I think we all agree it would be bad to have an air line rupture. I
don't think sheetrock or plywood would contain the shrapnel, regardless
of pipe material.
Schedule 40 PVC air piping is better than OK. It's much safer than iron
pipe.
I'd be scared to buy a house with old rusty iron pipe -- I can't tell
how often the previous owner drained it, and I don't know how close it
is to rusting through from the inside. I'd feel unsafe and I'd replace
it with schedule 40 PVC immediately. Old PVC is still PVC, and it's
still just as strong as ever. (I can't remember if PVC deteriorates
long term with UV exposure, but there's not much danger of that indoors
anyway. Heck, here in Seattle there's not much UV exposure outdoors
either <g>.) Half-inch schedule 40 pvc is rated to 480 psi -- that's a
whole lot more than most flexible air lines can say. If any line in
your shop is going to rupture, it's probably going to be a flexible
line, since they get dragged around, get stuff dropped on them, and are
rated for less pressure to begin with. This is extra scary considering
the fact that we all tend to work with flexible lines in close proximity
to our bodies.
Can anyone document a firsthand example of a schedule 40 pvc air system
(meaning schedule 40 pipes & fittings) rupturing? Is this an urban
myth?
BTW -- Not that these considerations are anywhere near as important as
safety, but pvc is much easier to work with (easy to cut, no threading
machine needed) and it is much cheaper (10:1 last time I looked) than
iron.
keithka
> -----Original Message-----
> From: Berry Kercheval [SMTP:kerch@parc.xerox.com]
> Sent: Thursday, October 02, 1997 10:25 AM
> To: Eric Murray
> Cc: shop-talk@Autox.Team.Net; kerch@parc.xerox.com
> Subject: Re: PVC air piping
>
> I don't think anyone -- or at least very few people -- here is going
> to tell
> you "Yes, your PVC air piping is OK". Basically: no, PVC air piping
> is
> fundamentally unsafe. A (guessing here) 5 gallon tank and who knows
> how much
> pipe at 100psi holds a LOT of energy. When it all comes out a little
> hole
> spectacular things can happen. Bad things.
>
> And sheetrock really isn't very strong where impact is concerned. It
> is quite
> easy to punch your fist through it.
>
> Now, what would I do in your place? I don't think I'd use it. I'd
> take some
> measurements, go to the hardware store, get $40 worth of black pipe
> and
> fittings and screw it to the outside of the sheetrock. Sure it's
> ugly, but
> it's a garage, not your living room. And it's safe.
>
>
> --berry
>
> Berry Kercheval :: kerch@parc.xerox.com :: Xerox Palo Alto Research
> Center
>
|