Which step is not part of addressing air in discharge lines?

• A. Stop
• B. Verify priming
• C. Check for leaks
• D. Increase throttle

Answer: (D)

The main idea here is removing trapped air from the discharge lines by ensuring the pump is properly primed and the system is free of air leaks. When air is present, you want to stop the pump to safely assess and correct the situation, verify that the pump is actually primed, and check for leaks that could be drawing air into the lines. Verifying priming means confirming there’s a continuous water column filling the pump and discharge piping so water can flow smoothly rather than pushing air ahead of the water. Checking for leaks helps you locate any weak connections or seals where air could be entering the system and preventing proper discharge.

Increasing throttle does not address the root issue of air in the lines. Simply speeding up the pump won’t purge trapped air and can even worsen conditions by causing cavitation or noisy operation. It’s not a corrective step for air removal, whereas stopping, verifying priming, and checking for leaks directly target the presence of air and how to eliminate it.