SGropp Posted December 23, 2008 Share Posted December 23, 2008 Anybody out there have some real life experience / advice on how to properly plumb a compressed air piping system for a shop? I have a bunch of 1'' shed. 80 gray PVC water pipe. Is this okay to use in a compressed air system ? I thought the larger size pipe would give less restriction to airflow and some increased storage volume. The maximum line pressure would be 125 psi or less. I was going to use glued fittings for joints and elbows with IPT bushings for the outlets. Which way should the line drain ? Back to the compressor tank or towards the filter /regulator end ? How should the drain points be constructed and where located ? I have a secondary 80 gallon receiver that I want to incorporate into the system ,where in the run should this go ? The compressor is installed out back of the shop with a run of about 30' to the forge / fabricating area. I am not using the air to run a hammer, just small air tools , plasma cutter and paint sprayer. I am looking for help on doing this right, maximizing air flow and pressure at the work end and minimizing moisture and and condensation / icing problems in the line. Quote Link to comment Share on other sites More sharing options...
Glenn Posted December 23, 2008 Share Posted December 23, 2008 When I talked to Ingersol-Rand the tech there said NOT to use plastic for compressed air. The plastic can get brittle and fail. His recommendation was sch 80 black iron pipe, threaded couplings. Larger size pipe will deliver more volume. He also suggested that the pipes run on a slope and have a trap to collect water from the system. Just crack the valve to drain any condensation. Quote Link to comment Share on other sites More sharing options...
sidney brink Posted December 23, 2008 Share Posted December 23, 2008 I plumed the air in my shop with 1'' sch 40 pvc.25 years ago still working fine. I run 200 psi. Just allow room at each end of run for expansion . It gets longer when the shop warmes up.the first 10' is steel for heat build up.I have drop legs for moisture traps where they drop from ceiling hung main line.I also have second tank for more volume at far end of main to help large impact hammer. Quote Link to comment Share on other sites More sharing options...
ironrosefarms Posted December 23, 2008 Share Posted December 23, 2008 (edited) Years of seeing piped air in my grandfathers service station as a kid it was all black iron pipe as my wee mind remembers it was about 3/4", drain traps under every vertical rise (it was one of my jobs to drain the water out of the lines, what fun!)... Later when grandpa closed up shop dad went to work for his uncle. Uncle used plastic 1" pipe throughout his new auto repair shop, all went well for the first 16 months he was in business then one of the pipes blew at the fitting and injured a customer who was standing just outside the shop door. They dug 5 pieces of plastic pipe out of the mans chest and arm. Uncles insurance company refused payment due to the installation not being up to the standards recommended by the manufacturer of the compressor being used. Needless to say, I wouldn't recommend plastic for compressed air, black iron is going to be more expensive but won't be near as apt to being damaged by vibration, impact, or chemicals. Edited December 23, 2008 by ironrosefarms Quote Link to comment Share on other sites More sharing options...
ptree Posted December 23, 2008 Share Posted December 23, 2008 My experience is from the then worlds largest and best maker of forged steel valves and fittings 1/8" to 4". We had 2500 Hp of compressors across a 42 acre site. I was the pipefitter supervisor for about 18 months. PVC is not compressed air pipe. It will indeed get brittle, especially if the compressor has oil blowby as most recip's do. There are a few plastic compressed air pipe systems on the market, but not easy to obtain for small jobs. The best all around pipe for a small shop is schedule 40 black iron, and cast fittings. Slope the pipe to a trap. If the compressor is equipped, then back to the compressor, if not add one. Best method in piping is to plumb compressor into the side of a largeish receiver, receiver equipped with drain, plumb out the top of the receiver. Run all mains sloped to a trap. Pull all drops off the TOP of the mains, and run vertical drops down past a horizontal tap to a drip leg. Equip the drip leg with a drain. Be regular in draining, especially in an unheated shop that may see freezing. I would use ball valves for the drains as they don't tend to get damaged as easily as gate or globe valves from the grunge in condensate. Quote Link to comment Share on other sites More sharing options...
