Almost no water supply or heating system can be imagined without a check valve for water. This reinforcing part not only allows other components of the systems to function normally, but also protects them from different kind emergency situations. What is this device and why is it needed? In the features, classification and application of the check valve, we understand further.

What it is

A non-return valve is a shut-off device that ensures the flow of water in only one, correct, direction and prevents its return movement. Its structure is quite simple:

• metal case-cylinder, which consists of two parts with threads or flanges;
• shutter made of metal or plastic with a gasket;
• spring supporting the shutter.

If water does not pass into the pipeline or a special pump hose, the spring holds the shutter and the valve itself remains in the closed state. When the water begins to approach the valve and creates enough pressure to weaken the spring, the valve opens and water flows through the device without problems into the pipeline or the corresponding hose.

Check valve for water

If the pressure decreases for one or another regular or emergency reasons, the spring again supports the shutter and the movement of water stops. In turn, the drop in the pressure level causes the valve to return to its original position, that is, it closes. At the same time, the water that is already directly in the pipeline or hose also holds the valve, thereby preventing it from opening and blocking the reverse flow.

What are the types of valves

Check valves for water differ from each other in design, mounting method, material and dimensions. Let's go through the main types of locking devices and their characteristics.

By design type:

1. Ball - equipped with a locking metal ball, pressed against the seat by a spring.
2. Spool lifting - have a locking piece in the form of a spool.
3. Swivel lifting - equipped with a locking cover fixed on the axis of the housing.
4. Disc - have a locking disc connected to a spring-loaded stem.

Advice. For small diameter piping, it is recommended to use ball or lifting rotary valves, for large diameter- disk or spool lifting.

Mounting type:

1. Coupling - involve fastening with the help of threaded transitions.
2. Flanged - fastened with flanges.
3. Wafer - fastening is made by bolting the flanges, between which the valve structure is located directly.

Choose the right valve for your plumbing system

By type of material:

1. From cast iron - mechanically strong, relatively inexpensive, but not very resistant to corrosion valves for pipelines of large diameter.
2. Made of brass - reliable, low maintenance and corrosion resistant valves for small diameter pipelines.
3. Made of stainless steel - resistant to aggressive substances and corrosion, durable valves for pipelines of any diameter. Practical impeccable qualities cause a very high cost of devices.

Advice. Optimal for use in everyday life will be a valve made of combined materials: body - brass or cast iron, spring - stainless steel, valve - plastic.

Why and where are such valves needed?

There are a number of situations where the use of the device is not just desirable, but necessary. Let's find out where and why these devices are most often installed.

Firstly, to water pipes in houses where hot and cold water are supplied separately - through their risers with different levels pressure. During the opening process, when both cold and hot water at the same time, the liquid is forced through from higher to lower pressure, as a result of which hot water can enter the cold riser or vice versa. Only a shut-off valve will help to exclude this.

Secondly, in gas or electric. Such storage devices are filled by means of pressure cold water, which, upon subsequent heating, increases the pressure in the system and, already being hot, begins to rush back into the cold line - the valve will block the wrong fluid flow.

Scheme: check valve connection

Third, in the system autonomous heating with several circuits that differ in purpose and coolants. In this case, the individual skin circuit has its own hydraulic resistance and its own circulation pump different power - the shut-off valve will not allow powerful pump provoke a return movement of water in a circuit with a weaker pump.

Fourthly, to the deep well pump. Everything is simple here: pump equipment can be placed at a depth of tens of meters - in the event of plant shutdown in the absence of shut-off valve water will tend to “leave” the pipeline into the well, which is unacceptable.

Now you know that the functioning of water supply and heating systems without a check valve would be very difficult. This device is designed to support smooth operation systems and prevent emergencies, which means that it can bring great benefits: significantly facilitate and secure your life.

