With the cost of copper these days I was wondering what the group thought about pvc for plumbing air around the shop? Imprint on the side of the pipe says it is rated to 290-320 psi depending on size so it is well under the range of what my compressor is making.
PVC air lines
- Thread starter Eprodrx7
- Start date
Biy is this a can of worms.
Do a search.
We have argued pro and con over this for years.
I come down on the side that says no to PVC.
I have always considered copper to expensive.
Even at the old prices.
(It has dropped lately will no construction going on.)
I use black iron pipe.
Do a search.
We have argued pro and con over this for years.
I come down on the side that says no to PVC.
I have always considered copper to expensive.
Even at the old prices.
(It has dropped lately will no construction going on.)
I use black iron pipe.
Mezzanine
Well-known member
The group says do a search... This has been discussed ad nauseum, but the general consensus is NO. Go black iron or copper. Copper has come down in price significantly in recent months, so it is worth considering.
porschedude996TT
Well-known member
Copper has dropped in half by the way...
wantedabiggergarage
Member Emeritus
In commercial shops, it is OSHA fineable. In home shops, you should know that it is rated for water, NOT AIR. Water bursts, and won't explode like air.
Also, if you really want plastic, the approved plastics, are a specific ABS (color specific to air) and Pex-al-Pex. These make copper seem reasonable.
Also, if you really want plastic, the approved plastics, are a specific ABS (color specific to air) and Pex-al-Pex. These make copper seem reasonable.
StingRay
Well-known member
PVC is dangerous and not rated for air. I'm doing my shop in copper right now and yes it's expensive. It's also versatile and easy to work with. I considered the aluminum systems but just couldn't get past the versatility of copper and the availability of fittings. Black iron is the other logical choice for the same kinds of reasons.
The trouble with PVC is that it shatters. With a compressible fluid inside, that yields an explosion with shrapnel. I use PVC for underground air lines, with copper or black pipe risers on either end.
The tried-and-true method is iron pipe and is the only acceptable system in most commercial structures. The main reason for using iron pipe is, in the event of a fire, the piping system will not rupture due to heat alone. A ruptured compressed air system can make a small fire a very large and hot fire in an exceedingly short period of time.
For home use, I think you have a couple other options. Pex tubing, or copper. Most PEX is rated for about 125 PSI at 90F, or thereabouts. However, they now make a product called AluPEX or similar, which has an aluminum tube imbedded in the plastic. It is rated by the manufacturer for compressed air.
Copper is the other obvious choice. However, be sure you buy and use the corect solder. In most copper systems, the rated pressure of the pipe is limited by the solder joints. There are tables available which show the rated pressure and temperature for various solder joints and tube sizes and types.
If you go with either of those options, take a moment to shut off your air supply when you're not working. Just close the tank valve. Then, should you have a fire while you're not around, it will reduce the possibility of your air system fanning the flames.
The tried-and-true method is iron pipe and is the only acceptable system in most commercial structures. The main reason for using iron pipe is, in the event of a fire, the piping system will not rupture due to heat alone. A ruptured compressed air system can make a small fire a very large and hot fire in an exceedingly short period of time.
For home use, I think you have a couple other options. Pex tubing, or copper. Most PEX is rated for about 125 PSI at 90F, or thereabouts. However, they now make a product called AluPEX or similar, which has an aluminum tube imbedded in the plastic. It is rated by the manufacturer for compressed air.
Copper is the other obvious choice. However, be sure you buy and use the corect solder. In most copper systems, the rated pressure of the pipe is limited by the solder joints. There are tables available which show the rated pressure and temperature for various solder joints and tube sizes and types.
If you go with either of those options, take a moment to shut off your air supply when you're not working. Just close the tank valve. Then, should you have a fire while you're not around, it will reduce the possibility of your air system fanning the flames.
Tman
Well-known member
With nice modern hose reels I almost see no need to run hardline. My pal has harline in his shop and you still trip over an airhose anyway. I have a short 20 ft coil line and a reel with 100 feet of line in my 1400 sq/ft shop. The short coil hose is great for work in my dirty bay. anything else including outside and the coiled line hooks to the reel for 120 feet of capability.
