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Active Member

Posts: 36

Location: Guilderland, NY (Near Albany)


Tuesday, October 6th 2009, 6:32am

How to drain a backflow preventer when winterizing sprinklers

I am preparing to do a winter blow-out for my sprinkler system. I had a plumber install a Watts 007 Double check valve assembly, it is located outside the house.

I have a blow-out/drain port downstream from the backflow preventer (outside), as well as before the DCVA (inside) I have read that it is bad for the Doublecheck valve to blow air through it, and that the air compressor should be hooked up after it (so, outside in my case).

I have already cut off the water source to the sprinklers and drained the inside piping. After I do the blow-out, how do I go about draining the water from the 007 itself?



Senior Member

Posts: 15

Location: Montana


Saturday, April 3rd 2010, 6:43pm

Hookup downline from your backflow preventer, shut off the ball valves on the backflow preventer, and then blow out your sprinkler system. When you have completed this, open both ball valves 1/2 way, and open both test cocks on the backflow to allow the backflow to drain.

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