I am working on upgrading and extending my compressed air system in my shop.
I started with a cheap direct drive compressor with a 25 gallon tank. The compressor has died. I was never happy with the noise, I had to wear hearing protection when it ran, so I replaced the compressor with a belt drive model, but it only has an 8 gallon tank. I am happy with the new compressor, I can still hear the radio while it runs, but want to a) pipe the two compressors so I have the 25 gallon reserve when needed for spraying or other air tools and b) extend the system so that I don’t have to leave hoses all overt the floor and can have more than one device attached at a time (gun, sander, blow off hose).
My question is in the choice of pipe to use. I see three options
1) PVC
2) Copper
3) Galvanized or Black.
I don’t like PVC or like to work with it. I would prefer to use copper, I think it looks nicer than galvanized or black pipe, and I find it much easier to work with. I don’t like fooling with pipe dope, and threading all the joints, plus since I don’t have a pipe threader I am limited to premade lengths for my lay out. What I don’t know is if Copper has the strength to handle the pressure (135 PSI) and the durability to handle the repeated pressurization/ depressurization cycles.
Any thoughts are appreciated.
Jim in Chicago.
Replies
Try McMaster-Carr
http://www.mcmaster.com/
pg 184 and up... there is a wide selection of tubing available with many connection options.
Good luck -
ThanksIt is not so much the fittings that I am looking for, but the reassurance that copper and soldered joints will be able to handle the working pressure of the system.I went to Copper.org and foud a bunch of info that says the piping can handle the pressure, assuming the correct grade (type k or l) but the soldered joints are a question.Anybody use soldered copper pipe for air distribution?thanks
I've not used soldered copper joints for air but it sure works good for water in pressures in excess of 200 psi. Exception is if the water pipe is allowed to freeze.
Thanks to all who replied, I can now move forward with copper. I prefer to work with copper, it is so much easier to work with, adjust and modify, in my opinion.I am a general contractor, and my HVAC sub prefers to run all his main piping for boiler water in steel pipe. When he does the work it looks beautiful, when i do it it looks bad and I am covered in grease and pipe dope. I guess there is no substitute for experience. Although his woodwork looks about as good as my steel pipe work. He didn't know about copper at high pressure, he rarely gets above about 10 to 12 lbs in his systems.thanks again to all.
Totalhome -I recently had my air system piped with black iron, 3/4" for all the runs and drops. The plumber that did the install said there are long term corrosion problems with copper. I can't substantiate this by any means and have no idea how long 'long term' refers to. But in my case I just feel more secure with that hice heavy wall steel pipe containing the air pressure.I'm doing some of the minor branch piping and terminations. I use teflon tape and pipe dope, not nearly as messy as it first appears. I'm fortunate in that I have some pipe threading equipment along with an engine lathe I can use sorta as a pipe machine for cutting and threading. Wihtout it, I doubt that I'd attempt iron piping.A plumber friend piped his air compressor with copper and has had no trouble with it so far as I know.You've already ruled out plastic with good advice and presence of mind.
Being in the apartment business for some twenty five years, I have had a whole lot more problem with steel pipe corroding, galvanized or black, than I have with copper pipe.
Edited 1/14/2006 11:05 pm ET by tinkerer2
Hi,
We are currently building out a new production facility at work (we make active pharmacueticals) and for our comp air system we spedfcified type L cooper. Two things to consider in designing your system 1. piping size at any given pressure will regulate flow (cfms, I prefer to run oversized pipe and regulate pressure at the points of use) 2. make sure you have good water and oil traps (copper will corrode).
Also if using copper consider using flare fittings over soldering the system together, air production is a huge expense a manufacturing, and even a small leak compounded over years becomes a huge expense.
