Newsgroups: rec.crafts.metalworking
Subject: Re: remote compressed air
From: John De Armond
Date: Wed, 23 Jun 93 08:51:51 GMT

gary_preckshot@lccmail.ocf.llnl.gov (gary preckshot) writes:
 
>>   1) can copper pipe (the type used for plumbing) be used?
 
>What's wrong with PVC?  It's cheaper and easier to use.
 
There have been several reports in the racing trades of PVC piping exploding
and injuring mechanics.  Seems  that the inevitable oil carryover
weakens the pipe and when it fails it fails by breaking instead of
tearing.  The shrapnel produced is injurious.  I recommend soldered copper
pipe or threaded galvanized pipe.  Since copper water pipe is about
as cheap as PVC, there really isn't any justification to take the change.
It took a friend and I less than a day to ring my shop with 1" copper
pipe complete with 8 downcomers with valves and quick couples.
 
>>   3) regardless of the type of pipe, what is the minimum diameter
>>      I should use?
 
For the length you mentioned and because it is cheaply available from
discount building supply places, I'd recommend 1" pipe for headers and
3/4" for taps.
 
John
 

Newsgroups: rec.crafts.metalworking
Subject: Re: remote compressed air
From: John De Armond
Date: Fri, 25 Jun 93 07:42:19 GMT

gary_preckshot@lccmail.ocf.llnl.gov (gary preckshot) writes:
 
>> There have been several reports in the racing trades of PVC piping exploding
>> and injuring mechanics.  Seems  that the inevitable oil carryover
>> weakens the pipe....
 
>I don't know if you noticed, John, but the guy was talking about buried
>pipe.  My advice was to use copper or iron in exposed locations.  Most
>shops I know use iron pipe for air in a ring around the shop because
>inevitably somebody rams the pipe with something heavy.
 
Yes, I noticed but I figured he'd have to get the pipe to and from
"underground".  Making the transition from PVC to copper seems like
a lot of effort to me.  Around here Home Depot sells copper water pipe
almost as cheap as PVC and cheaper than sch 80 PVC.  Fittings are
literally within pennies of each other.  With the right tools, copper is
as fast to join as PVC, the secret being having a trigger operated torch
burning MAPP gas.  With copper being almost as cheap and no harder
to work, why fool with an inferior product?
 
John