Patented diaphragm check valve maintains bubble-tight seal in whatever position it is mounted. Valves are not dependent upon gravity, mounting positions or reverse flow. Its patented diaphragm automatically positions itself against the valve seat in an identical location each time. Valve are also chatterproof as well as leakproof. Since there is no internal sliding or loose parts to slam or vibrate, chattering is eliminated and operation is silent. Request catalog CKM.