Check valve for water: video

Check valve for water: photo

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H In order for the plumbing system in a private house to function correctly, it is necessary to install it correctly, not missing the little things. For example, inconspicuous, but very important device is a check valve for water pump. If this element is missing or becomes unusable, then the water station system will not work properly. Water will enter the house with a noticeable delay, the pressure will be poor, and if the pump is weak, it will completely disappear. The presence of a valve allows you to get water instantly after you open the tap.

Product appearance

This device is most often installed at special stations that are included in the water supply system. The task of this element of the system is to prevent the mixing of water. It works according to the following principle: the liquid can pass only in one direction, it cannot go to the opposite part of the pipe. This is necessary so that water from a well or well cannot go back and is sent to the water supply. If the system is equipped with such a valve, then when opening the tap, you will not need to wait until the pump pumps water: it will flow immediately. In the absence of a device, air accumulates in the system, and you must first release it, waiting for the water to flow.

The station itself can be located both on the surface of a well or well, and in a specially designated place in the house. In this case, a pipe will be lowered into the well, equipped with a debris screen and a check valve for water for the pump.

If the pump is used in a city apartment, then given element allows you to avoid the effect when, when one tap is opened, the pressure drops in another. This design in the apartment will not hurt if you plan to install a boiler. It will need to be mounted not only on the riser of cold, but also on hot water. This will help to avoid the loss of heated fluid. Without this device, some of your water will go to the neighbors living on the floor below. Thus, the check valve saves energy, as it saves the system from unnecessary losses.

Check valves for pumping stations: types of construction

On sale you can find a large number of similar devices that differ in design, material, size, and each has its own characteristics during installation:

• The check valve for water for the pump can most often be found with a lifting type locking element. The device is equipped with a shutter that rises up or falls down, preventing the movement of water. When water enters, the valve rises and allows it to pass, and when the pressure drops, the valve lowers and prevents the liquid from returning. The mechanism moves thanks to a special spring.

• Return parts for pump ball type. This type devices has a spherical valve that blocks the path of the liquid. With the pressure of the water pressure, the spring raises the ball, and the system passes water, and after the pressure drops, the element closes.

• disk element. It has a shutter in the form of a disk, which moves along its axis with the help of a spring.

• Bifold devices. Their shutter has two flaps that fold under water pressure, and when there is no pressure, they close; All this is driven by a spring.

In everyday life, the part with lifting type mechanism. It can be repaired by replacing the spring.

Coupling spring check valve: types by material

Products can be made from different materials:

• Brass is the most popular material. It does not rust, easy to maintain, well suited to all types of pipes.

• Cast iron cases can be found much less frequently. This material is subject to corrosion, various deposits accumulate on it quite quickly. Usually, cast iron products are used on large diameter pipes, and they are not used in everyday life.

• Stainless steel. She is the most reliable, but also the most expensive material: elements from it will last much longer than any others. They are not afraid of corrosion and exposure to various substances, deposits do not accumulate on the body.

• Combined: the body of such a product can be made of different materials, for example, combine brass and stainless steel. The shutter of any device is most often made of plastic.

Helpful information! Choosing a valve for home use buy brass. It serves for a long time, and its cost is much lower than steel.

Differences in the method of attachment

Most devices are attached by means of a coupling. This requires two threaded adapters, which are matched to the size of the pipeline. Flange type fasteners can also be used. Most often they have cast iron elements large diameter. Such flanges are tightened with bolts. This type of fixation is also relevant for small products, when there is no room on the pipe for other fastening.

The spring check valve is the most commonly used. It is used in apartments for installation on a pipeline, water heater, such products are installed after the meter, which does not allow it to turn in the other direction. Devices of this type do not allow the pipes to empty if the water in the riser is drained.

The device of the spring mechanism: it consists of a brass body, which is disassembled into two parts. A movable spool is placed between the halves. It is usually made of plastic. Such a spool is set in motion by water pressure and a spring.

Related article:

Check valves for submersible pumps: installation rules

Before starting installation, you need to choose the right place where the part will be installed. The location is dictated by the type of submersible pump. You can pick up any element, it will interact with the device, regardless of its type, brand and model. This is due to the fact that the principle of operation of the equipment is the same. It is quite possible to replace check valves for submersible pumps on your own, for this you will need to carefully study the proposed material.

