PVC and Compressed air

[rockycmt]

I am thinking of running a 1 inch PVC pipe from my garage to my basement from my compressor. Will PVC w/ glue joints support the 100psi? I jave a surplus of pipe and wanted to use this up before buying anything new?

Chris

[Redwood]

PVC is not recommended for compressed air applications by any manufacturer.
The pipe can explode with great force!
I have seen a hole punched in a block wall by PVC from an exploding pipe!:eek:

[hj]

DO NOT use PVC for compressed air at any pressure. Either steel pipe, or copper tubing with soldered or brazed joints.

[Gary Swart]

With the price of copper and the hassle of using threaded steel pipe it is tempting to look at PVC isn't it. But as others have pointed out, PVC is not a safe material for compressed air. As it ages it becomes more and more brittle and therefore is subject to bursting. When it bursts, shards of plastic are shot out with great force. When I plumbed my shop's air, I used copper. Of course copper was much more affordable at that time, but if I had it to do over, I'd still use copper. I'd just modify my plan to use less material.

[Southern Man]

I am thinking of running a 1 inch PVC pipe from my garage to my basement from my compressor. Will PVC w/ glue joints support the 100psi? I jave a surplus of pipe and wanted to use this up before buying anything new?

Chris

I've had PVC in my residential garage for compressed air going on ten years. It's ASTM D1785 Schedule 40 and in 1/2" size rated for 600psi.

[msgale]

granted, if the pipe explodes there is a problem. But,i cannot understand why water is safer, at the same pressure, than air?

[Terry]

But,i cannot understand why water is safer, at the same pressure, than air?

It's because you haven't read what it can do, nor have you worked with it like the rest of us.
Air is highly compressible, and therein lies the danger.

[Redwood]

granted, if the pipe explodes there is a problem. But,i cannot understand why water is safer, at the same pressure, than air?

Water does not compress. It may be under pressure, but it doesn't compress.
Because of that there is no stored energy.

Compressed air on the other hand is just that... Air compressed and stored under pressure... There is a huge amount of stored energy!

[Redwood]

I've had PVC in my residential garage for compressed air going on ten years. It's ASTM D1785 Schedule 40 and in 1/2" size rated for 600psi.

Read This!
They don't even want you to test it with compressed air!



PVC Schedule 40 pipe and fittings is intended for pressure applications where the operating temperature will not exceed 140 ° F.

Pipe and fittings are manufactured from virgin rigid PVC (polyvinyl chloride) vinyl compounds with a Cell Class of 12454 as identified in ASTM D 1784. PVC Schedule 40 pipe are Iron Pipe Size (IPS) conforming to ASTM D 1785.

PVC Schedule 40 fittings conform to ASTM D 2466. Pipe and fittings are manufactured as a system and are the product of one manufacturer. All pipe and fittings are manufactured in the United States. Pipe and fittings conform to National Sanitation Foundation (NSF) Standard 61 or the health effects portion of NSF Standard 14.

Installation complies with the latest installation instructions published by Charlotte Pipe and Foundry and conforms to all local plumbing, building, and fire code requirements. Solvent cement joints are made in a two-step process with primer manufactured for thermoplastic piping systems and solvent cement conforming to ASTM D 2564. The system is protected from chemical agents, fire stopping materials, thread sealant, plasticized vinyl products, or other aggressive chemical agents not compatible with PVC compounds. Systems is hydrostatically tested after installation. Testing with compressed air or gas is not recommended.


http://www.charlottepipe.com/Default.aspx?Page=PVC40&type=PVCCPVC



DO NOT USE CHARLOTTE PIPE PRODUCTS
FOR COMPRESSED AIR OR GASES
Charlotte Pipe and Foundry Company products are not
intended to be used for distribution or storage of
compressed air or gases. Use of Charlotte Pipe products
in inappropriate applications could result in product
failure, serious injury or death.

