344 Flashcards
The two units of measuring liquid pressure are
Psi and ft of head
The available NPSH of a system should be____ the required NPSH of the pump.
Equal to or greater than
The formation of vapor pockets, or bubbles, within a liquid is called
Cavitation
The horsepower required to actually drive a fluid-handing pump is called the ___ hp
Brake
One electrical horsepower equals ___ watts
746
The area that surrounds and houses the packing in a pump is called the
Stuffing box
When installing four or more packing rings, you should stagger the joints ____ degrees apart
90
The most common mechanical seal configuration is the ____ seal
Single internal
In some mechanical seals, the rotating element is secured to the shaft by a
Boot
The major cause of bured seals is
Improper lubrication
After grouting a baseplate, you should allow the grouting mixture to set for at least
48hr
When removing springs from pump feet, you should measure movement with a
Dial indicator
Unwanted movement of a pump shaft along its axis is called
Endplay
Cavitation is caused by
Pressure loss
Loss of clearance between wearing rings is called
Ring seizure
On a pump that has both bearings on the same side of the impeller, the bearing nearest the impeller is called the ___
bearing
Inboard
The most common sign of cavitation in a pump impeller is
Pitting on the back sides of the vanes
In general, runout on a shaft should not exceed ____ inches
0.003
Too much clearance befween the stationary rings and the impeller or rotating nings of a centrifugal pump wil cause
Fluid leakage
When installing a new gasket, you may wish to apply ___ to the lower half of the casing
Shellac
The most commonly used type of all rotary pumps is the ___ pump
External gear
In a vane-type rotary pump, what keeps the sliding vanes in contact with the pump housing?
Centrifugal force
The riser used to vent a system at the discharge side of the pump should be about ___ times as long as the diameter of the pipe.
5
Internal bearings on rotary pumps are most often lubricated by
The fluid being pumped
If a rotary pump is not delivering fluid at its discharge side, the first thing you should do is
Stop the pump