Check Valves are used to allow flow through a pipeline in one direction and prevent flow (check) from returning in the opposite direction. Check valves are commonly installed on the discharge side of the pump. The most important role of a check valve is to act as the automatic shut off valve when the pump stops to prevent draining of the system. Pressure Surge (Water Hammer) can be greatly controlled by selecting the correct check valve. DeZURIK factory trained representatives and application engineers can assist you in sizing and selecting the correct check valve for your application.