API API Pressure Vessels & Storage Tank Standards 2

Question 1

API Standard 620 differs from API Standard 650 in that API 620 covers tanks designed for:

Accepted Answer

Low-pressure service up to 15 psig, including cryogenic and refrigerated storage

Answer

API Std 620 applies to large welded low-pressure storage tanks (up to 15 psig) including those used for refrigerated or cryogenic service, which API 650 does not cover.

Question 2

Under ASME Section VIII Division 1, the required hydrostatic test pressure for a new pressure vessel is typically:

Accepted Answer

1.3 times the maximum allowable working pressure (MAWP)

Answer

ASME VIII Div. 1 requires a hydrostatic test at 1.3× MAWP (adjusted for material strength at test vs. design temperature) to verify structural integrity.

Question 3

API RP 579-1/ASME FFS-1 'Fitness-For-Service' assessments are used to:

Accepted Answer

Evaluate whether equipment with known damage or flaws can continue safe operation

Answer

API 579/ASME FFS-1 provides assessment procedures to determine if pressure equipment with corrosion, cracks, or other damage remains fit for continued service.

Question 4

In API Std 650, a 'floating roof' tank design is primarily used to:

Accepted Answer

Minimize evaporative VOC losses from volatile petroleum products

Answer

Floating roofs rise and fall with the liquid level, eliminating the vapor space above the liquid surface and dramatically reducing evaporative emissions.

Question 5

What is the purpose of an 'annular plate' in an API 650 aboveground storage tank?

Accepted Answer

To provide a wider bottom plate at the shell-to-floor junction for stress distribution

Answer

The annular plate (bottom ring plate) is a wider plate at the shell-to-floor junction that distributes the shell load and resists stress concentration at this critical area.

(API) American Petroleum Institute Certification Practice Test

(API) American Petroleum Institute Certification Practice Test

API API Pressure Vessels & Storage Tank Standards 2