You are not logged in.

Dear visitor, welcome to SPRINKLER TALK FORUM - You Got Questions, We've Got Answers. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.

bdnannac

Unregistered

1

Tuesday, July 17th 2012, 12:58pm

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?

Wet_Boots

Supreme Member

Posts: 4,043

Location: Metro NYC

2

Tuesday, July 17th 2012, 3:20pm

If the PVB is a Wilkins 720, it can release water during a large drop in pressure. Not a problem, though.

bdnannac

Unregistered

3

Tuesday, July 17th 2012, 3:33pm

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.

Wet_Boots

Supreme Member

Posts: 4,043

Location: Metro NYC

4

Tuesday, July 17th 2012, 9:21pm

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.

bdnannac

Unregistered

5

Wednesday, July 18th 2012, 12:58am

OK thanks Wet_Boots. I guess I'll replace the 3 old ones and see if that does the trick.

Wet_Boots

Supreme Member

Posts: 4,043

Location: Metro NYC

6

Wednesday, July 18th 2012, 8:38am

First, check the plumbing upstream of the PVB. You're looking for any shutoff valve that is partially closed.

bdnannac

Unregistered

7

Wednesday, July 18th 2012, 4:37pm

Good idea! I'll do that first. Thanks again.

Rate this thread