EPC School: Mechanical (Static) Common Questions -1

Thursday, July 19, 2012

Mechanical (Static) Common Questions -1

EPC-School 2012

M for Mechanical

Topic- Static

1) When the system pressure reaches set pressure the pressure safety valve

a) lifts fully to relieve the pressure

b) lifts proportional to the increase in system pressure above the set pressure

c) does not lift

2) Safety valve opening is proportional to the rise in system pressure over and above the set pressure.

(a) True (b) False

3) A conventional pressure safety valves (without bellows) is installed on a pressure vessel operating at 90 barg at 250 C. The safety valve is set to pop at 100 barg. The valve is having a back- pressure of 5 barg at the outlet. The Cold Differential Test Pressure (CDTP) on the test bench will be

a) 90 b) 100 c) 95 d) 105

4) Pilot operated relief valves allows the system to be operated more close to the set pressure

(a) True (b) False

5) Rupture Devices are single use devices

(a) True (b) False

6) Relief valves installed on LPG spheres are to be inspected as per

a) Indian Boiler regulations Act

b) Static and Mobile Pressure vessels rule (SMPV)

c) Gujarat Factories Act

d) None of the above

7) 18/8 SS…..

a) Have 18Ni-8Cr nominal composition

b) Have 18Ni-8Mo nominal composition

c) Have 18Cr-8Ni nominal composition

d) Have 18Cr-8Mo nominal composition

8) PSV calibration in work shop is done at

a) Set Pressure

b) Back Pressure

c) Cold Differential Test pressure

d) Design pressure

9) Following heat exchanger is preferred to handle unclean, hot hydrocarbons.

a) Fixed tube heat exchanger

b) U Tube heat exchanger

c) Floating head heat exchanger

d) Hair pin exchanger

10) In radiant zone, source of heat to the processing fluid inside the tube, is from…

a) Burner flame

b) Hot gases

c) Refractory

d) All of the above

11) Purpose of inner and outer ring in spiral wound gaskets is to

a) Contain and protect sealing elements

b) Prevent buckling

c) Direct more of the bolt load to sealing element

d)All of the above

12) In SAP maintenance activity on a piece of equipment is entered in

a) Work order

b) FIR/FAR

c) Notification

13) Tube to tubesheet joints in a shell and tube heat exchanger can be

a) Expanded

b) Expanded and seal welded

c) Strength welded

d) All of the above

14) Baffle plates in a heat exchanger tube bundle is used for

a) supporting the tubes

b) guiding the flow of the shell side fluid

c) None of the above

d) Both (a) & (b)

15) In case of air fin coolers, fins are provided on the tubes

a) to improve heat transfer

b) to provide additional strength to tubes

c) to prevent damage to tubes as they are exposed to atmosphere

d) All of the above

16) Refinery piping has been constructed as per

a) ANSI B 31.3

b) ASME Sec VIII Div.1

c) API 610

d) None of the above.

17) For a leak free flanged joint the following are necessary

a) gasket of correct specification

b) parallelity of flange faces

c) Tightening at correct torque

d) All of the above

18) Disadvantage of floating head type shell & tube heat exchanger is

a) it cannot accommodate expansion of tubes

b) it cannot be cleaned on shell side

c) Floating head gasket leak will result in shutdown of the exchanger/unit.

d) All of the above

19) Hydrotest of a heat exchanger is done to ascertain

a) tube leaks

b) tube to tubesheet joint leaks

c) gasket leaks

d) all of the above

20) Dye penetrant test can be applied to detect

a) defects below the surface

b) defects open to the surface

c) Both

d) None of the above

21) In case of pipes

a) OD is a fixed standard value

b) ID is a fixed standard value

c) None of the above

22) Hydrotest pressure in a heat exchanger is usually

a) 1.5 times design pressure multiplied by temperature correction

b) equal to design pressure

c) 1.5 times operating pressure

23) Maximum set pressure of the pressure relief device installed on a pressure vessel

a) equal to design pressure

b) 1.1 times design pressure

c) hydrotest pressure

d) 1.1 times the normal operating pressure.