WOW! you guys are quick. I did a search and came up with nothing for just "pvc" so thanks for responding anyway. It seems the general consensus is NO but what do the yes guy claim for reason? I think the black pipe will be the ticket. More so because I hate sweating joints.
Thanks again for the quick responses
Thanks again for the quick responses
pattenp
Well-known member
Has anyone used copper with compression fittings (No sweating joints) for air lines? I was thinking about putting in copper airline and using the compression type connectors. I know the sweat connectors are cheaper but I too hate sweating connections. Was wondering what the downside may be of using compression fittings.
Oh and I apologize, I should has started another post instead of hijacking this one.
Oh and I apologize, I should has started another post instead of hijacking this one.
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Stuart in MN
Well-known member
They usually say, "I've had PVC pipe in my garage for years and it hasn't blown up yet", while ignoring all the facts presented to them.
As mentioned, the main problem is that PVC is rated for use with non-compressible fluids, and not for compressible gases. If there's a break or leak, liquid will just leak out but compressed gas will rapidly expand and make the PVC shatter. There is at least one brand of ABS pipe that is rated for compressed gas use, but it's a specialized product you're not going to find at Home Depot.
A 10' length of type "L" copper is less than $12.00. I think that's a good price. P.V.C. I think is a no no.
what can happen with the PVC, is its a ticking bomb while pressurized with something compressed. All it takes is for something to hit one of the pipes and the pipe will shatter and the shrapnel will fly as if you shot it out of an air cannon. This can (and has) cause serious injury.
nadogail
Well-known member
PVC, like you get at the store, is a "No Go" for compressed air. Plastic pipe for airlines from somebody like Harrington Plastics or Ryan Herco can be, in some circumstances, be a good choice.
I have, when working at a printed circuit board plant, purchased and installed plastic air line piping and fittings from Ryan Herco. Compared to schedule 40 PVC, they had a thicker wall section and were a distinctive green color. The cement to join this stuff was also unique. We used plastic air line because we were around chemicals that ate copper and steel pipes for lunch.
Because I was spending somebody elses money, I have no idea how the costs compare.
I have, when working at a printed circuit board plant, purchased and installed plastic air line piping and fittings from Ryan Herco. Compared to schedule 40 PVC, they had a thicker wall section and were a distinctive green color. The cement to join this stuff was also unique. We used plastic air line because we were around chemicals that ate copper and steel pipes for lunch.
Because I was spending somebody elses money, I have no idea how the costs compare.
ahaidet
Well-known member
Problem with hose reels and no hardlines is that the rubber hose does not allow the moisture to condense. In a properly set up hardline setup you will have drops to drain moisture from lines. Unless you have some kind of serious dryer before it enters the reel (one that uses refrigerant.. etc) Depending on the type of work you do moisture in the lines may not bother you but for others it can be. Big deal when using things like blast cabinets and paint guns.
"compressible fluid?" I think you mean a compressible gas. The large systems I have in use are a mix of copper and flex tubing for each user bay. Eight 25 HP compressors in groups of 2 with a chiller type dryer for each group. We have fire valves on the air systems both on the mains and in the oil tank rooms. In a fire a link melts and a spring shuts the valve cutting the air off to the thunder pumps used to pump the bulk oils and windshield washer fluid.
Black pipe is harder to work with, can rust inside and cause problems down the road.
I have the compressors turned off via a worker or via timers after hours. Had a intercooler split on a system and the compressor came on and ran for many hours. It was not made to run no load and blew oil all over the place enough to trip a smoke alarm from the oil mist.
The home system is copper and I turn the compressor off when not in use. For most systems copper has advantages.
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sberry
Banned
I have a lot of it done similar, under slab too with guarded risers or transition to metal. I used mostly 3/4 40, never had a problem with it. It I do I will go over or around it.
In a small shop it is easy to over estimate the need for hydrants, even in our shop it really boiled down to half a dozen places, most garages need 2 or 3 and sometimes you don't really find out where the ideal location is till you been at it a while.
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Charles (in GA)
Well-known member
If you are referring to the Nibco Chem Aire pipe and fittings which I have suggested in previous posts on this subject, I noticed it disappeared from the Nibco website and emailed them. The discontinued it about a year ago.
