When drafting raise RPM to ______

When drafting raise RPM to ______

• A. 1500-1800 RPM
• B. 800-1000 RPM
• C. 1000-1200 RPM
• D. 1200-1400 RPM

Answer: (C)

Drafting relies on keeping the pump running at a steady, moderate speed so it can develop and maintain suction from the source. Raising the engine RPM to about 1000–1200 helps keep the priming system in the correct operating range, ensuring a consistent prime and sufficient water flow to the pump without overworking the engine. This range minimizes the chance of losing prime due to suction fluctuations or air in the lines, while also avoiding the risks that come with running much higher RPMs, such as cavitation, excessive wear, or instability in pump discharge pressures. If you run too low, the pump can lose prime or fail to deliver adequate flow. If you run too high, you risk over-revving the pump, producing more wear and potentially unstable pressures. The 1000–1200 RPM range hits a balance that supports reliable drafting performance.

Drafting relies on keeping the pump running at a steady, moderate speed so it can develop and maintain suction from the source. Raising the engine RPM to about 1000–1200 helps keep the priming system in the correct operating range, ensuring a consistent prime and sufficient water flow to the pump without overworking the engine. This range minimizes the chance of losing prime due to suction fluctuations or air in the lines, while also avoiding the risks that come with running much higher RPMs, such as cavitation, excessive wear, or instability in pump discharge pressures.

If you run too low, the pump can lose prime or fail to deliver adequate flow. If you run too high, you risk over-revving the pump, producing more wear and potentially unstable pressures. The 1000–1200 RPM range hits a balance that supports reliable drafting performance.