the air inside an empty container.

Now let's look at the end result of the problem. When there is a water supply failure, the pipes are left empty. There is no check valve on the inlet pipe, and water from the storage tank flows freely into the system. When the temperature drops, the thermostat will turn on the heating element. Without water, the heater will simply burn out, but this is only half the problem.

There is another danger. The heating element is hot and water appears in the water supply. A large amount of steam and excess pressure suddenly forms inside the tank, which does not have time to be released back into the pipeline. The tank is guaranteed to burst in several places. Boiling water will pour into the apartment. For this reason, it is better not to overthink it, but simply install a water relief valve.

Design and operation

There is nothing complicated about the design of a safety valve for a water heater. Most often, the safety unit is made as a single piece. A safety valve and a check valve are contained within one housing.

The standard product diagram looks like this:

• The bronze case inside has two chambers. The design resembles the letter "T". There are two threads cut on the body of the check valve chamber for fastening to the water supply. The safety valve chamber housing is equipped with a water drain fitting.
• Inside the check valve there is a spring that holds a rod on which a round plate is attached. When closed, it prevents water from flowing back from the tank into the empty water supply.
• A safety valve similarly has a stem with a spring and a round plate. Most models are equipped with a forced water release lever. This element is directly connected to the stem.

The water heater usually comes with the cheapest safety valves without a lever. It’s better to throw them away and buy a quality product.

IN general outline The operating principle of the safety valve looks like this:

• As water is drawn, the pressure inside the tank drops. The safety valve is closed. Due to the pressure difference, the check valve opens and the tank begins to refill. When the pressure in the water supply and inside the container is equal, the check valve closes.
• The boiler thermostat turns on the heating element. The liquid begins to heat up, increasing in volume. If the pressure reaches a critical level, but there is no water supply, the safety valve is activated. Hot liquid is drained through the fitting. After normalizing the pressure, the spring returns the mechanism to its original position.

The thermostat constantly monitors set temperature and periodically turns on the heating element. If there is no analysis, the pressure will constantly increase with each increase in water temperature. During this period, liquid drips from the fitting. This is normal operating time. To prevent water from pouring onto the floor, a transparent reinforced hose is fixed to the fitting with a clamp, diverting its end into the sewer.

Types of security groups and the principle of choosing the appropriate model

A standard safety valve for a boiler may differ in design in several design features. These nuances do not change the functionality of the device, but only simplify use and maintenance. To choose the right safety unit, you need to know what safety valves for boilers are and how they differ.

Lever models

The most common type of standard safety assembly is the lever model. This mechanism can be activated manually, which is convenient when checking or draining water from the boiler tank. They do it like this:

• A horizontally located lever is installed vertically;
• direct connection to the stem activates the spring mechanism;
• the safety valve plate forcibly opens the hole and water begins to flow from the fitting.

Even if the tank is not completely emptied, a control drain is performed monthly to check the functionality of the safety unit.

The products differ in the design of the lever and the fitting for discharging water. If possible, it is better to choose a model with a flag fixed to the body. The fastening is made with a bolt that prevents children from manually opening the lever. The product has convenient form herringbone fitting with three threads, which provides reliable fixation hose.

The cheaper model does not have a flag lock. You can accidentally catch the lever with your hand and unnecessary drainage of water will begin. The fitting is short, with only one threading ring. It is inconvenient to fix the hose onto such a protrusion and can tear it off under strong pressure.

Models without lever

Safety valves without a lever are the cheapest and most inconvenient option. Such models often come complete with a water heater. Experienced plumbers simply throw them away. The units operate similarly to lever models, but there is no way to manually perform a control drain or empty the boiler tank.

Models without a lever come in two versions: with a cover at the end of the body and blind. The first option is more convenient. If clogged, the cover can be unscrewed to clean the mechanism. A blind model cannot be tested for functionality and cannot be descaled. The fluid discharge fittings for both valves are short with one threaded ring.

Safety components for large water heaters

Water heaters with a storage tank volume of 100 liters or more are equipped with improved safety valves. They work in a similar way, only they are additionally equipped with a ball valve for forced drainage, as well as a pressure gauge.

Particular attention should be paid to the fluid drainage fitting. It's threaded. Secure fastening prevents the hose from being torn off by strong pressure and eliminates the inconvenient use of the clamp.

