No-flow condition pump operation for diesel engine driven fire pumps shall be conducted at what frequency?

• A. Biweekly
• B. Monthly
• C. Weekly
• D. Quarterly

Answer: (C)

The concept being tested is how often a diesel engine–driven fire pump should be exercised in no-flow condition to verify it will start and develop pressure even when no water is being pumped. The standard practice is to perform the no-flow test monthly. This involves starting the pump with the discharge line blocked to prevent flow, allowing the engine to reach its governed speed and for the pump to develop pressure, all while no water leaves the system. Doing this monthly checks the condition of the engine, starting system, fuel system, lubrication, and cooling, ensuring the unit is ready to operate when needed. Conducting no-flow tests more or less often than monthly either wastes fuel and causes unnecessary wear (if done weekly or biweekly) or delays detecting developing issues (if done quarterly). Regular monthly testing, combined with annual full-load testing with discharge, keeps the pump reliably prepared without imposing excessive maintenance burdens.