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mihomeowner

Unregistered

1

Saturday, May 25th 2013, 3:46pm

Needing to replace PVB Assembly

Hello,
I didn't shut the water off to my sprinkler system in time last winter and we got an early freeze and I got a crack in my PVB and one of the nearby pipes (the downstream pipe).

Anyway, I am racking my brain getting started. My setup looks almost exactly the same as this guys:
Conbraco 1" PVB (see pictures)

There is a crack in the PVB casing, so repairing the internals isn't going to work. Need to replace the entire thing. This is what I am thinking of ordering to replace it:

http://www.sprinklerwarehouse.com/Conbraco-Backflow-Pressure-Vacuum-Breaker-p/cdc4a-505-02f.htm

Which should work. My only problem is, how the heck do I get the old one off? I went out with some wrenches and thought it would be fairly easy but I can't figure out what to unscrew. Then I started researching, and have seen some people sawing off the piping which seems to be what I have to do.

There are two valves on the PVB. Does only one of these typically screw in, and the other needs to be welded on? If that is correct, does it matter which one gets threaded?

Slightly confused!!! Thanks for any help.

Wet_Boots

Supreme Member

Posts: 4,056

Location: Metro NYC

2

Saturday, May 25th 2013, 5:45pm

a PVB isn't designed to be replaced like a light bulb - both isolation valves are threaded - cut the pipe to remove the old one - employ a union or a slip coupling to get the new one in

mihomeowner

Unregistered

3

Saturday, May 25th 2013, 9:53pm

a PVB isn't designed to be replaced like a light bulb - both isolation valves are threaded - cut the pipe to remove the old one - employ a union or a slip coupling to get the new one in
Any tips or places on the internet I can read about removal?

https://www.youtube.com/watch?v=JkNpNF6BYVE

Check out that video and see how the guy removes his (fast forward to about 1:30) ... he cuts one and then twists the whole thing off. Then he screws the whole thing on and solders the pipe.

Is that correct?

Scott76

Active Member

Posts: 46

Location: Kansas City

4

Monday, May 27th 2013, 2:09pm

Seeing as your backflow is one of the most expensive parts of the system, the best way to install one is on unions so it can be removed and placed inside during winter.

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