Original models

For lovers of aesthetics and comfort, manufacturers offer original safety components. The product is equipped with a pressure gauge, chrome plated, and given an elegant shape. The products look beautiful, but their cost is high.

Difference in body markings

High-quality products must be marked on the body. The manufacturer indicates the maximum permissible pressure, as well as the direction of water movement. The second marking is an arrow. It helps determine which side to place the part on the boiler pipe.

On cheap Chinese models there are often no markings. You can figure out the direction of the fluid without an arrow. The check valve plate must open upward in relation to the boiler pipe so that water from the water supply flows into the tank. But it’s impossible to determine the permissible pressure without markings. If the indicator does not match, the safety unit will constantly leak or will not work at all in an emergency.

Other types of valves

When they try to save money on a safety group, they try to install a blast valve designed for the heating system on the water heater. The nodes are similar in functionality, but there is one nuance. The blast valve is not capable of releasing liquid little by little. The mechanism will work when the excess pressure reaches a critical point. The blast valve can only release all the water from the tank in the event of an accident.

Separately, it is worth considering installing only a check valve. The mechanism of this unit, on the contrary, locks the water inside the tank, preventing it from draining into the pipeline. If there is excess pressure, the working plate with the rod is not able to operate in reverse side which will cause the tank to rupture.

Installation and adjustment of the safety unit

Anyone can install a safety valve on a boiler without the help of a plumber. Correct wiring diagram indicates that the safety unit is attached to the cold water inlet pipe of the water heater. Below are taps, filters and other piping elements.

The valve is installed on the water heater in the following sequence:

• The safety valve is installed directly on the cold water inlet pipe going inside the water heater. Often a detachable adapter is placed between them - “American” for ease of dismantling during maintenance.
• Fum tape is wound onto the threads of the pipe or adapter to seal the connection. The safety assembly is screwed on so that the arrow on the body is directed towards the boiler.
• When screwing the safety valve onto the water heater, you need to stop when you feel a stop. On cheap models there is no mounting fuse. The part is screwed four turns. You can't turn it anymore. The thread of the pipe will close the channel of the fitting for draining water.

After installation, it is worth looking inside the housing from the check valve side. Inside the hole you can see the seat and the locking mechanism plate itself. To check the functionality, press the plate with a finger or pencil. It should move inward, and when released, return to its original place.

When the entire circuit is assembled, begin adjusting the security unit:

• The water heater is filled with water, voltage is applied and the thermostat is set to the maximum temperature. You have to wait until complete heating occurs, and the automation will turn off the heating element.
• Drops of liquid should appear from the fitting. If they are not there, turn the adjusting screw until a positive result is obtained.
• After adjustment, use the lever to bleed a little water from the tank, after which the mechanism is returned to closed state. The drip from the fitting will stop. A new portion of water will flow inside the tank. The heating element will heat it up, and the liquid will again begin to drip from the fitting.
• The mechanism, adjusted to the maximum temperature, will always work when the permissible limit is exceeded. Now you can set a lower operating temperature on the regulator, for example, 50–60 o C. When this threshold is reached, liquid will not drip from the fitting.

On the performance of the forced drain lever and operation when maximum temperature The security group is checked once a month. If the adjusting screw is missing and the mechanism does not operate according to the required parameters, the part is replaced.

Malfunctions and solutions

A faulty boiler safety valve is detected by liquid constantly flowing from the fitting or when there are no drops at the maximum heating temperature. A failure is considered to be the absence of forced drainage when the lever is raised.

Let's consider possible malfunctions:

• Liquid constantly flowing from the fitting appears at high pressure in the water supply. If the safety group is designed for 6 Bar, then at 7–8 Bar the excess will be constantly released into the line. You can check by forced draining using the lever. If the dripping stops after bleeding, then the problem is in the high pressure of the water supply. It is necessary to install a gearbox at the entrance to the house.
• When water continues to flow after releasing the pressure, the cause is a clogged working spring. If the safety group can be disassembled, all elements are cleaned of dirt and put in their place.
• The absence of a drip and forced drainage indicates a clogged fitting or the entire working mechanism. There is only one way out - disassemble and clean.

