swingcheck

A swingcheck, also known as a swing check valve, is a type of check valve used to prevent backflow in piping systems. It operates with a hinged or pivoting disk that swings across the valve seat to block reverse flow, while forward flow pushes the disk open to permit passage.

In normal operation, fluid pressure from the inlet side pushes the disk away from the seat, opening the valve and allowing flow. When the flow tries to reverse, the disk swings back into place and seals against the seat, stopping backward flow. The main components typically include the valve body, seating surface, the swing disc, and a hinge or pivot; some designs incorporate guides to stabilize disk motion.

Swingchecks are valued for their simple, robust, and compact construction. They come in full-bore or reduced-bore configurations and are manufactured from materials such as cast iron, ductile iron, stainless steel, and bronze to suit different fluids and environments. They generally require little maintenance and operate without external power sources.

Limitations include the potential for water hammer if reverse flow is abrupt, as the disk can slam shut and create pressure surges. They may exhibit higher pressure drops and slower response compared with some other check valve types, and are not always ideal for highly pulsatile or very high-velocity systems. Correct installation orientation and adequate upstream flow are important to prevent disc chatter and ensure reliable sealing.

Common applications include water and wastewater systems, chemical processing, oil and gas, and HVAC piping.