What is the role of priming the pump during hydrant operations?

• A. To remove air from the suction line and create a prime for the pump.
• B. To speed up the engine's torque.
• C. To increase spray pattern.
• D. To cool the pump.

Answer: (A)

Priming the pump is about clearing air from the suction side so the pump can fill with water and develop suction to lift water from the hydrant. When air remains in the suction line, the pump can’t sustain a water column and will pull air instead of water, causing loss of flow or a stall. By priming, you fill the suction line and pump with water, creating a continuous column that the pump can pull from the hydrant, allowing water to reach the pump and onward to the discharge.

This role isn’t about increasing engine torque, changing the spray pattern, or cooling the pump, so those options don’t fit the purpose of priming.