Swing check valve vs lift check valve: which to choose
A check valve passes flow one way and closes on reversal, protecting pumps from reverse rotation and networks from draining. The two main types, swing and lift, behave quite differently.
TAZ Engineering Team · · 6 min
Swing check valve
A disc hinged on a pin swings open with the flow. Resistance is low and the design suits large sizes. It is installed on horizontal lines and on vertical lines with upward flow. The steel 19s53nzh is an example. Its weakness is that a heavy disc can slam shut when a pump trips.
Lift check valve
A disc lifts vertically off the seat, in a body similar to a globe valve, so resistance is higher. It is compact and tight and is used in small and medium sizes, including steam and high pressure, normally on horizontal pipe with the bonnet up.
Water hammer and slam
Slam happens when flow reverses before the disc has closed. Pumping stations with long rising mains use fast-closing designs (spring-assisted, dual-plate, tilting disc) or damped closure. A separate guide covers this.
How to choose
Large sizes, water and low loss: swing check. Small sizes, steam and high pressure: lift check. Pumps with long rising mains: fast-closing or damped check valves. State the medium, DN, PN, pipe orientation and pump duty.
Checklist
- medium
- DN and PN
- pipe orientation
- flow direction
- allowable loss
- water hammer risk
- pump type and rising main length