[Greenbuilding] [BULK] Re: [BULK] Re: [BULK] Re: PEX tubing

[Lawrence Lile]

The trick we finally settled on was to check the pressure in the afternoon, hopefully at the same temperature as the day before.  24 hours without any pressure drop ought to prove the point.  
 
What actually occured though, was we filled the pipes in the evening after a long day's sun, then checked them in the morning after a chilly May morning. Pressure was down about 5 lbs.   After a lot of running around, shouting, pointing fingers, and whacking people over the head with rubber chickens, the pressure was back up by afternoon all by itself.  The contractor, never hearing about Boyle's law, let all the air out of the pipes, checked a bunch of connections, re-pressurized them, squirted soap all over them, and this sort of thing went on for a day or two until I showed up on site and said "Well of course there will be less pressure on a cold morning."  
 
--Lawrence Lile, P.E. 

________________________________

From: greenbuilding-bounces at listserv.repp.org on behalf of Chris Green
Sent: Thu 1/18/2007 9:11 PM
To: Greenbuilding at listserv.repp.org
Subject: [BULK] Re: [Greenbuilding] [BULK] Re: [BULK] Re: PEX tubing



Lawrence Lile wrote
> If the temperature drops from the time you pressurize it, to the time
> you check the pressure in a few days, your plumbers will run around like
> keystone cops trying to find the nonexistent leaks.  A little drop in
> temperature can cause a drop in air pressure in the pipe.  We struggled
> with this, and delayed pouring concrete for a few days while trying to
> figure it out. 
>
>
> Lawrence Lile, P.E., LEED AP
>  
Thanks. I wasn't aware of this, and would probably never have thought of
it.

Cheers,

Chris Green.

_______________________________________________
Greenbuilding email list
List info: http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.org
List email: Greenbuilding at listserv.repp.org
Managed by BuildingGreen, Inc. http://www.buildinggreen.com <http://www.buildinggreen.com/> 
      publisher of Environmental Building News and GreenSpec(r)
Hosted and archived by REPP / CREST http://www.crest.org <http://www.crest.org/>