Impeller shroud – the plate that semi-closed impellers have on the back and closed impellers have on the front and back.
Impeller vane – this is the part of the impeller that imparts the force onto the water. It spins the water outward through centrifugal force and as the water is spun out, the vacuum created draws more water through the eye. Vanes are usually curved backward because this design is more efficient than radial and forward vanes.
Volute – is the part of the pump casing that is around the impeller and “funnels” the water to the discharge line.
Discharge – where the water leaves the pump.
Shaft sleeve – protects the shaft from wear caused by the packing in the stuffing box.
Shaft – supports the impeller and connects to the motor shaft using a coupler. The shaft is supported by bearings which reduce friction.
Packing – seals the opening where the shaft passes through the pump casing. The packing is lubricated by water and should drip 10 to 15 times per minute. If the packing nuts are too tight, it will drip less than that which indicates the packing is not getting enough water to be properly lubricated and will cause packing failure. Packing can be replaced by mechanical seals.
