Check valves are characterized to avoid the return of the flow direction in a conduit. When the way is open and under the pressure of the flow the mechanism offers low resistance and a minimal pressure decrease. GRM Valves and instrumentation offers 4 types of check valves:
Disc type check valve: Meaningless positioning because doesn’t work by gravity. The flow is open when the pressure pushes the spring that holds the seal and this closes the flow when it returns back.
Swing type check valve: The retention is originated by a swing check. It works by gravity law so must be set in a determinated position. There is also available double swing check valve which is based in two semicircular checks that turn in an axis and seal the flow when they are aligned. They allow less pressure decreasing but have less watertight capability.
Lift type check valve: Designed to open the flow by a determinate pressure and then avoid the return of the flow.
Ball type check valve: The flow gets blocked by a movable ball that is pushed by water pressure to a non-disturbing lateral side. Then, when the pressure stops the ball return to the initial position and blocks the flow.
Materiales: Stainless steel, carbon steel, brass, aluminic bronze, bronze, zinc plated steel.