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angel85lx 08-30-2011 10:28 PM

has any one used pvs pipes for air supply
I was at a shop and they had all there air supply running on pvc I a guessing It's pdc since it had purple cement on the joints. Has anyone used that ?

dinger 08-30-2011 11:27 PM

Moving this to tools and garage, it's been discussed there quite a bit. In some states, it's illegal for commercial use. I would be very nervous around the stuff, I have seen one line blow, shrapnel everywhere.

tech69 08-30-2011 11:42 PM

not a great idea but if you insist at least cover it completely with good duct tape. It's illegal in Ca, but so is washing a car without a dedicated drainage system.

angel85lx 08-31-2011 01:25 AM

Ok good know I was just surprised when I seen it. I was thinking of using cooper pipes since It's going to be just garage use. Or is steel pipes a better choice.

Irelands child 08-31-2011 05:30 AM

Steel or copper is fine. PVC/ABS isn't and from a personal attempt to use it without doing my homework. It WILL eventually shatter and with 100psig air pressure, you can be rest assured that when it does, pieces will be stuck in places that could hurt - a lot. Mine shattered in small jagged pieces at the joints when disassembling after I finally did my homework and put up copper. Evidently the glue weakens the base material. Also, any ding or nick is a starting place for a failure.

There will be folks that will 'testify' that they have used it for years and no problem - they are lucky - so far.

Dave W

shine 08-31-2011 05:59 AM

sch40 jet stream in every shop since 78 and here at the farm for 13 years. i have never had a failure nor have i seen one.

Chevymon 08-31-2011 06:37 AM

I'm surprised at your comments Shine. You know your stuff well, and give good advice, but this is an accident waiting to happen. And when it does, it can be deadly. Also, I know that you run low air pressure in your shop.

shine 08-31-2011 06:50 AM

my compressor shuts off at 90. no need for any more pressure since no air tool runs at more than 45. i've heard all the stories and warnings but have never seen it happen. sch40 is jet stream 600psi water . like i said i used it first in 1978 and have used it ever since. if it ever blows i will have to switch i guess . black pipe sucks as it corrodes in weeks of installing. then holds moisture in it something terrible. copper is the way to go but just too damn high for me. they have even stopped using copper in homes now. everything is plastic pipe now.

trees 08-31-2011 07:13 AM

I built my shop a couple of years ago and installed Sch40 in the walls before covering with 3/4 OSB. I put the compressor outside on a slab and built a room for it. I placed insulation in this room for some sound proofing and left a six inch opening under the eaves for cooling air. Pictures of this compressor room were posted in a thread on my garage build and precipitated a lot of discussion on the merits, better described as demerits, of PVC plumbing for air lines. Consensus was it was not a good ideal. My Bud had put PVC in his shop 20 years ago and has never had a failure so thought there would not be any problems for me, especially since I covered all the pipe except from the compressor to the wall connection. Oldred who is a very wise and experienced guy pointed out that this connection was not good and I should replace it with a flexible line (and he did not approve of my selection of PVC either) Now it is confession time. I was sand blasting for about 2 hours in 90* weather and the compressor was cycling regularly during that time. I finished up and was at the sink, liberally sponging off the sweat and sand when there was a loud pop and momentary rush of air on the other side of the wall. I went to the compressor room and the feed line had separated at the union in the line. The collar was intact, but not on the union. I then reconnected the union, thinking the vibration had made it back off, and turned the compressor on. At about 30 PSI, there was a big leak at the union. Further investigation revealed that the union had distorted from the 175 PSI and heat build up under the extended use of the compressor. I then tried another repair, only to learn the 1 inch line was also swelled and the T fitting that had a pressure gauge plugged in one end and and the main line turning into the shop wall in the other was swollen and cracked. Now I went and had a high pressure line made up and used black iron fittings to take the air to the PVC line inside the walls. We are in the process of installing a high volume fan to come on with the compressor to move fresh outside air to reduce the overall temperature in the room. Some day when I quit building cars, I will bite the bullet and replace all the PVC with either copper (preferred because of its better heat transfer coefficient) or black iron (much cheaper). Do I feel unsafe in the shop? No, because all the pipe is covered.


shine 08-31-2011 07:21 AM

just curious trees, why do you need 175 lbs of pressure ?

oldred 08-31-2011 07:30 AM

Shine I am very much surprised as I thought you to be very safety conscious but PVC is extremely dangerous and many documented accidents have occurred from it's use. Being an old system is not proof of safety, it is simply proof of luck and that luck could run out at any time. If you want to continue using this stuff that's your business but please don't suggest to anyone else to do the same. The dangers of using PVC are not myth or "urban legend" but are a known fact, although the only occurrences I saw of ruptures were from impacts we regularly received "Safety Grams" which detailed accidents of all types that involved injuries and over the years several of these injuries were from pipe ruptures-every single one of those involved PVC.

Besides PVC is a terrible choice for air line moisture removal because of it's poor cooling characteristics even if it was safe to use.

Angel85lx, PVC is dangerous, accidents resulting from it's use have happened and and it is not OK to use. It is not just illegal in California, OSHA and IMSHA have banned it's use for transporting gasses including air (unless buried or enclosed in steel conduit) due to injury causing accidents resulting from it's use, they did so for a good reason!

Chevymon 08-31-2011 07:45 AM

PVC also deteriorates with age. Here is what HUB said about piping and cost.

shine 08-31-2011 07:46 AM

in all the years i've been at this i have never seen a failure. i'm sure they happen all the time but i would bet it is more the installers fault than the product .
most guys have 3 horse compressors and try to turn them up thinking it will give them more air. wrong. in less than a min the extra will be gone. mine shuts off right before 90. i could set it at 150 but why ??? you could set it at 70 and still get the same results . air tools run at 45, guns at 25 so why store 125 lbs of pressure.
i promise if mine ever blows i will post about it . but it has been in this shop for 13 years.

lanier ledford 08-31-2011 07:53 AM

plastic pipe aie lines
sand blasting requires high psi to remove rust, more psi; more cleaning, more heat, and eat a hole. more sand, less cleaning, less heat, moving faster also reduces heat.
What about she. 80, doesn't it have a higher psi rating?

shine 08-31-2011 07:58 AM

sch 40 burst pressure is 1900 sch 80 is 2900. 1/2 in. 3/4 is about 400 lower.
and no you do not need more pressure to blast. my blasting rig runs at 35 lbs .

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