products » check valves : function & design

			Function & Design Working Principles A check valve allows flow in one direction but stops flow in the opposite direction. It is also referred to as "non-return valve". STATIC CONDITIONS •  In static conditions (no flow) The check valve is normally closed. The spring tension forces the plunger into its seat keeping the check valve closed. DYNAMIC CONDITIONS •  In dynamic conditions (flow) The water pressure exceeds the spring tension. The plunger is lifted off its seat allowing water to flow through the valve. BACKFLOW CONDITIONS •  In backflow conditions (reversed flow) If the pressure downstream of the valve increases (back pressure conditions) or if the system pressure upstream of the valve decreases (backsiphonage conditions) causing the flow to reverse direction, the spring-loaded plunger closes and prevents backflow.