During a capacity test, what should the design net pump pressure be in psi?

• A. 100 psi
• B. 150 psi
• C. 200 psi
• D. 250 psi

Answer: (B)

In a capacity test, design net pump pressure is the pressure the pump must develop at the discharge to move water through the hose layout to the nozzle at the intended flow. The standard value used for this test is 150 psi because it represents a realistic, repeatable condition that accounts for typical nozzle demands plus friction losses in common hose configurations. Testing at 150 psi ensures the pump can deliver the rated GPM under ordinary field conditions and allows for fair comparison between apparatus. Lower or higher pressures would either underrepresent actual operating demands or impose nonstandard conditions that skew the assessment. So, 150 psi is the chosen design net pump pressure for this test.