Glossary of Pump Terms: W
Water hammer:
Occurs in a closed piping system as a result of the pressure being rapidly increased when the liquid velocity is suddenly increased. This damaging effect is usually the result of sudden starting, stopping, change in pump speed, or the sudden opening or closing of a valve. Water hammer can usually be controlled by regulating the valve closure time, surge chambers, relief valves or other means.
Water Horse Power (W.H.P.):
The calculated horse power coming out of the pump using the formula WHP = head x gpm/3960
Watt:
A measure of power. 746 watts equals one horsepower.
Wear ring:
Used with closed impeller pumps to restrict leakage from the high-pressure side of the pump to the low-pressure side. Should be replaced when the recommended clearance is doubled.
Welded metal bellows:
A seal design used to eliminate the use of elastomers. Excellent for cryogenic and hot applications. Not as effective for hot petroleum applications because of “coking” problems.
Wet end:
The part of the pump that gets wet from the pumping fluid. Includes the volute, stuffing box, impeller wear rings, and shaft or sleeve.
Glossary of Pump Terms: Y
Yield point:
Where the metal passes from the elastic to the plastic range.