Module A Flashcards
Which of the following pumps are dynamic:
- Centrifugal
- Axial
- Reciprocating
- Mixed-flow
- Centrifugal
- Axial
- Mixed-flow
What is absolute pressure?
Gauge pressure plus atmospheric pressure
As pressure is reduced, the boiling point of a liquid ___________
Decreases
What happens when a liquid vaporizes in a closed system?
Cavitation can occur
A tank 20 ft high is full of brine. The S.G. of brine is 1.03. What would the reading be on a pressure gauge connected to a pipe leading from the bottom of the tank?
8.9 psi
When the pump inlet is ____ the level of liquid in the supply reservoir, the pump has a suction head.
below
What source of energy is available to allow liquid to enter a pump with suction lift?
Atmospheric Pressure
__________ is the component that converts mechanical energy into kinetic energy.
Impeller
The NPSHR must be _________ the NPSHA
Less than
A pump converts mechanical energy into ___________
Hydraulic Energy
Unless otherwise stated, pump performance _____ are based on handling cold water
curves
What are the four factors that affect friction loss thorough a pipe?
- Type of Pipe
- Length of pipe
- diameter of pipe
- type of fluid flowing through the pipe
The flow produced by a pump varies ___________ with the impeller diameter
directly
If the impeller diameter in a pump is increased in a pump, the _________ will increase at an equal rate
Flow
Unless otherwise stated, pump performance curves are based on handling _____________
cold water
The __________ produced by a pump varies with the square of the impeller diameter
Head
The head produced by a pump varies with ______________
the square of the impeller diameter
What is located between the suction and discharge in a regenerative turbine pump?
The stripper
Which type of pump is not dynamic?
Reciprocating
The stripper in a regenerative turbine pump is located between the:
the suction and discharge
Calculate the pressure created by 75 ft height of fresh water.
= 75 ft x 0.433
= 32 psi
Calculate the height of fresh water necessary to create 175 psi.
= 175 psi/ 0.433
= 404 ft
Calculate the pressure (P) created by oil held at a 80ft height. Oil has an S.G.= 0.8.
P = 80ft x 0.433 x 0.8
P = 27.712
P = 28 psi
Calculate the pressure (P) created by seawater held at a 60ft height. Seawater has an S.G.= 1.03
P = 60ft x 0.433 x 1.03
P = 26.7594
P = 27 psi
How many feet of head (ft) of fresh water produces a pressure (P) of one psi?
Height = P /0.433 x SG
Height = 1/0.433 x 1
Height = 2.309
Height = 2.31 ft
A pump has to pump fresh water up a vertical pipe 100 feet high. What is the pressure (p) due to the weight of the fresh water?
P = Height x 0.433 x SG
P = 100 ft x 0.433 x 1
P = 43.3 psi
A pressure loss of 50 psi is equivalent to how many feet of head (ft) of fresh water?
Height = P /0.433 x SG
Height = 50/0.433 x 1
Height = 115.473
Height = 115 ft
A river pump supplying a plant with fresh water for cooling is 300 feet lower than the equipment it is cooling. The water pressure (P) at the plant must be 100psi. Calculate the required discharge pressure (P) at the river pump.
P = Height x 0.433 x SG
P = 300 ft x 0.433 x 1
P = 129.9 psi
Since we need 100 psi at the plant
P = 129.9 + 100
P = 229.9
P = 230 psi