I gave thought to emailing their distributors looking for left over stock, but haven't yet. Need to do my 60x60 building yet.
Here is OSHA's position on PVC air piping.
http://www.osha.gov/dts/hib/hib_data/hib19880520.html
Charles
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Torque1st
MEMBER EMERITUS
Charles, the problem with using a discontinued product is changes or repairs down the line. Iron and copper pipe are available everywhere and will be for the foreseeable future.
As far as running PVC underground. Generally it is considered safe. However one of the examples quoted in OSHA discussions is the 3' deep crater left after an underground PVC line failed at some factory. I have no idea what pressure they were running and what type of PVC it was.
One shop in my city had a PVC line fail spontaneously in the middle of the night throwing fragments all over the shop. The shop owner repaired the break with another length of PVC... -Slow learner.
As far as running PVC underground. Generally it is considered safe. However one of the examples quoted in OSHA discussions is the 3' deep crater left after an underground PVC line failed at some factory. I have no idea what pressure they were running and what type of PVC it was.
One shop in my city had a PVC line fail spontaneously in the middle of the night throwing fragments all over the shop. The shop owner repaired the break with another length of PVC... -Slow learner.
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Air is a fluid.
In fact, any material that is incapable of supporting a shear stress a fluid. All gasses are fluids but not all liquids are fluids. The corn starch and water mixture you probably made as a kid is not a fluid, as it is capable of supporting a shear stress. Yet, it is a liquid, as it can take the shape of it's container and it forms a boundary on it's free surface. Therefore, the colloquial substitution of the word "fluid" for the word "liquid" is not correct usage.
Personally, I prefer PEX or Copper for air systems for the rust reason you mentioned. Expensive pneumatic automation equipment does not take kindly to rust dust clogging up the works!
However, the fire code for commercial structures strictly prohibits it from what I've read. In addtion, most fire fighters will mark the building "no entry" on their inspection sheets and some insurance carriers will even deny fire insurance coverage on non-iron air systems.
Stuart in MN
Well-known member
Chem-Aire is the stuff. It appears Ryan Herco (mentioned earlier) still has Chem-Aire ABS pipe: http://www.ryanherco.com/Auto/SECindex.cfm?FAM=175&SEC=165
My 2 Cents.
Like everyone else has said. Dont Run PVC. It's a ticking time bomb. I have PVC water lines in my granite shop, where we run a high pressure, and it bursts every now and again.
If you are going to be running a production shop or are using your air system allot then go copper. Not only is is safer but will last forever. I have my granite shop plumbed with 1.25" copper lines through out. Plus if you move you can cut it out and take it to the next location.
At my house I used PEX. I was hesitant at first as its only rated at 125psi but it has held with no problems. All the lines are inside the walls so if there is any type of explosion it will be contained inside the walls. Also, when I am not using the system, I bleed it down. I have had the PEX in my house for a year now. Touch wood, no problems.
Good luck...
Like everyone else has said. Dont Run PVC. It's a ticking time bomb. I have PVC water lines in my granite shop, where we run a high pressure, and it bursts every now and again.
If you are going to be running a production shop or are using your air system allot then go copper. Not only is is safer but will last forever. I have my granite shop plumbed with 1.25" copper lines through out. Plus if you move you can cut it out and take it to the next location.
At my house I used PEX. I was hesitant at first as its only rated at 125psi but it has held with no problems. All the lines are inside the walls so if there is any type of explosion it will be contained inside the walls. Also, when I am not using the system, I bleed it down. I have had the PEX in my house for a year now. Touch wood, no problems.
Good luck...
Torque1st
MEMBER EMERITUS
Using PEX inside the walls effectively deactivates one of the functions of the air distribution system. That function is cooling the air and separating the water vapor from the air stream by condensation. To remove the water the line material must be thermally conductive, plastic does not transfer heat well. The line also has to be out where the air can cool it by convection. If the line is inside a wall or even embedded in insulation water removal will suffer.
Torque1st
MEMBER EMERITUS
Disagree based on what? PEX is used because it does not corrode in concrete and is flexible enough to withstand concrete stress cracking among other things. Not because it transfers heat well.
back2class
Well-known member
- Joined
- Jan 7, 2009
- Messages
- 2,723
This is the WORST idea I have herd all day! Definately NOT!