Air or Gas Testing
- Not Recommended
Air or compressed gas test are sometimes performed
instead of hydrostatic (water) test. DANGER: Charlotte
Pipe and Foundry Company does not recommend air or
gas testing, consistent with PPFA User Bulletin 4-80
and / or ASTM D 1785. Pipe and fitting materials
under air or gas pressure can explode, causing
serious injury or death. Charlotte Pipe will not be
responsible or liable for injury or death to persons or
damage to property or for claims for labor and / or
material arising from any alleged failure of our products
during testing with air or compressed gasses. Page 4
http://www.charlottepipe.com/Documents/PL_Tech_Man/ABS_PVC_pipe_fittings-TM.pdf

Looks like you might want to repipe that compressed air system!

[Steve_P]

all of the "don't do it" replies are correct and this is why pressure vessels, etc, are hydro-tested. Water is essentially not compressible and therefore does not have the potential energy that a compressed gas, like air, does. I know some people use plastic but I certainly would not.

I did my shop with copper also, 175 psi is no problems on 3/4 cu tube and soldered joints.

[rockycmt]

Point well taken. I WILL NOT be doing this.

[Bill Arden]

Glued PVC is bad, but they do make plastic air hose.

I use polyethylene tubing all the time for pneumatics.

[Gary Swart]

Polyethylene obviously is a totally different material than PVC. If the polyethylene hose bursts, you just have a hole in the hose and a whole lot of lost air.

[Redwood]

When PVC bursts chunks fly with a lot of force.

[Southern Man]

[SIZE="6"] ...
Looks like you might want to repipe that compressed air system! Maybe I'll just cover it with chain mail. :D

[hj]

In that case copper might be cheaper.


I've had PVC in my residential garage for compressed air going on ten years. It's ASTM D1785 Schedule 40 and in 1/2" size rated for 600psi

That makes as much sense as saying that you have had a male lion living in your house for 10 years and there is no way it will attack and kill you. What happened up until today, has no bearing on what could happen 10 minutes from now. And the older PVC pipes get the more fragile they become.

[msgale]

whereas the water will just split it w. no major force .

good point.

thank you. now i feel better.

[Southern Man]

In that case copper might be cheaper.

quote;
I've had PVC in my residential garage for compressed air going on ten years. It's ASTM D1785 Schedule 40 and in 1/2" size rated for 600psi

That makes as much sense as saying that you have had a male lion living in your house for 10 years and there is no way it will attack and kill you. What happened up until today, has no bearing on what could happen 10 minutes from now. And the older PVC pipes get the more fragile they become.

The rating of the pipe is 600 psi. There is a safety factor on top of that; let's ignore that for now. My compressor shuts off at 80 psi, so the pipe is 7.5 times stronger than it has to be.

For your analogy to make sense the lion has to be 1/7.5 times my size, or about 21 pounds. Lot of folks have cats that size. :)

[sjsmithjr]

My compressor shuts off at 80 psi, so the pipe is 7.5 times stronger than it has to be.

The OP specifically stated an operating pressure of 100 psi.

The American National Standards Institute/American Society of Mechanical Engineers limit the operating pressure of PVC to 100 psi and prohibit the installation of such systems unless the above ground portion is encased in conduit or casing.

The Plastic Pipe Institute recommends against the use of PVC for compressed air (or other gas) in exposed piping.

ASTM says no to the use of PVC for compressed air in exposed piping.

OSHA says no to the use of PVC for compressed air in exposed piping. It's use for this purpose has resulted in serious injury.

The industry as a whole says no to the use of PVC for compressed air in exposed piping. Anyone giving advice to the contrary is just plain wrong.

[Southern Man]

The OP specifically stated an operating pressure of 100 psi.

The American National Standards Institute/American Society of Mechanical Engineers limit the operating pressure of PVC to 100 psi and prohibit the installation of such systems unless the above ground portion is encased in conduit or casing.

The Plastic Pipe Institute recommends against the use of PVC for compressed air (or other gas) in exposed piping.

