Swing Check Valves

Swing check valves, like all check valves, are used to prevent back flow in the line. The pressure of the fluid passing through a system opens the valve, while any reversal of flow will close the valve. The swing check valve functions by allowing flow forces to move the closure element, it is a hinged clapper which swings or rotates around a supporting shaft.
The disk swings away from the valve-seat to allow flow in the forward direction, and returns to the valve-seat when upstream flow is stopped, to prevent backflow.
Swing check design is one of the most common and best check valve for general-purpose use. These valves produce the lowest pressure drop, when compared with other check valves of the same size, the internal contours and shapes allow them to fully open at low fluid velocities and create a smooth flow path through the valve.
The design is simple and easy to maintain and can be used for either horizontal or vertical (fluid flowing upward) pipe layouts. Because of their design, swing checks are not fast-closing valves due to the travel distance from full open to close.