Torque1st Re: PVC air lines
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Using PEX inside the walls effectively deactivates one of the functions of the air distribution system. That function is cooling the air and separating the water vapor from the air stream by condensation. To remove the water the line material must be thermally conductive, plastic does not transfer heat well. The line also has to be out where the air can cool it by convection. If the line is inside a wall or even embedded in insulation water removal will suffer.
This is also why I said in my first post that if you are a heavy user, do not use PEX, use copper. I have a dryer on my system. That way the air is cool and dry before it even meets the PEX. However the odd times I have started my system and not turned on the dryer I have never had any problems with moisture. All of my traps have stayed dry.
Honestly I have had both in my homes and I picked the PEX in my new house because it was so easy to run and hook up. In my last house it took me a day to install copper. It took me 2 hours to install PEX in my new house.
I look at it this way. If you want a built proof system go with copper. But if you want a cheap and easy to install system, for light use, I would pick PEX.
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Using PEX inside the walls effectively deactivates one of the functions of the air distribution system. That function is cooling the air and separating the water vapor from the air stream by condensation. To remove the water the line material must be thermally conductive, plastic does not transfer heat well. The line also has to be out where the air can cool it by convection. If the line is inside a wall or even embedded in insulation water removal will suffer.
This is also why I said in my first post that if you are a heavy user, do not use PEX, use copper. I have a dryer on my system. That way the air is cool and dry before it even meets the PEX. However the odd times I have started my system and not turned on the dryer I have never had any problems with moisture. All of my traps have stayed dry.
Honestly I have had both in my homes and I picked the PEX in my new house because it was so easy to run and hook up. In my last house it took me a day to install copper. It took me 2 hours to install PEX in my new house.
I look at it this way. If you want a built proof system go with copper. But if you want a cheap and easy to install system, for light use, I would pick PEX.
akdiesel
Well-known member
Please explain your comment as too why this not a good idea.
pattenp
Well-known member
I too would like to know why this is such a bad idea. Oh and by the way, thanks for the condescending response.
rsanter
Well-known member
I used to work for a plastic molding company. we made lots of products including ABS and PVC fitting.
I have never really see a PVC pipe fail when used with air and I have seen several people use them. so, with that I had never understood why they would not hold up to the air pressure.
OK, back to the top. I went to work for a plastic company and we had a tester for pressure testing fittings and such. the tester is enclosed for safety so I decided to put it to the test.
took 2 fittings with a piece of pipe between them and then also took an expansion repair coupling.
installed the item, bled the air out and pressure testing the item. It is amazing to see those items take anywhere from 3-10 times the rated pressure. you can even see how the item expanded or streched a bit before failing. some wouldnt even fail before we maxed the testing limit.
ok, so I repeated a couple of the tests without bleeding the air. this means that there would be mostly air in the pipe or fitting with the pump pressurizing it by pumping water into the system.
depending on the item they failed EXPLOSIVELY at between 1/3rd and 1/2 of the rated pressure.
I can tell you that was one fun job. part of my job was to test and fail parts so we can document as well as taking care of certification testing.
my boss nick named me the 'manager of breaking ****'
so forget all you hear about theory of what it may do. I can tell you what it WILL do when tested.
typically test presure it 2.5 times rated pressure
bob
I have never really see a PVC pipe fail when used with air and I have seen several people use them. so, with that I had never understood why they would not hold up to the air pressure.
OK, back to the top. I went to work for a plastic company and we had a tester for pressure testing fittings and such. the tester is enclosed for safety so I decided to put it to the test.
took 2 fittings with a piece of pipe between them and then also took an expansion repair coupling.
installed the item, bled the air out and pressure testing the item. It is amazing to see those items take anywhere from 3-10 times the rated pressure. you can even see how the item expanded or streched a bit before failing. some wouldnt even fail before we maxed the testing limit.
ok, so I repeated a couple of the tests without bleeding the air. this means that there would be mostly air in the pipe or fitting with the pump pressurizing it by pumping water into the system.
depending on the item they failed EXPLOSIVELY at between 1/3rd and 1/2 of the rated pressure.