If the part is not removable or cannot be repaired, it should be replaced immediately.

The water heater safety group is not a component that you skimp on. Repairing a boiler will cost more.

A check valve for a water heater is inexpensive (from 160 rubles), externally unremarkable, and its purpose is simply not known to many. Therefore, the mandatory installation of it seems to some “advanced” smart people to be an optional whim of a drunken plumber. But everything is for the time being. After the water heater explodes one day, simultaneously destroying half of the apartment, the opinion about the need to use a check valve for the water heater will change dramatically, unfortunately, somewhat late. Learn from other people's mistakes, gentlemen!

Why do you need a check valve in a water heater?

A check valve for a boiler is sometimes called a safety valve. There is no mistake in this. Design feature shut-off valves for a water heater, is that it consists of two valves located perpendicular to each other. One of them, located in a larger diameter tube, is reverse. The other, located in a tube of smaller diameter, is safety.

The non-return valve is used to prevent liquid from flowing out of the boiler into the water supply network when the pressure in the tank exceeds the pressure in the cold water supply network (CWS).

The safety valve is essentially a relief valve, automatic device, triggered by excess pressure at the inlet in front of the valve.

Both devices have the same design, disc type. Vary throughput and setting pressure. Simply put, the diameter of the pipes and the stiffness of the clamping springs.

How to choose a check valve for a water heater

These devices differ in:

• Nominal pressure (PN). There are: 0.6; 0.7; 0.75; 0.8; 0.85 MPa. About what nominal pressure The specific safety device can be found out from the inscription on the device body, but it may not be there. In this case, you should focus on the lower value, i.e. 0.6 MPa.

It’s hard to see in the picture, but in fact, the difference between the springs of the check valve and the safety valve is clearly visible in the holes of the pipes.

Some manufacturers of storage water heaters recommend using a pressure reducing valve () to set the water pressure in the cold water system 20% below the start value of the safety valve. For example, for a device designed for 0.6 MPa, the pressure in the indoor cold water network should be 0.48 MPa.

Of course, the process of organizing such adjustment is quite troublesome. You will need to purchase and install at least one pressure gauge. There is information on how to choose a pressure gauge, but it will be possible to actually control and, if necessary, quickly regulate the pressure level, and this is necessary not only for the normal operation of the boiler, but also for other devices. For example, for efficient work.

• Thread diameter. 1/2″ or 3/4″ inch.

• The presence or absence of a reset function. A small lever or flag intended not so much for draining (very slowly), but for monitoring the operability of the safety valves. Contrary to popular belief, the color of the lever does not carry any information about the nominal pressure of the device. Can be: black, red, blue or yellow.
• Cost. From 160 to 1600 rubles.
• Manufacturers. Italian companies Remer, ITAP. The well-known European concern Ariston and many other nameless Chinese manufacturers.

Nothing is said about the pressure at which the check valve begins to open, but its value can be judged from the water heater operating manual. For example, for the Termex model, RZL series, it is said that the pressure in the cold water system should be 0.05-0.6 MPa.

Why is my water heater check valve dripping?

It is known that water in a closed vessel increases in volume when heated and will inevitably find a way out, even if this requires tearing the metal tank.

Therefore, let's accept as dogma that an efficient safety valve, when the water is very heated (from 80°), should leak (drip slightly) from a pipe specially designed for this purpose, releasing excess liquid pressure in the tank.

To drain water leaking from the drain pipe, it is convenient to use a transparent hose from the hydraulic level, with outlet to the sewer.

However, if we talk about moderate heating up to 60°, then the safety valve may not drip. Yes, maybe, if the following conditions are met:

• The inlet pressure must be at least 20% lower than the pressure at which the safety valve begins to open.
• The design of the boiler tank must have in its upper, spherical part, a sufficiently large supply of volume filled with air, acting as a hydraulic accumulator.

In fact, the practical search for the optimal compromise between acceptable temperature, pressure and absence of leakage has been carried out experimentally for quite a long time. Universal method there is no solution to this problem. It all depends on the specific circumstances.

Water heaters are the most common devices for organizing hot water supply in a private home; sometimes they are also installed in high-rise apartments.