24) Pressure vessels are designed as per

a)ASME Sec VIII Div . 1

b)ANSI B 31.3

c)API 650

d)API 661

25) Strength of the metallic material _____________ with temperature

a)increases

b)decreases

c)Remains same

d)None of the above

26) Steam generators come under which statutory body

a)Gujarat Factories Act

b)SMPV

c)IBR

d)None of the above

27) Square pitch tube layout in a exchanger tube bundle is preferred when

a)Shell side cleaning is expected

b)Shell side design temperature is more than tube side

c)Tubes are stainless steel

d)All of the above

28) In piping specification EC38EA, C stands for

a)Carbon steel

b)Corrosive service

c)C – Crude service

d)Copper

29) In piping specification EC38EA “8” stands for

a)800 pound rating pressure

b)8” inches nominal dia of the pipe

c)Corrosion allowance of 8mm

d)Corrosion allowance of 6.0mm

30) A common method used for testing of weld joint at site is

a)Hammer test

b)Destructive test

c)Radiographic test

31) Hydrotest of heat exchangers is cleared at site by

a)Maintenance engineers

b)Operations engineer

c)Inspection engineer

d)None of the above

32) A check valve is

a)Non return valve

b)Gate valve

c)Globe valve

d)None of the above

33) A check valve can be used as an isolation valve

a)True

b)False

34) Pneumatic test of pressure vessels is normally avoided in an operating plant due

a)Leakage detection is difficult

b)Code does not permit the same

c)Hazard of an explosion and damage

d)All of the above

35) Cerawool lining on heater shell in radiant section is done only

a)In furnaces with fuel gas firing only

b)In furnaces with fuel oil firing only

c)In furnaces with combination firing

36) The temperature of flue gas in furnace air preheater outlet should be

a)At least equal to dew point temperature

b)As low as possible to maximize the heat recovery

c)At least 15 C more than dew point conditions

37) The tube skin temperature of the heater could increase due to

a)Fouling inside the tubes

b)Flame impingement

c)Drop in pass flows

d)One or more of the above

38) In cooling water heat exchangers the maximum permissible water outlet temperature is

a)43 C

b)Inlet plus 5 deg C

c)No limit

39) In cooling water exchangers, the minimum recommended velocity to minimize fouling in tubes is

a)2 m/sec

b)0.5 m/sec

c)0.9 m/sec

d)No limit

40) Low point drains are critical from inspection due to

a)Dead end formed in the LPD

b)Vibrations in the LPD

c)Both

41) The minimum design life of a heater tube is

a)20 years

b)Unlimited life

c)100000 hrs

42) Metallurgy selection of equipment components depends on

a)Operating conditions

b)Corrosion characteristics

c)Economics

d)Material Availability

e)All of the above

43) There is a high temperature spot on the radiant shell of fired heater. The area will be cooled by

a)Air

b)Water

c)Steam

d)None. Shutdown the unit

44) What is CUI?

a)Critical Unit Indicators

b)Corrosion Under Insulation

c)Commonly Used Instruments

d)None of the above

45) Thermography is typically used for

a)Measuring temperature of heater tubes

b)Measure temperature of electric panels

c)Measure temperature of refractory lined pipe

d)All of the above

46) Primary protection for under ground piping from corrosion is

a)Wrapping coating

b)Keeping the sand dry

c)Increasing corrosion allowance.

47) Underground piping in protected from corrosion by

a)Impressed current cathodic protection system

b)Sacrificial anode cathodic protection system

c)Either of the above

48) Water used for hydrotest of SS316 stainless steel piping should have

a)Chlorides less than 30 ppm

b)Chlorides less than 100 ppm

c)Potable water can be used

49) Material selection for hydrogen service typically in hydrotreaters is done as per

a)Bechtel standard

b)API 941

c)Inspection engineer requirements

d)Site urgency

50) A heat exchanger is being hydrotested at 38 barg. What should be the pressure gage range

a)0 – 25 barg

b)0 – 40 barg

c)0 – 60 barg

d)0 – 200 barg

51) A waste heat steam generator is under the purview

a)IBR

b)Factories Act

c)Static and Mobile Pressure Vessel rule

52) A heat exchanger is having 1000 tubes and 230 tubes are leaking. Is this acceptable case for

using the heat exchanger

a)Yes

b)No

53) The component in Crude that causes high temperature corrosion is

a)Nitrogen

b)Chlorides

c)Sulphur

d)All of the above

54) Atmospheric corrosion is taken care by

a)Metallurgy upgrade

b)Use zinc coating

c)Painting

55) Which of the following are corrosion control strategies?

