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P&ID, PFD & Documentation interview questions

30 real P&ID, PFD & Documentation 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 PFD?

Junior
  1. A.instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  2. B.process flow diagram showing major equipment, main process streams, operating conditions and the heat and material balance table, without instrumentation detail
  3. C.process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against
  4. D.document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
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2. Which term means: "process flow diagram showing major equipment, main process streams, operating conditions and the heat and material balance table, without instrumentation detail"?

Junior
  1. A.Revision status IFR/IFD/IFC/As-built
  2. B.PFD
  3. C.Tie-in schedule
  4. D.P&ID
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3. Which statement is correct?

Junior
  1. A.PFD — list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  2. B.PFD — circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
  3. C.PFD — process flow diagram showing major equipment, main process streams, operating conditions and the heat and material balance table, without instrumentation detail
  4. D.PFD — document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
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4. What is P&ID?

Junior
  1. A.piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
  2. B.list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  3. C.unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  4. D.document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
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5. Which term means: "piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction"?

Junior
  1. A.P&ID
  2. B.ISA 5.1 tag letters
  3. C.Tie-in schedule
  4. D.Piping class
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6. Which statement is correct?

Junior
  1. A.P&ID — list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  2. B.P&ID — unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  3. C.P&ID — letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
  4. D.P&ID — piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
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7. What is ISA 5.1 tag letters?

Junior
  1. A.instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  2. B.document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
  3. C.letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
  4. D.circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
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8. Which term means: "instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)"?

Junior
  1. A.Piping class
  2. B.Equipment datasheet
  3. C.ISA 5.1 tag letters
  4. D.PFD
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9. Which statement is correct?

Junior
  1. A.ISA 5.1 tag letters — document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
  2. B.ISA 5.1 tag letters — instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  3. C.ISA 5.1 tag letters — process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against
  4. D.ISA 5.1 tag letters — letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
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10. What is ISA 5.1 instrument bubble?

Junior
  1. A.table of every PFD stream's flow, composition, temperature, pressure, phase and physical properties, the basis for all equipment sizing
  2. B.circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
  3. C.unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  4. D.process flow diagram showing major equipment, main process streams, operating conditions and the heat and material balance table, without instrumentation detail
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11. Which term means: "circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function"?

Junior
  1. A.ISA 5.1 instrument bubble
  2. B.Line number
  3. C.Equipment datasheet
  4. D.ISA 5.1 tag letters
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12. Which statement is correct?

Junior
  1. A.ISA 5.1 instrument bubble — document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
  2. B.ISA 5.1 instrument bubble — unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  3. C.ISA 5.1 instrument bubble — circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
  4. D.ISA 5.1 instrument bubble — letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
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13. What is Line number?

Mid
  1. A.piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
  2. B.unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  3. C.table of every PFD stream's flow, composition, temperature, pressure, phase and physical properties, the basis for all equipment sizing
  4. D.list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
Reveal the answer + AI explanation — free account

14. Which term means: "unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH"?

Mid
  1. A.Line number
  2. B.P&ID
  3. C.ISA 5.1 instrument bubble
  4. D.Tie-in schedule
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15. Which statement is correct?

Mid
  1. A.Line number — instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  2. B.Line number — piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
  3. C.Line number — letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
  4. D.Line number — unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
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16. What is Piping class?

Mid
  1. A.list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  2. B.unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  3. C.instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  4. D.letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
Reveal the answer + AI explanation — free account

17. Which term means: "letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID"?

Mid
  1. A.Piping class
  2. B.ISA 5.1 tag letters
  3. C.ISA 5.1 instrument bubble
  4. D.Revision status IFR/IFD/IFC/As-built
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18. Which statement is correct?

Mid
  1. A.Piping class — piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
  2. B.Piping class — letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
  3. C.Piping class — unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  4. D.Piping class — circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
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19. What is Heat and material balance?

