Pump2 Flashcards
Density
Density is the mass of a substance per unit of volume. Pounds/ cubic foot.
Specific gravity
Specific gravity is the ratio of density of a substance that of water.
Pressure
Pressure is a measure of intensity of effort described as force per unit of area
Force divided by area
Pressure
The portion of weight on earths atmosphere that there’s down on the area of one square inch. It is average to 14.7 psi at sea level.
Atmospheric pressure
As you raise in altitude height above sea level the amount of atmosphere above you is
Reduced
Quote The altitude whenever you mentioned, atmospheric pressure or absolute pressure
Is the pressure of a liquid in the system red by a pressure gauge, it is in addition to atmospheric pressure, it is expressed in a gauge reading
Gauge pressure
Is a pressure plus the atmospheric pressure.
Absolute pressure
Absolute pressure
Yeah, for gauge reads 20 psig. Add 14.7
Expresses pressure below atmospheric pressure. It is frequently measured in mercury.
Vacuum pressure
Before pressure gauges were developed, measuring the height of a liquid was the only way to obtain pressure reading.
Head pressure
Head pressure
Head pressure is the height in feet of a column of water that is 1 ft.² at the base
This is the pressure at which liquid flushes into a vapour at a given temperature
Vapour pressure/boiling point
Do all liquids have the same vapour pressure versus temperature curve
No, everyone is unique.
Cavitation
When the pressure of a liquid is reduced to or below its vapour pressure, small bubbles or pockets of vapour called cavitation begin to form.  As these vapour bubbles moved to regions of higher pressure, they collapse or implode. 
Aeration
Where a partial vacuum is created at the pump inlet , suction flange leaks, can draw air into the pump, this reduces the amount of liquid that can pass through the pump.
Aeration
Because the air is combustible, this causes erratic delivery, which intern affects the pumps, performance and efficiency. It can also cause loss of priming the pump.
This occurs when particles of liquid no longer move parallel with the axis of the pipe
Turbulent flow or nonlinear flow
What is total head made up of?
Head pressure and velocity head
If enough vapour is formed, it completely stops liquid Flow into the pump
Vapour bound
What causes turbulent flow?
Bends, abrupt changes and cross sections, fittings and pipe, velocity that is too high
If you have a loss of velocity, what happens
Increasing pressure
Pump head
Velocity, head, friction head, section head, discharge head, net, positive section head, net positive suction head required
Single stage double suction pump
They are split in the middle to allow for easy removal and inspection
 The casing includes a single section in that that splits to allow equal flow to each side of the impeller, and the volute that continues around both the top and bottom halves of the casing.
Single stage double suction pump
Both suction and discharge flanged nozzles are in the bottom half
Multi stage horizontal pump
The pressure is developed by centrifugal pump with a single impeller is limited. To increase this pressure several impellers are mounted in a series on the same shaft, each impeller is surrounded by its own volute or diffuser. The combination of these is called a stage.
Radial flow centrifugal pump
Most common
Axial flow pump
Propeller
Axial flow pumps produce
Relatively low discharge head, but they produce large flow
Peripheral pumps
High speed pumps /regenerative turbine pumps.
One disadvantage of high-speed pumps
Require a higher NPSHA, to prevent liquids in Flushing into a vapour
Regenerative, turbine pumps
High heads and low flow application
What separates the suction in the discharge on regenerative turbine pump?
The stripper
