If a system's average static pressure is 175 psi, what hydrostatic test pressure is required?

If a system's average static pressure is 175 psi, what hydrostatic test pressure is required?

• A. 150 psi
• B. 200 psi
• C. 225 psi
• D. 250 psi

Answer: (C)

Hydrostatic testing uses a pressure higher than the system’s normal operating pressure to ensure the piping and joints can withstand stress and to reveal leaks. The common practice is to set the test pressure at about 125% of the system’s working (or static) pressure. Take 175 psi and multiply by 1.25: 175 × 1.25 = 218.75 psi. Test pressures are usually listed in standard increments, so the closest practical value is 225 psi. This provides a sufficient safety margin above the normal 175 psi operating level. That’s why 225 psi is the best choice. Lower values like 200 psi wouldn’t meet the 125% margin for this setup, and higher values like 250 psi go beyond the typical required margin without added benefit for this scenario.

Hydrostatic testing uses a pressure higher than the system’s normal operating pressure to ensure the piping and joints can withstand stress and to reveal leaks. The common practice is to set the test pressure at about 125% of the system’s working (or static) pressure.

Take 175 psi and multiply by 1.25: 175 × 1.25 = 218.75 psi. Test pressures are usually listed in standard increments, so the closest practical value is 225 psi. This provides a sufficient safety margin above the normal 175 psi operating level.

That’s why 225 psi is the best choice. Lower values like 200 psi wouldn’t meet the 125% margin for this setup, and higher values like 250 psi go beyond the typical required margin without added benefit for this scenario.