-w
Copper is used more for gas and water than any other applications. The gas is usually at a fairly low pressure and water pressures higher than 50 Lbs. are rare. Black iron or galvanized
pipe I think is the best idea. Given the large selection of different length pipe nipples available at home centers, I can't imagine that you couldn't come close to hitting the run
lengths that you are looking for. I think some stores even offer pipe threading services. You
could use teflon tape on the fittings in lieu of pipe dope. If you decide to use copper I would
imagine that soldering would be perferable to compression fittings as far as leakage is conerned.
Ron
Copper tubing is not used for natural gas delivery.EDIT: Actually, I'm going to retract that comment pending a code check, it may just be a California issue.UPDATE: Yep, copper has been permitted by the NFGC for natural gas delivery for some time (and I should have known that since I installed some really cool gas lamps this summer using 1/4" flexible copper tubing). I think my question on this stems for the perception that there are sulfide corrosion issues using copper with natural gas.
Edited 1/2/2006 11:15 am ET by tangomike
You are right to not use PVC, if only for the reason that PVC is brittle and when you combine brittle with 135 psi you may well end in the ER.
Copper is a standard piping material for compressed air delivery systems that are under 2" in diameter. Sweated joints have more than enough strength to provide a lifetime of service at these pressures, and it's non-corrosive.
Copper will do fine. It does come in three wall thickness IIRC, ID as K, L, or M. M is the thinest IIRC and is used for heating systems. Your results may vary.
Don't forget that all your 'drops' should leave the main line heading up, then do 180 (this helps to keep water at bay. The main line should, if possible be pitched such that the water all moves to one point, where you can add a valve to drain the water. A drain valve at each drop is also a good idea, IMHO.
The water pressure at our house is 123 psig for reference.
Thanks for all the replies and informationNow I know what the options are
What kind of a tool do you run at 135psi?
I don't run the tools at 135 PSI, but plan to keep the line at full pressure and put the regulators at each drop so I can set the tools for different pressures. If I regulate the entire line down I am limited to the lowest tool pressure for all the tools, and that may not make sense.
I hope not, I have had it in my shop for 10years. Have not had a problem. Isn't the stuff rated for like 600psi
-Lou
I plumbed my air supply system with 1/2" copper & solidered joints. It has been in use for 3 years without any problems. Pressure ranges between 125 - 175 lbs.
My dad used 1/2" soldered copper. It worked well for many years. I used 3/8" black iron and it has also worked well for about 12 years. Don't use PVC. It can take the pressure, but can shatter if you bang it or drop a board against it. When it shatters, it's like and IED and you don't want to be there.
One piece of advice. I have quick disconnects on the end of each branch. Some of them are now leaking a little and the compressor runs occasionally even when I'm not using it. I'd put a valve in the line between the compressor and the piping. I posted a question on Knots about remotely operated valves a month or so ago and got the usual good reples. Someday I'll even get around to putting a valve in.
I'll keep it short. Copper.
Mike
As mentioned, PVC is a no! no! When I was a lad we had a compressor plumbed in with steel pipe. Try as we could, we could not make it leak proof. On the other hand the water comes into our house at over 200 psi. The engineer told us there was no plastic that was safe at that pressure so we used copper. Obviously we have a pressure regulator. I think I will use copper when I install an air compressor. I notice the main line bringing it here is plastic.
http://www.tptools.com/statictext/tech_notes.asp?mscssid=LQTUW0XD4L198L9TMT4M6966ETGU7GL2
Go to ...
Air Line Hookup - Metal Piping Diagram (pdf)
It's all been done before so follow the advice of TP Tools. Can't tell how many times I've been to shops where guys think it's some genetic thing about doing such things without instructions. Type L or K copper is acceptble. OSHA forbids PVC...safety thing. Drops go up then down.
Chemaire is acceptable for air lines. It's ABS plastic.
http://www.nibco.com/assets/ChmairOvrw.pdf
New guy here chiming in with my $0.02 worth. I generally followed the TP Tools layout, plumbed with Type L copper in my two-car garage-sized shop. Been very pleased with the results.
