Pipe fittings are plumbing equipment designed to regulate the flow of the working medium through water supply networks. This type of mechanism includes any valves and cranes installed on communications.
Definition and purpose of valves for water supply
Shutoff valves differ from regulating ones in that they are designed to completely stop the movement of the medium, and not to control the throughput of the pipeline. Such devices have a number of common features:
- wide range of working pressure and temperature;
- anticorrosion coating that prolongs the life of the metal;
- required bandwidth.
Water fittings are made of plastic, brass, bronze, cast iron and steel.
Principle of operation
The shut-off valve works according to a simple principle - during its twisting, the cross-sectional area of the housing passage opening changes, as a result of which the fluid movement stops. In more detail, the operation of the device can be described by the example of a pipeline valve:
- The operator rotates the flywheel.
- Thanks to the threaded connection, the stem begins to move.
- The stem pushes the shutter. The process is controlled by a guide.
- The shutter closes the opening of the housing, preventing the movement of fluid.
The locking device should not be used to regulate the flow. Prolonged exposure of water to metal elements leads to their grinding and loss of efficiency for complete blocking of communication.
Types and arrangement of shutoff valves
Fittings for plastic water pipes are classified depending on the purpose, design, field of application, operating conditions and method of fastening. The choice of device is influenced by the material of manufacture - it must be suitable in terms of characteristics for installation on a particular highway.
Depending on the application, the following types of fittings are distinguished:
- Locking This class of products is the most numerous - it accounts for ¾ of the total devices used. Used to completely turn off the media flow in the line and start it if necessary. Shut-off products include valves, taps and valves. They are used to regulate the movement of various media - gas, steam, water.
- Regulatory. Devices of this type of shutoff valves of water supply systems have valves and are called regulators of liquid level, pressure, environment. They move due to the operation of the electric drive. One of the common names for such models is throttle valves.
- Safety Thanks to these devices, communications for various purposes are protected from excess pressure over acceptable values. If this indicator becomes higher than normal, a partial discharge of the working environment occurs. Safety valves include bursting discs, bypass valves, pulse devices.
- Protective. The main significance of such mechanisms is the prevention of accidents and breakdowns with unacceptable process parameters for the highway. In addition, the mechanism prevents the flow of the medium in the opposite direction. Protective fittings include shut-off and non-return valves.
- Distribution and mixing. It has another name - multi-way. These devices include control valves and three-way valves. Products are used to mix media or distribute work flows in several directions.
- Control Designed for monitoring and regulating fluid levels in boilers and vessels.
- Phase separation. Used to separate working environments in different states. Such devices include condensate drains and oil separators.
Shut-off valves can only be in two positions - “fully open” or “completely closed”. Depending on the type of shutter, the valves are classified into wedge, disk, parallel. When creating irrigation systems, shutoff valves for water pipes with a timer are used.
According to the connection method, the devices are divided in accordance with the following classification:
- Flanged. This type of hardware is represented by round, rectangular and triangular models. Square devices are intended for environments with limited indicators of pressure - no higher than 2 atmospheres. A round shape is preferable - a minimum of resources is spent on its production, and in terms of reliability it surpasses other types.
- Waferless. The range of proposed products of this type is quite extensive in terms of how it is connected to pipelines, pipes of containers and vessels. Models of this group can be chucked, choke, welded and socket.
Shut-off valves are installed on HDPE, metal-plastic, polypropylene and stainless steel lines.
Key selection criteria
When choosing water fittings, several criteria should be considered:
- Destination It can be used for external and internal networks.
- Material. If it is necessary to use valves or regulators in an aggressive environment, it is better to choose a ceramic product. This material is less susceptible to destruction than plastic and metal.
- Maintainability.
- Appearance. When choosing fittings, which is planned to be placed in sight, it is worth considering the style of the interior.
When choosing a brand, it is better to rely on trusted manufacturers. These include the company "Valtek", which implements sanitary engineering in Russia and the CIS countries.
Mounting Features
When choosing water fittings for an apartment, you should make sure that it corresponds to the pipeline according to the following indicators:
- the same sectional shape;
- the same diameter;
- the possibility of reliable connection of the locking device and the pipeline: the identity of the flanges, matching threads.
Basic rules for installing water fittings:
- Any work should be performed only on the disconnected section of the highway. It is important to make sure that there is no working medium left in it, and that the temperature and pressure are normal. Air vents and drains should be open. Warning signs are placed on each side of the fittings along the pipeline.
- Pre-assembly preparation of the connecting elements of the locking structures involves their cleaning from dirt and traces of corrosion.
- Install locking or control mechanisms only on straight and level sections of the highway. It is forbidden to mount it on bends, as this can reduce the tightness of the water supply system.
- For heavy elements of shutters and gate valves, support structures should be provided.
- Tighten fasteners to perform special tools. To prevent the flanges from warping, they must first be tightened from one edge, then from the opposite.
- Welding is carried out only on fittings with an open shutter.
When installing the locking elements, it is important to pay attention to the correspondence of the position of the device to the direction of flow of the medium. It is indicated on the body of cranes, valves and gate valves. For pipelines with the possibility of two-way movement of liquid or steam under high pressure, 2 stop valves are designed for different flow directions.
The cost of stop valves starts from 100 rubles and can reach 200 thousand rubles.The price depends on the size, material of manufacture, features of the operation of the device.
