ARAMCO EQUIPMENT INTERVIEW QUESTIONS
Date: 28‐11‐ϮϬϭϲ
1. MDMT:
Minimum design metal temperature
2. High - Alloy Steels:
Steels with a total alloying content more than 5%.
3. Low - Alloy Steels:
Steels with a total alloying content of less than 5% but more than specified for carbon steels
4. Nominal Thickness:
The value of the design thickness required to withstand all primary loads, and includes allowance for
corrosion.
5. PFD:
Process Flow Diagram.
6. Utility Services:
Water, air and nitrogen services.
7. Equipment Davit
A davit for the lifting of equipment shall be specified for vessels containing removable internals such as
trays, packing and relief valves.
8. Vortex Breaker:
The use of vortex breakers or guying devices in order to maintain internal stresses, due to wind-induced
vibration within allowable limits, is prohibited.
9. Telltale Holes
Telltale holes in reinforcing pads shall be protected with wooden plugs or packed with rust preventative
grease such as Denso paste.
10. VPCI
The interior surfaces of vessels, including internals, shall be protected from corrosion by use of a nontoxic
vapor phase corrosion inhibitor such as COTEC VCI-309 or 307 or equivalent, (depending on the
metallurgy of the vessel) applied at a rate of 0.1 kg/m³.
11. Nozzle
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Threaded nozzle connections shall be protected with threaded plugs.
Vessels waiting for installation have the flanged connections and all other machined surfaces protected
by a coating such as MIL C16173 Grade IV, which is easily removed in the field and fitted with steel
or
Wood cover, 3 mm thick and neoprene gaskets.
12. Pad plate
Leveling shims are installed with a minimum top elevation of 25 mm from the top of concrete foundation.
This is to allow a minimum thickness of 25mm of non-shrink cement based grout.
13. Anchor bolt
The minimum anchor bolt diameter shall be 20 mm (¾"), except when specified otherwise by the vendor
for small equipment
14. What is the Equipment?
 Transfer the process fluids from one place to another place it is called equipment. Two
types of equipment are there,
1. Static equipment
2. Rotary equipment
15. What is a Static Equipment?
16. What is a Heat Exchanger?
 Heat transfer between two different liquid media.
17. Types of Reactor
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Pressurized water reactor
Pressurized heavy water reactor
Sodium cooled water reactor
High temperature gas cooled reactor
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Valve Tray
Sieve Tray
Chimney tray
Bubble cap tray
Seal tray
18. Types of Trays
19. Types of Heat exchanger
 Shell and Tube heat exchanger
 Air cooled heat Exchanger
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Double pipe
Plate frame heat exchanger
Electric Heat exchanger
Spiral heat exchanger
20. Types of packaging
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Structured Packaging
Random Packaging
Ball rings
Catalyst and Desiccant packaging
21. What is pressure vessel?
 A container designed to withstand internal or external pressure, which can be imposed by
an External source, by the application of heat from a direct or indirect source, or by any
combination thereof. This definition includes unfired steam generators and other vapor
generating vessels, which use heat from the operation of a processing system or other
indirect heat source
 Equipment include strainers, pressure containers used for
Transferring liquids as an integral part of a piping system and devices that serve
The purposes of mixing, separating, distributing, metering and controlling flow.
22. What is drum?
23. What is column?
 It is the vertical equipment with internal trays and packaging are used for process
application
 Column is using for separation of gases or liquids
24. What are drum internals?
Demister pads, Baffles, Vortex breakers, Distribution piping.
25. What are drum elevation requirements?
NPSH, minimum clearance, common plat forming, maintenance, operator access.
26. What are drum supports?
Skirt for large drums, legs, lugs, saddles for horizontal drums.
27. What are necessary nozzles for non-pressure vessel?
Inlet, outlet, vent, manhole, drain, overflow, agitator, temperature element, level instrument, and steam out
connection.
28. What are necessary nozzles for pressure vessel?
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Inlet, outlet, manhole, drain, pressure relief, agitator, level gauge, pressure gauge, temperature element,
vent and for steam out.
29. What is preferred location for level instrument nozzles?
Away from the turbulence at the liquid outlet nozzle, although the vessel is provided with a vortex breaker,
instrument should be set in the quiet zone of the vessel for example on the opposite side of the weir or
baffle or near the vapor outlet end.
