pumps quistinoeer.doc

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1. Back pedaling.

2. Flash steam.

3. Live steam.

4. Motoring.

5. Quenching.

6. State for which condition each type of pump class would be

particularly suited.

7. How does the application of a power driven pump differ from a

direct acting pump?

8. What is the purpose of cylinder clearance?

9. What method is used to lessen pressure fluctuations with in

single stage piston pumps?10.Name other instances for reciprocating devices where clearance

is of importance.

11.Single piston pumps are often fitted with air chambers to do

what?

12.State the equation used to calculate the volume pumped with a

piston pump.

13.What is a ball check valve?

14.What is so attractive about the ball check valve?

15.Plunger pumps are frequently fitted with more than one ballcheck valve, why?

16.How is the volume control in plunger pumps obtained.

17.Which type of pump suffers from cavitation?

18.What is meant by the term "adjustable stroke"?

19.Which type of pumps are suited for an adjustable stroke?

20.Can the reciprocating pump function in the vertical conditions?

21.Which type of pumps requires a pressure relief valve on the

discharge?

22.State one particular reason for employing a diaphragm pump.

23.What force opens and closes the exhaust and inlet valves of areciprocating pump? State, whether the same mechanism

applies to all or only to liquid fluids.

24.State under which condition a reciprocating pump must be

fitted with a relief valve and when not.

25.State the location for the position of a relief valve on certain

reciprocating pumps.



26.External gear pump:

1. How does the external gear pump function?

2. List several uses for an external gear pump.

3. Where are the in- and outlet valves?

4. What prevents the liquid being return to the inlet?

27.The internal gear pump:

1. List several applications for an internal gear pump.

2. Sketch and label an internal gear pump.

28.The sliding vane pump:

1. Sketch and label a sliding vane pump. Indicate how the

vanes are mounted inside the rotor. Show the flow

direction of the fluid pumped.

2. State typical applications for a sliding vane pump.

3. Explain how the vanes slide in or out.

29.The two screw pump:1. List several typical applications of a two-screw pump.

2. State how the screw pump discharges its fluid.

30.The three lobe pump:

1. Sketch and label a three-lobe pump. Show turning the

direction of the lobe.

2. State several prime applications.

31.What is meant with the term "spiral casing"?

32.What forces deliver the fluid to the center of the pump

impeller?

33.Diffuser pump:

1. Sketch, label and describe a diffuser centrifugal pump.

2. Name in order the area of the diffuser pump, which

converts the high velocity energy into pressure energy.

3. State how the stationary diffuser vanes are attached to the

pump casing.

4. Why are the volute diffuser and volute pumps are alsocalled radial flow pumps?

34.Axial flow pump:

1. Sketch, label and describe how vertical axial flow pumps

function.

2. Name the various characteristics of the axial flow pump.

3. State applications for an axial flow pump.



4. Axial flow pumps are fitted with suction bells. Sketch,

label and explain its purpose.

35.Mixed flow pump:

1. Sketch, label and describe how mixed flow pumps

function.

2. Compare the axial flow pump with the mixed flow pump.

3. State applications for the mixed flow pump.

4. State one outstanding feature of the mixed flow pump.

36.Turbine or regenerative pump:

1. Sketch, label and describe a turbine pump.

2. Name the type of application for this type of pump.

3. Could a turbine pump have more than one stage?

37.Define the following pump terms:

1. Concentric.

2. Periphery.3. Impeller.

4. Turbine pump.

5. Multistage pump.

38.Multistage centrifugal pump:

1. Describe the operation of a three stage centrifugal pump.

2. Describe the basic construction of a multistage pump

employing the opposed impeller configuration. Provide

the reason for the opposed impeller configuration.

39.Which type of pump has the suction and discharge nozzles

usually located at the lower part of the casing?

40.Explain briefly the construction of a barrel pump.

41. Describe the type service this pump usually provides.

42.41 Describe one other method of driving a pump, with no seal

at all.

43.If no sleeve is used, then explain the method used to protect the

shaft.

44.How are sleeves secured to the shaft?

45.With a diagram explain a water shield.

46.Name and describe 5 ways on how to minimize axial pumpthrust.

47.Why are some single-inlet impellers fitted a backside wear ring

and a balancing hole?

48.Explain the term "axial imbalance".

49.Sketch and label various priming methods.

50.State the units used to express the quantities pumped.



51.How does temperature affect pump output?

52.Describe various ways of regulating the capacity of positive

displacement pumps.

53.How does the capacity regulation differ between a reciprocating

and a rotary pump?

54.Describe various ways of regulating the capacity of a

centrifugal pump.

55.How should axial and mixed flow pumps be started?

56.Why are large centrifugal pumps started with the discharge

closed?

57.Why must the positive displacement never be started with

discharge closed?

58.Describe what takes place when the suction valve of centrifugal

pump is throttled when in operation?

59.Describe how the casing of a centrifugal pump can become tohot.

60.Describe the code requirements when two or only one boiler

feedwater pump is used.

61.Explain the reasons for requiring two boiler feedwater pumps

when firing solid fuels.

62. Please explain the difference between single-plane and two-

plane balancing?

63.Due to cavitation damage we are going to replace the first stage

impeller of a two-stage, between-bearing, horizontal pump.

Should we replace the wear rings of the first stage impeller

only, or should we replace the wear rings of both impellers so

that the wear on all the impeller rings would be the same?

64.Does a rotor needs re-balancing after a certain period of

operation? Is there any specific type of work done on the rotor

that would require it to be re-balanced again? If so, what would

be the balance criteria?

65.some pumps are designed to have the impellers mounted on the

shaft with a loose fit while others are designed with an

interference fit. Which type is preferable and why?66.When is a tandem mechanical seal arrangement preferable to a

double seal arrangement, and vice-versa?

67.What is the limit to the positive head at the suction side of a

centrifugal pump? What are its effects, if any, on the pump

performance?

68.Does pump NPSHR increase with increased in liquid viscosity?

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