What is the purpose of establishing prime in a pump operation?

• A. To remove air from the pump and provide a continuous water supply to the discharge.
• B. To increase engine RPM beyond design.
• C. To reduce the need for hydrant supply.
• D. To cool the pump.

Answer: (A)

Priming a pump means filling the pump and suction piping with water so there are no air pockets. This allows the pump to develop suction and pull water from the source, creating a continuous supply to the discharge once the pump starts. Without a prime, air in the suction line prevents the pump from building enough vacuum to lift water, stopping flow. In a fire pump operation, establishing prime ensures immediate water delivery and prevents dry running. The other choices aren’t about getting the pump to draw water from the source or keep a continuous discharge; they cover RPM changes, hydrant supply requirements, or cooling, which aren’t the purpose of priming.