A check valve, clack valve, non-return valve or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. These can be supplied in various designs the most common being:
Swing Check Valve
Tilting Disk Check Valves
Wafer Check Valves
Disk Check Valves
Piston Check Valves
Ball Check Valves
Duo-Check Valves
Non-Slam Check Valves
