Rule 3800 G.P.H General Purpose Centrifugal PumpGeneral Purpose Centrifugal Pump End Suction Centrifugal Pump The Rule General Purpose Pump is designed for use as a washdown pump and or to circulate water to your livewell tank(s). Heavy duty construction for use on commercial or pleasure boats. 1 1 2" (38mm) inlet and 1 1 2" (38mm) discharge outlet. The Rule General Purpose Pump must be mounted below the waterline. It does not deliver high pressure, nor is it self priming. It delivers lots of water