Where is the emergency valve installed on the water heater? Installation and adjustment of the safety valve for the boiler

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 mandatory details fittings is safety valve for a water heater. As a rule, this protective element is supplied complete with the main device, but some budget models may be sold without 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.

The storage water heater contains water throughout its entire 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 more high temperature, while cold water comes 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 begins, the water, having hit the hot metal, will quickly boil, forming a large amount of steam, which will create a very high pressure. This pressure will be enough to destroy the device.

To prevent an explosion from occurring, it is necessary to install check valve for a water heater that needs to 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 with the hot water taps closed, it simply will have nowhere 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.

It is obvious that 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 (excessive 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 body. 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, allowing 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 the tube 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 a hose of a 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. You can use it to 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.

Installation

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 thread, 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 a drain valve with a tee on a pipe with hot water inappropriate. It will be impossible to drain water through it, and there is no need for extra detachable connections 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 forcibly 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. Can choose safety device with slightly less pressure than the boiler, but by no means 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.

When operating any heating equipment, it is very important to follow all recommended safety precautions. This applies not only large installations, which are used in construction or production, but also 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 the school physics course. 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:

• doesn't allow hot water get back into the 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 excess occurs normal indicators pressure and temperature;
• makes it possible to safely drain 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. On both ends large cylinder threaded parts are fixed, which are needed to connect the safety valve with 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.

The check valve inside the small cylinder is rated for higher pressure. As soon as this indicator becomes critical, a spring is activated, opening the valve. Thus, excess water will be reset.

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 occurs not in the boiler itself, but in another device, most often in a heating boiler. So the work indirect boiler and the boiler are closely interconnected. For this type of water heater, it is necessary to select a suitable safety valve.

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 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 you open a hot water tap at this moment, 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 selecting a safety valve for domestic 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 valve capacity. 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 technical data sheet of the device, 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 heats up to desired temperature, excess liquid will begin to flow out through the safety valve, which means it is quite suitable for operation. If water does not flow through the valve, it is most likely faulty.

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 also 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).

A safety valve is essentially a relief, automatic device that is triggered by overpressure at the inlet before the valve.

Both devices have the same design, disc type. They differ in throughput and pressure settings. 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. You can find out what the nominal pressure of a particular safety device is from the inscription on the device body, but it may not be there. In this case, you should focus on lower value i.e. 0.6 MPa.

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 opening start value safety valves. 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. There is no universal way to solve this problem. It all depends on the specific circumstances.

From the quality of the binding storage water heater electric type Not only the duration of its operation will depend, but also the level of safety during operation. This is one of the most serious moments when installing a boiler and requires special attention. Correct strapping for a water heater is called a safety valve built into the cold water supply system.

The integration of a safety valve protects against a sudden increase in pressure in the internal part of the unit, significantly exceeding the norm. The question arises, what is the reason for such a jump? As we were able to establish, during heating the liquid increases in volume and, therefore, expands. Due to the tightness of the heater reservoir, the resulting excess simply has nowhere to go - the tap is turned off (as a rule, a check valve is installed on the supply).

Further heating of the liquid may cause increase in pressure. At this moment, there is a danger of exceeding the tensile strength of the unit and rupturing its walls. To avoid such an explosion, a safety valve is installed for the boiler.

Some owners may ask: is it worth the hassle of installing a fuse when you can simply remove check valve. Experts answer this in the following way: at a relatively high and uniform pressure in the water supply system, such a scheme will function, but for some time. This does not mean that such actions are a way out of the situation. The fallacy of this scheme is due to a number of reasons:

1. The pressure in the water supply system is not stable.
2. Excess water is removed from the boiler into the water supply, exposing a heating element.
3. By heating the air, the boiler will fail after a while.