30. What is preferred location for process nozzles on drum?
Minimum from the tangent line.
31. What is preferred location for steam out nozzle on drum?
At the end opposite to the maintenance access.
32. What is preferred location for vent?
AT the top section of drum at the end opposite the steam out connection.
33. What is preferred location for pressure instrument nozzle on drum?
Must be anywhere in the vapor space, preferable at the top section of drum
34. What is preferred location for temperature instrument?
Must be in liquid space, preferably on the bottom section of drum.
35. What is preferred location for drain?
Must be located at the bottom section of drum.
36. What is NPSH?
NET POSITIVE SUCTION HEAD: It is measure of the pressure drop of the liquid as it moves form the
inlet of the pump to the eye of the impeller, determined by testing and expressed in feet of water by pump
manufacturer.
37. Tell about reactor?
Heart, mixing, chemical reaction, heat generated-absorbed, agitation, jacket, heating coils, cooling.
38. Where furnaces shall be located?
Furnaces shall be located upwind or side wind of process units to blow any combustible leaks away from
the open flame, Min 90M away from tanks and 30M away from control room.
39. What should be stack height?
Stack height shall be minimum 6M above working platform in the vicinity of 25m radius.
40. Where spiral heat exchangers are used?
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Generally in chemical plants
41. How piping is positioned for spiral heat exchangers?
Piping positioned to allow opening of covers and the removal plates.
42. What are the types of tube arrangements?
U-tube, Fixed tube, kettle arrangement.
43. What is full form of TEMA?
Tubular exchanger’s manufacturers Association.
44. Which fluids to be sent through tubes?
Fouling and/or corrosive fluids (Easy cleaning and cheaper to replace tubes than shell), hotter fluid: To
reduce heat loss to the surroundings except steam. refrigerant, cooling fluid.
45. What should be clearance between flanges of exchangers?
1000 MM.
46. Where plate exchangers are used?
Low pressure, low temperature applications.
47. Where used DOUBLE PIPE OR FIN TUBE EXCHANGERS?
Used when liquid has a greater resistance to heat flow than another or when the surface area is small.
48. Where used AIR COOLER EXCHANGERS?
To cool tower overhead vapors.
49. What insulating materials are used?
Asbestos, calcium silicate, cellular glass, cellular silica, diatomaceous silica plus asbestos, Mineral fiber,
mineral wool, magnesia, polyurethane foam.
50. Where jacked screwed flange is used?
For spectacle discs, one flange is jacked screw flange. This flange has two jacked screws 180 degree apart
which are used to create sufficient space between flange for easy removal and placement of line blind or
spectacle blind.
51. Where blind flange is used?
It is used with view to future expansion of the piping system, or for cleaning, inspection etc
52. What are types of towers?
Stripper, Vacuum tower, trayed, packed towers.
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53. What is batch shell process?
Feed, heat, condense, heat more, and condense low quality.
54. What is chimney tray?
It’s a solid plate with central chimney section, used at draw off sections of the tower.
55. What factors to consider while setting tower elevation?
NPSH, Operator access, Maintenance access, Minimum clearance, re boiler type, common area, type of
support, Tower dimensions, type of head, bottom outlet size, foundation details, and minimum clearances.
56. How to located tower maintenance access nozzles?
At bottom, top and intermediate sections of tower, must not be at the down comer section of tower and in
front of internal piping.
57. How to locate feed nozzle?
Must be oriented in specific area of tray by means of internal piping.
58. How to located temperature and pressure instruments?
Temperature in liquid space, at down comer side and pressure in vapor space, in area except down comer
sector.
59. What will be check during torqueing? Before Torqueing?
A. Before Torqueing
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Check the Flange faces and Cleanliness
Verify the Gasket type, size, color code and ratings
Sequence of torqueing and Torque value
Calibration of Torque wrench
Flange Alignment
Bolt Details and Specifications
B. During Torqueing
 Sequence of Torqueing
 Procedure of Torqueing
 Check the Cap between matting flanges
60. What is the Inspection required before Box-Up?
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All nozzles should be reinstated
All internal man ways should be closed and inspected
Final internal installation and cleanliness inspection to be completed
Verify the open NCR’s
Check the Flange faces
Verify the Gasket type, size, color code and ratings
Sequence of torqueing and Torque value
Calibration of Torque wrench
61. How many types of gasket using for pressure vessel?
 Spiral Wound gasket
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O ring gasket
RTJ gasket
Spiral wound with PTFE
Teflon gasket
Compressed asbestos gasket
PIKOTEK gasket
62. Main parts of Pressure vessel?
 Inlet, outlet, vent, manhole, drain, overflow, agitator, temperature element, level instrument, and
steam out connection.