Most pumps are already equipped with the required part from the factory. There is such a device both at the inlet and at the outlet. Additional devices such devices are not required.

If you have purchased Vacuum pump, then the check valve must be installed in front of the accumulator, but after the unit itself. Ball or spool type devices interact best with this species. If the pump is surface, it may have several of these elements at once. One of them is installed in a hose through which water flows. The part must be placed at the end of the hose lowered into the water. The second element is mounted in front of the accumulator. Any type of product is suitable for such a device. Some models are an exception; the manufacturer indicates in the instructions for the device which are required.

In order to install the return element, you will need to embed it into the pipe. To do this, you need to purchase fittings and couplings. Before starting work, the water must be shut off or the system must be stopped so that the water flows do not interfere. Then in Right place the desired element is inserted.

Helpful information! You can make the fixation stronger with the help of a fum tape. Make sure the element is right side otherwise it won't work. If it is lifting, check if the axle is vertical.

Items for pumping stations installed after the ratchet. They are located on the main suction pipe. It is possible to install directly in front of the station, but this option is inferior to the first one in quality, since in this case the amount of water can be significantly reduced.

The pipe can be filled not only with water, but also with air, which is sucked in by the pump. Air entering the system will make it noisy. If the station uses vibration pump, the valve is best placed in front of the receiver. You can choose any place in the injection pipe for this, but it is desirable to place it in a place accessible for maintenance.

The object is mounted most often in front of the station. When installed on a running system, it is required to position it between the pump and the station. The same is done if the system has a receiver. The pipeline is divided into two parts, on one of which a valve is placed. Then, with the help of a drive, the pipes are connected again.

The correct operation of the pipeline depends on the direction in which the water flows in the device. In order for the plumbing to be serviceable, it must be equipped with auxiliary device, in our case, the non-return valve for water will serve as an assistant. In this article, we will go into the details of selecting and installing these irreplaceable mechanisms and consider how the devices are put into operation.

The tasks of all types of water valves include simplification plumbing work and protection against pressure drops in the pipeline, in particular if the operation of the pump is disturbed. In addition, each individual type also has specific tasks, as it is needed in the water main. There are several varieties that make the water check valve multifunctional:

• devices with a locking mechanism are divided into ball disk, petal, spool;
• divided according to the type of fixation: interflange, flange, coupling;
• according to the speed of shutting off the water, the valve can be: slamming and smooth.

Each option has its own individual characteristics which are important to consider when buying.

So, the ball valve is a ball spring mechanism. The disk type of the valve contains a special disk in its structure. Both of these designs are able to work with maximum high pressure water that is acceptable for polypropylene pipelines at home. Often similar design installed after the pump from a well or other source. Look at the photo how the device looks like.

The petal device can be used exclusively in low-pressure pipes; the spool design is typical for spool options, which is the main working element. All these devices are made of brass or polypropylene, they are mainly installed before and after the counter.

The inter-flange check valve for water is installed in domestic pipelines strictly according to outdated technology, while the flange and coupling options are bolted or threaded for normal fixation. If necessary, a ball working spring mechanism can also be used.

The slamming mechanism works instantly when water enters, and the smooth one works somewhat slower, but at the same time withstands more long term services. The photo will tell you how the mechanism works.

Each of the types of return devices can be used both for a water pump and for the purpose of being placed in a working pipeline. Moreover, all valves have separate functional features and fixed outside the counter.

Attention! Do not allow used control units to be used in the home until the non-return valve has been studied. These specifications must be verified at the place of purchase.

Functionality of Check Valves

The rotary check valve and other types serve as a kind of fuse for plumbing structures from pressure drops and water hammer, which result in a sudden stop of the pump. Thanks to this thoughtful device, all pipes are now safe, as they have partially automated processes. In particular, they focus on the use of the wafer and ball version, as they have long proven their effectiveness to consumers.

