PUMPSENSE FLUID ENGINEERING PRIVATE LIMITED

Weekly Q/A List :

Q1 : Which of the following is not a primary function of the pump casing?

  • a. Transmit torque from the driver to the impeller
  • b. To convert kinetic energy into pressure energy
  • c. To develop dynamic head
  • d. Directing flow into and out of impeller
  • e. Provide support to the bearing bracket
  • f. Incorporate nozzles to connect suction & discharge piping.

Answer


Q2 : A pump develops 100 m head while handling kerosene with specific gravity of 0.8. What head will the pump develop if the liquid handled is water:

  • a. 120m
  • b. 100m
  • c. 80m
  • d. 60m

Answer


Q3 : A pump lifts water from a sump. Static height of the pump center line from the water level in the sump is 5m. Friction loss in the suction pipe line 0.5m, vapor pressure at pumping temperature is 0.5m and the atmospheric pressure is 10.3m of water column. What is the approximate NPSH available at this installation?

  • a. 14.3 m
  • b. 4.3 m
  • c. 4.8 m
  • d. 14.8 m

Answer


Q4 : Which of the following statements about cavitation is not true?

  • a. Cavitation occurs when NPSH available is less than the NPSH required by the pump.
  • b. Cavitation is caused by the collapse of air bubbles in the suction side of the pump.
  • c. Cavitation does not occur during part flow operation since available NPSH is high.
  • d. Cavitation occurs only on the suction side of the impellers.
  • e. Cast Iron impellers have the least ability to resist cavitation damage.

Answer


Q5 : The following diagram shows pump performance curve superimposed on system characteristics. Can you identify the various terms in the table?

Description

  • a. System Resistance Curve
  • b. Friction Head
  • c. Static Head
  • d. Total Dynamic Head
  • e. Head Capacity Curve
  • f. Operating Point
  • A. (a) - 2 (b) - 5 (c) - 4 (d) - 6 (e) - 1 (f) - 3
  • B. (a) - 1 (b) - 4 (c) - 6 (d) - 5 (e) - 2 (f) - 3
  • C. (a) - 2 (b) - 6 (c) - 4 (d) - 5 (e) - 1 (f) - 3
  • D. (a) - 1 (b) - 4 (c) - 5 (d) - 6 (e) - 2 (f) - 3

Answer


Q6 : For each of the following duties which is the most appropriate type of impeller:

  • a. Radial flow
  • b. Francis Vane
  • c. Mixed Flow
  • d. Axial Flow
  • 1. c - b - a - d
  • 2. a - d - b - c
  • 3. d - a - b - c
  • 4. b - a - d - c

Answer


Q7 : In a pumping system where the major component of the total head is friction, which of the following three methods of flow control is the most energy efficient?
The flow through a pump can be controlled by:

  • a) Throttling
  • b) Connecting or disconnecting pump running in series or parallel
  • c) Speed control

Answer


Q8 : Which of the following properties are important for selecting the material of construction of an impeller:

  • a) Endurance Limit
  • b) Corrosion Resistance
  • c) Abrasive Wear Resistance
  • d) Cavitation Resistance
  • e) Casting and machining properties
  • f) Tip speed
  • g) Cost
  • h) Working Pressure
  • i) Galling Characteristics

Answer


Q9 : According to American Standard NFPA20 for fire pumps, pumps are generally provided with gland packing and mechanical seals are not used. What is the main reason for using gland packing in place of mechanical seals for these pumps?

  • a) Gland Packing is easily installed.
  • b) Gland Packing is cheaper than mechanical seal.
  • c) Leakage tends to increase gradually giving early indication of impending failure.
  • d) Gland Packing is less sensitive to the axial movement of shaft compared to mechanical seal.
  • e) Gland Packing is easily replaced when the gland is split.

Answer


Q10 : The following is a list of some of the Quality Assurance checks carried out by a pump manufacturer:

  • a) Shaft Ultrasonic test
  • b) Casing UTS, hardness test, chemical test
  • c) Impeller - chemical analysis
  • d) Impeller – dynamic balancing
  • e) Casing - hydrostatic pressure test
  • f) Pump - Performance test
  • g) Pump - dimensional check
  • h) NPSH test

The following is a list of the Test Reports as required by a user:

Please identify the QA document which contains the appropriate test report from the following options:

A.  B.
C.  D.

Answer


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