 Saddle, Skirt, Leg, Lug, Support, Demister pad, Baffle plate, Vortex breaker, Davit arm
63. How many types of internal inspection?
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Tray Test
Leak test
Cleanness test
Visual inspection
64. What is the document required for material Receiving?
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Aramco approved documents
RFI
Purchase order
Delivery note
Mill test certificate
IRC-Inspection release certificate
65. How you will find Equipment was in Preservation?
 All nozzles should be end blinded with temporary gasket
 Installed the pressure gauge to ensure the nitrogen filled
 Marking on the equipment which shows VpCI is present ( Vapor phase Corrosion Inhibitors )
66. Which type of grout using for Static equipment?
 Non-Shrink cement based grout
67. What is the purpose of blank nut are welded on equipment skirt?
 The bottom heads of vertical vessels that are externally insulated are provided with 12 mm blank
nuts. Blank nuts are welded on edge and located on 300 mm square centers.
 Fire proofing
68. Where you get reference from verticality Tolerance?
 32-SAMSS-004 / 13 Page / Para 14
 PIP VEFV 1100/1102
69. What is the External Inspection on vessel?
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Orientation to be check
Elevation
Verticality ( Plumpness )
Centering (Foundation center to Equipment center )
 Anchor Bolt tightness
 Visual inspection of equipment to ensure that damages
70. What is Peaking? Banding?
 Peaking
Deviation at vertical weld joints shall not exceed 13 mm.peaking at vertical weld joint shall be
determined using a horizontal sweep board 900 mm long.
 Banding
Deviation at horizontal weld joints shall not exceed 13 mm.peaking at horizontal weld joint shall
be determined using a vertical sweep board 900 mm long.
71. Types of Air cooled heat Exchanger?
 Forced Draft (Fan – Top and Bundle – Bottom )
 Induced Draft ( Fan - Bottom and Bundle - Top )
72. Main parts of Air cooled heat Exchanger?
 Plenum, Fan, Pulley, Tube Bundle, Motor, Structural Attachment, Inlet and Outlet
73. Sliding side Bolt full Tight Required? True or false
 False
74. What are the tools required at the time of Inspection?
 Measuring Tape, Sprit Level, Feller gauge, Right angle
 Theodolite and Dumpy level
 Plumpness
75. How to measure belt thickness of driver and driven
76. What is your responsibility during Installation?
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Verify the pre installation inspection status
Plant drawing to be verify
Check the orientation
Check the Foundation cleanliness
Check and verify the anchor bolt condition
77. What are the inspections to be done before installation?
 Verifying foundation release
 Pad plate elevation
 Projection of anchor bolt
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 Distance between anchor bolt dimensions
 PCD
 Visual Inspection Of Equipment
78. What are the two types of static equipment?
Vessels, exchangers, drum, reactors, boilers etc.,
79. What is Horizontal Equipment tolerance?
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Equipment Center to Bottom of base plate 0,-3 mm
Centering of Equipment 3 mm
Levelness of base plate ± 3 mm
Diagonal ± 6 mm
BCD ± 6 mm
80. Which type of equipment is using Saddle?
Horizontal vessels & Exchangers
81. What is the inspection to be check during PRE INSTALLATION?
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Verifying foundation release report
Pad plate elevation
Padding voids
Projection of anchor bolt
Distance between anchor bolt dimensions
PCD
82. Maximum Tolerance for Vertical Equipment?
 0.8mm / 1 M (Max 19 mm)
83. What is the Inspection point of TWO MATING FALANGES?
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Check the Flange faces
Check the flange alignment
Check the bolt hole are going freely moving
Check the flange offset
Verify the Gasket type, size, color code and ratings
Sequence of torqueing and Torque value
Calibration of Torque wrench
84. What is Qc Roles and responsibility?
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Monitoring the process as per the ITP, Data sheet and approved drawings
