Piping Piping Codes and Standards 1 — Questions and Answers
Question 1: Which ASME code governs the design of process piping in chemical and refinery plants in the US?
- ASME B31.1 — Power Piping
- ASME B31.3 — Process Piping (Correct answer)
- ASME B31.4 — Pipeline Transportation Systems for Liquids
- ASME B31.8 — Gas Transmission and Distribution Piping
Correct answer: ASME B31.3 — Process Piping
ASME B31.3 is the governing code for process piping in petroleum refineries, chemical plants, pharmaceutical plants, and related industries.
Question 2: Under ASME B31.3, what is the minimum required hydrotest pressure expressed as a multiple of design pressure?
- 1.1 times the design pressure
- 1.5 times the design pressure (Correct answer)
- 2.0 times the design pressure
- 2.5 times the design pressure
Correct answer: 1.5 times the design pressure
ASME B31.3 requires a hydrostatic leak test at a minimum of 1.5 times the design pressure to verify structural integrity and leak-tightness.
Question 3: What does API 570 cover?
- Design of new process piping systems
- Inspection, repair, alteration, and rerating of in-service piping systems (Correct answer)
- Installation of underground fuel pipelines
- Qualification of pipe welders
Correct answer: Inspection, repair, alteration, and rerating of in-service piping systems
API 570 is the Piping Inspection Code covering inspection, condition monitoring, repair, alteration, and rerating of metallic and FRP piping systems after initial installation.
Question 4: What is the primary purpose of ASME B16.5?
- To specify pipe wall thickness schedules
- To provide dimensional and pressure-temperature rating standards for pipe flanges and flanged fittings (Correct answer)
- To govern welding procedures for pipe joints
- To define pipe material grades and chemical composition
Correct answer: To provide dimensional and pressure-temperature rating standards for pipe flanges and flanged fittings
ASME B16.5 establishes dimensional standards, materials, and pressure-temperature ratings for steel pipe flanges from Class 150 through Class 2500 in sizes NPS 1/2 through NPS 24.
Question 5: Under ASME B31.3, what is a 'Category D' fluid service?
- High-pressure service above 1500 psig
- Non-flammable, non-toxic service where design temperature is from -29°C to 186°C and gauge pressure does not exceed 1035 kPa (Correct answer)
- Underground buried piping only
- Any cryogenic service below -100°F
Correct answer: Non-flammable, non-toxic service where design temperature is from -29°C to 186°C and gauge pressure does not exceed 1035 kPa
Category D is a lower-risk classification in B31.3 for services with limited hazard potential, allowing simplified examination requirements.
Question 6: Which API standard provides guidance on corrosion under insulation (CUI) inspection?
- API 570
- API 581
- API 583 (Correct answer)
- API 574
Correct answer: API 583
API 583 provides guidance for inspection practices specifically addressing corrosion under insulation (CUI) and corrosion under fireproofing (CUF) in process facilities.
Piping Piping Codes and Standards 1
Which ASME code governs the design of process piping in chemical and refinery plants in the US?