The VPO electric motor driven rotary vane primer is mounted directly on a Waterous midship pump transmission. A separately mounted model VPOS is also available. With the priming valve, it forms a complete, dependable, factory installed priming system.
Vacuum Activated Priming Valve (VAP):
This valve consists of a stainless steel valve stem, spring and pressure disk in a plastic valve body. A rubber disk forms the seat for the valve stem and also forms a seal between the priming valve inlet and the pump body. A rubber diaphragm forms a seal which allows the valve to open and close while isolating the interior of the priming valve from atmospheric pressure