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Piping & Hydraulics interview questions

27 real Piping & Hydraulics questions from the Process Design bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.

1. What is ASME B31.3?

Junior
  1. A.ΔP = f (L/D) (ρv²/2) using the Darcy friction factor, with fittings added as equivalent length or K resistance coefficients
  2. B.process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  3. C.bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  4. D.check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
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2. Which term means: "process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure"?

Junior
  1. A.Water hammer
  2. B.Pipe schedule
  3. C.ASME B31.3
  4. D.Liquid line velocity
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3. Which statement is correct?

Junior
  1. A.ASME B31.3 — ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
  2. B.ASME B31.3 — process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  3. C.ASME B31.3 — bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  4. D.ASME B31.3 — API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates
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4. What is Liquid line velocity?

Junior
  1. A.wall-thickness designation (Sch 40, 80, STD, XS) where nominal size stays fixed and inner diameter shrinks as the schedule number rises
  2. B.typical design of 1–3 m/s for pump discharge and 0.5–1.5 m/s for suction to limit pressure drop and protect NPSH
  3. C.bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  4. D.pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
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5. Which term means: "typical design of 1–3 m/s for pump discharge and 0.5–1.5 m/s for suction to limit pressure drop and protect NPSH"?

Junior
  1. A.Water hammer
  2. B.Flange pressure class
  3. C.Liquid line velocity
  4. D.ASME B31.3
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6. Which statement is correct?

Junior
  1. A.Liquid line velocity — typical design of 1–3 m/s for pump discharge and 0.5–1.5 m/s for suction to limit pressure drop and protect NPSH
  2. B.Liquid line velocity — pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  3. C.Liquid line velocity — process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  4. D.Liquid line velocity — check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
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7. What is Erosional velocity?

Junior
  1. A.API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates
  2. B.ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
  3. C.pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  4. D.ΔP = f (L/D) (ρv²/2) using the Darcy friction factor, with fittings added as equivalent length or K resistance coefficients
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8. Which term means: "API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates"?

Junior
  1. A.Pipe schedule
  2. B.Darcy-Weisbach pressure drop
  3. C.Water hammer
  4. D.Erosional velocity
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9. Which statement is correct?

Junior
  1. A.Erosional velocity — pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  2. B.Erosional velocity — process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  3. C.Erosional velocity — bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  4. D.Erosional velocity — API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates
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10. What is Flange pressure class?

Junior
  1. A.typical design of 1–3 m/s for pump discharge and 0.5–1.5 m/s for suction to limit pressure drop and protect NPSH
  2. B.ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
  3. C.check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
  4. D.API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates
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11. Which term means: "ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group"?

Junior
  1. A.Pipe stress analysis
  2. B.Flange pressure class
  3. C.Darcy-Weisbach pressure drop
  4. D.Two-phase flow regimes
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12. Which statement is correct?

Junior
  1. A.Flange pressure class — ΔP = f (L/D) (ρv²/2) using the Darcy friction factor, with fittings added as equivalent length or K resistance coefficients
  2. B.Flange pressure class — ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
  3. C.Flange pressure class — process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  4. D.Flange pressure class — typical design of 1–3 m/s for pump discharge and 0.5–1.5 m/s for suction to limit pressure drop and protect NPSH
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13. What is Darcy-Weisbach pressure drop?

Mid
  1. A.API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates
  2. B.ΔP = f (L/D) (ρv²/2) using the Darcy friction factor, with fittings added as equivalent length or K resistance coefficients
  3. C.process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  4. D.ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
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14. Which term means: "ΔP = f (L/D) (ρv²/2) using the Darcy friction factor, with fittings added as equivalent length or K resistance coefficients"?

Mid
  1. A.Erosional velocity
  2. B.Flange pressure class
  3. C.ASME B31.3
  4. D.Darcy-Weisbach pressure drop
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15. Which statement is correct?

Mid
  1. A.Darcy-Weisbach pressure drop — bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  2. B.Darcy-Weisbach pressure drop — API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates
  3. C.Darcy-Weisbach pressure drop — pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  4. D.Darcy-Weisbach pressure drop — ΔP = f (L/D) (ρv²/2) using the Darcy friction factor, with fittings added as equivalent length or K resistance coefficients
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16. What is Two-phase flow regimes?

