10. Explain the difference between Hydrogen Induced Cracking (HIC) and Stress Corrosion Cracking (SCC).
API 510 (Pressure Vessel), API 570 (Piping Inspection).
: Define what secondary stress is and explain how it differs from primary stress in static equipment design. Flange Design
Answer: A pressure vessel is a container designed to hold liquids, gases, or vapors at a pressure greater than 15 pounds per square inch (PSI). Pressure vessels are widely used in various industries, including oil and gas, chemical processing, and power generation. static equipment interview questions updated
has no moving parts and contains pressure (e.g., pressure vessels, heat exchangers, piping, storage tanks).
PWHT involves heating a welded component to a specific temperature below its transformation range, holding it, and cooling it uniformly. It is performed to: Relieve residual stresses induced by welding. Soften hardened zones in the Heat Affected Zone (HAZ).
: Be prepared to list and compare types like shell and tube, plate and frame, and spiral heat exchangers. Material & Safety Analysis : Define what secondary stress is and explain
: Check flange faces, verify gasket type/rating, calibrate the torque wrench, and check bolt specifications.
Minimum Design Metal Temperature (MDMT) is the lowest temperature at which a component can safely hold pressure without risking . If a vessel operates below its MDMT, standard carbon steel becomes brittle and can fail catastrophically under impact or pressure loads. ASME requires impact testing if the design temperature falls below certain curves. Explain Sulfidation and Hydrogen Induced Cracking (HIC).
Key points: differentiation between prescriptive (code) and risk-based intervals, data quality, damage mechanisms (corrosion, creep, fatigue), documented follow-up actions. Follow-up: What minimum data do you need to run an RBI assessment? has no moving parts and contains pressure (e
design. Justify your choice based on maintenance cost vs. mechanical reliability." Updated Twist: For 2026, include a requirement for Sustainability Integration
Which option do you want?