How much pressure is used to proof-test a flexible hose assembly?

• A. It is less than operating pressure.
• B. It is exactly equal to operating pressure.
• C. It is three times the operating pressure.
• D. It varies but generally about two times operating pressure.

Answer: (D)

Proof testing a flexible hose assembly involves applying a pressure higher than what the hose will normally see in service to verify there are no leaks or weak spots. The goal is to stress the hose just enough to reveal potential failures without exceeding what the hose and fittings can safely handle.

Because you want a margin above the normal operating conditions, the test pressure isn’t equal to operating pressure and it isn’t set at an extreme like triple the pressure. It’s typically varied depending on the hose design, materials, and certification, but in practice it’s about two times the operating pressure. So if the system normally runs at 1,000 psi, the proof test would be around 2,000 psi. This balance helps ensure reliability without risking damage from over-pressurization.