Similar protective structure has the following functions:

• protects your living conditions from flooding, especially if there is an increase reverse flow water, of course, if the device is correctly installed after the meter;
• if a rotary check valve is installed in the sewer line, this ensures that there is no bad smell, especially if the structure is not used for a long time;
• does not allow various kinds of contaminants to enter the pipeline, if their passage from the pump is observed.

When arranging apartment buildings experts recommend installing check valves in the lower floors where pipelines are located, as this reduces the risk of flooding of apartments. Under such circumstances, the wafer device is popular.

Choosing a home plumbing service device

At the time of buying defense mechanism for installation in a water supply system, follow several parameters, then the installation will delight with its operational features owner. We bring to your attention a few simple rules.

1. Before buying, study the design features and connecting element valve. Full compliance with the diameter on the pipeline is important. In modern households, everyone is trying to use coupling options, since it is through the connection that most plumbing systems are assembled.
2. Analyze the principle of operation of the check valve. If you yourself do not understand this, check with the seller or the available documentation for the product, if it is branded. If you observe some violations or malfunctions, refuse to purchase.
3. If there is a requirement to buy a wafer, flange or ball mechanism for a pump or other technical purposes, be sure to compare their capabilities with the characteristics of the environment in which they will be fixed.
4. The material of manufacture must be selected based on specifications water supply: plastic is suitable for polypropylene structures. If a non-return valve is needed for a hot pipeline, it is better to choose an attachment from durable metal, since many propylene structures cannot withstand high temperatures.
5. Brass products are considered an excellent alternative for all fragile structures. They have high protection against mechanical and temperature deformations, and also in the design have a ball mode of action (not in all models).

Attention! All designs of protection against water hammer in the pipeline must be purchased reasonably, taking into account not only the selection rules, but also a number of functional features.

Installing a check valve in the main line

The installation of a non-return water valve on the pipeline in the house is carried out after the pump (if present) and after. It is worth noting that the installation tactics largely depend on what type of design you have chosen. Familiarize yourself with the principle of installing valves in the photo.

Device direct action that ensures the movement of water in only one direction is called a check valve. The shut-off valves function due to the circulation of the liquid and do not require the connection of power sources.

The mechanism maintains the stability of the heat and water supply systems, and also protects the water supply from damage in case of accidents. Find out how the device works and what tasks it solves.

The locking device prevents the flow of liquid into reverse side. It has small size and maintains the desired pressure in the system. Consider the need to use the device in residential premises. It is used in the following cases:

On water pipes. Circulation of hot and cold water in private and apartment buildings distributed in separate pipes. Sometimes the pressure difference leads to the fact that hot water squeezes cold water out of the chamber of a domestic mixer and it becomes impossible to adjust the temperature of the liquid. The valve brings the pressure to normal values.

At the water heater inlet. The filling of the boiler takes place under pressure. When warming up and increasing pressure, the displaced coolant will be sent back to cold pipe. The valve prevents outflow.

In system individual heating in the presence of several heating circuits (boiler, underfloor heating, batteries) that have different meanings hydraulic and pressure indicators. The locking device normalizes the performance.

Before the meter. The question arises, why do you need to mount a check valve on the water meter? The answer is simple: shut-off valves are necessary, because they protect the device from possible damage that can be caused by water hammer, and prevents the turbine from rotating in the opposite direction.

V autonomous system water supply provides water supply submersible pump. It lifts the liquid to the surface and delivers it into the house at an angle. 5°-10° at a distance up to 10 m. Installing a check valve will prevent water from flowing into the well when the pump is turned off.

The principle of operation of the device is as follows: after the water supply to the pipe cavity is stopped, the valve is pressed down by a spring mechanism and remains in the closed position. At the moment when a pressure is formed in front of the valve, sufficient to weaken the spring, the valve opens and water begins to flow into the pipe.

When the pump is turned off, the pressure drops, the valve is pressed again and shuts off the flow. In addition to the compression force of the spring, the valve is affected by the pressure of the pipeline, preventing the valve from opening.