ASTM says no to the use of PVC for compressed air in exposed piping.

OSHA says no to the use of PVC for compressed air in exposed piping. It's use for this purpose has resulted in serious injury.

The industry as a whole says no to the use of PVC for compressed air in exposed piping. Anyone giving advice to the contrary is just plain wrong.

600/100 = factor of safety = 6. But that ignores the factor of safety of the rating, which is probably 2, so that the actual FOS = 12. That big ol' lion in the house is now very small indeed. For a system used intermittently in a residence I see no problem.

[Redwood]

600/100 = factor of safety = 6. But that ignores the factor of safety of the rating, which is probably 2, so that the actual FOS = 12. That big ol' lion in the house is now very small indeed. For a system used intermittently in a residence I see no problem.

http://www.osha.gov/dts/hib/hib_data/hib19880520.html

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=20202

And you my friend are the recipient of todays award!

http://i44.photobucket.com/albums/f2/Redwood39/darwinaward.jpg

It always amazes me that someone when presented with overwhelming evidence that the position they have taken is wrong, and the opinion is shared by many others will continue to argue their point...

There must be a word for that...

[hj]

You are quoting a rating for PVC when it was new. As it ages it becomes brittle, and will rupture at a much lower pressure. Few compressed air systems work at more than 125 psi, but there have been countless failures of PVC air systems, ALL using schedule 40 or 80 pipe, occassionally with fatal results. But I guess what we should have done is say, "DON"T DO IT!" and then let you do whatever you want to. I guess saving a couple of dollars in material costs is MUCH more important than having a safe installation.

[Southern Man]

http://www.osha.gov/dts/hib/hib_data/hib19880520.html

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=20202

......

OSHA regs don't cover homeowners. :D

[Southern Man]

You are quoting a rating for PVC when it was new. As it ages it becomes brittle, and will rupture at a much lower pressure. Few compressed air systems work at more than 125 psi, but there have been countless failures of PVC air systems, ALL using schedule 40 or 80 pipe, occassionally with fatal results. But I guess what we should have done is say, "DON"T DO IT!" and then let you do whatever you want to. I guess saving a couple of dollars in material costs is MUCH more important than having a safe installation. PVC gets brittle how, exactly? Sunlight, right? There's not much of that on the ceiling of my garage. Maybe you should check where the failures have occurred. My guess probably during testing, and a pipe was nicked or weakened by the guy installing it.

[Furd]

I had a PVC compressed air distribution system in my garage workshop some 35 years ago. I never had any problems with it but that doesn't mean it was safe. One thing that I did was to have a flexible hose between the compressor storage tank and the fixed piping to eliminate vibration and stress on the PVC. Very early on in the use of PVC piping it was discovered that repeated vibration OR stress induced by forcing PVC piping into alignment was a major cause of early failure.

When I learned that Washington state (through the bureau of Labor and Industries) had prohibited PVC in compressed air systems I discontinued using the PVC air line in my shop.

In my NOT so humble opinion, given the results of years of testing and the high failure rate of PVC piping in compressed air systems, only a fool would use PVC for compressed air.

There is another possible factor in the high failure rate of PVC compressed air piping and that is that all oil-lubricated compressors have a certain percentage of the lubrication oil carry over to the air. There is no doubt whatsoever that petroleum products are detrimental to PVC. Just one more reason not to use PVC for compressed air systems.


I'm quite sure there are hundreds of home shops that have PVC piping in compressed air distribution systems and they have had no failures. I personally know of someone that installed a PVC distribution system and even after I told him of the Washington state prohibition he dismissed the danger just as Southern Man is doing. Just because some people are lucky is no reason to tempt fate.

[Gary Swart]

I liken this discussion to what many woodworker make when rationalizing the non use of blade guards and splitters on their table saws, or some drivers make about seat belts. They feel since they have not used a blade guard in (fill in the years) they some how are immune to the danger, or they have been driving for 50 years and never have need a seat belt. You can make all the BS excuses you want, PVC is not a safe material for compressed air and it's stupid not to buckle up. Southern Man, you can use all the PVC you want in your shop for compressed air, but please do not advise others to do so.

