Swing Check Valves
A swing check valve is mounted with a disc that swings on a hinge or shaft. The disc swings off the seat to allow forward flow and when the flow is stopped, the disc swings back onto the seat to block reverse flow. The weight of the disc and the return flow has an impact on the shut-off characteristics of the valve.
An important thing to be aware of when installing a swing check valve is, that it is not completely maintenance free since the disc needs to be cleaned once in a while. Furthermore, a lever is often mounted to enable visual check. Therefore, swing check valves are often installed where personnel is present.