Used 3/4" around the tops of the walls for distribution, with 1/2" drops in the corners feeding filter/regulators and runs along the lower walls with periodic quick connect taps.
A few things I did:
- the compressor feeds a vertcial run via a flexible steel hose. This helps isolate the plumbing system from compressor vibration, and the initial vertical run catches some of the inevitable condensation.
- this vertical run feeds the upper distribution runs at their highest point... in other words, the pipes slope downward from this point to direct condensation toward the far end of the runs.
- taps off the distribution "system" are taken from the top of the pipe... helping to minimize moisture in the tapped off air.
- vertical drops extend down past the filter/regulator units to a valve at floor level used to drain the system.
- used plenty of sweat-type ball valves (good for 600 psi) to isolate various parts of the system.
- finally, I put unions where the compressor ties into the system and ahead of each filter/regulator unit, so it can be disassembled for maintenance.
Overkill? Maybe, but it works for me, and was fun to build :-)
Not the greatest pics, but hopefully good enough.
Wow! There isn't a spec of dust in your shop. What are you using for dust collection? Very nice shop. Do you have a pic of the missing angle?
Thanks! We just moved into our new (to us) home two years ago, and the biggest selling point (to me) was the heated detached two-car garage that was to become my shop. I'd had plans to build a shop for years at our former place, but somehow never got around to it. This one was ready-made, all I had to do was finish it out. I installed a drain tile and sump pump system (it's half underground and had a water problem), dry-locked the walls and epoxied the floor, upgraded the electric and installed the air system, then moved in the tools. I've attached the other two views.
Dust collection consists of the Grizzly unit, shop vac, and Delta air cleaner seen in view 2... though truth be told I have spent more time working on the shop than working in the shop to date (which partly accounts for the lack of sawdust)... but that's changing. The Grizz will eventually be plumbed along the wall, but for now I drag his hose from machine to machine as I work.
I just finished the wood rack seen in #2, and putting up cleats along the lower wall (same as up above) - not seen in these pics. Next is storage to hang from them. The "real" projects are just now ramping up.
Again, thanks for the compliments... this new lair of mine is like a lifelong dream come true :-)
Edited 1/18/2006 9:38 am ET by DClark
Congratulations on the shop. It's a fine setup. Thanks for the other shots. I really enjoy seeing how people layout their shops and build workspaces and storage fixtures. I really like the storage cabinet under your tablesaw extension table. Do you keep blades in the upper portion of the box?
Yes... the upper section contains several slide out hardboard panels with pegs on each side on which to hang blades... and also a space for my Freud Super Dado set in its case. Down below holds my tenoning jig. The cabinet is notched front and back to rest on the extension rails of the saw's mobile base, so it can be lifted off and easily removed if needed.
I really like my workbench which consists of a Grizzly maple top sitting on Shop Fox legs (I know... I could have built a bench... but this got me up and running quickly and you could park a tank on it and it wouldn't budge). There was enough adjustment to the legs so I could set it up at a perfect height to serve as the table saw's outfeed table. I built cubbies underneath to hold all my portable power tools in their cases (drills, sanders, biscuit joiner, etc.). On top of that is a shelf for larger stuff (like the rails for the portable panel saw). Nothing fancy, but it works.
I'm still developing my workflow, but tried to keep things flexible enough so minor adjustments can be easily made... the wall cleat system is the biggest advantage here... nothing on the walls has to be permanently attached :-)
Thanks!
DClark,
My father has used PVC in two shops and it works fine, but I am leery of the burst issue. On the other hand, couldn't PVC burst and fragment when used for water. 90psi is 90psi, does it mater if it is water or air? I suppose most water pipe is not exposed and subject to the potential impacts an air system is.
Not to steal your thread, but can you comment on the effectiveness of the Delta air cleaner in your garage based shop? I have a similar shop setup and would like to install a cleaner so I don't have to open the door and run all the warm (or cool) air out of the shop everytime I generate dust (especially sanding dust). Thanks.