[Southern Man]

The system isn't used very often and when it is charged, is connected via a rubber hose and quick connects. The oiler is located on the end near my bench so doesn't contaminate the system that can be used to inflate tires. Comparing it to driving without a seat belt or cutting wood without a guard, or owning a live lion is rather silly but if it make you feel good I'm happy for you.

[hj]

Just because OSHA rules do not apply to homeowners, does not make it safe to disregard their advice. Your best source is to call your state's industrial safety division and ask them if there have been any incidents in your area of bursting PVC air lines, because obviously you are not going to believe us. I hope you do not do your own plumbing systems, because few people with your "I can do what I want to", attitude install them correctly.

[Furd]

Southern Man, you claim to be a civil engineer. Would you not adhere to ASTM specifications for reinforcing steel in a bridge you designed?

Would you ignore the specifications for a steel I-beam used to support some structural part of a building that was being remodeled to open up a room? How about if the building was a residence that had lally columns in the basement holding up the main floor and the architect had a structural engineer calculate a specific steel to spread the load to the outside walls. Would you just substitute a steel stud because steel is steel?

How about a gas grill connected to a natural gas line? Would you use a piece of air hose that had a 200 psi maximum use pressure with a 800 psi burst pressure? Would you justify that usage by saying that the natural gas is less than 1/2 psi pressure? Would you use a piece of garden hose to connect a furnace to the gas line using the same justification?

Admit it, you don't give a damn about specifications when the specifications might somehow inconvenience you. I's glad you live on the other side of the country from me and I will never have to subject myself to ANYTHING you might have had a part in engineering. In short, you are a disgrace to all engineers.

[Steve_P]

the pressure rating of PVC and the resulting factor of safety is meaningless. The fact is that PVC is NOT intended for compressed air use and the makers state that. I'm sure there are miles of PVC being used in compressed air systems in people's garages, but it's still not a smart thing to do. Catastrophic failure will not be friendly to anyone around. The only time I would ever consider using PVC for compressed air is if it was buried underground- where failure couldn't cause personal injury.

[Southern Man]

Southern Man... you are a disgrace to all engineers. Actually, your analogies are all invalid. There are plenty of old structures that don't meet current specifications and are performing fine. In fact, many current standards are designed using these as an empirical basis. As one who claims to have experience, I'm surprised that you don't know that. ;)

[Redwood]

Can you say, "I've adopted an indefensible position?"

[Southern Man]

Sure you can. You can also say something derogatory about corn mash. :D

[Redwood]

No need...
Your doing great on your own...
Keep talking....:D

[Southern Man]

Gotta love the guys who "know the code" but don't have a clue about the engineering principles behind them. In their minds they are never wrong. ;)

[Redwood]

Like the fact that air compressors have a tendency to have a small amount of oil from the compressor in the air and many of these oils have proven to adversely effect PVC.

The only compressors that would not have this oil in the air would be a much higher quality than what you have in your garage...

It's great that you know more than the engineers at Charlotte pipe but I'll stick with their advice...

Here's your shovel keep digging!

http://www.komatsuamerica.com/images/products/pc4000shovel.jpg

[Bill Arden]

I'm not going to touch the whole PVC debate since I will admit that I don't know enough to say if PVC will degrade...

Personally, I would not trust all those glued PVC joints not to have small air leaks.
And then there is whats called "the creep rate" of most glues.

However as I said before there are other plastics that are approved for air lines and, as I understand it, the original poster just wanted a cheaper solution than copper or steel.

So back to the original question.
1. Yes it is possible to use a plastic pipe, but you have to use the right type.

[hj]

The original poster wanted to use PVC because he already had it, not because he wanted any other type of plastic. We gave him the recommended answer. What he or anyone else does with it is beyond our control.