a)Accept corrosion and replace component periodically

b)Add wash water , corrosion inhibitor, control operating parameters

c)Metallurgy upgrade

d)All of the above

56) Corrosion in the hydrocarbons streams processed is due to

a)Sulfur

b)Chlorides

c)Nitrogen

d)all of the above

57) As per IBR act, what is the minimum capacity of the closed vessel in which water is converted into steam under pressurized condition.

a) 22.25 liters

b) Five gallons

c) 22.5 liters

d) Three gallons.

58. IBR code is provides guidelines for the efficiency of the boilers

a) True

b) False

59. Boilers are used to generate:.

a) HP steam

b) MP steam

c) LP steam

d) All of the above

60. Exhaust flue gases are used in following boiler

a) Auxiliary boiler

b) HRSG

c) Waste heat boiler

d) None of the above

61.Out of following which is boiler mountings.

a) Fusible Plug

b) Economiser

c) Steam Trap

d) None of the above

62.Out of following which is not a boiler accessories;

a) Super heater

b) Feed pump

c) Steam Trap

d) Safety valve

63. In alloy steel total alloying element is less than 10 percent:

a. True

b. False

64. What are the composition of the P22 material

a. 1.25% Cr and 0.5 % Molybdenum

b. 2.25% Cr and 0.5 % Molybdenum

c. 2.25% Cr and 1 % Molybdenum

d. 2.5% Cr and 0.5 % Molybdenum

65. Which material is not suitable at temperature less than equal to 385 deg C ideally

a. SA 106 Gr B

b. SA 335 P22

c. SA 335 P5

d. SA 335 P9

66. Natural circulation can be takes place due to density difference of the water and steam in the

boiler.

a. True

b. False

67. Deaerator is used to remove:

a. Only O2

b. Only CO2

c. O2 and Co2 both

68. Dosing of which chemical act as oxygen scavenger in boiler feed water system.

a. Hydrazine Hydrate

b. Morpholine

c. Tri sodium Phosphate

d. Di-sodium phosphate

69. pH is derived by :

a. Measuring Hydrogen ion concentration in milligrams per liter of

solution

b. Measuring Hydrogen ion concentration in kilograms per liter of

solution

c. Measuring Hydrogen ion concentration in grams per liter of

solution

d. None of the above

70. Which part of the boiler is more prone to sulfur corrosion

a) Economiser

b) Super heater

c) Evaporator

71. Hydrostatic test of the vessel shall be carried out at what pressure as per ASME Sec VIII DIV-1,1995 Edi;

a. 1.5 times the design pressure

b. 1.25 times the design pressure

c. 1.5 times of the operating pressure

d. 1.25 times of the operating pressure

72. Corrosion means:

a) Destruction of metal as a chemical reaction only

b) As a electrochemical process only

c) Combination of a and b

73. For galvanic corrosion one of the important requirement is

a) Two metal in contact without any electrolyte

b) Two metals in contact having different electrode potential in

presence of electrolyte

c) Two metals in contact with same electrode potential in presence of

electrolyte

74. Carry over of which impurities results in the corrosin on the turbine blades.

a) Magnesium

b) Calcium

c) Silica

d) Phosphate

75. Which chemical is used as a pH booster in steam drum.

a) Phosphate

b) Hydrzine

c) Caustic

d) Chlorides

At what temperature, Stress corrosion cracking takes place generally in presence of chlorides

a) More than 60 Deg C

b) More than 60 Deg F

c) Ambient temperature

77. SA 106 Gr B is fully killed carbon steel material

a) True

b) False

78. After hydrostatic test , pressure shall be released of any pressure vessel from the:

a) Low point drain when high point vent is in closed condition

b) High point vent when low point vent is in closed condition

79. Finned type tubes in the heat exchangers are used for

a. To increase the heat transfer

b. To decrease the heat transfer

c. Ease of cleaning

80. Algae formation can be avoided in the cooling towers by dosing

a) Phosphate

b) Chlorine

c) Calcium

d) Magnesium

81. Reverse osmosis means

a) The passage of water from a more concentrated solution to a less

concentrated solution through a semipermeable membrane under pressure.

