What is the proper sequence to recover a prime after a long layoff if the pump becomes air-bound?

• A. Re-prime, purge air, open line
• B. Close valve, re-prime, check for leaks, purge air, re-open line
• C. Open line, re-prime, purge air, close line
• D. Close line, re-prime, purge air, reopen line

Answer: (B)

When recovering a prime after a long layoff, the first goal is to stop more air from entering the pump and to isolate it from the rest of the system. Closing the valve accomplishes that, so the pump can be primed without air being drawn back in. After isolating, re-prime to force water into the pumping chamber and push out existing air. Checking for leaks is important because any air leakage on the suction side would kill the prime or reintroduce air, so you want to address those leaks before proceeding. Purging the air afterward ensures all trapped pockets are expelled so the prime holds. Finally, reopen the line to restore discharge flow with a solid prime in place. This sequence—isolate first, re-prime, check for leaks, purge air, then reopen—properly establishes a reliable prime and minimizes the chance of re-entraining air.