Can I run copper pipe as a supply line for my air compressor?
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Yes, it's done all the time and is safe.
yup..I agree. Just do this, wherever ya have a drop from horz. to a down leg, add a "rams curl" tee outta the top and ell it from there..keeps water from draining into yer supplies..and slope back to the compressor, or add a drain valve at the lowest point.
Solder like ya would for water, but you can use 50/50 tin lead, no neeed for lead free solder...unless ya like drinking the condensate.
Also, check out the auto drains for the comp. Water and air is a nightmare on finished work and yer tools.
Spheramid Enterprises Architectural Woodworks
"I've..seen all good people turn thier heads, so, satisfied, I am on my way.."They kill prophets for profits"..And, that's...the truth.........phhatt
yup, yes again, Cu best way to go.
See this is your 2nd post, if not said already, welcome.
I guess I get to be the dissenting voice. Copper is much better than PVC and much easier to assemble than steel pipe, but ...
1) It's much more vulnerable to physical damage than steel pipe.
2) If a joint becomes unsoldered in a fire, then you've got compressed air fanning the flames.
Just a clarification to your message:
NEVER, EVER USE PVC FOR COMPRESSED AIR PIPING!
PVC is not rated for compressed gas service because it is UNSAFE. It can be affected by compressor and tool oils, and it's brittle: if it fails it can produce schrapnel which can injure or kill people. It's perfectly fine for liquid and low pressure vent services- and it's even used for some liquids which eat most metals for breakfast.
As to worries about fire, do what the chemical plants and refineries do to protect gas-filled vessels (i.e. without liquid): install a "fusable link" in your piping or vessel. This is something which will burn FIRST and relieve the pressure before the tank ruptures. It's also done to protect piping using automatic valves- by using airlines which will rupture in fire and allow the valve to close before the actuator melts off of it.
In your case, the ideal way to accomplish this is by using a piece of airline hose to connect your compressor to your piping system. It's generally a good idea to isolate compressors from rigid piping mechanically anyway, so your hose will do both jobs admirably. In the fire case you're much more worried about failure of the compressor tank than of the piping.
As to using copper, I think it's the best option for air lines for most people. Easier to install without leakage, and less likely to leak or corrode and fail later.
I see people use pvc in their shops all the time. I bet at leat half the shops I can walk into are PVC. maybe its a higher schdule
maybe theri hasnt been a rule against it or not enough news about it bursting
I dont doubt what you say, just hvent really heard anyone say dont do it.
Re: copper pipe for air compressorWhat size is best -- 1/2" or 3/4" -- for, say, a 50' run?
air don't care...but really, whats the CFM ya plan on using? I would go 3/4 for mains, and 1/2 for drop legs..just cuz the fittings are more readily available, and the pipe is less $..
Spheramid Enterprises Architectural Woodworks
"I've..seen all good people turn thier heads, so, satisfied, I am on my way.."They kill prophets for profits"..And, that's...the truth.........phhatt
Thanks to you and buildingbill. 1/2" would probably do it, since I am only running nailers -- no air tools. I thought i read somewhere that a bigger hose (or in this case abigger pipe) effectively increases the size of the storage tank on your compressor. Is that true?
yeah but...you lose from friction loss. An equation is available, but not from me.........basically,a longer run delivers a dropped PSI at the end point. Might be a deal, with some operations, might not...yer call.
Spheramid Enterprises Architectural Woodworks
"I've..seen all good people turn thier heads, so, satisfied, I am on my way.."They kill prophets for profits"..And, that's...the truth.........phhatt
A LONGER hose of the same diameter increases pressure loss relative to a shorter one. For hoses of equal length, the LARGER DIAMETER hose produces less pressure loss at the same flow. But with an impulse tool like a nailer, storage within the hose is a factor as well.
If what you're using is a nailer, what you need is impulse pressure rather than raw continuous flow (i.e. like you need to run a die grinder etc.). The demand for flow is instantaneous and of short duration- you're taking a "slug" of air into the gun and then the demand stops. Storage nearest your gun is the most valuable. A length of large-diameter hose will actually be quite helpful- more helpful than merely having a bigger tank on your compressor, because during the delivery of a nail it's the air in the HOSE which does the work. If the air stored in the hose itself is greater in volume than the displacement of the gun's cylinder, you'll get more pressure and more constant pressure at the inlet to your gun throughout the travel of the piston. Given the response time of the average pressure regulator, it takes a fair while for the air in your tank to completely recharge the hose after the gun has cycled and the nail has been driven home. Listen to the hiss from your compressor's tank when the compressor is off and you'll probably notice this.