Burnt out heaters are not the most a big problem. Much more importantly, there is a danger of unexpected pressure changes in water pipes. The liquid, falling on the heated heating element, quickly turns into steam, sharply increasing the pressure. Under such conditions, the walls of the boiler are guaranteed to rupture. A large number of boiling water and steam, pushed by pressure, will fill the room, threatening everyone in it with serious injuries.

Principle of operation

In addition to the main structure, a safety valve for a water heater consists of several more elements. They are housed in a brass or nickel housing. In most cases, the device looks like an inverted letter T. It is attached to the bottom of the tank on the water heater check valve, capable of preventing liquid from leaking out of the tank when the pressure in the pipes drops.

The perpendicular branch contains another valve, which is activated after the pressure increases and discharges excess liquid through the fitting. The operating principle occurs in several stages.

1. If the tank pressure is lower than that occurring in the pipes, when filling or opening the tap, the poppet plate in the check valve is pressed out by the water pressure. When the pressure level returns to normal, a spring mechanism presses the plate against the protrusion of the housing, limiting the flow of liquid.
2. During active heating, the temperature of the liquid slowly increases, and at the same time the pressure increases. Until it reaches the maximum value, the mechanism is not activated.
3. After reaching the limit level, the pressure compresses the fuse spring, opening outlet channel of the fitting. Excessive volume of liquid from the reservoir is removed through this channel. After the pressure drops to the normal level, the spring closes the flow and water removal stops.

Based on the above, it can be understood that liquid will periodically drain from the fitting channel. This phenomenon occurs when water is heated and pressure in the water supply system decreases. If you regularly notice water at the fitting, this means that the safety valve for the boiler is operating normally.

However, at the same time there is a need to drain the flowing liquid. To carry out the procedure, a tube of a suitable size is attached to the nozzle: it must be tighten with a clamp to ensure secure fastening. The standard operating pressure in the water heater tank is from six to ten bar. Without reliable fastening, the tube will simply break off, so the choice of clamp must be approached with special care. Tighten it tightly and lead the tube to the nearest sewer drain.

The tube to the fitting must be transparent, ideal option there will be a reinforced hose. This helps control the performance of the system, and the reinforcement provides additional protection against pressure.

Valve operating principle

Features of different types of valves

If we talk about a standard safety valve for a boiler, they are not very different in appearance. However, there are small nuances, responsible for the ease of use of the device.

The image shows valves equipped with release levers. Their purpose is to periodically check serviceability:

• the lever is moved to a vertical position;
• it activates the spring mechanism, pulling it along with it;
• As a result, a channel opens through which water flows.

Release lever on valve

The differences between the models shown are that the valve located on the left has a fixed lever special bolt. This eliminates the possibility of involuntary opening and complete removal of liquid.

The following image shows valves without a positive fluid release lever. The left model has a threaded lid at the top. It is intended for maintenance of fuses. If necessary, unscrew it to remove blockages, scale and other contaminants.

Valves without lever

The right model is the least preferred option. It does not have any markers, a water release lever or a service hole. This is the cheapest and lowest quality product coming from China. There is no need to talk about reliability and durability. You can use it only as a temporary replacement at your own peril and risk.

Pressure rating note

There are a few other notable differences. The arrow shown on the body indicates water flow direction, as well as an inscription informing about maximum pressure, which the device can withstand. At first glance, the details seem insignificant. But if you can easily figure out the direction of liquid flow (to do this, just look at the location of the poppet-type valve), then the situation with ratings is more complicated.

By what signs can you distinguish between a six and ten bar valve? Only by experience. You may ask, how do suppliers differentiate them? No, only according to the inscriptions in the documents. Experts do not recommend purchasing devices without any markings on the case. Of course, the cost of labeled products may be higher than that of analogues, but it is better not to save on this issue.

Fitting shape

In addition, it is worth paying attention to the shape of the fluid removal fitting. In the left model this element is quite long and has a nonlinear shape. It will be easy to attach the tube to it, and the length is quite enough for secure fastening with a clamp.

