Valve manufacturer Flomatic’s Drain-Back Plug, Model 48, for submersible pump water well installations, is designed to drain the riser pipe. It activates when a weight drops into the well drop pipe. The plunger is stroked by the weight and opens the valve, which closes when the drop weight is removed. NSF 372-certified, and designed in all stainless steel with Buna-N resilient seating. Reduces pulling weight from 20 to 50%, making it easier to pull pipe and pump.