For installation on a water pipe you will need some tools and Additional materials. One of the required fittings is a safety valve for a water heater. As a rule, this protective element is supplied with the main device, but some budget models may be sold without a valve.

Purpose of the fuse

There are three main tasks that a safety valve performs:

• ensures safe operation of the water heater;
• protects heating elements from dry heating;
• if necessary, allows you to drain water from the water heater.

A safety valve is installed on storage water heaters (boilers). To better understand its principle of operation, you need to know how the boiler is designed and how it works.

IN storage water heater water is present throughout the entire period of operation. The heating element turns on depending on the temperature to which the thermostat is adjusted.

Cold water enters the water heater through a pipe at the bottom of the tank. Hot water flows out of the tank through a pipe that is built into the bottom and installed inside, so that its upper end almost reaches the top of the tank.

This allows you to select first upper layer, which has a higher temperature, while cold water flows from below.

If there is not enough backwater in the main, the water can be drained through the pipe, which is designed for filling.

If there is no water, the heating elements will simply overheat and burn out. Even if they do not have time to burn out before filling, the water, hitting the hot metal, will quickly boil, forming large quantities steam, which will create very high pressure. This pressure will be enough to destroy the device.

To prevent an explosion from occurring, it is necessary to install a check valve for the water heater, which must be located on the inlet pipe for cold water. In this case, when the pressure in the cold pipeline decreases, liquid will always remain in the container, preventing overheating of the heating elements.

But installing a check valve alone is not enough. Moreover, if you install only it, the consequences may be even worse than without it.

The water entering the water heater will stop as soon as the pressure in the boiler becomes equal to the pressure in the cold pipeline. After heating begins, the water will expand inside, and when closed taps to dispense hot water, there will simply be nowhere for it to go and the pressure will begin to increase. All this is fraught with an explosion, the consequences of which can be the most unpredictable and tragic.

Obviously, for normal operation you just need to provide a drainage device that will produce an emergency release of water when the pressure reaches a certain threshold (excess value). It is implemented as a safety relief valve for the boiler.

Device and principle of operation

The device for preventing a serious accident looks surprisingly simple, and its dimensions are small - it fits in the palm of your hand. It is a small mechanism consisting of two perpendicularly located spring-loaded valves enclosed in one metal case. Essentially, these are two cylinders (tubes), one of which is slightly larger than the other.

The first larger diameter tube, usually 1/2 inch, with two threads at the ends, has a check valve installed that allows fluid to flow in only one direction. The flap in it is located across the pipe and can move along it by several millimeters, opening or closing the passage.

Under the influence of pressure directed towards the water heater, the flap opens, compressing the spring. As soon as the pressure in the pipeline and behind the valve is equalized, the valve closes under the action of a spring.

In a tube of smaller diameter, located perpendicular to the first, a second valve is installed, the spring of which is adjusted to open at a certain pressure, exceeding the pressure for the first valve. This is a fuse that protects against explosion.

Thus, when the pressure rises and the check valve does not allow water to flow into the supply cold pipeline, the second valve opens and it is discharged through the drain pipe.

The nozzle may have special notches that make it easy to put on the hose. suitable diameter. This hose must be secured with a clamp and led either into the sewer or into a container that will have to be emptied from time to time. This will have to be done infrequently, since the amount of water squeezed out during operation of the water heater will be small.

Very often, a plastic flag is provided in the design to force the opening of the drain device. With its help you can check the functionality of the fuse. To do this, you just need to open it and make sure that the piston stroke is free, it is not clogged with rust and scale, and the spring force is enough to return the valve to the closed state.

The safety valve body is often marked with an arrow indicating the direction of water flow to facilitate installation. The small pipe is usually marked with a marking indicating the pressure in pascals at which the emergency valve opens.

or incorrect installation of the safety valve, constant leakage of liquid or very strong overheating of the water heating equipment may occur.

The safety valve for the water heater is installed on the pipe that supplies cold water to the container. Due to the presence of threads at the ends of the device, it is installed without welding or soldering, its installation is simple. Be sure to follow the direction of the arrow on the body, indicating the direct flow of cold water. To seal the threads, you must use flax with packaging paste or FUM tape.