SGropp Posted December 23, 2008 Author Share Posted December 23, 2008 Ptree, Are you suggesting I put the secondary receiver tank right after the compressor tank ? or further down the line? I have heard both success and horror stories about using PVC in compressed air systems. Is it better to use galvanized steel pipe with galvanized fittings to minimize rusting problems or is it not worth it ? Thanks for all your help, this is the kind of information I was looking for. Quote Link to comment Share on other sites More sharing options...
mcraigl Posted December 23, 2008 Share Posted December 23, 2008 I recently ran airlines in my shop using 1/2" black iron. Pretty much as Ptree suggested, except I don't currently have a supplemental reciever tank. My compressor is in a tool shed behind the shop. I ran the iron pipe down the wall of the shed, underground to the shop, back up the wall and through it at about 5' from the floor. I put in a "t" vertically at that point with a Mudleg, or dripleg going down, and the filter/lubricator/regulator on the leg going up that feeds the main running around the shop at the top of the wall. the mains slope down as they go away from that vertical "feeder leg", and have a drip leg at each end also. Shop is heated, so I was hoping to get away with the one drain at the point of entry (cold air hitting warm pipe), and one drip leg at each end of the main as opposed to one at each outlet. I guess we'll see in due time. Quote Link to comment Share on other sites More sharing options...
Glenn Posted December 23, 2008 Share Posted December 23, 2008 As I recall cast are sch 40 but the heavier forged fittings are for sch 80 and above. Which is better cast or forged fittings, and why? Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted December 24, 2008 Share Posted December 24, 2008 (edited) Call me old fashioned. From the compressor I have a nipple to a regulator/trap. This close nipples to a tee ( up ). This feeds one shop line. From that I have a nipple to a cross. The cross ( 3 remaining ) feeds plasma ( top ) and other shop line ( horizontal ) and the bottom is drip. ALL the connections on fittings ( post regulator ) have QD's . I have air hose ( standard 3/8 rolled ) running to location for first shop hose, short run to plasma and other shop hose location. THe plasma has a little hundred dollar filtration unit on the back of it with a needle drain. One shop hose has a vertical stand pipe ( 2 feet long ) with fitting on top to recieve the ( UNCOILED ) air line and a nippled exit for a 6 foot hose. Bottom has a ball valve to drain. The other shop line has no drip tee. The whole system being plumbed in air hose was the FASTEST easiest way for me to get air when I bought the new compressor 12-15 years ago ( 60 gallon 14 cfm singlestage ). From one ( first ) shop line I can use the 6 foot hose for die grinder ( dedicated hanger by chopsaw ) or switch to air blower or tire inflator or butterfly impact etc. for whatever needs I have. I can also chuck on a 50 foot extension hose from there to inflate truck and or trailer tires or use tools on repair work in the shop drive. You will notice I said uncoiled feeder to this location. Coiled hose will freeze eventually. Ask me how I know this. The entire air system goes up at the compressor and hangs on nails or is supported through on ceiling joists. The compressor gets drained as regularly as I can remember to do it. I have a one foot piece of hose that goes in the bottom of the cross on end of compressor tree ( with the ballvalve on compressor in off position ) that will drain any residual that builds up. I can reach any spot in the shop with compressed air and that works for me. BTW I observed a group of millwrights do an addition to a material handling station once ( industrial size, industrial needs ). The whole thing was plumbed in plastic to connect all valving etc to the factory lines. The factory was a blow molding plastics plant. 150 lbs air 24-7 from 3 large screw compressors. All factory was plumbed in sch 40 pipe ( some welded, some screwed of course ). I mentioned the fact that plastic was junk comparitively( I was on safety team ) and was informed that THIS plastic was rated 600 lbs or some such figure and that it was made for the issue at hand. Engineers spec'd it. Glued fittings. Fast foreward a year. Some form of trauma ( can't recall ) hits piece of plastic line and of course there you have a piece of broken plastic line with 150 lbs of air coming out of it. Maint eventually killed the leak. No personal injuries IIRC. Life is full of issues like this in that many things are not safe but still purported to be and spec'd safe by people alleged to be in charge of safety. Good use of bandwidth for this thread, thank you for the time. Edited December 24, 2008 by Ten Hammers Quote Link to comment Share on other sites More sharing options...
