Any tips or advice for setting up air supply lines for a small shop?
I’m in the construction phase of making a shaping room and have made a separate room for a compressor. I’ve seen different ways of running supply lines from the compressor and would like some input. The compressor won’t be more than 15’ away and won’t go any higher than 100psi.
I’d like to use a hard line with an outlet for a short hose. I’ve been using regular air hose for a supply line but have had my share of problems with cracked leaking hose and bad connectors. I’ve seen galvanized pipe, copper pipe and even pvc but I’m unsure what to use and what size pipe.
PVC will probably be the least expensive. Make sure you check the rating/schedule on it so it will hold the psi that you have your compressor set up for. I have a friend with a t 2 1/2 car garage workshop that did what you are doing and it worked out great. He has a quick disconnect fitting appx. every 4 feet. He mounted/strapped the pipe on the exterior of the dry wall in case there was a leak and it would be easier to track down and fix.
Check out: www.tiptools.com. They have a guide for installing air lines that explains why pipe is the best. If its not in the catalog anymore pm me and I can send you a copy. Metal pipe helps moisture laden air from your compressor to condense therefore allowing your water separator/filter to work. Its very good info. I have used pvc for quite some time and am currently switching to pipe.
If you want it to last do it with copper. You won’t have great draw so 1/2" will work just fine. All you have to do is a little soldering. You’ll never get any rust or corrosion if you use all brass and copper fittings. I did Stretch’s factory about a year and a half ago and he hasn’t missed a beat. Pneumatics are the way to go for much of the sanding process, not to mention all the other things that air operated tools do much better than anything else.
random orbital sanders with various pads produce a very predictable sanding procedure, with less effort. The tools are so much lighter than the traditional Milwaukee equipment used over the years. This is not to say there isn’t a place for angle grinders and polishers. They do have there place.
small variable speed high speed air grinds with the light 2" discs are invaluable for fine work. Then there the work of spray color work, cleaning tools, blanks and yourself up with blasts of air pressure. You also get to pump up a tire or soccer balls in a jiffy too. A compressor is a damn important tool in any custom fabrication shop. My little pancake compressor has been going for 15 years with only one trip for service. It enables be to fin tune foils and blow the rinse water out a classic old fly reel like nothing else can.
Google “pvc air lines” and you may rethink using it even though it is the cheapest way to pipe your system…
I recall reading that it could build up static and explode when used as an air delivery system…though I’ve seen it used with no problems in other shops - so far…
Personally, I use a hose reel that lets me pull out hose to a desired length and reels it back in to keep it out of the way when not needed. Use decent hose, clamps and fittings and you shouldn’t have problems. Stay away from cheap, discount, off-brand stuff.
I worked at a shop in San Diego that used PVC. A PVC T joint in the spray room cracked and blew the plug that the quick-connect was attached to. Luckily I had just walked out of the room when it happened.
The shop that I currently work at uses copper lines.
If you want it to last do it with copper. You won’t have great draw so 1/2" will work just fine. All you have to do is a little soldering. You’ll never get any rust or corrosion if you use all brass and copper fittings. I did Stretch’s factory about a year and a half ago and he hasn’t missed a beat. Pneumatics are the way to go for much of the sanding process, not to mention all the other things that air operated tools do much better than anything else.
No Worries, Rich
Mahalo Halcyon,
I did a little research and it sounds like copper is the way to go. Stories of exploding pvc with shrapnel were enough. The runs from the compressor are pretty short so it shouldn’t be too expensive. I know how to solder copper and have all the little tools to do the job.
If you don’t mind I do have a few questions?
Did you use type L tubing?
I read on a auto shop forum that it was smart to put a drain at the bottom of a drop to release the condensation. Did you put drains at the bottoms of the drops and if so what kind, brass ball cock or something else? I have a water/oil separator that I use for spraying paint and was thinking of putting it at the end of the line where I’m going to spray. It is a small unit so I don’t want to put it before all the supply piping. I’m thinking that it isn’t that big of a deal to dry my air for blowing foam dust off of blanks and tools.
Why did you use 1/2" instead of 3/4"? If you don’t know the answer to that questions then it doesn’t matter. If the 1/2" is working for a big shop like Stretch’s then I’m sure that my little closet will be fine.
Thanks for the help and sorry for the brain picking.
I was checking online and found pictures of exploded pvc piping used for compressed air. Evidently it is a huge no no for supply piping. Most of what I found was that most people would eventually change their systems to copper. Even the black pipe and galvanized piping would cause rust scales to form which would create problems. Copper is the best/safest for long term use.
