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View Full Version : Why not blow air through RPZ's ??


Green Sweep
12-15-2006, 09:34 AM
The other day, I was leaving a house that I was working on. While driving through the plan, I noticed 4 houses in a row that still had RPZ's outside. My first thought was - Wow, did all of these people not winterize yet? I pulled my van over & decided to take a look. They all had Febco 3/4" RPZ's with no unions to remove for the winter. Just out of curiosity, I knocked on one of the doors & told the woman that I noticed her backflow was still outside & asked if she had her system winterized yet. She said that she did. I explained to her that typically, backflow preventers are removed for the winter & that is why I stopped. I gave her (& her neighbors) business cards & left.
So, obviously, this irrigation contractor does not remove RPZ's for the winter - he just blows through them. Thinking back, I have blown air through RPZ's in the past that someone else installed because I had no other choice. Any RPZ's that I blew air through were fine the following spring.
So, apparently doing this does not cause immediate damage to the RPZ like it would a water meter. Does it lessen the life span? Why are we told not to blow air through RPZ's & go to great lengths to install unions & remove & reinstall every year? Have any of you guys seen RPZ's damaged from air pressure?

Thanks,
Rob

Midlo Snow Maker
12-15-2006, 10:16 AM
90% of all bf's here are blown through, and are outside and left there for the winter

Flow Control
12-15-2006, 10:33 AM
I can just image the possible up roar you caused with trying to be nice.

Installation Contractor " Hello"

Lady "YOU NEVER WINTERIZED OUR SYSTEM CORRECTLY, YOU DID NOT REMOVE THE THING ON THE OUTSIDE OF THE HOUSE"

Contractor " What are you talking about"

Lady " SO AND SO FROM X COMPANY SAID YOU DID NOT DO IT RIGHT, NOW MY SYSTEM IS GOING TO BREAK AND YOU ARE GOING TO BE RESPONSIBLE FOR PUTTING A NEW ONE IN"

Contractor "Who the Fudge??, What a ?>!"

Nice :dancing:

DanaMac
12-15-2006, 10:46 AM
90% of all bf's here are blown through, and are outside and left there for the winter
ditto - I've taken off 2 or 3 in 11 years now. Not many unions on ours. We blow through them. you'll find different opinions on this.

Wet_Boots
12-15-2006, 11:19 AM
I explained to her that typically, backflow preventers are removed for the winter & that is why I stopped.Have you never read the instructions that come with an RPZ? The Febco 825Y series include instructions for the partial dismantling of the device, to clear out all the water. No removal required or recommended. The same procedure would apply to any RPZ with the relief assembly located so as to retain water. No need to remove the devices. Not ever.

The presence of the RPZ does not imply that air was blown through it, since there is the last testcock available to blow air through. I'm more apt to have a downstream hose bib for winterizing.

This visit and 'explanation' was not only unnecessary, it betrayed some ignorance about some winterizing procedures.

The Watts 009 RPZ seems to have the works all on one level, and I have blown air through them and saw nothing remaining.

PurpHaze
12-16-2006, 12:56 PM
Here's the "Operations and Maintenance Manual" for FEBCO RPZs and includes winterizing procedures.

jerman.com/backflowpreventers/FEBCO/825mmrpd.pdf

Wet_Boots
12-17-2006, 10:24 AM
Another winterizing practice that I question the necessity of, is the bringing indoors of an above-ground sprinkler pump, since they all possess sufficient drain openings to prevent freezing. I'd rather see them bolted to a platform, and hard-wired with a cutoff switch.

Flow Control
12-17-2006, 10:26 AM
Another winterizing practice that I question the necessity of, is the bringing indoors of an above-ground sprinkler pump, since they all possess sufficient drain openings to prevent freezing. I'd rather see them bolted to a platform, and hard-wired with a cutoff switch.

Totally agree with your statement.

Dirty Water
12-17-2006, 12:13 PM
Another winterizing practice that I question the necessity of, is the bringing indoors of an above-ground sprinkler pump, since they all possess sufficient drain openings to prevent freezing. I'd rather see them bolted to a platform, and hard-wired with a cutoff switch.

I pull the suction line out of the water, drain the pump/pressure tank and pull the breaker.

No problem yet.

Currier
12-17-2006, 11:37 PM
We never pull backflows or pumps.

JB926
12-18-2006, 03:08 PM
if you blow air long enough through a RPZ you will start to melt or warp the gaskets. a 3/4" rpz will not because you prob arent blowing through it long enough only a couple zones. Now a 2" with 50 zones and those gaskets will be trash and will prob make it vent and drip water and your a__ is changing them next year