ptree Posted December 24, 2008 Share Posted December 24, 2008 I will go over several issues asked. SGOPP, put the extra receiver, if you have one, as close to the compressor as possible. The air is at its hottest and wettest there. Air will hold only a fixed amount of water at a given temp. Some as saturated air cools a bit, it condenses water. So.. Run that compressor tank outlet line into a big receiver. Use the biggest connection in the receiver that allows you to enter from the side. Plumb in the line size of the compressor tank outlet. When the compressor is running to fill there will be a small pressure drop as the air enters the big receiver, thru the reduced opening. The pressure drop will slightly cool the air, and moisture will precipate out. Drain this tank often. In a big shop there are air pilot air drains that will drain for a bit every time the compressor runs. Galvanived pipe and fitting are not worth the extra cost in an air line. If available free or same cost go ahead. They will not protect any better than the blowby compressor oil does, if you drain the water out. Cast iron fittings are basically schedule 40. Forged steel fittings are usually not a schedule rated fitting but rather pressure class. For instance, the lowest rated fittings we made were class 2000#. These were good for 2000PSI, at the rated temp, usually 850F. These are more of a steam fitting, or other high pressure high temp service fitting. They are also oftem used in high pressure hydraulic systems for large size lines. In a petro refinery, there are millions of these fittings, but not too oftem in a small home shop. Another advantage of a forged fitting is they are not brittle, but this should not be a big advantage unless you have a forklift, that may hit the lines. We made class 2000#, 3000#, 6000# and 9000# in sizes from 1/8" to 4" and some to 8" Imagine a cast irom 4" tee, but only drilled out to a 1/2" pipe size and you would have the class 6000". Can you visualize a class9000# 2" cross? As I noted there are plastic systems rated for airline. Having been in industry since 1978, I will not use them. I will use schdule 40 black iron systems, rolled and clamped systems like Vitaulic, and for higher pressure systems forged steel and welded piping. Worked with all, and made the forged. Quote Link to comment Share on other sites More sharing options...
cami Posted December 29, 2008 Share Posted December 29, 2008 An air system can be quite simple. I don't believe in overbuilding. I, for example, only need to run some hand tools and an arc air gouger. I don't need a marvel of compressed air system design that delivers rose scented air at a perfect pressure with a dewpoint of -40 degrees. If the tools run well and the exaust air is slightly dryer than a garden hose I'm somewhat happy. Wherever I've worked we've just used hose for runs. No fuss, no muss. I recall that one place had pipe for the drops at each work station but everything else I saw was just hose....never did ever look in the compressor shed though. Sidney Brink mentioned running pipe near the compressor end in consideration of the heat at the compressor outlet. I can relate. I had a hose from the compressor to resovior on an old service truck blow out on me once. The six inches nearest the compressor head were in rough shape. It did last for a few years though... Quote Link to comment Share on other sites More sharing options...
ptree Posted December 29, 2008 Share Posted December 29, 2008 Rose scented air? I do believe in suppling clean dry air, lubricated if required as it extends air tool life dramatically. If your air arc gouge is suppling very wet air, I would think that it would be quite exciting. Quote Link to comment Share on other sites More sharing options...
cami Posted December 29, 2008 Share Posted December 29, 2008 Pardon my sense of humour. I can picture the expression you had on your face as you typed your message, ptree. I've seen it at parties whenever I've opened my mouth. Seriously: Gouging with bad air isn't too exciting, really. It's just a pain. I worked in one shop with a rotary screw compressor whose oil seperator wasn't doing its job too well and the boss just topped up the oil each shift. I could take a blow gun and draw oily lines on my work. The gougers ran fine but if you had subsequent welding to do then you had to grind or cook the oil off first. Not too efficient. I believe in thoughtful design but would caution against obsessing too. I'm not promoting the thoughtless git-r-done method but sometimes there is a point where one must just run the line and get back to billable work. Quote Link to comment Share on other sites More sharing options...
