Pumps Flashcards
An archmedian screw pumps water by rotating a [BLANK] in a [BLANK]
Thread; trough
If a substance needs to remain within a limited range of temperatures as it flows to the point of use, the distribution system may require (a)
Insulated pipes
A centrifugal pump is suitable for pumping waste, because of the [BLANK] head requirement and because the pump can move [BLANK]
Low; small particles
Pumps for high viscosity materials generally need to be [BLANK] pumps
Positive-displacement
Which kind of pump is generally used for moving grease, mastic, concrete, and other nearly solid materials?
Piston
The eye of a pump impeller is above the level of the supply liquid in the [BLANK] condition
Suction lift
Total dynamic head (TDH) is the sum of the [BLANK], the [BLANK], and the [BLANK]
Static head; head loss; velocity head
The horsepower input to a pump is called [BLANK] horsepower
Brake
In order to use the performance curve for a centrifugal pump, you must know the pump’s [BLANK] and its [BLANK]
Speed; Impeller diameter
Which pump curve will tell you at what total head the best energy transfer takes place?
Efficiency
End-suction centrifugal pumps make up about [BLANK] % of the pumps used in industrial plants
80
In a multistage centrifugal pump, each stage increases the [BLANK] of the fluid
Velocity
The open impeller is used mainly for pumping fluids containing [BLANK] solids
Large
I’m a centrifugal pump, wearing rings prevent damage to the [BLANK] and [BLANK]
Impeller; casing
The purpose of shaft sleeves is to prevent the [BLANK] from causing wear on the [BLANK]
Packing; shaft
In a lineshaft turbine, the [BLANK] surrounds the [BLANK]
Bowl; Impeller
Diffuser vanes in an axial-flow propeller pump
Straighten the fluid flow
The main difference between the axial-flow propeller pump and a mixed-flow propeller pump is the shape of the
Impeller
What causes electrochemical corrosion in a pump?
Combining incompatible materials
Regenerative turbine pumps can be used only to pump fluids with
Low viscosity
In an external-gear pump, the fluid is carried between the teeth of [BLANK] and the [BLANK]
Both gears; pump housing
In an internal gear pump, fluid is carried between the teeth of [BLANK] and the [BLANK]
Both gears; crescent
Lobe pumps are similar to [BLANK] pumps in their construction and operation
External-gear
In a screw pump, fluid moves because of the
Progressing cavities between threads
The diameter of the impeller of a vane pump is [BLANK] the diameter of the housing. The centerline of the impeller is [BLANK] the centerline of the housing.
Smaller than; offset from
The piston that pumps the fluid in a direct-acting reciprocating pump is commonly driven by
Air
Single-acting reciprocating pumps discharge fluid on the [BLANK] stroke
Forward (only)
The piston that pumps the fluid in a power reciprocating pump is commonly driven by an
Electric motor
Compared to a piston, the plunger of a power pump is typically [BLANK] and has a [BLANK] stroke
Longer; longer
An air-driven reciprocating pump can deliver fluid at a pressure higher than the supplied air pressure if the fluid piston is [BLANK] the air piston
Smaller in diameter than
Most metering pumps are [BLANK] pumps
Reciprocating
Most metering pumps are lubricated by the
Fluids they pump
The force that moves the diaphragm in most diaphragm pumps is provided by the
Hydraulic fluid
What actuates the valves of diaphragm pumps?
Fluids being pumped
Rotary pumps used for metering are usually [BLANK] pumps
Vane
In a flexible-tube pump, the [BLANK] forces fluid out of the discharge port
Roller
The problem of leakage in a pump used for moving liquid chemicals is eliminated by the [BLANK] pump
Magnetic-drive
A dry type sump pump retains its prime because the
Suction intake is above the impeller
The [BLANK] and the [BLANK] of a reciprocating slurry pump require the most maintenance
Cylinder sleeves; valve seats
The advantage of a vortex pump is that the
Fluid makes little contact with the impeller
A little leakage through the packing on a pump is usually [BLANK] because it [BLANK]
Desirable; lubricates the shaft
Pumps designed for use under suction lift conditions require an
Injection-type stuffing box
Pumps that operate at temperatures over 450° are usually packed with
Aluminum
When preparing to install new packing in a pump, your first step should be to
Shut off and lock out the power
What forms the seal in a packingless seal?
Boiler condensate
Overfilling the oil reservoirs on a pump can result in
Overheated bearings
Greases used for lubricating bearings of pumps should be free of
Mineral fillers
If a pump’s bearing seals need frequent replacement, the problem may be caused by a
Rough shaft
The major maintenance problems in rotary pumps are usually confined to the
Bearings and seals
If a reciprocating pump loses its ability to provide enough pressure, the problems may be [BLANK] but you should check the [BLANK] before replacing them
Worn piston rings; internal check valves
