Fixing Irrigation Pump Prime Loss: The Missing Foot Valve

Why Your Centrifugal Pump Loses Prime

A homeowner with a 7.5 HP centrifugal pump drawing from a pond experiences prime loss. The system worked initially but failed the next morning despite filling with 30 buckets of water. The pump is water-cooled and primed through a hole in the suction piping.

The Critical Missing Component

The expert identifies the likely culprit: no foot valve (check valve) at the end of the suction line in the pond. This valve keeps water in the suction line when the pump is off, maintaining prime. Without it, water drains back into the pond, and the pump must be reprimed every start.

Solution

Install a foot valve at the submerged end of the suction line. Ensure it's properly sized for your pipe diameter and includes a strainer screen to prevent debris entry. This simple addition should resolve the priming issue and allow reliable automatic operation.