When testing at pressures over 100 psi, which fluid may be used?

When testing at pressures over 100 psi, which fluid may be used?

• A. Fresh water may be used for test pressure over 100 psi
• B. Air may be used for test pressure over 100 psi
• C. Oil may be used for test pressure over 100 psi
• D. Saltwater may be used for test pressure over 100 psi

Answer: (A)

Testing at higher pressures uses a hydrostatic method with a non-compressible fluid to safely and accurately check the piping for leaks. Fresh water is ideal because water transmits pressure evenly without storing energy, so any leak shows up clearly and the system can be pressurized and depressurized safely. It’s also non-flammable, readily available, and easy to remove after the test. Using air at high pressures is risky since air is compressible, which makes readings unreliable and can lead to dangerous energy release if a component fails. Oil is flammable and can contaminate the piping, and saltwater is corrosive and difficult to flush, making both unsuitable for high‑pressure testing.

Testing at higher pressures uses a hydrostatic method with a non-compressible fluid to safely and accurately check the piping for leaks. Fresh water is ideal because water transmits pressure evenly without storing energy, so any leak shows up clearly and the system can be pressurized and depressurized safely. It’s also non-flammable, readily available, and easy to remove after the test. Using air at high pressures is risky since air is compressible, which makes readings unreliable and can lead to dangerous energy release if a component fails. Oil is flammable and can contaminate the piping, and saltwater is corrosive and difficult to flush, making both unsuitable for high‑pressure testing.