Eliminate the defects during process
Ensure the execution of work as per Specified requirement
Should be vigilant
Convey the irregularities found to the concern authorities
85. What is the Difference between Tank & Pressure Vessels?
Tank
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Pressure Vessels
86. What is Plumpness Tolerance for API 650 Tank?
 1/200 mm
87. API 650 Tank tolerance?
 Radii measured at 0.3 m above the bottom corner
Tank Diameter
12m
12m to 45m
45m to 75m
Above 75m
Radius Tolerance
±1/2 in
±3/4 in
±1 in
±1 ¼ in
88. PIP drawing attached for RFI? Yes or No
YES
89. DEGREE calculation 0° 2m diameter of ANCHORBOLT foundation?
90. Tell about API 650 tank and usage?
91. Types of Tray testing?
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Leak test
Tightness test
Levelness
Deflection
92. Write the name of five International stds?
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API 510-Presure vessel inspection code-In- service, alteration, Re rating
API560-Rules for construction of fired heater
API 530-Calculation of tube thickness of fired heater
API 661-Shell and Tube heat exchanger for general refinery service
API 662-Plate frame heat exchanger for general refinery service
API 572-Inspection of pressure vessel
ASME SEC II-Material
ASME SEC VIII-Rule for construction of pressure vessel
ARAMCO EQUIPMENT INTERVIEW QUESTIONS
Date: 28‐11‐ϮϬϭ
1. MDMT:
Minimum design metal temperature
2. High - Alloy Steels:
Steels with a total alloying content more than 5%.
3. Low - Alloy Steels:
Steels with a total alloying content of less than 5% but more than specified for carbon steels
4. Nominal Thickness:
The value of the design thickness required to withstand all primary loads, and includes allowance for
corrosion.
5. PFD:
Process Flow Diagram.
6. Utility Services:
Water, air and nitrogen services.
7. Equipment Davit
A davit for the lifting of equipment shall be specified for vessels containing removable internals such as
trays, packing and relief valves.
8. Vortex Breaker:
The use of vortex breakers or guying devices in order to maintain internal stresses, due to wind-induced
vibration within allowable limits, is prohibited.
9. Telltale Holes
Telltale holes in reinforcing pads shall be protected with wooden plugs or packed with rust preventative
grease such as Denso paste.
10. VPCI
The interior surfaces of vessels, including internals, shall be protected from corrosion by use of a nontoxic
vapor phase corrosion inhibitor such as COTEC VCI-309 or 307 or equivalent, (depending on the
metallurgy of the vessel) applied at a rate of 0.1 kg/m³.
11. Nozzle
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Atmospheric
Caustic Embrittlment
Hydrogen blistering
Soil corrosion
103. What is galvanic corrosion'?
When two different metals are electrically connected, either by direct contact or by an electrical
conductor
104. What is contact corrosion (crevice corrosion)?
A type of corrosion that occurs at the point of contact
105. Types of tube arrangement
 U tube
 Fixed tube
 Kettle arrangement
106. What is Preservation?
Preservation is the activity to preserve the material, components and equipment’s from physical condition
and from the climatic condition.
 Preservation started when the material or equipment arrived at laydown area
 To cover the nozzle by blind flange to prevent dust entry and cover the polythene covers where
ever it is possible
 Nitrogen purging is required to avoid inside corrosion and maintain the pressure 5 PSI
 To check the pressure twice in a month
 Should be keep in 150mm above the ground
107. Four main parts of gasket
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Inner ring
Outer ring
Filler and
Hoop
108. Steps of Preservation
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Transportation
Storage
Construction phase
Commissioning phase ( From pipe tight conditions onwards )
109. What is Gauge Ring?
OD or ID of gasket the ring provide Mechanical stability, Safe guard against unraveling of windings.
110. Before Tray installation inspection
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Internal Cleaning
Manhole face should be protect from mechanical damages
Reference line and location marking to be done
Ring levelness check
Mockup should be done and recorded
111. after tray installation inspection
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Orientation and measurement to be check
Check the no loose hardware’s is left
Ensure that All parts are fitted properly
Tray must be clean
Check the down comers clearance
Weir plate level and height
Bolt torqueing to be check
Final check before closing of man way is necessary
112. Which fluids to be sent through tubes and shell
 Fouling and/or corrosive fluids ( easy cleaning and cheaper to replace tubes then sheet)
 Hotter fluids (To reduce heat loss to the surrounding except steam, refrigerant)
 Cooling fluids
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