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Piping Questionnaire

• 1. What is the ASME code for design of piping systems in Process piping (Refineries & Chemical Industries)?
  • Answer: B 31.3
• 2. Which American institute standard does piping engineer refer in general?
  • Answer:
  • A. The American Petroleum institute (API).
  • B. The American Iron & Steel institute (AISI).
  • C. The American Society for Testing and materials (ASTM).
  • D. The American National standard institute (AISI).
  • E. The American welding society (AWS).
  • F. The American Water Works Association (AWWA).
  • G. The American Society for Mechanical Engineers (ASME).
• 3. What are the different pressure piping codes for ASME B31 ?
  • Answer:
  • A. ASME B31.1 - Power piping.
  • B. ASME B31.2 - Fuel Gas Piping.
  • C. ASME B31.3 - Process piping.
  • D. ASME B31.4 - Pipeline Transportation system for liquid hydrocarbon & other liquid.
  • E. ASME B31.5 - Refrigeration Piping.
  • F. ASME B31.8 - Gas transmission & distribution piping system.
  • G. ASME B31.9 - Building services piping.
  • H. ASME B31.11 - Slurry transportation piping system.
• 4. What are the different sections of ASME code? Where these sections are referred?
  • Answer:
  • 1. ASME section I : - Rules for construction of power boiler.
  • 2. ASME Section II : - Materials.
  • Part A – Ferrous materials.
  • Part B – Non-Ferrous materials.
  • Part C – Specification for electrodes & filler wire.
  • Part D – Properties.
  • 3. ASME Section IV : - Rules for construction of Heating Boiler.
  • 4. ASME Section V : - Non- destructive Examination.
  • 5. ASME Section VI : - Recommended rules for care & operation of heating boiler.
  • 6. ASME Section VII : - Recommended guidelines for care of power boiler.
  • 7. ASME Section VIII : - Rules for construction of pressure vessels. (Division I & II)
  • 8. ASME Section IX : - Welding & Brazing qualification.
• 5. Which American standard is reffered for selection of following piping element? A. Flanges B. Butt Welded fittings C. Gasket D. Socket & Threaded fittings E. Valves F. Pipes.
  • Answer:
  • A. Flanges :-
  • I. ASME B16.1 : - Cast iron pipe flanges & flanged fittings.
  • II. ASME B16.5 : - Carbon steel pipes flanges & flanged fittings. (Up to 24”)
  • III. ASME B16.47 : - Large Diameter steel flanges. (Above 24”)
  • B. Butt welded fittings :-
  • I. ASME B16.9 : - Steel butt welding fittings.
  • II. ASME B16.28 : - Butt-welded short radius elbows & returns bends.
  • C. Gasket :-
  • I. ASME B16.20 / API -601: - Metallic gaskets for pipe flanges- Spiral wound,
  • Octagonal ring Joint & Jacketed flanges.
  • II. ASME B16.21 : - Non metallic gasket.
  • D. Socket & Threaded fittings :
  • I. ASME B16.11 : - Forged steel socket welding & threaded fittings.
  • E. Valves :-
  • I. ASME B16.10 : - Face to face & end to end dimension of valves.
  • II. ASME B16.34 : - Flanged & butt-welded ends steel valves (Pressure &Temperature ratings)
  • except Ball, Plug & Butter fly Valves.
  • F. Pipes :-
  • I. ASME B36.10 : - Welded & Seamless wrought iron pipes.
  • II. ASME B36.19 : - Stainless steel pipes.
• What are the commonly used ASTM CARBON STEEL PIPES ?
  • Answer:
  • Carbon Steel : -ASTM A53 Gr. A/B, ASTM A106 Gr. A/B/C
• What are the commonly used ASTM STAINLESS STEEL PIPES ?
  • Answer:
  • Stainless Steel :- ASTM A312 TP304/TP304L/TP304H/TP308/TP310/TP316/TP316L/TP316H/TP317/TP321/TP321H/TP347/TP347H/TP348/TP348H.
• What are the commonly used ASTM ALLOY STEEL PIPES ?
  • Answer:
  • Alloy Steel :- ASTM A335 Gr.P1/P2/P5/P7/P9/P11/P12/P22.
• What are the commonly used ASTM WROUGHT IRON FITTINGS ?
  • Answer:
  • I. Carbon Steel :- ASTM A234Gr.WPA/B, ASTM A420 Gr.WPL6(used for low temp)
  • II. Alloy Steel :- ASTM A234 WP1/WP5/WP7/WP9/WP11/WP12/WP22.
