Check-valve slam test

Screen a check valve for slam / water-hammer risk from its placement and the reverse velocity it would see when the driving head is lost — a targeted transient safety check.

• Pump-discharge check valves that could slam on a pump trip.
• Deciding whether a plain swing check is safe or a damped / non-slam type is needed.

The reverse velocity at the instant of closure is estimated from the flow-deceleration rate and the valve’s dynamic characteristic and compared against a slam-risk threshold; a fast-closing valve on a rapidly-reversing line is flagged.