Check valves are devices designed to prevent the return flow of the working fluid.
They are installed in pipe systems to prevent leakage and loss of working fluid and to protect devices from damage that would produce backflow of fluid. These are self-acting devices, which perform their function automatically, without a drive system. They allow the fluid to flow in one direction, otherwise, their shut-off body automatically closes the bright opening of the pipe and thus prevents undesired backflow of fluid.
Closing is done with the help of a spring and the pressure force of the return fluid.
Check valves can be mounted in a horizontal and vertical positions, and since they allow the flow of working fluid only in one direction, it is necessary to pay attention during installation that the direction of the arrow on the valve housing corresponds to the direction of movement of working fluid in a given pipeline.
They are used in plants for obtaining, preparing and distributing water, in communal facilities, in irrigation systems, in various plants of the chemical and petrochemical industry and in energy plants.
Non-slam check valves are made for nominal diameters DN 50 to DN 500 (mm), nominal pressures up to NP 25 (bar), on request up to 40 (bar) and temperatures up to 150 (° C).
The housing and the shut-off body are made of structural steel by welding, provided that the sealing part of the shut-off body is made of stainless steel.
The sealing ring is made of technical plastic of appropriate hardness or other suitable material, and the plain bearings are made of bronze.