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Dan123

Unregistered

1

Monday, June 10th 2013, 8:40pm

New PVB install

Hello all!
I'm going to install a Conbraco 4A-505-02F 1 in. Freeze Resistant PVB Backflow Preventer, the reason I picked this one, because it was the cheapest one that is freeze resistant.

My questions is, would i be acceptable to run 1", sch80 PVC from the basement, up to this PVB and then back down to the ground to the manifold? Or should I use copper instead? Is sch80 pvc not allowed outside exposed? I'm in Wisconsin if that matters.

The reason I would like to use PVC is for the ease of install, and the cost, but if copper is required, I'm capable of installing that instead.

Thanks!

Dan123

Unregistered

2

Monday, June 10th 2013, 8:47pm

Also, what do you think about the "Wilkins WKZW3-8-1F 8 in. Backflow Winterizer Valve 1 in. FPT Outlet"
Seems pretty expensive, but handy to have installed?
I read you shouldn't blow air through the PVB, but wasn't this device designed to do exactly that?
Also its unclear to me, does this valve also have back flow protection in it?
Does anyone have any recommendations or links on any other through wall items like this to connect up the PVB like this? or should I just build my own.

Wet_Boots

Supreme Member

Posts: 4,088

Location: Metro NYC

3

Monday, June 10th 2013, 10:01pm

Despite it's strength, sch 80 pvc wouldn't be used indoors. You can, however, use sch 40 CPVC pipe and fittings indoors. Otherwise, go with copper. And definitely go through the exterior wall with copper.

Those expensive shutoffs are a service convenience for when customers aren't home, and you must winterize the system completely.

If you really expect to leave a PVB filled with water over the winter, you can expect it will need repair or replacement the following spring, and if you aren't going to treat a PVB in that shabby manner, then you don't worry about so-called freeze-resistant PVBs.

Dan123

Unregistered

4

Tuesday, June 11th 2013, 9:33am

Thanks for your help Wet Boots!
I would never leave the PVB outside all winter, I just wanted the freeze resistant one in-case there is an early freeze before I have it winterized.

Wet_Boots

Supreme Member

Posts: 4,088

Location: Metro NYC

5

Tuesday, June 11th 2013, 11:25am

The freeze resistant model I'm most familiar with has an internal relief that is designed to only open under very high pressure, and let water run out from under the device cover. This protection would only work with the water supply turned on. I don't expect this relief is something that can reset itself, so a replacement part would probably be in order next season. If the internal relief wasn't in place on this particular model, the water would freeze and crack the plastic cover. That is sort of a six-of-one half-a-dozen of the other, so far as freeze damage goes.

As long as the system is properly winterized in time, the PVB will survive any winter temperatures in its outside location. The only important precaution is to have a drain valve open on the plumbing supply, to release any water that manages to get by the system shutoff valve.

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