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New Member


Monday, November 10th 2003, 8:46am

Winterization...Air comes out backflow

I am winterizing my sytem myself for the first time. When I hook my compressor to the spigot after the backflow device, the air comes out the backflow device (bell top) instead of pressurizing the main line to the sprinkler heads. How do I stop the air from coming out the backflow device?


Rays Sprinklers

Supreme Member

Posts: 493

Location: USA


Monday, November 10th 2003, 12:50pm

is it a PVB....? Once the water is clear from the backflow and the line, you can shut off the valve after the PVB (on the backflow) so that air wont go past it..
Rays Above and Beyond Automatic Lawn Sprinklers


Starting Member


Saturday, October 8th 2005, 7:32am


I am having the same problem as john4man. I have a hunter controler, with hunter SRVs and Watts PVB 800M4 FR. I closed the main in the basement, open the faucet outside (mounted below the PVB). Open both screws, before and after teh PVG. Once all is drained, I then hook up the compressor to the testcock on the inlet side of the PVB, close the testcock passed the PVB (passed mean water comes from the house, goes thru PVB and then there is the testcock I am talking about). Turn the controler on. Turn the compressor on. And yes, air comes out of the PVB. I have tried all combinations and the PVB does not seem to be closing... Do I need to remove the stem inside the PVB? Do I need to manually open the SRV?

Thanks for the time!!


Active Member

Posts: 43

Location: USA


Sunday, June 25th 2006, 5:58pm

How many PSI are you running on your compressor when blowing out?
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New Member


Tuesday, October 10th 2006, 4:11pm

I am having the exact same problem with an AVB valve. All the air comes back through the AVB? I have a small air compressor but it has worked in all the past houses I have lived in. Do you need more pressure than I can supply?

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