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Vibrating PVB
I installed a new 3/4" PVB that goes to a 1" before reaching the valves. Could that cause the PVB to vibrate and spit water for up to a minute when the system is starting up? I checked the inside parts and they all look OK. It's a brand new PVB so I'm stumped. Any ideas?
If the PVB is a Wilkins 720, it can release water during a large drop in pressure. Not a problem, though.
It's a Conbraco 4A-504-02F 3/4 in. First couple of times it ran fine with no noises. Today I tried to see if it was a valve problem. Changed 3 of the diaphragms on the older valves and tried to isolate them. So when I start the system without 2 of the valves on there is no noise at all. Could this be a valve problem instead? The 2 valves in question are quite old.
Any time a PVB spills water, it is telling you the system design is suspect, because the water pressure should not be dropping so low when a valve opens. If your valves had flow controls, you could throttle them down.
OK thanks Wet_Boots. I guess I'll replace the 3 old ones and see if that does the trick.
First, check the plumbing upstream of the PVB. You're looking for any shutoff valve that is partially closed.
Good idea! I'll do that first. Thanks again.