For the 50% pump capacity test, what net pressure and duration are specified?

• A. 200 psi for 5 minutes
• B. 250 psi for 10 minutes
• C. 300 psi for 15 minutes
• D. 150 psi for 20 minutes

Answer: (B)

The test is about the pump’s ability to run at half its rated flow while still delivering a steady, high discharge pressure for a sustained period. At 50% capacity, the goal is to push the pump enough to verify it can maintain a reliable pressure without overheating or losing prime, which is why 250 psi is used and held for 10 minutes. This combination provides a realistic challenge that mirrors partial-flow operations in the field and checks both pressure stability and endurance.

The other options don’t align with this standard expectation: they either understate the load (lower pressure or shorter duration) or push the pump beyond the typical 50% test parameters (higher pressure or much longer duration), making them less representative of a 50% capacity scenario.