Check Valves

Check valves are an important type of fitting because they allow fluid to flow in only one direction. They work by having a spring inside the component that pushes the disc into the valve seat and keeps it closed. The flow must overcome the force of the spring. In the opposite direction, however, the flow pushes the disc into the seat, thereby keeping the valve closed.

Check valves are designed to achieve minimal pressure loss and low opening differential pressure while preventing backflow of the medium. Spring-loaded check valves can be installed in any position, but the lowest opening pressure is achieved in the vertical position of the valve with the flow direction downwards. An exception is larger wafer check valves, which close by the weight of their own flow. Such valves do not need to be installed so that gravity closes them.

Check valves can be used in domestic water distribution systems to prevent backflow through water meters – and thus inaccurate consumption measurement. Another useful function of a check valve can be its use in sewage pipes, ensuring smooth drainage into the public sewer system and protecting against the risk of flooding the house. BOLA company also offers check valves for heating systems.

When selecting check valves, it is important to distinguish between several types based on connection – there are threaded, wafer check valves, and valves with compression rings. It also depends on whether they will be used in copper or steel piping. Check valves also have different temperature ranges.

Some wafer check valves – also referred to as "butterfly" – do not contain a spring, because due to the large size of the fitting, it is sufficient for the flow direction to control everything.

Regarding the material, for example, the DN 80 ABO VALVE 824B080 check valve has a body made of ductile iron and a disc made of stainless steel.

Wafer check valves from the manufacturer ABO VALVE series 800 (flap) are mainly used for clean and waste water, sludge, thick and viscous liquids.