ptree Posted December 29, 2008 Share Posted December 29, 2008 Cami, No offense taken. I am more into doing things as well as I can, within the limits of my $, time and ability. I have been known to to lash ups when needed. But the original question was about plumbing a shop. If plumbing a shop, I would do it as well as possible and be done with it. I have been whipped a few times by air hose used in lieu of pipe. Not fun. I do come from the industrial tradition. I tend to try to pass on the hard learned lessons that provide max performance. In many cases, a one man, hobby shop can benefit from these lessons. If a compressor is blowing so much oil that it needs refill daily, that would indicate to me that a too high oil mist condition exists in the shop. Quote Link to comment Share on other sites More sharing options...
SGropp Posted January 2, 2009 Author Share Posted January 2, 2009 I appreciate the input on the subject. I too was trained in the tradition that the most cost effective [ time or money ] way to do a job was properly the first time around. However, not knowing any better, I plumbed the compressed air in my shop with hoses, which has worked fine for years. I got to thinking about how to do the job properly recently as we've had a long spell of below freezing weather and I've been having a lot of problems with ice blocking the lines. This means a lot of time spent clearing them or not being able to use air tools which has cut my productivity [$] for certain jobs. On overbuilding, yes it is quite possible to go to far, but we are craftsmen first and foremost and everything we do, artistic or utilitarian should reflect that skill and care and thought. If you are a professional and you have clients visit your work space , the whole set up; tools ,equipment and building should reflect that professional competence. It pays off in giving the client confidence that you can do the job you promised. And ultimately it is safer and more efficient . IMHO. I hate seeing beautiful old power hammers and industrial equipment cobbled together with whatever was laying at hand simply to'' get her done ''. Quote Link to comment Share on other sites More sharing options...
terrynewsmith Posted July 15, 2009 Share Posted July 15, 2009 in my humble opion pcv IS NOT IN ANY WAY USEABLE AS AIR LINE .. i was not anywhere close when mine failed ..it will fail from the oil in your air line and from vibration and freezing temps will make it worse very very quickley... think of your insurance company in many states it isnt legal a google search will show up some real horror storys terry it doesnt show up on xray either mine didnt just break it all broke into many sharp pcs terry Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted July 16, 2009 Share Posted July 16, 2009 I was a plumbing designer for many years and plastic pipe was never used for a compressed gas product in an industrial application. We spec'd copper or black iron most of the time with stainless steel on occasion, copper always had silver brazed joints. Yes you can run hundred foot long hoses across you shop and do just fine, lots of folk do. If you want to, fine. Now as to a compressed air system black iron with cast fittings is fine as most of the time the system is run at around 90 PSI or less as that is what most hand tools are rated for. It won't hurt you to have a 2" pipe instead of say a 1" pipe, think of it as a large horizontal receiver. Take-offs will come off the top of the pipe not the bottom or side, drains come off the bottom not supply lines, slope toward compressor and install automatic tank drain on compressor. Look for valves and fittings that are marked "WOG 125", this stands for, Water, Oil, Gas, 125 PIS and there aren't any of my air tools that run that high. Ball valves are a good idea as they seal very tight. If your shop is not heated put a heat trace tape on the pipe to keep it from freezing the the condensate. Just because we're blacksmiths don't mean we have to do things half baked.:cool: Quote Link to comment Share on other sites More sharing options...