I can tell you that was one fun job. part of my job was to test and fail parts so we can document as well as taking care of certification testing.
my boss nick named me the 'manager of breaking ****'
so forget all you hear about theory of what it may do. I can tell you what it WILL do when tested.
typically test presure it 2.5 times rated pressure
bob
fourfeathers
Well-known member
I'll go against the grain here, and say that for a hobbiest homeowner, a pvc system will be fine. Use some care in placement, don't hit it, and it SHOULD be ok. My home system is not full all the time, and I use a hose reel that will reach the whole garage. At the shop, we have had good luck (10 years) with a pvc setup.
Torque1st
MEMBER EMERITUS
Jesus what a load of bullcrap! Stupid idea!! Why don't you just expose yourself, the neighbor, your friends, your wife, and KIDS to a grenade with a smoking fuse. That is absolutely the most idiotic idea I have ever heard. Save a few bucks and maybe a few hours and frag someone.
Sorry, Rant off...
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Tman
Well-known member
We had PVC in the rodshop, only time it ever caused a problem was whan one of the guys pulled the hose too far and broke off the end. just a rapid loss of air, no 'splosion.
Stuart in MN
Well-known member
Like I said the other day...
Quote:
Originally Posted by Eprodrx7
WOW! you guys are quick. I did a search and came up with nothing for just "pvc" so thanks for responding anyway. It seems the general consensus is NO but what do the yes guy claim for reason?
They usually say, "I've had PVC pipe in my garage for years and it hasn't blown up yet", while ignoring all the facts presented to them.
buening
Well-known member
Bob, your tests only include new fittings that have not been exposed to fatigue from expansion due to pressure changes nor due to aged PVC that can become brittle, especially when exposed to UV rays.....although that isn't typically common in a garage. PVC may be fine for a little while, but after it expands and contracts due to pressure changes the fatigue will cause hairline cracks....which will cause a violent explosion with little PVC shreds as shrapnel. Factor of safety is commonly used when rating anything, and 2-3 is a common range for FOS.
From an OSHA article:
Information Date: 19880520
Record Type: Hazard Information Bulletin
Subject: The Use of Polyvinyl Chloride Pipe in Above Ground Installations.
"When PVC piping explodes, plastic shrapnel pieces are thrown in all directions."
"'We're seeing more incidents of explosive failure, and we're citing more employers for using PVC air system piping,' said Paul Merrill, senior safety inspector in L&I's Spokane office."
"'It's probably just a matter of time before someone gets seriously injured in one of these explosions unless everyone pays more attention to the manufacturer's warnings,' Merrill said.
Last year, a section of PVC pipe being used for compressed air exploded 27 feet above a warehouse floor. A fragment of the pipe flew 60 feet and embedded itself in a roll of paper. Fortunately, nobody was in the area at the time.
A PVC pipe explosion in a new plant in Selah broke an employee's nose and cut his face."
"PVC piping buried 3 feet underground at a Yakima manufacturing plant exploded, opening up a crater approximately 4 feet deep by 3 feet across."
"Only one type of plastic pipe has been approved for use with compressed air. That pipe, Acrylonitrile-Butadiene-Styrene (ABS), is marked on the pipe as approved for compressed air supply."
http://www.osha.gov/dts/hib/hib_data/hib19880520.html
Torque1st
MEMBER EMERITUS
The plastic pipe manufacturer's catalogs and/or websites all have warning NOT to use PVC for compressed gas.
When a friend of mine built his shop a years ago they were installing PVC air lines when I was there one time. I asked about it, and they said it'll be fine, just make sure it's glued properly.
A few months later when I stopped by there was PVC shrapnel on the floor and a busted pipe on the wall.
I can't remember if he said it just burst or if it was hit with something, but in either case it's not a safe situation.
Myself, I have galvanized pipe.. got it at the same price as black pipe.
A few months later when I stopped by there was PVC shrapnel on the floor and a busted pipe on the wall.
I can't remember if he said it just burst or if it was hit with something, but in either case it's not a safe situation.
Myself, I have galvanized pipe.. got it at the same price as black pipe.