b)The passage of water from a less concentrated solution to a more

concentrated solution through a semipermeable membrane under pressure

82. Is oxygen corrosive?

a) Yes

b) No

83.In Electrode E7018, Numeric 70 indicates :

a) Tensile stress of electrode metal is 70 Psi

b) Tensile stress of electrode metal is 70 Ksi

c) Tensile stress of electrode metal is 70 Mpa

d) Tensile stress of electrode metal is 70 Kg/cm2

84. One bar pressure equal to

a) 1.02 kgf/cm2

b) 14.05 psi

c) all of the above

d) None of the above

85. In fire tube boiler

a) Flue gases in tube side and water is outer side

b) Flue gases in outer side and water in tube side

c) Both of the above

d) None of the above

86. Heat transfer in the boiler can be take place by means of:

a) Radiation and conduction

b) Radiation and convection

c) Convection and conduction

d) Radiation, convection and conduction

Answers to Above Questions-

1. (a) lifts fully to relieve the pressure

2. (b) False

3. (c ) 95

4. (a) True

5. (a) True

6. (b) Static and Mobile Pressure vessels rule (SMPV)

7. (c) Have 18Cr-8Ni nominal composition

8. (c) Cold Differential Test pressure

9 (c ) Floating head heat exchanger

10 (d) All of the above

11 (d) All of the above

12 (c ) Notification

13 (d) All of the above

14 (d ) Both (a) & (b)

15 (a) to improve heat transfer

16 (a) ANSI B 31.3

17(d) All of the above

18(c ) Floating head gasket leak will result in shutdown of the exchanger/unit

19(d) All of the above

20 (b) defects open to the surface

21 (a) OD is a fixed standard value

22 (a) 1.5 times design pressure multiplied by temperature correction

23(a) equal to design pressure

24 (a) ASME Sec VIII Div . 1

25 (b) decreases

26 (c) IBR

27 (a) Shell side cleaning is expected

28 (a) Carbon steel

29 (d) Corrosion allowance of 6.0mm

30 (c) Radiographic test

31 (c ) Inspection engineer

32 (a) Non return valve

33 (b) false

34 (c) Hazard of an explosion and damage

35 (a) In furnaces with fuel gas firing only

36 (c ) at least 15 C more than dew point conditions

37 (d) One or more of the above.

38 (a) 43 C

39 (c ) 0.9 m/sec

40 (c) Both

41 (c ) 100000 hrs

42 (e) all of the above

43 (c ) Steam

44 (b) Corrosion Under Insulation

45 (d) All of the above

46 (a) Wrapping coating

47 (c ) Either of the above

48 (a) Chlorides less than 30ppm

49 (b) API 941

50 (c ) 0 – 60 barg

51 (a) IBR

52 (b) No

53 (c) Sulfur

54 (c ) Painting

55 (d) All of the above

56 (d) All of the above

57 (b) Five gallons

58 (b) False

59 (d) All of the above

60 (b) HRSG

61 (a) Fusible Plug

62 (a) Super heater

63 (a) True

64(c) 2.25% Cr and 1 % Molybdenum

65 (a) SA 106 Gr B

66 (a) True

67 (c ) O2 and Co2 both

68 (a) Hydrazine Hydrate

69 (c) Measuring Hydrogen ion concentration in grams per liter of solution

70 (a) Economiser

71 (a) 1.5 times the design pressure

72 (c) Combination of a and b

73 (b)Two metals in contact having different electrode potential in presence of electrolyte

74 (c ) Silica

75 (a) Phosphate

76 (a) More than 60 Deg C

77 (a) True

78 (b)High point vent when low point vent is in closed condition

79 (a) To increase the heat transfer

80 (b) Chlorine

81 (a)The passage of water from a more concentrated solution to a less concentrated solution through a semipermeable membrane under pressure.

82 (a) Yes

83 (b) Tensile stress of electrode metal is 70 Ksi

84 (a) 1.02 kgf/cm2

85 (a) Flue gases in tube side and water is outer side

86 (d) Radiation, convection and conduction

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# posted by Rahulkap @ 9:58 AM

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Thursday, July 19, 2012

Mechanical (Static) Common Questions -1

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