Why do I need a check valve?

The installation of a plumbing and heating system is a very important and important task that needs a professional approach. This is due to the need for the right combination and selection of all the necessary components. In this article, we will describe why a check valve is needed and what should be paid special attention when selecting and installing it.

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What is a check valve?

Non-return valve is one of the types of pipeline fittings that performs a protective function and prevents the working medium from moving in the opposite direction of the main flow. These locking devices have a fairly simple and understandable design, which greatly simplifies the procedure for their operation and installation.

Most residents of apartment buildings and private houses are wondering why a check valve is needed in the water supply system? In fact, it is this type of protective armature that not only ensures the correct functioning of the water supply system, but also allows significant savings.

Important! The main saving factor is that the water is delayed in the system, and does not go back.

Why use a non-return valve?

This device is suitable for installation on any type of communication:

1. It is mandatory to install a return water valve in systems where water is withdrawn from a well or well. The main task of this device is to maintain pressure in the system, which in turn prevents water leakage, even in the event of problems with electricity supply.
2. Also due to the presence of a non-return valve, the life of the pumping equipment is significantly extended, because it never functions "on dry".

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Types of check valves

The check valves differ among themselves not only in construction, but also in the way they are connected to the common piping system. The type of fastening can be as follows:

• All-in-one connection - welding or soldering, which can be performed on a pipeline of any material. This method of fastening differs quite a lot of labor, but if done correctly it provides excellent tightness.
• Flange mount - two elements, which resemble a disk in shape, are tightened together by means of special bolts. This connection option is often used in large-volume pipelines.
• Clutch connection - best suited for small in volume piping systems and is a fastening assembly with an internal thread. Most often this method is used in private buildings.
• Wafer type fastening - designed for products that are flat and executed by fixing them between two flanges.

Important! The most suitable method of fixing should be chosen, in advance consulting with a specialist, since it is on this characteristic will depend on the features of the installation work.

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Scope of application

There are plumbing systems where the use of a non-return valve is mandatory, as well as pipelines in which the use of this valve is recommended by specialists. Its use has found this equipment both in the industrial sector and housing and communal services, and in residential areas.

To understand better why a check valve is needed, it is necessary to know in which household situations it is applied. Basically these are the following directions:

• for equipping risers for cold and hot water supply in apartment buildings;
• in the process of operation of storage systems of water heating - boilers, electric and gas columns;
• for equipping an independent heating system in a private house;
• when using deep pumps to supply water from wells.
  

Central water supply systems in apartment buildings

Often, each apartment produces hot and cold water, which is done by using separate risers. In general, the pressure in different systems is different and sometimes this difference can be very significant.

When using water, we usually open both mixers simultaneously, which allows us to get the water flow of the desired temperature. As a result of this action, water moves in a direction from a higher pressure level to a smaller one.

That's why there are situations when the riser overpowers a weaker pipeline with greater pressure, and as a result of this interaction, the water can flow back through the pipe.

Important! If the water supply system is improperly installed, there may be a situation where a hot stream appears in the riser intended for cold water.

This situation can be avoided by using a check valve, which is installed directly after the water meter. In these cases, the installation of reinforcement is mandatory and documented among the basic requirements of water supply organizations.

Installation of water heaters of storage type

If you decide to install a boiler or a column in your apartment, experts will definitely advise you to install a check valve in the area of ​​cold water entry into the system. This recommendation is mainly connected with the peculiarity of the heater effect.

Such a device is usually filled by the pressure of cold water, and during operation, due to the natural processes of physics, when the liquid is heated, the level of its pressure increases. Thus, the hot water tends to begin a reverse movement along the main with a cold liquid. By this example, we hope that you understand more clearly why a check valve is needed, because it is the one that prevents such a phenomenon.

The organization of independent heating in the house

The use of check valves is necessary if you are installing an autonomous heating system to heat a private living area. This need is connected with the use of several working circuits, which can have different temperatures of the working medium and different functional purposes.

For example, the following systems are often equipped:

• circuit for heating water in a storage device - boiler;
• circuit for water supply of heating radiators;
• circuit for the realization of warm floors.

Each of the above systems has its own hydraulic resistance, which is regulated by a circulation pump with a variety of pressure characteristics.

With such an autonomous heating system, users often encounter a situation where a pumping equipment with a higher power can provoke the reverse movement of the working flow through a system with less powerful pumping equipment. The emergence of such a situation is not only undesirable, but also unacceptable. Therefore, experts insist on the mandatory installation of check valves at the outlet of each circulation pump.

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Features of the

The valves differ not only in purpose and method of fastening, but also in a constructive structure. Most often, the following types of check valves are used to equip water supply systems.

Wafer type

The main advantage of this type of armature is the democratic price and small dimensions. The most rational use of such structures for systems where there is a significant space deficit. The installation of this equipment is quite simple, because it is enough to pinch between the main elements of the structure. The main condition is to install the check valve in the correct position so that the water flow freely passes in the desired direction.

The main working unit of this design is represented by a clamping disk, which is fixed by means of a spring of a certain rigidity. Under the pressure of the flow, the valve opens, and when the physical effect weakens, it automatically closes, which prevents the movement of the working medium in the opposite direction.

Important! For water supply systems where there is a risk of water hammering, it is customary to use two-lever mechanisms with which to achieve high level protection. This kind of system is represented in the form of two circles, which are fixed on a common axis. Many mechanisms of this kind provide for shock-absorbing components that soften the impacts.

Petal

The working unit of such a non-return valve is presented in the form of a special spool valve, which has an axle located above the bore. Under the pressure of the water pressure, the flapping element is raised and the system is filled.

Important! When choosing such a check valve model, it should be borne in mind that a major deterioration of the equipment takes place when the main element is slammed when the working medium pressure decreases. Therefore, it is better to give preference to equipment with a damping system.

The main advantage of such check valves is the possibility of their operation in the construction of large diameter pipelines.

Lifting

Lifting check valves consist of a lifting spool that moves up and down. When the pressure of the working medium decreases, this system drops into the saddle area and completely closes the water supply system. A node of this type is mounted on the horizontal pipeline area in such a way that its axis is strictly vertical.

Important! The main advantage of this system is the ability to replace certain parts without replacing the entire assembly.

In this article, we told you why you need a check valve in the water pipe, what it can be and how it is used. Sincerely we hope that this information will help you make your water supply system as efficient and safe as possible.