Pump stages linked by flexible hose

摘要

A two-stage pump device features a main pump 10 for pumping a fluid and a priming pump 14 coupled to the main pump via a length of flexible hose. The priming pump has an axial flow bladed impeller for feeding fluid to and priming the main pump in response to either manual actuation or a switching device. The priming impeller may be arranged in the flexible hose and driven by a flexible drive shaft that is coupled to the main motor and main impeller. The priming pump remains operational to ensure air locks do not occur. The main pump is suitably adapted for mounting in an accessible location and the priming pump is suitably adapted for mounting in an inaccessible location. The switching device is either an automatic float/air switch or an in-built electronic control system and the two stage device is suitable for use as a boat bilge pump.