What is the minimum pressure of a pressure vessel?

What is the minimum pressure of a pressure vessel?

• A. 5 PSI
• B. 15 PSI
• C. 50 PSI
• D. 100 PSI

Answer: (B)

A pressure vessel is defined by its ability to hold pressure above the surrounding atmosphere, and many standards set a lower cutoff for that classification at 15 psi. In practice this means the maximum allowable working pressure (MAWP) must be at least 15 pounds per square inch gauge (psig) to be considered a pressure vessel. Since psig is pressure above atmospheric, 15 psig is about 29.7 psia. So the smallest pressure that still qualifies as a pressure vessel is 15 psi, making that the correct choice. The other options are either below the threshold (too small to be classified as a pressure vessel) or simply higher values, but the question asks for the minimum.

A pressure vessel is defined by its ability to hold pressure above the surrounding atmosphere, and many standards set a lower cutoff for that classification at 15 psi. In practice this means the maximum allowable working pressure (MAWP) must be at least 15 pounds per square inch gauge (psig) to be considered a pressure vessel. Since psig is pressure above atmospheric, 15 psig is about 29.7 psia. So the smallest pressure that still qualifies as a pressure vessel is 15 psi, making that the correct choice. The other options are either below the threshold (too small to be classified as a pressure vessel) or simply higher values, but the question asks for the minimum.