  • III. Stainless Steel :- ASTM A403 WP304/WP304L/WP304H/WP309/WP310/WP316/WP316L/WP316H/ WP317/WP321/WP321H/WP347/WP347H/WP348.
• What are the commonly used ASTM FORGED FITTINGS ?
  • Answer:
  • I. Carbon Steel :- ASTM A181. ASTM A105, ASTM A350 LF1/2.
  • II. Alloy Steel :- ASTM A182 F1/F2/F5/F7/F9/F11/F12/F22.
  • III. Stainless Steel :- ASTM A182 F6/F304/F304L/F304H/F310/F316/F316L/F316H/F321/F321H/F347/F347H/F348.
• What are the commonly used ASTM CAST FITTINGS ?
  • Answer:
  • I. Carbon Steel :- ASTM A216, ASTM A352 LCB/C.
  • II. Alloy Steel :- ASTM A217 WC1/WC6/WC9/C5/C12.
  • III. Stainless Steel :- ASTM A217 CA15, ASTM A296 CA15, ASTM A351 CF8/CF3/CH20/CK20/CF 8M/CF 3M/CF 8C/HK40.
• What are the commonly used ASTM PLATE MATERIALS ?
  • Answer:
  • I. Carbon Steel :- ASTM A285, ASTM A515, ASTM A516.
  • II. Alloy Steel :- ASTM A387 Gr.2/Gr.5/Gr.7/Gr.9/Gr.11/Gr.12/Gr.22.
  • III. Stainless Steel :- ASTM A240 TP410/TP405/TP430/TP304/TP304L/TP309/TP310S/TP316/TP316L/TP317/TP321/TP347/TP348
• What is the basic difference between Pipe specification A106 Gr.A / Gr.B/ Gr.C.?
  • Answer:
  • Difference is due to the Carbon content.% of carbon content in : -
  • I. ASTM A106 Gr. A – 0.25 %
  • II. ASTM A106 Gr. B – 0.30 %
  • II ASTM A106 Gr. C – 0.35 %.
• . What is the difference between pipe specifications ASTM A312 TP 304 & ASTM A312 TP304L, ASTM A312 TP 316 & ASTM A312 TP 316L?
  • Answer:
  • Difference is due to the Carbon content. The Letter “L” denotes lower percentage of carbon. % of carbon content in : -
  • I. ASTM A312 TP 304 - 0.08 %
  • II. ASTM A312 TP 304L- 0.035%
  • III. ASTM A312 TP 316 - 0.08 %
  • IV. ASTM A312 TP 316L- 0.035%
• How can flanges be classified based on Pressure- temperature ratings?
  • Answer:
  • Flanges are classified based on pressure temperature ratings as: -
  • A. 150#
  • B. 300#
  • C. 400#
  • D. 600#
  • E. 900#
  • F. 1500#
  • G. 2500#
  • Pressure temperature rating carts in the standard ASME16.5 specify the non-shock working
  • gauge pressure to which the flange can be subjected to at a particular temperature.
  • IN GENERAL,
  • RATINGS 150 300 ARE TERMED AS LOW PRESSURE RATINGS
  • RATINGS 400 600 900 ARE TERMED AS INTERMEDIATE PRESSURE RATINGS
  • RATINGS 1500 2500 ARE TERMED AS HIGH PRESSURE RATINGS
• How can flanges be classified based on facing?
  • Answer:
  • Flanges are classified based on facing as: -
  • A. Flat face. (FF)
  • B. Raised face. (R/F)
  • C. Tongue and groove. (T/G)
  • D. Male and female. (M/F)
  • E. Ring type joint. (RTJ)
• How can flanges be classified based on face finish?
  • Answer:
  • Flanges are classified based on face finish as: -
  • A. Smooth finish.
  • B. Serrated finish.
• Where the smooth finish flange & serrated finish flange finds its use?
  • Answer:
  • The smooth finish flange is provided when metallic gasket is provided and serrated finish flange is provided when non-metallic gasket is provided.
• What are the types of serrated finish provided on flange face?
  • Answer:
  • A. Concentric
  • B. Spiral (Phonographic)
• How the serration on flanges is specified?
  • Answer:
  • The serration on flanges is specified by the number, which is the Arithmetic Average Rough Height (AARH).
• Where the concentric serration is insisted for face finish?
  • Answer:
  • Concentric serration are insisted for face finish where the fluid being carried has very low density and can find leakage path through cavity.