Howzit DMP, Copper may be a choice in dry climates but being one who does a lot of plumbing work I have seen copper pipe that has flaked til it burst. It probably takes a long time before it happens but in Hi it will eventually. Had it happen at a Mauna Kai condo in Princeville. Aloha,Kokua
Know you asked Halcyon but, just had a couple of points re: your questions…
So long as the seals are good (no air leaks), easiest is to use ball cocks for drain/release valves.
Condensation is formed in the pressure tank so, the norm is to have the separator as close to the source as possible. Why let it into the supply system. I’ve been spraying lacquer for years with no problems with the separator at the tank outlet. If you are worried and want / can afford it, with a piped system, put a separator at each end.
The longer the run (pipe/hose) from the compressor the less the pressure at the outlet (gun). I forget the exact formula but it’s something like 1 psi loss per 5 ft. of run. If you want your gun spraying at 30 psi and you have a 30 to 50 ft. run from the tank - and the outlet pressure at the tank is set at 30 psi - you probably only realize 20 to 25 psi +/- and are spitting globs. Plus, your hose is 1/4 or 3/8 “… so, no use using anything over 1/2” pipe because your compressor is only working harder to keep the larger 3/4" pipe up to pressure and you’re probably getting more loss at the gun.
Copper is the “Caddilac” but really an unnecessary expense for most shop air systems. Copper usually bets used in situations where the air is going to be used for direct human consumption like hospitals, etc. Galvanized or black steel will work just fine. After building or re-building about 16 or 17 manufacturing plants over the last thirty years around the country that is the M.O. Tips for using hard airlines are: 1) Keep as many unnecessary bends (street els, 90’s, etc) out as possible as the lower your line PSI and help create more moisture in the stream. 2) Depending on your compreesor type and the part of the country you are in (climate) you may need more than a good inline water trap on the system and have to put an air dryer unit in the system. Usually a system running under 3HP will only need an inline water trap.
SS
PS. I expect lots of guys are going to say they have been using PVC for the last 25 years and nothing has ever blown up. I am happy they have been so lucky, but I would just very gently and quietly say to each and everyone of them, “You are insane.” PVC airlines are illegal in every state I know of becuase of their propensity for exploding. When a copper or steel line wears out (rare) they spring a pinhole leak.
I build such systems out of Type “L” copper with “Bridgit” non-lead alloy solder – it’s the best there is. All threaded fittings are brass. Such materials are code for commercial use.
Filters with cut off valves on there inlet side and drip legs with a blow off valve on the drip leg adjacent to filters are a good call. Get first class filters. The ones from Harbor Freight are junk. Go to an auto paint supply for them. I use Smith-Cooper ball valves exclusively they’re worth the price. Make all of the terminal outlets finish with a 1/2" FIP x Copper drop eared 90 el. This will make for good secure place to draw the pressure from. Fittings that are insecure and flopping around spell trouble. Strap all lines every four feet. All runs should be graded to drip legs ahead of each manifold. All main manifold lines should be graded downward to last outlet. No running traps in lines. Such a system purges itself with daily use at each sight. For long runs with lots of outlets run 3/4" with 1/2" side outlet tees. The lines with low use 1/2" is fine. Master regulator placed right at main tank outlet.
If you going to have more than two sights drawing air simultaneously run the main line in 3/4".
All the outlets will step down to 3/8" but the idea is not to starve anything down by telescoping and have enough compressed air in reserve so you can work for a while without running out of pressure.
For my uses 85 p.s.i. works fine. Stretch runs his tank (it’s a monster) at a higher pressure but all the lines run about 90 to 95 p.s.i. Having a fairly good sized holding tank can make all the difference.
Another thing I may add to this thread for those who are using compressed air for painting, blowing dust off boards ect. and specially doing epoxy work is abating contamination from rust, oil and water in the air lines.
This filter is something I swear by.
It forces the air thru a roll of toilet paper and by doing so it removes particles as small as .01 microns.
thanks for your expertise. I would use galvy or black pipe if I lived closer to someone that could accurately cut and thread the pipe. Copper although expensive will be easier for me to fabricate and install. It will be overkill for sure but I want to set the system up and not have to worry about it for a long time.
Thanks for the tips. I’ll probably upgrade to a better moisture separator and put it at the compressor. Compressor is a 30 gal. belt driven 220 unit, forgot what the hp’s are.
My runs will be 10’ to one room with 2 outlets and 15’ to another room with 2 outlets.
I can see that 1/2" is the way to go. I didn’t know that there was a pressure drop in hard line pipe with air. I thought that was exclusive to liquids from friction loss.
i would use PEX …its for water plumbing …but hold like 250psi
you can use the stainless rings and the brass connectors…supple plastic is not so brittle…and its much less expensive than copper…but then again copper never goes down in price…
It took me a while I had to read your post several times but I have a pretty good picture on what I need to do. Thank you for the specifics on the ball valves.
My system is going to be very small so the separator at the compressor will be the ticket.
