API 510 Pressure Testing Procedures 2

Question 1

According to API 510, what is the minimum hold time for a hydrostatic pressure test on a pressure vessel before inspection begins?

Accepted Answer

10 minutes

Answer

API 510 requires the test pressure to be held for at least 10 minutes before inspection commences.

Question 2

When performing a pneumatic pressure test, the initial pressure should be raised to what level before pausing to check for leaks?

Accepted Answer

25% of test pressure

Answer

Pneumatic tests require an initial hold at approximately 25% of test pressure to allow a preliminary leak check before proceeding.

Question 3

Which condition would require a pressure vessel to undergo a retest after repairs?

Accepted Answer

Replacement of a corroded nozzle

Answer

Repairs involving pressure-boundary components such as nozzles typically require a pressure retest per API 510.

Question 4

What is the primary reason water is preferred over air or gas for hydrostatic testing?

Accepted Answer

Water is nearly incompressible, releasing little energy if a failure occurs

Answer

Water's incompressibility means minimal stored energy, making a failure during hydrostatic testing far less dangerous than pneumatic testing.

Question 5

Per API 510, when hydrostatic testing is not practical, which alternative test may be used with documented justification?

Accepted Answer

Pneumatic test

Answer

A pneumatic test may substitute for a hydrostatic test when hydrostatic testing is impractical, provided additional safety precautions are taken.

(API 510) Certified Pressure Vessel Inspector Practice Test