So depending on the displacement of your gun, there may actually be a situation where a 100 foot 3/8" hose works better with your gun than a 50 footer of the same bore!
Edited 2/2/2005 5:17 pm ET by moltenmetal
well said, point taken.
Spheramid Enterprises Architectural Woodworks
"I've..seen all good people turn thier heads, so, satisfied, I am on my way.."They kill prophets for profits"..And, that's...the truth.........phhatt
I use 3/4 because the wolume is more ans helps cut down on condensation in the line. If you use an air/water seperator put it down near the far end(away from tank) to allow for the air to condensate. This allows the seperator to do its job.
Do a google on it and you will get all kinds of warnings.http://www.lni.wa.gov/Safety/Basics/HazAlerts/902.aspOctober 1990
PVC pipe not to be used in compressed air systemsThe Department of Labor and Industries warned consumers and employers in May 1988 that plastic-polyvinyl- chloride (PVC) pipe cannot be used in compressed air piping systems without risk of explosion. By law, employers must protect their workers by avoiding the use of unapproved PVC pipe in such systems. Existing compressed air systems that use PVC piping must be completely enclosed, buried or adequately guarded according to specifications approved by a professional consulting engineer. Only Acrylonitrile-Butadiene-Styrene (ABS) piping was approved for use with compressed air, provided it was marked on the pipe as approved for compressed air supply. In October 1989, the Plastics Pipe Institute (PPI) amended their original recommendations for thermoplastic piping in the transport of compressed air and other gases. WISHA's (Washington Industrial Safety and Health Act) Division of Consultation and Compliance Services now will accept thermoplastic compressed air piping that meets the following guidelines (recommendation B, to the PPI 1972 recommendation):"The Plastics Pipe Institute recommends that thermoplastic piping intended for the transport of compressed air or other compressed gases be buried or encased in shatter-resistant materials, unless the piping has been manufactured from materials which shall resist shatter-type failures under the anticipated conditions. Specifically, above ground installations of thermoplastic piping should only be made using products which have been suitably evaluated and which are recommended by the manufacturer for the particular intended service."It is recognized that while adequacy of strength is an important element in the safety of a compressed gas piping system, consideration must also be given to the nature of failure should accidental failure occur, whatever its cause. Above-ground piping which fails by shattering can present a serious hazard to personnel by the resultant flying shards, or pipe fragments, which are rapidly propelled by the released energy of the suddenly decompressing gas. Because the inclination of a material to fail by shattering is determined not only by the nature of the material, but by pressure, pipe and fitting dimensions, and by the nature of the gas, the evaluation of shatter resistance should consider all these and any other pertinent factors."NOTICE TO EMPLOYEES: If you suspect that a pressurized PVC piping hazard exists, bring it to the attention on your employer. If you do not obtain satisfactory results, you may file a confidential complaint with the Department of Labor and Industries. Complaints are investigated promptly. Call the Department's toll free number at 1-800-423-7233.NOTICE TO EMPLOYERS: If you have questions about the suitability of a material for air system piping, call the Department of Labor and Industries Regional Office for a free consultation.
Bill all that being said I still bet, like someone else said, half the shops will have PVC.
I think its because people are scared to run copper. Dont know how to sweat it.
The shop I'm in has PVC, just waiting for it to explode!
Doug
I,m afraid of pvc and really not to keen on copper. My shop compressor doesnt kick off till 250 psi. That why I lean towards black iron.
When I air-test new copper plumbing runs before flooding them, I charge them up to 120psi and then close the ball valve on my test gauge and wait. Gotta have a zero psi loss after 3 hours before I consider them good to go. But I've never charged even type L to 250psi. I don't honestly know if it's rated for that kind of pressure.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Type L copper will handle 200 lb preasure with no problem. Air condition lines are run much higher than that.
I've seen the aftermath of a PVC pipe or fitting shattering in a compressed air system a couple times, and it's pretty spectacular. Fortunately, both times no one was in the way (although in one case I was standing in an adjacent building, it sounded like a bomb went off) but there was a lot of shrapnel and broken parts everywhere. Also, in both cases there was no warning - everything seemed normal beforehand, nobody bumped into the pipes or anything - they just blew.
