4Th Class Power Engineering Chapter 73

Front 1

Reciprocating pumps:

1. Are high-pressure pumps

2. Must be primed

3. Use mechanical seals

4. Should be started with the suction and discharge open

1) 1, 3, 4

2) 1, 2, 3, 4

3) 1, 4

4) 1, 2

5) 2, 3

Back 1

3) 1, 4

Front 2

When a pump discharges into a vessel operating at 300 kPa, the 300 kPa is referred to as:

1) Pressure head

2) Discharge head

3) Dynamic head

4) Friction head

5) Total head

Back 2

Pressure head

Front 3

To prevent cavitation in a centrifugal pump:

1) The pump should have high suction head

2) A pump should have a low suction pressure

3) The pump should have low discharge head

4) The suction valve should be throttled

5) A pump should have high discharge head

Back 3

The pump should have high suction head

Front 4

A rotary pump:

1. Is a variety of dynamic unit

2. Does not have discharge pulsations

3. Should be equipped with a relief valve

4. Has the highest capacity of any pump

5. Never requires casing lubrication

1) 2, 3

2) 3, 5

3) 3, 4

4) 1, 2

5) 1, 3

Back 4

1) 2, 3

Front 5

Centrifugal pumps do not develop good suction lift because:

1) Their internal component clearances are too high

2) The speed is too low

3) Atmospheric pressure is usually too low

4) They favor pressure rather than volume

5) The pumped medium relative density is too high

Back 5

Their internal component clearances are too high

Front 6

A positive displacement stand by pump will have the:

1) Suction valve closed and the discharge valve open

2) Suction valve and the discharge valve closed

3) Vent and drain valves open

4) Suction valve and the discharge valve open

5) Suction valve open and the discharge valve closed

Back 6

Suction valve closed and the discharge valve open

Front 7

It is generally accurate to say that:

1) A water height or depth of 10.34 m results in 1 kPa

2) 9.8 kPa pressure results from every metre of water depth or height

3) 10.21 kPa will result from 1 metre of static water head

4) Atmospheric pressure has no bearing on static water head

5) 1 kPa will result from a water head of 9.8 m

Back 7

9.8 kPa pressure results from every metre of water depth or height

Front 8

A circulating pump is usually:

1) A reciprocating pump

2) A high head unit

3) A small capacity unit

4) Connected with some type of heat exchanger system

5) A once-through device

Back 8

Connected with some type of heat exchanger system

Front 9

Centrifugal pumps convert rotating mechanical energy into kinetic energy then:

1) Back to mechanical energy

2) Absorb the energy

3) Discharge the kinetic energy

4) Into potential energy in the form of pressure

5) Into centrifugal force

Back 9

Into potential energy in the form of pressure

Front 10

Cavitation of a pump refers to when the:

1) Pump is steam driven

2) Pump is filled with air

3) Suction valve is open

4) Oil ring is damaged

5) Pump is filled with vapor

Back 10

Pump is filled with vapor

Front 11

The difference between static suction head and static discharge head is:

1) Static suction head

2) Total static head

3) Static discharge head

4) Equivalent head

5) Dynamic head

Back 11

Total static head

Front 12

A high pressure pump is the:

1. Volute

2. Diffuser

3. Centrifugal

4. Regenerative

5. Diaphragm

1) 1, 2

2) 3, 5

3) 4, 5

4) 1, 3

5) 2, 4

Back 12

4, 5

Front 13

A rotary pump:

1. Is a variety of dynamic unit

2. Does not have discharge pulsations

3. Should be equipped with a relief valve

4. Has the highest capacity of any pump

5. Never requires casing lubrication

1) 3, 4

2) 1, 3

3) 2, 3

4) 3, 5

5) 1, 2

Back 13

2, 3

Front 14

The name given to pumps that use gear teeth, vanes, lobes, or screws to move the fluid being pumped, is the _____ type.

1) Rotary

2) Dynamic

3) Reciprocating

4) Radial flow

5) Axial flow

Back 14

Rotary

Front 15

A diffuser pump:

1. Has stationary guide vanes surrounding the impeller

2. Has a higher efficiency than a volute type

3. Has high suction lift

4. Does not have to be primed

1) 4

2) 1, 2

3) 2, 3

4) 1

5) 3

Back 15

1, 2

Front 16

The capacity of a centrifugal pump should only be reduced by:

1) Closing both suction and discharge valves

2) Throttling the discharge valve

3) Throttling the suction valve

4) Opening the pump casing vent valve

5) Closing the suction valve

Back 16

Throttling the discharge valve

Front 17

Centrifugal pump power requirements are decreased when:

1) The volume moved is decreased

2) The discharge velocity is high

3) Discharge pressure is decreased

4) The casing pressure drops

5) The discharge head is at minimum

Back 17

The volume moved is decreased

Front 18

Which type of pump produces the greatest suction?

1) A variable displacement pump

2) A positive displacement pump

3) A volute centrifugal pump

4) A volute centrifugal pump

5) A regenerative pump

Back 18

A positive displacement pump

Front 19

The capacity of a centrifugal pump:

1) Is fixed and can only be altered by changing the impeller

2) Indicates that the unit is a positive displacement type

3) Varies with discharge pressure

4) Can be altered by speed variation only

5) Should be varied by suction valve manipulation

Back 19

Varies with discharge pressure

Front 20

If a pump is cavitating, what can you do to prevent or reduce the cavitation:

1) Open the vent valve and close the suction valve

2) Close the discharge valve

3) Close the casing vent valve

4) Raise the suction pressure

5) Partially close the suction valve

Back 20

Raise the suction pressure

Front 21

Turbine pumps are best suited for:

1) Heavy viscous fluids

2) High capacity low-pressure service

3) High capacity high-pressure service

4) Low capacity low-pressure service

5) Low capacity high-pressure service

Back 21

Low capacity high-pressure service