Troubleshooting PVBs Flashcards
What causes continuous water discharge from a PVB’s air inlet valve?
A malfunctioning or debris-clogged air inlet valve, or a damaged valve seat.
How do you troubleshoot a PVB that fails to hold pressure?
Check the internal components for wear, debris, or damage, and ensure the check valve and air inlet valve seal correctly.
Why does a PVB leak from the bonnet or cap assembly?
Worn or damaged O-rings, improperly tightened parts, or cracks in the bonnet/cap.
What could cause a PVB to fail at preventing backflow?
An improperly seated check valve, insufficient air gap, or partially closed valve
Why is there a high-pitched noise from a PVB during operation?
Air is being drawn through a partially open air inlet valve, or water is flowing through a restricted check valve.
What if the PVB’s air inlet valve doesn’t open during a test?
Check for debris or damage in the air inlet valve and ensure the spring mechanism is working properly.
What causes a PVB to discharge water intermittently?
Fluctuating line pressure or debris in the air inlet valve.
Why might a PVB freeze and crack in winter?
The PVB wasn’t properly winterized or insulated, allowing water inside to freeze and expand.
What might cause a sudden drop in downstream pressure when using a PVB?
A failure in the check valve or air inlet valve, leading to back-siphonage or significant pressure loss
