Chapter 19 - Pumps Flashcards
The general class of pumps that use a rapidly turning impeller to impart kinetic energy or velocity to fluids.
The pump casing then converts this velocity head, in part, to pressure head.
Also called a kinetic pump.
Velocity Pumpq
The rotating set of vanes that forces water through a pump.
Impeller
- A measure of energy possessed by water at a given location in the water system, expressed in feet (or meters).
- A measure of the pressure (force) exerted by water, expressed in feet (or meters).
Head (Pressure)
- In a pump, the percentage of water taken into the suction end that is not discharged because of clearances in the moving unit.
- In a motor, the difference between the speed of the rotating magnetic field produced by the stator and the speed of the rotor.
Slip
A pump consisting of an impeller on a rotating shaft enclosed by a casing that has suction and discharge connections.
The spinning impeller throws water outward at a high velocity, and the casing shape converts this high velocity to a high pressure.
Centrifugal Pump
A centrifugal pump, commonly of the multistage diffuser type, in which the pump shaft is mounted vertically.
Vertical Turbine Pump
A type of positive-displacement pump consisting of a closed cylinder containing a piston or plunger to draw liquid into the cylinder through an inlet valve and force it out through an outlet valve.
When the piston acts on the liquid in one end of the cylinder, the pump is termed to be single-action; when the piston acts in both ends, the pump is termed to be double-action.
Reciprocating Pump
A type of positive-displacement pump consisting of elements resembling gears that rotate in a close-fitting pump case.
The rotation of these elements alternately draws in and discharges the water being pumped.
Such pumps act with neither suction now discharge valves, operate at almost any speed, and do not depend on centrifugal forces to lift water.
Rotary Pump
A centrifugal pump in which water enters from only one side of the impeller.
Also called an end-suction pump.
Single-Suction Pump
A centrifugal pump in which the water enters from both sides of the impeller.
Also called a split-case pump.
Double-Suction Pump