SWING TYPE Check Valve

Check valves are used in pipe lines to reduce water hammer and to prevent back flow of water to the pumps from rising mains. Reflux valves are generally used on rising mains as they permit water to flow in one direction only and check all the return flows. These are operated by pressure alone, having no external means of control.

In large diameter pipes, the door, in single-door pattern would close slowly and reflux flow would cause water hammer due to surge. Therefore, multi-door pattern is resorted to, in such cases, so as to reduce the time required for closure. The flow may be controlled by means of flaps swinging up and down with pressures on to seats (swing check).