What is the purpose of priming a pump during drafting?

• A. To draw air into the suction line
• B. To remove air from the pump and suction line so water can be drawn and flow can start
• C. To prime the discharge outlet
• D. To increase intake pressure artificially

Answer: (B)

Drafting relies on creating a continuous water column in the suction path so the pump can actually draw water from the source. Priming accomplishes this by removing air from the pump and suction line and filling the system with water. When air pockets are present, the pump can’t establish suction, the water column breaks, and flow won’t start. By priming, you eliminate those air pockets, allowing atmospheric pressure to push water into the pump and initiate flow.

If air remained or if air were drawn in, the pump would lose its prime and no water would be delivered, even though the pump is running. That’s why priming is about evacuating air and filling the suction path with water.

The other options don’t fit: drawing air into the suction line would prevent priming; priming the discharge outlet doesn’t address creating suction; and priming isn’t about increasing intake pressure artificially—it's about establishing a water-filled path so pumping can begin.