31. Which of the following piping is more health hazardous Fuel oil piping, Process piping with caustic, process piping with HF acid, sulphuric-acid piping?

Process piping with HF acid

32. What could be the consequence if there is a steam piping with a low pocket but without any steam trap?

Condensate build-up would happen to a point that a slug will be pushed by the steam flow. This slug condensate could cause the water hammer and it could damage the piping.

33. Explain steam tracing?

It is a process to prevent the fluid passing through a process line from freezing by keeping the temperature high for free flow of fluid and thus maintaining pumpability.

34. What should be done before conducting flushing and hydro-test?

Certain components such as control valves, orifice plates, rotameters, safety valves, thermowells are dropped or replaced with temporary spools before the hydro test.

35. What is the need for a dampner in the piping of a reciprocating pump?

It is used to handle pulsation

36. Why do we use a full bore valve in connecting pipeline of launcher receiver?

It is used for pigging.

37. Classification of flanges according to facing?

Flat face, raised face, tongue and groove, and ring type joint

38. What are the different types of gaskets?

Full face, spiral wound, octagonal ring, metal jacketed, and inside bolt circle

39. Where should we do a branch connection in a pipeline?

The branch should on the top side of the pipe if the fluid is gas, air, or steam. The branch connection should be on the bottom side of the pipe if the fluid is liquid.

40. Where should a boiler feed water pump must be located?

It must be located close to the deaerator, because these pumps takes water from the deaerator.

41. What is the need for drip leg in a steam line?

It is used to remove the condensate if there is a rise in the pipe along the flow direction. So if there is no drip leg in a steam line then it could cause pipe damage due to a water hammer.

42. What is the need for high point vent and low point drain in a pipeline?

The high point vent will remove the air during the hydro test and the low point drain would drain the water after the hydro test.

43. Why do we use blind flange in a pipeline?

It is used if there is a change that should be done for piping in the future and also for cleaning and inspection.

44. Where should be a centrifugal pump must be located in a vacuum service?

It must be located directly below the tower

45. What are the requirements for suction line?

Reducer, strainer, block valve, pockets, proper straight length

46. What are the requirements for discharge piping?

Pressure indicator, reducer, block valve, check valve

47. How can we locate feed nozzle?

It would oriented in a specific area of tray by means of internal piping.

48. What are the types of compressor drives?

Gas turbine, electric motor, steam turbine, and gas engine

49. What is galvanizing?

It is the process in which the surface of iron or steel will be covered by zinc

50. What is the need for a loop in a piping?

It is to control the expansion and contraction of a pipe due to the change in fluid temperature.

51. Explain full couplings?

A pipe segment can be connected to the other one with the help of this device

52. What is the need for strainers in a pipeline?

Strainers can remove solid particles from liquids, mostly strainers are placed in mainline so that all the process fluid will pass through them.

53. What are the types of strainers?

Basket strainers, Wye strainers, and Start-up strainers

54. What is the need for a steam trap in a pipeline?

A steam trap is used in a pipeline to separate the condensate and the steam

55. What are the types of steam trap?

Impulse, thermodynamic, mechanical, and thermostatic

56. What is the need for valve in a pipeline?

A valve can start, stop, or control the flow of liquid or gas in a pipeline

57. What is threaded joints?

This type is mostly used for many industries because many small size pipes can be joined by this method and it can be done without any material concern.

58. Why do we use tees and crosses in a pipeline?

It is used when more than two branches of piping is to connected at the same time

59. What are the types of pressure relieving devices?

Relief valves, safety valves, safety relief valves, conventional and balance valve, and frangible disk.

60. Explain the set pressure?

It is the inlet pressure at which the safety or relief valve is adjusted to open, this pressure is set without any back pressure on the discharge of the valve.

61. Explain overpressure?

If there is a pressure increase over the set pressure of the primary relieving device it is the overpressure

62. What is accumulation?

If there is an increase in pressure over the maximum allowable working pressure of the vessel during the discharge through the safety or relief valve, expressed as a percent of that pressure.

63. What is blow-down?

It is the reduction of the flowing pressure the set point that is needed for a device to dose. It can also be described as the difference between the set pressure and the resetting pressure of a safety valve

64. Explain back pressure?

It is the pressure that is created on the discharge side of the safety valve, this pressure could be created by the flowing fluids when it passes through the relief discharge piping.

65. How to select a pipe?

It must be selected according to the size, material, and thickness

OIL & GAS CAREER GUIDANCE : INTERVIEW QUESTIONS & ANSWERS - PART 2