[Shop-talk] Winterizing Sprinkler System

[Steven Trovato]

It sounds like you have it under control.  I 
assume you are talking about a backflow 
prevention valve?  BPV = PVB  = BVP?  Apparently, 
there are different types of these and there are 
different places they can be installed, depending 
on local codes and whether the original installer 
did it right.  I never worried about it and never 
had a problem.  The way my system is, I can't 
really think of another way.  Your experience 
with the large vs small compressor is the same as 
mine.  It is not the pressure, it is the volume 
of air that you need.  I found that the larger 
compressor was better, but the small one was good 
enough.  And yes, I never got mine 100% dry.  It 
was just drained enough that no water would 
freeze and expand enough to break anything.  I 
think you did fine.  I don't think a professional 
service company would do more than that.

-Steve

At 08:24 AM 11/8/2019, Jim Stone via Shop-talk wrote:
>The Amazon adaptor arrived yesterday, so I 
>thought I’d update this with some new 
>information.  The adaptor was well made and the 
>shut-off valve proved to be very handy; it was 
>well worth the $20.  It also came with excellent 
>instructions that mostly agreed with what was 
>said here, with one exception: it said “avoid 
>blowing compressed air through the PVB because 
>doing so may damage the BVP.”  I assume my 
>system has a BVP in it, but can’t find it and 
>just went ahead and blew it out from the basement as discussed.
>
>The instructions also recommend that the 
>compressor should be "as large as possible, 
>preferably 15 gallons or larger.”  I think 
>that is good advice, as my little HF 8 gallon 
>compressor was barely (I think) up to the 
>task.  I initially set it to 50 lbs, the 
>recommended pressure, but it was only putting 
>out about 40 lbs during use, so I turned that up 
>to get it a little higher.  Even so, the 
>compressor would fully extend the spray heads 
>for the first 15 seconds or so, then just bubble 
>water out with the head retracted.  The 
>compressor ran constantly while the system was 
>on, so I gave it a rest between blowing out each 
>zone.  I also blew out each zone at least three 
>times, but there was sill some spray at the 
>beginning each time.  I am going to do it one 
>more time today, but know it won’t be 
>completely dry.  I assume it won’t be an issue 
>when the little bit of water remaining in the 
>system freezes, but someone please let me know 
>if I am wrong about this.  My 60 gal compressor 
>is about 150 yards away from the water inlet, 
>but I could make that work if necessary.
>
>Just in time, as the cold weather arrived today, 
>with the first below freezing temps expected tonight.
>
>Cheers,
>Jim