The Sun said:sushi94 said:
other thing to consider is the backflow valve may hold wather in the ball in the valve. I had one split open because of the water still in the valve.
You need to open the pitcocks to drain out the PVB. This is my step by step list:
1) Turn off main valve down by the water meter.
2) Turn system on to relieve pressure.
3) Turn shut off valves on PVB to 45 degrees.
4) Open pitcocks on PVB.
5) Drop insulated wrap over the PVB.
6) Forget it until spring.
I haven't lost a PVB yet following these steps.
I just built an insulated plywood box to go ever the whole thing. Drain water and set the box on top.