It is recommended to install a tap or drain valve between the inlet pipe and the safety valve. This is necessary because if you often drain water using a safety valve, the elasticity coefficient of the spring will decrease and the nominal opening pressure of the valve will change. Drainage will be needed when repairing a boiler, for example, in case of replacing heating elements or when mothballing a house in winter period, when liquid is drained from all systems to prevent it from freezing and destroying pipes.

The tap must be placed on the side outlet of the tee in such a way that it is impossible to shut off the pipe between the water heater and the safety valve, otherwise the latter will not work. To ensure that air enters the water heater and does not create a vacuum that prevents draining, you can open one of the hot taps on the mixers.

Install drain valve with tee to pipe with hot water inappropriate. It will be impossible to drain water through it, and excess detachable connections no use in the water supply.

If you want to hide the safety valve, you can slightly lengthen the vertical section of the pipe. But the distance from the tank to the valve should not exceed 2 m.

If water drips through the valve for no apparent reason (without heating), this may indicate high pressure in the system (above normal). In this case, it is recommended to install a reducer on the water supply system and adjust the pressure. If the water in the tank is cold, the pressure is not higher than 4 bar, and the valve continues to drip, then this is most likely a defect and the device must be replaced.

Functionality check

After installing the safety valve, you must check its functionality. To do this, you need to fill the container cold water. You need to fill with the tap open so that air comes out of the boiler. After water flows from the hot tap, you need to turn off both taps.

Water should not drip from the safety valve, but when opened by hand, it should come out under pressure approximately equal to the pressure in the water supply. There is no need to measure it, since it is easy to determine visually.

After heating has started, you should not turn on the hot water taps for some time. This will create increased pressure in the tank. Droplets will appear in the drain tube or simply from the valve hole (if there is no tube) as liquid begins to be displaced from the tank. This means that the safety valve is in working order and the water heater can be safely used.

The need for selection occurs in the event of a fuse failure, leakage or loss for some reason. If you need to buy a new safety valve, then pay attention to its response pressure. It is necessary to compare with the boiler pressure, which is indicated in the passport. Another indicator is the setup step. Typically it is 0.5 bar. You can choose a safety device with a slightly lower pressure than the boiler, but in no case with more.

A valve for a boiler should not be confused with a similar device for heating, since the latter is designed for lower pressure. It is also impossible to install a check valve instead of a safety valve, as it will not perform its functions and the heater may explode.

It is advisable to pay attention to the material of the case and choose brass, since it is more ductile, does not crack, lasts longer, although it is more expensive.

Storage water heaters are installed not only in private houses that are not connected to central communications, but also in apartments for comfortable waiting for completion repair work, planned by public utilities.

For safe operation of water heating equipment, it is necessary to purchase and install a safety valve for the boiler, which protects the household appliance from pressure surges in the cold water supply system. In addition, this valve is also called a non-return valve, since it prevents water from flowing back out of the storage tank in the event of an emergency shutdown.

Therefore, if there is no water in the cold water supply system, you do not have to worry about the safety of the electrical heating element. The heating element will not remain “dry” and will not burn out. The presence of a safety valve will allow you to easily drain the water from the boiler if you need to clean the container from accumulated deposits in the process of heating water or replace a heating element that has expired.

A properly functioning safety valve can provide long and stable work storage boilers.

In the process of heating water in the storage tank of the water heater, its volume increases. IN closed system According to the laws of thermodynamics, as the temperature of a substance increases, the pressure level also increases.

To control the temperature of water in boilers, manufacturers install thermostats and thermostats on their products. If these devices fail, the water in the tank will boil, which will lead to a noticeable increase in pressure and even greater heating of the liquid.

The avalanche-like course of the described process will ultimately lead to the formation of a crack in the walls of the storage tank, through which some of the hot water will pour out. The free space will immediately be filled with cold water coming from the water supply system.

This will lead to instantaneous boiling of all the liquid in the tank, accompanied by the release huge amount steam and, as a result, the explosion of the container, expanding under its influence.

The safety valve will not allow the pressure to exceed permissible values ​​by discharging part of the liquid into the sewer system.