Mid
  1. A.table of every PFD stream's flow, composition, temperature, pressure, phase and physical properties, the basis for all equipment sizing
  2. B.unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
  3. C.list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  4. D.piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
Reveal the answer + AI explanation — free account

20. Which term means: "table of every PFD stream's flow, composition, temperature, pressure, phase and physical properties, the basis for all equipment sizing"?

Mid
  1. A.Line number
  2. B.P&ID
  3. C.Heat and material balance
  4. D.ISA 5.1 tag letters
Reveal the answer + AI explanation — free account

21. Which statement is correct?

Mid
  1. A.Heat and material balance — piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
  2. B.Heat and material balance — circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
  3. C.Heat and material balance — process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against
  4. D.Heat and material balance — table of every PFD stream's flow, composition, temperature, pressure, phase and physical properties, the basis for all equipment sizing
Reveal the answer + AI explanation — free account

22. What is Equipment datasheet?

Mid
  1. A.list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  2. B.table of every PFD stream's flow, composition, temperature, pressure, phase and physical properties, the basis for all equipment sizing
  3. C.instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  4. D.process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against
Reveal the answer + AI explanation — free account

23. Which term means: "process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against"?

Mid
  1. A.ISA 5.1 instrument bubble
  2. B.PFD
  3. C.Equipment datasheet
  4. D.P&ID
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24. Which statement is correct?

Mid
  1. A.Equipment datasheet — process flow diagram showing major equipment, main process streams, operating conditions and the heat and material balance table, without instrumentation detail
  2. B.Equipment datasheet — circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
  3. C.Equipment datasheet — document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
  4. D.Equipment datasheet — process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against
Reveal the answer + AI explanation — free account

25. What is Tie-in schedule?

Senior
  1. A.process flow diagram showing major equipment, main process streams, operating conditions and the heat and material balance table, without instrumentation detail
  2. B.process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against
  3. C.list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  4. D.instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
Reveal the answer + AI explanation — free account

26. Which term means: "list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements"?

Senior
  1. A.ISA 5.1 instrument bubble
  2. B.Revision status IFR/IFD/IFC/As-built
  3. C.Tie-in schedule
  4. D.ISA 5.1 tag letters
Reveal the answer + AI explanation — free account

27. Which statement is correct?

Senior
  1. A.Tie-in schedule — document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
  2. B.Tie-in schedule — instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  3. C.Tie-in schedule — list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  4. D.Tie-in schedule — unique pipe identifier encoding size, service code, sequence number, piping class and insulation, for example 6in-P-1203-A1A-IH
Reveal the answer + AI explanation — free account

28. What is Revision status IFR/IFD/IFC/As-built?

Senior
  1. A.circle whose horizontal line marks location: no line for field mounted, solid line for main panel, dashed line for behind-panel or software function
  2. B.list of a brownfield project's connections into live lines with tie-in type (hot tap, blind flange, cut-and-weld), isolation and shutdown requirements
  3. C.instrument tag where the first letter is the measured variable (F, P, T, L) and the following letters are functions (I indicate, C control, T transmit, A alarm)
  4. D.document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
Reveal the answer + AI explanation — free account

29. Which term means: "document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed"?

Senior
  1. A.Revision status IFR/IFD/IFC/As-built
  2. B.ISA 5.1 tag letters
  3. C.Heat and material balance
  4. D.Equipment datasheet
Reveal the answer + AI explanation — free account

30. Which statement is correct?

Senior
  1. A.Revision status IFR/IFD/IFC/As-built — document lifecycle of issued for review, for design, for construction and finally as-built, with cloud marks and revision triangles showing what changed
  2. B.Revision status IFR/IFD/IFC/As-built — process document giving duty, fluids, design pressure and temperature, materials and nozzle schedule that a vendor bids against
  3. C.Revision status IFR/IFD/IFC/As-built — letter-number code fixing material, pressure rating, corrosion allowance and valve types for a service, referenced by every line on the P&ID
  4. D.Revision status IFR/IFD/IFC/As-built — piping and instrumentation diagram showing every line, valve, instrument, interlock, insulation and spec break, the master document for HAZOP and construction
Reveal the answer + AI explanation — free account

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