The shape of the similar element in the right model is different. It has a characteristic expansion at the end, but the most important thing is the length of the fitting. It will be quite difficult to install a tube on it and even more difficult to ensure reliable fastening. The use of artisanal methods will not guarantee a good result, and difficulties with drainage may arise in the future.

For large volume boilers

Each of the devices described above is designed for a storage water heater with a volume of fifty to sixty liters. To tanks bigger size use other systems, each of which integrates special equipment. Most often this ball pressure gauge or a valve that controls pressure.

Ball pressure gauge

They are equipped with a fitting for removing liquid standard thread to improve the reliability of fastening and solve the problem with clamps. This type of device has a high price, but the level of quality is significantly higher than other systems.

A significant disadvantage for many owners may be appearance tap. Especially for such people, the production of fuses has been launched, which not only have practical benefits, but can also decorate the interior of the room. Their cost can significantly reach the price of the boiler itself, so everyone will have to assess the feasibility of such a purchase for themselves.

Installation of other valves

There are cases when, instead of the factory pressure surge protection system, a heater tank is installed blast valve. It is intended primarily for emergency removal of liquid into the heating system. Although their functionality is largely the same, the basic principle of operation is fundamentally different.

The blast-type valve performs its functions only during an emergency. It is needed to urgently remove all water from the tank. It is not intended for periodic bleeding of small portions of liquid. Considering all this, you should not expect correct functioning from such a craft.

Another example is mounting only check valve. Its mechanism will not allow liquid to drain at low pressure in the system, but it will not be able to save you from sudden surges in the tank. As practice shows, such an assembly is also not functional.

Diagram of all components safe operation water heater

Selection and installation

The fuse should be selected based on the pressure that the device can withstand. This figure is usually included in the registration certificate. In addition, the volume of the tank may influence the choice. There are systems with a response threshold of six, seven, eight, ten Bars. These are the most common values ​​for tripping the fuse.

The installation process is quite simple.

1. Wrap a special tape or flax tow around the threads for a tight seal.
2. Screw the valve onto the pipe.
3. Continue to tighten it all the way with your hands, and then turn it a few times using the wrench.
4. Don't forget about making the right choice places for its installation. Experts recommend attaching it directly to the cold water inlet pipe.

After this, you can install a check valve system, or as it is also called - constipation. But these are reinsurance measures; a device with similar functions is already included in the fuse system, and it is also often integrated into water meters.

The diagram demonstrates location ball valve . It is used to remove liquid from the tank during winter storage or during dismantling. Drying may also be required during maintenance or repair. In most cases, it is installed on a tee, which, in turn, is connected to the fuse system.

You shouldn't save money on this important detail, like a fuse. This device will not only help you maintain the functionality of the heater, but may also save you from serious injury. Pressure surges in the water supply are a common occurrence, and no one is immune from tank failure. Spend some time installing safety valves to ensure your safety.

In our catalog you will find shut-off and control valves for the safety of heating and water supply systems. On this page you can select and buy safety valves for use in various temperature conditions and water pressure in the piping systems of private homes and commercial properties. The materials for their production are stainless steel or brass High Quality Therefore, all products are designed for long term use.

Protectively relief valve : purpose and types

Pressure safety valve is a device used to protect a heating or plumbing system from possible water hammer and overpressure working environment. The use of safety valves is prerequisite in creating any process pipeline. The absence of safety valves can lead to breakdown of engineering and plumbing equipment, leakage of water from pipeline system, injury to people.

Depending on the energy source, valves can be of the following types:

valve indirect action,

direct pressure safety valve.

In addition, these fittings can differ in the method of immersion: spring or weight, in the method of releasing excess liquid: closed or open valves, and also in the capacity: low, medium and full lift safety valve.

Safety valve: price, delivery terms

In the FORWATER online store you can order and buy a pressure safety valve from manufacturers Emmeti, ITAP, WATTS the right type thread and size. The presented models are certified and meet the tightness standards in accordance with GOST 9789-75.