In addition to ensuring the integrity of equipment in the event of critical situations, safety valves perform several other functions: important functions, which include:

• preventing heated water from returning to the water supply from the boiler;
• smoothing out pressure surges in cold water at the entrance to the water heater tank, which prevents the possibility of water hammer;
• dumping excess liquid from the tank at the moment of a critical increase in temperature and pressure;
• providing the ability to drain water from the storage tank of the water heater for scheduled maintenance preventive maintenance and necessary repairs.

Valves currently produced by manufacturers may have varied design. The kit, along with the main product, may include pressure gauges, various shut-off valves and etc.

When choosing a safety valve for a boiler, you should take into account the fact that the purchased device must correspond to the parameters of the hot water supply system in use in the house.

The diagram clearly shows the design of a safety valve for a water heater (boiler), all elements of which are equipped with signs with inscriptions

How does this valve work?

The boiler safety valve also functions as a check valve, which is reflected in its design. Schematically, the product can be represented as two thin-walled cylinders located at right angles to each other, having different sizes, endowed with a common working cavity.

If you look inside the cylinder bigger size, then you can see a check valve installed there, the design of which includes a plate, a spring and a seat machined into the body of the product. The thread on both sides of this part of the protective device allows it to be connected to the inlet pipe of the electric boiler.

Inside the smaller cylinder also contains locking device, similar in design to the check valve described above, and differing from it only in the presence of a stiffer spring.

Most models of safety valves have a function for adjusting the opening pressure, produced by changing the degree of compression of the spring. The drainage hole is located directly behind the locking mechanism. It is recommended to connect a transparent tube to this hole, which allows you to observe the water discharged from the tank.

The safety valve operates according to the following algorithm.

• When the tap mounted on the inlet line is open, water flows freely into the container through the hole created by pulling the check valve plate away from the seat. In this case, the incoming liquid does not have access to the drainage hole, because the safety spring has a rigidity designed for a higher pressure compared to the water supply value of this value.
• When the boiler is completely filled, the pressure level in the tank and in the main line is equalized, causing the check valve to close. An increase in the temperature of the heated water in the storage tank causes an increase in the pressure force on the check valve plate, which is pressed even tighter to the seat. Therefore, heated water can no longer return to the cold water supply pipes.
• When users start using hot water household needs, the pressure inside the water heater begins to drop and reaches a value less than the tap value. At this moment, the plate is pressed away from the seat and the process of filling the tank with water begins.
• If the thermostat breaks down, an uncontrolled rise in temperature will begin, which will cause pressure to rise to a critical level. Here, as a result of compression of the safety valve spring, it will be possible for outflow excess liquid through the drainage hole into the sewer system through a transparent hose.

A small lever is necessary to force the opening of the drainage hole, through which water is discharged and pressure is reduced

Excessive energy consumption without a check valve

A hot water supply system with a water heater can operate without shut-off valve, but then if the pressure increases, hot water will be squeezed out into the supply line. This will result in excessive consumption of electricity, because the device will have to heat large quantity water.

The extra wound kilowatts will need to be paid for, which will not add joy to the owner of the apartment or house. In addition to the financial side of the matter, there are also practical inconveniences. After all, instead of cold water, warm water may run from the taps.

These problems must be added to the disadvantages that were described above. Therefore, do not agree to install a water heater without installing a safety valve.

The cost of this brass product is incomparable with the costs incurred to purchase a boiler.

Information on the safety valve body helps you select the correct part for initial installation or replacement during water heater repair.

The procedure for connecting a water heater

After installing the water heater, begin connecting it. To do this, take a tee, try it on, screw it onto the cold water inlet pipe, marked in blue. If there are not enough threads, then several turns are added with a special device so that the tee is installed correctly.

Then they wrap the thread with tow, coat it with paste to ensure a tight connection, and screw on the tee, tightening it with an adjustable wrench. Next, a tap is screwed onto the side outlet of the tee to ensure quick drain water from the boiler in case of replacing a burnt-out heating element or descaling the tank.

The connection is also sealed with tow or tape for threaded connections. A safety valve is connected to the bottom of the tee, focusing on the arrow showing the direction of cold water entering the water heater. The arrow is located on the valve body.

Next, one part of the American one is screwed onto the safety valve. The second part of the American connection is screwed onto the tap and a connection is made to the first part. Then a transition coupling is screwed into the tap for connection to the water supply with propylene pipes.

