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BodegaBay
04-26-2007, 02:47 AM
Many years ago a lawn irrigation specialist recommended I use thermal cover in addition to winterizing my PVB (24" above ground). I think the name of the product was "Polar" something. It worked for many years in my old house -- never had a PVB froze yet.

However, in my new house I installed a new PVB last year and it just cracked yesterday over a two week period where the weather got frozen again.

I have two questions:

1. Anyone know the thermal cover I'm speaking of? It's green and looks like a pillow but open on one end so you can slip it over a PVB assy.

2. What's high quality PVB (3/4" opening). Thanks.

PurpHaze
04-26-2007, 09:20 AM
1. Anyone know the thermal cover I'm speaking of? It's green and looks like a pillow but open on one end so you can slip it over a PVB assy.

Here's one: http://protecoversusa.com/ You can do a web search for "backflow blanket" and others show up.

2. What's high quality PVB (3/4" opening). Thanks.

Watts, FEBCO, Wilkens all have them.

Wet_Boots
04-26-2007, 09:34 AM
Watts does offer a line of PVBs with an internal bypass, that's designed to blow a bit of water when the device begins to freeze.

BodegaBay
04-26-2007, 01:02 PM
Thank you guys.

BTW, the unit that I bought last year was a Watts with that internal bypass. I guess I didn't drain it fully and that little water might have caused the crack. Don't know if Watts' warranty will cover this...

Wet_Boots
04-26-2007, 02:23 PM
Warranty coverage for leaving water in a backflow preventer over the winter? Oh, ha-ha, it is to laugh.

BodegaBay
04-26-2007, 04:32 PM
Ok, ok... I thought I'd give it a shot with the distributor. If I can sweet tallk them into it, I'll be the one laughing!

Wet_Boots
04-26-2007, 05:11 PM
Hey, no harm in trying. Do understand that the 'freeze protection' depends on the water still being turned on, so that a flow through the bypass can prevent the thing from freezing completely solid.