API 510 practice test

API 510 · Question 1 of 2557:21

I. Thickness measurements, inspection intervals and vessel integrity (calculations)

Using the thin-wall circumferential stress formula for a cylindrical shell (t = PR / (SE - 0.6P)), find the required thickness for P = 150 psi, corroded inside radius R = 30 in., S = 20,000 psi and E = 0.85.

Press A-D or 1-4 to choose an answer while this question is on screen.

0.226 in.0.132 in.0.532 in.0.266 in.

Patch is off during timed tests. On the free 10-question check and in untimed course practice, Patch walks you through your answers.

Every question is original and written to American Petroleum Institute's published content outline, and every explanation cites the code section or source it relies on. Expert-reviewed: every question was checked by a pressure vessel inspection professional with 13 years in the industry (Oct 20, 2026).