Next, connect to hot water. To do this, screw the first part of the American onto the boiler outlet pipe, marked in red. The second part of the American is screwed onto the shut-off valve. Make a connection.

Then an adapter coupling is also screwed onto the tap to solder the propylene pipe. All that remains is to connect the boiler to the cold and hot water supply system. Propylene pipes can be replaced with flexible liner.

The connection diagram for a water heater (boiler) to hot and cold water supply systems shows the sequence in which the device is installed

Alternative way to install a check valve

This method was invented by a craftsman who was faced with the problem of contamination of a safety valve with sediment from a tank of hot water under pressure. If a piece of rust gets under the piston plate onto the seat, the valve will no longer work correctly. It remains open all the time.

To prevent such a development of the situation, it is necessary to install the valve at the level of the middle of the tank. That is, in the same way as described above, a tee is connected to the inlet pipe of the boiler, and then the connection is made a little differently.

The drain valve is screwed on from below, a pipe is pulled to the side, corners are placed, a pipe is placed again, and a safety valve is installed somewhere at the level of the middle of the tank. After it comes a shut-off valve and fitting, through which the device is directly connected to the water supply.

With this method, the valve always remains clean and the poppet piston does not “hang” above the seat. In addition, in the absence of water in the system, such a flexible connection serves as a kind of water seal.

You can learn more about this editing method from the video.

When using the boiler, make sure that the drain hole on the safety valve is not clogged or blocked. The drain can become clogged with rust, small solids, and other impurities found in tap water.

To check its operating condition, a reset is performed periodically small amount water by pressing a special lever or turning the handle. The instructions included with the water heater safety valve indicate how the valve's forced opening mechanism operates.

Installing a filter for cleaning tap water partially solves the problem. It is not advisable to change the factory settings of the spring stiffness in valve models equipped with such adjustment.

Such intervention may lead to destruction of the water heater tank due to exceeding the permissible pressure values ​​inside household appliance.

Forced discharge of water from the boiler in order to reduce the pressure in the tank is carried out by pressing the lever

Water is constantly dripping - what to do and how to fix it?

Some boiler owners are faced with the problem of constant water seeping through the drainage hole. Water may drip from a drain for two reasons:

• incorrect valve setting;
• too high pressure in the cold water supply system.

The first problem can be resolved by replacing or adjusting the device, which must be done with a hex key. At the same time, slightly tighten the clamping nut located at the entrance to the valve.

You can get to this nut by partially disassembling the device, during which you remove the lever, nut and sealing washer. In general, you can solve the problem faster by purchasing a new valve.

The second problem related to high pressure in the system, disappears when installing a pressure reducing valve.

A tube with transparent walls is connected to the drainage hole without leading it into the sewerage system

Connecting the outlet in the form of a transparent tube from the drainage hole of the safety valve to the sewerage system through a pipe with an oblique inlet

Problems and solutions

You should start looking for the reason for the malfunction of the water heater as soon as the first signs appear. It is advisable to check all elements of the household appliance, starting with the thermostat, safety valve and heating element. Most often these are the parts of the boiler that break.

If a valve breaks down, technicians advise not to save money by repairing the part, but to immediately purchase a new analogue. The model is selected according to the pressure level for which the valve is designed, indicated on the product body. This information is also indicated in the safety valve instruction manual.

There are situations when the valve does not function due to a hidden defect, which is not possible to identify. There is no point in wasting time looking for defects in the design of the part, since the boiler must be used for its intended purpose.

Therefore, the defective valve is replaced with a new device. If the life of the installed safety valve is exhausted, it is also dismantled and a new device is installed. By replacing the valve, you don't have to worry about how the water heater works.

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

When disassembled, the safety valve allows you to see the screw that, using a screwdriver, adjusts the spring stiffness

Any novice craftsman can install a water heater and properly wire it. After reading the article and watching the videos, you can do everything yourself, saving on payment installation work made by third parties.

If you believe that everyone should do their job at professional level, then invite specialists. Experienced professionals will help you choose suitable model safety valve, purchase the missing fittings, and connect the boiler to cold and hot water in accordance with construction work standards.

Just don’t listen to those unfortunate craftsmen who consider safety valves to be unnecessary links in the piping chain of a water heater connected to the water supply. Never skimp on your safety!