What is the maximum test pressure recommended for pneumatic testing?

What is the maximum test pressure recommended for pneumatic testing?

• A. 2 psi
• B. 5 psi
• C. 10 psi
• D. 20 psi

Answer: (B)

Pneumatic testing uses air, which is highly compressible, so a flaw can release a lot of energy very quickly if pressure is raised too much. To keep the test safer while still allowing leak detection, the maximum recommended pressure is five pounds per square inch. Pressures higher than this—such as ten or twenty psi—greatly increase the risk of a dangerous rupture when a weak weld or joint is present. Using water for testing (hydrostatic testing) avoids that rapid energy release, which is why pneumatic tests are kept at a low limit. A value like two psi would be less effective for detecting issues, while five psi provides a practical, safer balance.

Pneumatic testing uses air, which is highly compressible, so a flaw can release a lot of energy very quickly if pressure is raised too much. To keep the test safer while still allowing leak detection, the maximum recommended pressure is five pounds per square inch. Pressures higher than this—such as ten or twenty psi—greatly increase the risk of a dangerous rupture when a weak weld or joint is present. Using water for testing (hydrostatic testing) avoids that rapid energy release, which is why pneumatic tests are kept at a low limit. A value like two psi would be less effective for detecting issues, while five psi provides a practical, safer balance.