Types and arrangement of check valves

The design of the valve is generally simple. It consists of only a few components, such as a body, a working element and a clamping element. Depending on the version, other parts can be found: stem, pivot pin, disc lever, spring, ball, elastomers and bearings.

There are four types home appliances according to the type of locking element:

Swivel. They work by rotating a steel rotary disk located inside the fitting.

Ball. The liquid flow is blocked by a spool made in the form of a ball.

lifting. The valve moves up, opening the way for water and goes down, blocking the flow. Devices are mounted vertically only.

Disk. The clamping disc acts as a locking element.

By type of connections, valves are divided into the following groups:

Coupling with thread. Designed for small diameter pipes. They are fixed by means of a thread cut into the inner or outer parts of the two couplings.

Wafer. They look like tabs. Installed between two adjacent flanges. Fastened with studs or bolts.

Flanged. Equipped with connecting flanges with sealing gaskets.

With holder for welding. Installation is carried out by welding. Suitable for pipeline sections in an aggressive environment.

According to the type of material from which the body is made, the valves are divided into plastic (polypropylene), brass and steel.

Dimensions stop valves depend on the type of plumbing equipment installed in the apartment or country house. Here are the main running varieties:

Valve size 1 inch. Is in high demand.

valve for water 1/2 inch. Not so popular due to weak bandwidth.

check valve 3/4 inch. Quality product for small diameter pipes.

When choosing a product, you need to be guided on 2 main characteristics: pressure and nominal diameter. The first is abbreviated RU (PN) - operating pressure. If the valve is marked with symbols RU-20 or PN-20, which means that it can work effectively at a pressure of no more 20 bar. The second parameter is called DN (DN)- conditional pass.

Marking DU-22 or DN-22 indicates that the nominal bore diameter of the device is equal to approx. 22 mm.

Parameter DN (DN) valve must correspond to the same parameters of all neighboring elements. The device should be installed with DU-25 (DN-25) only in conjunction with pipes and fittings marked as DU-25 (DN-25).

How to install the valve correctly

The easiest way is to install a check valve in a coupling version. It is suitable for embedding in heating and water supply systems both in apartments and in private houses. To protect metering devices and other network segments from the occurrence of water hammer, it is necessary to perform 3 simple steps:

Choose a location. In apartments, a water return valve is usually inserted to the meter or in front of the heating boiler.

Take the fittings of the required diameter and wrap the sealant on the thread: tape, thread or linen.

Fix the device with fittings, open the water tap and check the connection for leaks.

On the valve body, manufacturers stamp the image of an arrow. It shows the direction of water movement. Installation must be carried out with an eye to this landmark, otherwise the pressure will remain closed after completion of work and the locking device will have to be rearranged.

Let's give some advice:

In the circuit of a working plumbing system the valve is installed in front of the pumping station. To do this, a place is chosen on the pipe where a gap is made, and connected with a locking device.

As part of the sewer, the valve will help prevent the flow of waste and Wastewater v reverse direction. Installation is carried out on pipes of suitable diameter using a tie-in. The valve diameter can be 50-100 mm. Cast iron or plastic connections are made with a special adapter.

V single-circuit system heating valve is necessary to create pressure of the coolant due to heating, without using a pump. Installation is carried out similarly to the process of installing a valve on a water supply system.

Sometimes even reliable shut-off valves fail. If a breakdown occurs, you need to learn how to disassemble the check valve. This is not difficult. First you need to block the flow of working fluid and drain it from the system. Then you should unscrew the nuts, dismantle the flanges or fittings. Final stage- removal of the locking unit and replacement of failed parts. Assembly is carried out in reverse order.

It is necessary to carry out the installation of shutoff valves near the water meter very carefully so as not to damage the seal installed by the housing and communal services workers.

Situations when only cold or hot water comes out of the taps, and the coolant goes in the opposite direction through the heating boiler, may occur if the device does not work properly pumping system. This is due to a decrease in water pressure.