• How the Gaskets are classified based on the type of construction?
  • Answer:
  • Based on the type of construction, gaskets are classified as: -
  • A. Full face.
  • B. Spiral wound metallic.
  • C. Ring type.
  • D. Metal jacketed.
  • E. Inside bolt circle.
• What is the most commonly used material for Gasket?
  • Answer:
  • Compressed Asbestos Fibre.
• Which type of gasket is recommended for high temperature & high-pressure application?
  • Answer:
  • Spiral Wound Metallic Gasket
• What are the criteria for selection of MATERIAL OF CONSTRUCTION of Spiral Wound metallic Gasket winding material?
  • Answer:
  • The selection of material of construction for Gasket winding depends upon: -
  • A. The corrosive nature and concentration of fluid being carried.
  • B. The operating temperature of the fluid.
  • C. The relative cost of alternate winding material.
• What are the most common materials used for spiral wound metallic gasket winding?
  • Answer:
  • The most commonly used material for spiral wound metallic gasket winding is: -
  • A. Austenitic stainless steel 304 with asbestos filler.
  • B. Austenitic stainless steel 316 with asbestos filler.
  • C. Austenitic stainless steel 321 with asbestos filler.
• Which material is used as filler material for spiral wound gasket in case of high temperature services?
  • Answer:
  • For very high temperature services, graphite filler is used.
• What is centering ring in connection to spiral wound gasket?
  • Answer:
  • Spiral wound gaskets are provided with carbon steel external ring called centering ring to assist in centering the gasket while installation.
• What will be the AARH finish on flange face for using spiral wound gasket?
  • Answer:
  • 125-250 AARH finish.
• On which type of flanges the use of spiral wound gasket are restricted?
  • Answer:
  • ASME B16.5 does not recommend the use of 150# rating spiral wound gasket on flanges other than welding neck and lapped joint type.
• Up to what temperature limits the low strength carbon steel bolts should not be used for flanged joints?
  • Answer:
  • Flanged joints using low strength carbon steel shall not be used above 200-deg C or below - 28-deg C.
• How the pipe fittings are classified based on end connections?
  • Answer:
  • Pipe fittings are classified based on end connection as: -
  • A. Socket weld fittings.
  • B. Screwed end fittings.
  • C. Beveled end or Butt weld fittings.
  • D. Spigot socket fittings.
• Up to what temperature the carbon steel materials shall be used in general?
  • Answer:
  • Carbon steel materials shall be used for temperature up to 425-deg C.
• Which material is used for temperature above 426 deg C?
  • Answer:
  • Alloy steel materials shall be used for temperature above 426 deg C.
• Which type of material is used for corrosive fluid?
  • Answer:
  • Stainless steel materials shall be used for corrosive fluid.
• Which type of piping materials are used for drinking water, instrument air etc?
  • Answer:
  • Galvanized steel materials shall be used for drinking water, utility instrument air and Nitrogen lines (Low Pressure).
• What is the difference between Pipe and Tube?
  • Answer:
  • Pipe is identified by Nominal Bore and thickness is defined by Schedule whereas Tube is identified by OD
  • & its thickness as BWG (Brimingham wire gauge or 1/100 inch).
  • Pipe is used for MASS TRANSFER
  • Tube in general used for HEAT & MASS TRANSFER
  • Pipe is round in shape
  • Tube may be round or rectangular or any odd shape
• From which size onwards NB of pipe is equal to OD of Pipe?
  • Answer:
  • From the size 14” and onwards NB = OD of pipe.
• What should be the radius of long radius elbow?
  • Answer:
  • 1.5D (Where “D” is the diameter of the pipe.)
• What should be the radius of short radius elbow?
  • Answer:
  • 1D(Where “D” is the diameter of the pipe.)
• What is the basis of using of short radius & long radius elbow?
  • Answer:
  • Long radius elbow are used for small pressure drop whereas short radius elbow are used for high pressure drops. For catalyst flows vary long radius elbows are used.
  • Short radius elbows are used in jacketted piping,usually in small bore.
• Normally where do we use the following? A. Eccentric reducers B. Concentric reducers
  • Answer:
  • A. Eccentric reducers = Pump suction to avoid Cavitation, To maintain elevation (BOP) in rack.
  • B. Concentric reducers = Pump discharge, vertical pipeline etc.
• Concentric reducer is used in pump suction. (Yes / No). Explain.