RcRacer Posted July 16, 2009 Share Posted July 16, 2009 I installed my garage shop air using this diagram as a model. It is published on the TPTOOLS website. I get clean dry air from my IR compressor and use it mostly with a plasma cutter and air tools. The layout and filtering can be scaled to just about any setup. Use either black pipe or copper rated for pressurized use. If you are soldering joints, use silver solder and not lead. I used black pipe. Quote Link to comment Share on other sites More sharing options...
johnptc Posted July 16, 2009 Share Posted July 16, 2009 the above diagram is excellent. i vote for copper.......although it costs more its a fast to install and be reused etc. Quote Link to comment Share on other sites More sharing options...
cami Posted July 16, 2009 Share Posted July 16, 2009 Holy thread resurrection, Batman! Sadly, I am currently without a shop. I know: Wah, wah, wah. I'm strictly mobile and so the compressor goes on my truck and runs straight from a regulator into a hose; easy plumbing. By the way: If anybody has a 1000sf of shop space in the Nanaimo area with three phase power that they'll lease me for $1/year, please send me a message...serious enquires only! Quote Link to comment Share on other sites More sharing options...
48willys Posted July 16, 2009 Share Posted July 16, 2009 The way I did the shop,I mounted a 75' hose reel in the rafters centered in the building.I have a regular air hose feeding the hose reel and the regulator on the compressor.It works great for most of what we do with it,the best part is I can pull it out the front door or the back and still have enough to reach a good distance outside.Just with painting we use a hose pluged into the compressor with a disposable dryer/filter at the gun.That hose reel is the best though,the air hose never would get put up and would always be under/over/around everything.Now it gets put away. Quote Link to comment Share on other sites More sharing options...
cami Posted July 16, 2009 Share Posted July 16, 2009 48willys: I was wondering about those disposable filters. Obviously they work if you're using them...any comments about their limitations? I sometimes have to paint but it's just rails, guards, and machine parts. I want it to look good, but I won't be asking Chip Foose for a job anytime soon I'll use an extra receiver, a cheapie filter and a dry hose and things are usually fine. Amen on the reels. I worked in a shop where three welders worked on heavy equipment in side-by-side bays. Many days were fine but often, at the end of the day, we'd have our welding cables, an air line, and an extension cord each to untangle. Boss didn't spring for reels in the shop (we had them on our trucks though) but found it fine to pay us 1/4 hour a day to untangle and sweep our bays. I don't think they even did an analysis. Quote Link to comment Share on other sites More sharing options...
48willys Posted July 17, 2009 Share Posted July 17, 2009 The disposable filters always work ok for me,the only thing I can think of is you have to change them before they stop working.It's been a while since I did any painting but I think the new ones change color before they won't hold anymore water. Quote Link to comment Share on other sites More sharing options...
arftist Posted July 17, 2009 Share Posted July 17, 2009 RC Racers diagram is exactly how a proper air system is installed. Copper is suitable, but iron is perfectly usable as well. Quote Link to comment Share on other sites More sharing options...
mtnman Posted October 29, 2009 Share Posted October 29, 2009 I recently ran airlines in my shop using 1/2" black iron. Pretty much as Ptree suggested, except I don't currently have a supplemental reciever tank. My compressor is in a tool shed behind the shop. I ran the iron pipe down the wall of the shed, underground to the shop, back up the wall and through it at about 5' from the floor. I put in a "t" vertically at that point with a Mudleg, or dripleg going down, and the filter/lubricator/regulator on the leg going up that feeds the main running around the shop at the top of the wall. the mains slope down as they go away from that vertical "feeder leg", and have a drip leg at each end also. Shop is heated, so I was hoping to get away with the one drain at the point of entry (cold air hitting warm pipe), and one drip leg at each end of the main as opposed to one at each outlet. I guess we'll see in due time. I know this thread is not new, but I just found it and have a further question re the post above...I am also looking at running a line (plan to use black pipe) underground between the "auto" shop and the new smithy so I can use the one compressor to serve both locations. My concern was not being able to put a water drain lower than the underground run. Is that a problem? How did anyone address that? My underground run would be about 30 feet, and deep enough to get below the frost line and be safe to drive over on a gravel covered occasional use drive. Thanks for any and all advice, even if it involves telling me that I missed something simple and obvious!! :D Quote Link to comment Share on other sites More sharing options...
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