As others have pointed out, there's any amount of information out there on this subject. As far as I know, all PVC pipe manufacturers specifically warn against using their product for compressed air or other gases. There is one brand of ABS pipe I know about that is designed for compressed air use, but it's not very cheap and they don't have it at Home Depot.
I've read several OSHA documents on the subject as well. I imagine if there was a problem with PVC pipe in a commerical shop, the owner could face some legal problems. In a home shop, with a person's kids or spouse potentially exposed to danger...I don't even want to think about that.
If you go to a shop that has plastic air lines, ask whoever is in charge if they know just how dangerous PVC is in compressed air service. If they brush you off, report 'em to OSHA before somebody loses an eye, or worse...
Note that reinforced flexible PVC air hose IS rated for compressed air service, and unless you go below the minimum temperature limit the flexible stuff will not generate schrapnel of any consequence. There IS an ABS piping system which is rated for compressed air service to limited temperatures and pressures, but it's a particular brand and it most definitely is NOT ordinary rigid PVC or ABS water pipe, regardless of schedule. Sch 80 just means fatter chunks of schrapnel flying through the air when it ruptures...
As far as shutting down and venting prior to going home, that's good in theory but not in practice. A fusible link in the air system, preferably at the connection between the air system and the compressor, takes care of the firefighters without anybody having to remember to shut the compressor off before they go home, much less as they pull the fire alarm and run out the door...
I'm with you molten but down here in Texas I don't think OSHA does jack about anything.
I would have thought that the shop I work in could not stand a OSHA inspection to save its life.
I was told that shortly before I started that a disgruntled employee left and turned the place in to OSHA, apparently they came out and said "A-OK".
Beyond me how but..........
Doug
I just use that same flexible hose in my shop as I use on the job site , it's cheap ,it goes around corners , it can be fished through finished walls and be retrieved if you want to change your layout.
Why use any kind of solid pipe at all ? ....Rik.......
Why use any kind of solid pipe at all ?"
Art,
1: it won't burst
2: it condenses out moisture
3: ridged pipe can be pitched easily enough so that the condensed moisture (water) can be collected and drained.
4: it is just plain darn safer.
Ever see an accidentally cut hose whip around a shop with 175PSI behind it?
'Nuf said
WSJ
You know what you are talking about! Right on!
I hope you have eye and body protection!
Shacko
I agree with you but unfortunately I don't make the rules around the place.
Down here OSHA seemingly has no power, or chooses to no use it.
I play the odds every day driving to work, what's the diff!
Doug
Sphere said most of it; I'll add: Use type L rigid copper. Type M is too easy to ding and pierce.
Uncle Dunc's comment about a fire does raise an interesting point...but if you discharge the supply lines when the system is not in use that ceases to be an issue. Anyway, if you've got a fire big enough to unsolder pipes, you're probably gonna blow open the safety valve on the compressor itself as pressure in the storage tanks rises from the heat, so obviously the safest thing to do is to discharge the entire system when you're not using it.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Discharge it or turn the compressor off. If the popoff valve goes, There's no guarantee that it'll be blowing in the direction of the fire. I would be more concerned with the tank bursting in a bad fire with the switch left on and the compressor starts to run.
"I cut this piece four times and it's still too short."
Not much scarier to a firefighter than knowing there are pressurized tanks inside a burning premises. I agree: when ever not in use the entire system should be discharged and turned off.
BTW--any pro Firefighters out there know if you're required to place a pressurized gas warning sticker at the building entrances for ordinary compressed air tanks?
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
I am not a Fire Fighter, but have never seen any fire warning labels for just compressed air. For compressed flammable and/or toxic/corrosive, yes, but not compressed air.
Most commercial emusifier systems (sprinklers) now days are dry systems. The main valve is held closed by compressed air. We have four or five such systems in different facilities, and I don't recall seeing any warning about compressed air at the compressor or anywhere else for that matter.
What is used in commercial piping is color coding. In small shops and residential use, that may be as good an idea as any single warning sign.
I'll see if I can locate the color code index in one of my old text books.
Dave
Every compressor I've seen has a copper pipe running from the compressor to the storage tank.
As for solder, the specifications on the copper trade association website ('don't remember the URL), says that joints made with lead-free solder have a higher pressure rating.
Edited 2/2/2005 12:05 am ET by BarryO