API Pressure Vessels & Storage Tank Standards Flashcards
6 cards from real API practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 API Pressure Vessels & Storage Tank Standards flashcards as text
API Standard 650 applies to which type of petroleum storage vessels?
Answer: Welded aboveground steel tanks for oil storage at or near atmospheric pressure
API Std 650 covers the design, fabrication, erection, and testing of welded steel aboveground storage tanks operating at atmospheric or low pressure.
What does the 'design pressure' of a pressure vessel represent under ASME/API standards?
Answer: The maximum allowable working pressure (MAWP) used as the basis for vessel design
Design pressure equals or exceeds the maximum allowable working pressure and is the pressure at which vessel wall thickness and component ratings are calculated.
According to API Standard 510 (Pressure Vessel Inspection Code), the risk-based inspection (RBI) approach prioritizes inspection resources based on:
Answer: A combination of the likelihood of failure and the consequence of failure
API 510 RBI methodology ranks vessels by combining probability of failure (corrosion, damage mechanisms) with consequence of failure (safety, environmental, business impact).
In API Std 650 tank design, the 'one-foot rule' is used to calculate shell thickness at:
Answer: One foot above the bottom of each shell course to account for hydrostatic head
The one-foot rule calculates the required shell thickness at a point one foot above the lower horizontal seam of each shell course, reflecting hydrostatic liquid pressure.
Which inspection method is most commonly used to assess the floor thickness of an in-service aboveground storage tank without emptying it?
Answer: Magnetic flux leakage (MFL) floor scanning
MFL floor scanners detect corrosion-induced metal loss in tank floors while the tank is in service or after emptying, without requiring full entry.
The 'corrosion allowance' added to calculated pressure vessel wall thickness serves to:
Answer: Extend the operational life of the vessel by providing extra metal for expected corrosion
Corrosion allowance provides additional wall thickness beyond the calculated minimum so the vessel remains fit for service throughout its design life as corrosion progresses.