  • Answer:
  • No. Air pockets may form if concentric reducer is used at pump suction, which results in cavitation and cause damage to Pump. To avoid this problem, Eccentric Reducer with flat side up (FSU) is used in Pump Suction.
• Where the ERW & Seamless pipes are used?
  • Answer:
  • in general above 18” ERW pipes are used. Below 18” seamless pipes are used. Seamless pipes can sustain higher temperature & pressure.
• What is the main use of ASTM A53 & A106 Gr.B pipes?
  • Answer:
  • ASTM A53 pipes are mainly used for utility services whereas A106 Gr.B pipes are used for high Pressure & high temperature services.
• From which side of pipe will you take a branch connection?
  • Answer:
  • When fluid is Gas, Air or Steam and Cryogenic Service – Topside.
  • When Fluid is Liquid – Bottom Side.
  • steam is also sometimes taken from side to avoid dual phase flow of moist steam and dry steam
• Why don’t we take a branch for Cryogenic Service from bottom side though the fluid is in liquid state?
  • Answer:
  • There is the chance of ice formation during normal operation and since ice flows from the bottom of the pipe it will block the branch pipe connection.
• Why do we provide High Point Vent (HPV) and Low Point Drain (LPD) in piping?
  • Answer:
  • HPV – For removing Air during Hydro-test.
  • LPD – For draining water after conducting Hydro-test.
• What do you mean by Jacketed Piping?
  • Answer:
  • Piping where the most uniform application of heat/temperature is required to the process, where steam tracing is not capable of maintaining the temperature of fluid constantly.Usually used for molten sulphur, Polymers service etc.
• What is the minimum distance to be maintained between two welds in a pipe?
  • Answer:
  • The thumb rule is that the minimum distance between adjacent butt welds is 1D. If not, it is never closer than 1-1/2 inch. This is supposedly to prevent the overlap of HAZs. Minimum spacing of circumferential welds between centerlines shall not be less than 4 times the pipe wall thickness or 25 mm whichever is greater.
  • For this reason many company standards advice the minimum spool length of pipe which is usally 100mm in genral but may differ.But in cases where required the minimum distance for adjacent welds can be considered
• What are Weldolet and Sockolet? And where they are used?
  • Answer:
  • Weldolet and Sockolet are basically self-reinforced fittings.Weldolet is used for Butt weld branch connection where standard tee is not available due to size restrictions and the piping is of critical / high-pressure service. Sockolet is used for socket welding branch connection, which require reinforcing pad.
• What is the common Material Of Construction for Superheated high pressure Steam Lines?
  • Answer:
  • In general ,A 335 Gr. P 1 / P 11, Composition: 1Cr. – ½ Mo (P1) / 1¼ Cr. – ½ Mo (P11) is used
• What is the normal upstream and downstream straight length of orifice flow meter?
  • Answer:
  • In general Upstream - 15D Downstream - 5D
• What are the main function of valves?
  • Answer:
  • A. Isolation.
  • B. Regulation.
  • C. Non-Return.
  • D. Special purpose.
• What are the main types of ISOLATION valves used in the industry?
  • Answer:
  • 1. Gate valve.
  • 2. Ball valve
  • 3. Plug valve.
  • 4. Piston valve.
  • 5. Diaphragm Valve.
  • 6. Butterfly valve.
  • 7. Pinch valve.
• What are the main types of REGULATION valves used in the industry?
  • Answer:
  • 1. Globe valve.
  • 2. Needle valve.
  • 3. Butterfly valve.
  • 4. Diaphragm valve.
  • 5. Piston valve.
  • 6. Pinch valve.
• What are the main types of NON RETURN valves used in the industry?
  • Answer:
  • Check valve.
• TYPEs OF Special purpose valve?
  • Answer:
  • 1. Multi- Port valve.
  • 2. Flush Bottom valve.
  • 3. Float valve.
  • 4. Foot valve.
  • 5. Line blind valve.
  • 6. Knife Gate valve.
• what is the purpose of the spiral wound gasket colour coding?
  • Answer:
  • To identify the material (Based upon the gasket colour coding we can easily identify whether the correct gasket has installed or not during final walk down and before commissioning the line.)
• Commonly used Destructive tests?
  • Answer:
  • I Tension test
  • II Bend test
  • III Impact test
  • IV Hardness test
• Commonly used Non-Destructive tests?
  • Answer:
  • I Radiography testing
  • II Ultrasonic testing
  • III Magnetic particle testing
  • IV Penetrant testing
  • V Eddy current testing
  • VI Visual testing