If a pipe bursts with water in it the pieces of the pipe don't fly off at high speed because the water doesn't expand when the pressure is released. Air under the same pressure will expand with considerable energy throwing debris at high speed.
Most pressure testing of equipment meant to hold gas under pressure is actually tested with pressurized water so that a failure won't result in an explosion.
John W.
That makes sense, and my gut told me the same thing. Thanks for the info.
I agree with JohnWW - water is not compressable, whereas gasses are... so a rupture in a pipe carrying air at 90 psi has much more explosive force than a rupture in a 90 psi water pipe. I know a lot of folks have used PVC without issues, but I've heard too any horror stories about what can happen if a pipe gets hit or otherwise breaks to have gone that route. Copper is a bit more expensive, but to me the peace of mind was worth it... plus I needed the practice sweating pipes :-)
I'm pretty happy with the way the Delta air cleaner performs... it moves quite a bit of air, and seems to keep the airborne dust down to a minimum. As an aside... I first had it installed the other way around - blowing toward the back of the shop - but it kept blowing out the pilot light in my ceiling mounted gas heater! Once I turned it around the problem went away... go figure.
I found this discussion very informative. I am building a new shop and am at the point of installing my air line. I had in the past used PVC for air line, and had no issue with it for over 15 years with the same lines, but I guess I may have been the lucky guy that never had a bad issue. I will now, thanks to you guys, move on to something better than PVC and for sure safer.
I know this is not the issue you are discussing but water comes in three forms, -- solid like ice, liquid like potable water and gas like steam. Steam like the compressed air that you are talking about is extremely expansive. And with the elevated temperature can cause terrible destruction in an explosion. Though I've not experienced it a natural gas man once told me that a water heater with a defective thermostat and a defective popoff valve can pretty well level a two story building. That gives me some respect.
I have been using a copper pipe system for at least 15 years, without any problems, and I have no intention of changing to a black pipe system, though I must admit that I worry about the comment of a professional plumber who told me that there could be a danger if there was a small fire confined to one area of the shop, but away from the compressor itself. He said that the heat might be sufficient to melt the solder at a fitting, then the blast of air -- the compressor would still push huge volumes of air through -- would feed the flames and "accelerate the destruction of the garage". Hum..... at the time, it sounded to me like a "one in a million" situation, but I'm really not sure.
Any thoughts ?
Boisfranc, Canada
I agree... though I might place the odds at greater than "one in a million" against this happening. It would take a very hot fire to melt a copper solder joint... particularly with today's lead free solders that require the use of a mapp gas (not propane) torch. If you've got that kind of fire in your shop you already have a big time problem... a little additional air won't make that much of a difference IMHO.
BTW - I always turn my compressor off and close the main valve when I'm not using air in the shop... for no particular reason (my system doesn't "leak down" if left pressurized), I'm just anal that way. :-)
Edited 1/21/2006 9:27 am ET by DClark
Re: solder. use lead-free; it is considerably stronger than the leaded type still used in some applications (like electronics).
Everything you always wanted to know about copper tubing... a great resource:
http://www.copper.org/resources/pub_list/pdf/copper_tube_handbook.pdf
Oh, and definitely assemble with the 95-5 lead free solder typically used for water plumbing applications these days. According to the handbook, such joints are good for 625 psi at 150 degrees F (on pipe up to 1 inch in diameter - the largest likely to be used in an air system). The old 50-50 tin-lead is only good up to 150 psi.
My system's assembled with type L tubing... which itself is rated at around 500+ psi in the 1/2" and 3/4" sizes I used. I think I'm good.
Look at the FWW Tools and Shops Issue 2002, p. 51. The author, Roland Johnson recommends black pipe. Titled "Plumbing a Shop for Air", it's a good article.
Edited 2/1/2006 3:27 pm ET by CTWoodWkr
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