Which test verifies engine speed when the pump is not delivering water?

• A. No-load governed engine speed test
• B. Pump shift indicator test
• C. Intake relief valve test
• D. Pump engine control test

Answer: (A)

The key idea here is how the engine governor behaves when there’s no hydraulic load on the pump. When the pump isn’t delivering water, there’s effectively no resistance on the engine, so the governor should hold the engine at the set no-load speed. The no-load governed engine speed test directly checks that the engine maintains the correct RPM in this unloaded condition. This matters because having the engine run at the proper speed without flow ensures you’ll reach and maintain the proper pump RPM as soon as water is being pumped, giving predictable pressure and protecting the equipment from over- or under-speeding.

Other tests target different aspects of pump operation—suction relief valve tests relate to avoiding vacuum issues on the intake, pump shift indicator tests verify the gear/shift indicators are accurate, and pump engine control tests cover general engine-pump control functions. But they don’t specifically verify that the engine will hold the governed speed when there’s no load, which is what this test assesses.