The valve is a small cylinder, with a shutter mechanism and a spring in the form of a rounded rotating petal. In the absence of flow movement, the shutter is tightly closed, and with the advent of pressure it opens to stop the outflow in the event of a failure of the pumping unit.

The diameter of the shut-off valves for installation on the deep pump must correspond to the size of the pipe. This will make the connection as tight as possible. New models of pumps are already produced complete with check valves.

The deep-well pump must be equipped with a primary filter before installing the valve. The suction locking mechanism of the pump requires reliable protection, so the valve is threaded to a perforated stainless steel cage.

Shut-off devices designed for a surface pumping station solve the same problems as check valves for deep pump. The difference is that the fittings are mounted on the suction pipe of the pressure blower after the ratchet.

Usage locking device help prevent emergencies in heating and water supply systems, have a positive effect on the operation of pumping stations, eliminate filling water pipes air, will allow you to use water for some time even after turning off the well pump.

A horizontal check valve is a type of shutoff valve that is designed to prevent flow working environment in the opposite direction.

The scope of such devices is quite extensive:

Most often they are used in systems where there are several pumps. So that their simultaneous work does not lead to mutual influence. This allows you to protect the pumps themselves, as well as fittings and pipes from damage;

The presence of horizontal check valves in the system is an excellent safety net in case of accidents and emergency situations;

In systems of water supply, sewerage. The operation of any hydraulic system is associated with pressure drops. Valves of this type protect against the reverse flow of liquid. This is especially important in the case of sewerage;

They are used as make-up valves in various hydraulic drives;

In conjunction with filters. To protect the filter from reverse flow.

The device and principle of operation of the horizontal check valve

The horizontal check valve has a fairly simple device. It consists of a body, a locking element, a seat. Also, it may include additional components such as springs. They are mainly designed to reduce the frictional force when interacting with the valve seat. The valve is designed so that the pressure drop across it is in the range between 0.01 and 0.03 MPa. The body of the horizontal check valve is marked with an arrow that indicates the flow of fluid in the normal direction.

The principle of operation is as follows: when the fluid flows in the forward direction, the locking element is fully open. As soon as the liquid begins to move in the opposite direction, the locking element (under the influence of its own weight or springs) slams shut and the flow is blocked. Everything happens automatically. The horizontal check valve belongs to the class of direct acting fittings.

Wafer type horizontal check valves

Wafer variant is a popular and quite practical variety of such valves. It has small dimensions due to the absence of flanges for joining with the pipe. Both in construction length and in weight, this modification is several times smaller than conventional check valves. In view of this, wafer valves are characterized by less time and material costs for installation. They are easily mounted directly in a pipe break. Appropriate gaskets must be used for each specific fluid. When choosing, pay attention to the internal diameter of the valve, as well as the nominal pressure.

There are two main varieties of wafer horizontal check valves:

Disc spring check valves. The principle of operation is described above. A disc is used here as a locking element, which allows to reduce to the required minimum building length. In addition, this design provides a wide range of sizes. These horizontal check valves are available in diameters up to 200 mm;

Double leaf check valves. The diameter of this reinforcement can reach 700 mm. Due to their high strength and reliability, such valves are widely used in systems where water hammer can occur. To absorb such shocks, special dampers may be included in the composition of the valves.

During operation, the hydraulic check valve, regardless of the specific type, is subjected to serious stresses, in particular pressure and temperature. Therefore, it is extremely important point are the materials of manufacture. So body parts are made from brass, bronze, alloy steel, cast iron. Tightness on the saddle can be provided with rubber, plastic.

The Admiral plant is engaged in the production of high-quality valves, including wafer valves with a diameter of 400 mm or more. The plant's products can be used not only in water supply and sewerage systems, but also in technical pipelines at enterprises. To ensure high resistance to aggressive environments, titanium can be added to their composition.

The composition of the plant "Admiral" includes, which ensures the steady development and improvement of products. Each unit of production corresponds not only to domestic state standards quality (GOST), but also international (ISO). The client is able to order individual development for a specific object. The plant guarantees reliability, durability and ease of operation of check valves.