Mid
  1. A.typical design of 1–3 m/s for pump discharge and 0.5–1.5 m/s for suction to limit pressure drop and protect NPSH
  2. B.bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  3. C.pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  4. D.process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
Reveal the answer + AI explanation — free account

17. Which term means: "bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges"?

Mid
  1. A.Pipe schedule
  2. B.Liquid line velocity
  3. C.Pipe stress analysis
  4. D.Two-phase flow regimes
Reveal the answer + AI explanation — free account

18. Which statement is correct?

Mid
  1. A.Two-phase flow regimes — check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
  2. B.Two-phase flow regimes — wall-thickness designation (Sch 40, 80, STD, XS) where nominal size stays fixed and inner diameter shrinks as the schedule number rises
  3. C.Two-phase flow regimes — pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  4. D.Two-phase flow regimes — bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
Reveal the answer + AI explanation — free account

19. What is Pipe schedule?

Mid
  1. A.pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  2. B.check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
  3. C.typical design of 1–3 m/s for pump discharge and 0.5–1.5 m/s for suction to limit pressure drop and protect NPSH
  4. D.wall-thickness designation (Sch 40, 80, STD, XS) where nominal size stays fixed and inner diameter shrinks as the schedule number rises
Reveal the answer + AI explanation — free account

20. Which term means: "wall-thickness designation (Sch 40, 80, STD, XS) where nominal size stays fixed and inner diameter shrinks as the schedule number rises"?

Mid
  1. A.Darcy-Weisbach pressure drop
  2. B.Pipe stress analysis
  3. C.Pipe schedule
  4. D.Erosional velocity
Reveal the answer + AI explanation — free account

21. Which statement is correct?

Mid
  1. A.Pipe schedule — process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  2. B.Pipe schedule — bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  3. C.Pipe schedule — ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
  4. D.Pipe schedule — wall-thickness designation (Sch 40, 80, STD, XS) where nominal size stays fixed and inner diameter shrinks as the schedule number rises
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22. What is Pipe stress analysis?

Senior
  1. A.process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  2. B.check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
  3. C.ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
  4. D.pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
Reveal the answer + AI explanation — free account

23. Which term means: "check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed"?

Senior
  1. A.Flange pressure class
  2. B.Pipe stress analysis
  3. C.Erosional velocity
  4. D.Liquid line velocity
Reveal the answer + AI explanation — free account

24. Which statement is correct?

Senior
  1. A.Pipe stress analysis — bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
  2. B.Pipe stress analysis — wall-thickness designation (Sch 40, 80, STD, XS) where nominal size stays fixed and inner diameter shrinks as the schedule number rises
  3. C.Pipe stress analysis — ASME B16.5 rating (150, 300, 600 and up) whose allowable pressure falls with temperature according to the material group
  4. D.Pipe stress analysis — check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
Reveal the answer + AI explanation — free account

25. What is Water hammer?

Senior
  1. A.pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  2. B.check of thermal expansion, sustained and occasional loads against B31.3 allowables, typically in CAESAR II, with expansion loops or spring hangers added where needed
  3. C.process piping code for refineries and chemical plants covering design, materials, fabrication, examination and testing, with hydrotest at 1.5 times design pressure
  4. D.API RP 14E limit V = C/√ρ (C about 100 in US units) above which erosion of fittings and elbows in gas-liquid lines accelerates
Reveal the answer + AI explanation — free account

26. Which term means: "pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief"?

Senior
  1. A.Flange pressure class
  2. B.ASME B31.3
  3. C.Water hammer
  4. D.Pipe stress analysis
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27. Which statement is correct?

Senior
  1. A.Water hammer — ΔP = f (L/D) (ρv²/2) using the Darcy friction factor, with fittings added as equivalent length or K resistance coefficients
  2. B.Water hammer — wall-thickness designation (Sch 40, 80, STD, XS) where nominal size stays fixed and inner diameter shrinks as the schedule number rises
  3. C.Water hammer — pressure surge from rapid valve closure equal to ρ·c·Δv by the Joukowsky relation, mitigated by slower closure, surge vessels or relief
  4. D.Water hammer — bubble, slug, annular and mist patterns identified on a Baker map; slug flow is avoided in lines because of vibration and separator surges
Reveal the answer + AI explanation — free account

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