Compressed air system question

[L5wolvesf]

I believe I read here where EMT can be used to create a compressed air system. But I can’t find any details since a search of “EMT” doesn’t seem to get me anywhere. That would fit into my “budget” as far as the tubing goes. Is this correct and what kind of fittings are use to plumb it?

System would be roughly 40ft with one leg going to a 3/8 hose reel for inside the garage and another going to a disconnect for a 50 ft hose to outside when needed. There would be a possibility, in the future of another 20 ft leg to the other side of the garage.

FWIW, I have a 24 by 24 garage with 8 ft ceilings.

Thank you.

 

[sberry]

< No, its not air rated. Get some 1/2 black pipe or a couple air hoses and string them up.

 

[James-W]

No, its not air rated. Get some 1/2 black pipe or a couple air hoses and string them up.

I agree, as far as I know EMT (Electrical Metallic Tubing) is only used to run electrical wiring thru and nothing else.

 

[southalabama]

I've got a buddy that just uses air hose ran on a purlin in his metal building with a manifold splitter on the end. He's not painting nor sandblasting.

 

[JRC3]

I hear some guys use PVC. I also hear some disagree with using it.

I kid, I kid...

 

[RAYJAY]

I hear some guys use PVC. I also hear some disagree with using it.

I kid, I kid...

 

[Cyberbear]

EMT or PVC is not recommended for air pressure, the PVC has been known to cause damage when it explodes. Harbor Freight has hoses for cheap, but my personal preference is 1/2" American galvanized pipe, which is less prone to rusting than black pipe, which is why they don't use black pipe for water. Black pipe was originally designed for low pressure natural gas, I'm told.

 

[Firebrick43]

How the hell would emt hold air? You can't thread it, it's not thick enough. Sure you were not thinking ridgid metallic conduit?

 

[md21722]

Black iron or copper would be my picks, never heard of anyone using EMT and can't imagine the results. Can also get a length of 1/2" rubber as sberry suggests. I use the 1/2" stuff at Harbor Freight, cut to length, and use hose barbs. Once I had a HF 1/2" hose that was only 7/16" ID. I knew when my hose barbs wouldn't fit so I returned it.

 

[RAYJAY]

EMT or PVC is not recommended for air pressure, the PVC has been known to cause damage when it explodes. Harbor Freight has hoses for cheap, but my personal preference is 1/2" American galvanized pipe, which is less prone to rusting than black pipe, which is why they don't use black pipe for water. Black pipe was originally designed for low pressure natural gas, I'm told.

the galvanized is not good to use for air because the coating will come lose and screw up your air tools,

a good plan is tp tools pdf for lay out and items needed

http://www.tptools.com/tech-metal-piping.dlp


http://cached.tptools.com/Images/airline-piping-diagram.pdf

 

[Cyberbear]

I've never experienced a problem of any kind with the galvanize coming off of the pipe used for air lines. Perhaps the pipe quality on the east coast differs from that sold here on the left coast. My only problems experienced was when I used black pipe which rusted and clogged my pre-filter before going into the regulator. Out here natural gas was once responsible for flaking galvanize, hence the use of black pipe for gas only. But, nowadays I understand that the gas suppliers have long ago fixed that problem by a reformulation of the chemicals used in gas delivery.

 

[LS6 Tommy]

...my personal preference is 1/2" American galvanized pipe, which is less prone to rusting than black pipe, which is why they don't use black pipe for water.

You have that backwards. Black pipe is used for water all the time. Galvanized is not (anymore) and is not recommended for compressed gases due to the flaking of the zinc coating. The zinc is more corrosion resistant than the bare black pipe, but once it does corrode it peels off.

Tommy

 

[L5wolvesf]

OK, I guess I misread something regarding EMT. My bad.

 

[rburke65]

No....EMT not used for air. Just do the black pipe and forget the rest.

 

[sanddan]

If you want a leak free system, use copper.

If you want to chase leaks, use pipe.

Been there, done that.

 

[lakeroadster]

I just installed the air piping in my barn a few weeks ago and used galvanized pipe. I've used galvanized pipe in air line applications since the early 1980's... never had an issue with it flaking?

The pipe I bought this time, from Home Depot, was stamped "South Africa". EPA issues here I guess.

If you put the filter regulator at the end of the run, any particles will be caught by the filter.

the galvanized is not good to use for air because the coating will come lose and screw up your air tools........[/url]

... Galvanized is not (anymore) and is not recommended for compressed gases due to the flaking of the zinc coating. ...

Tommy

Question for the guys that say the galvanize is an issue with air tools... you running a filter?

 

[justanengineer]

JMO but one of the most overdone things on this site is plumbing for air. In a large shop thats 100'+ on a side sure, it makes sense to build a distribution system. On smaller garages like the OPs it violates my two favorite rules of engineering/design/fabrication/construction - 1. keep it simple stupid and 2. if aint broke, dont fix it. Personally I'd simply recommend placing a 50' hose reel above the compressor fed by a short flexible whip and maybe a second whip leading to a blast cabinet if you've got one. My last 700'-odd shop I did similar, the compressor closet was located next to the main door and also held a 3-hose reel unit, one was water (and unused), the others were 3/8" for small jobs and 1/2" for the large. The filter/dryer hung off the reel and a simple bypass allowed me to cut in/out dried air as necessary for painting. With one unit next to the door I could go anywhere in the garage and most of the way down my driveway as well. I also didnt have an unsightly run of pipe getting in the way, and when I moved I didnt have money/time wasted nor the same unsightly pipe for buyers to question the purpose of.

 

[sberry]

Get no argument from me with that.

 

[Stuart in MN]

JMO but one of the most overdone things on this site is plumbing for air.

The most overdone thing are the lame jokes about PVC for airlines.

 

[nehog]

I've got a buddy that just uses air hose ran on a purlin in his metal building with a manifold splitter on the end. He's not painting nor sandblasting.

This is what I have. My reel is on the side of my Rotary lift, and covers most of the shop. I have a second manual roll-up hose terminated at the compressor too. I've had to replace that hose once after about 10 years which was cheap and easy to do. My current hose is a cheap POS Craftsman one that I took off the roll-up because it was too stiff when cold.

 

[sberry]

The engineer hit on something above that is really the heart of all my babble. There is no real words to explain what it is but it is a reflex load calculation and backtracking to the same stuff the masters knew.
I done it all wrong, one of the first air lines I ran was inch, then I got the size and demand decent but used plastic etc, lots of stuff, seen plenty of others systems along the way and even very "farmer" or thrifty and under outfitted at times on a shoestring.
I even found a couple choke points in a previous system that I am none too proud of and really was hurting our big gun performance.
It was rare even in our shop and something that wouldn't be a factor on hobby shop. I could have/should have used a few more 3/4 on the thing I got now and it was mainly due to the fact I had free stuff I didn't realize and it would have saved me some 1/2 I was short on,,, but in 100 ft wtf does 18 inches mean or what does a pound savings on main mean on hi pressure air, to top it off only 2 turns, maybe 3 in the whole deal.
I will agree there can be restrictive and drop issues but they are very minor and not worth the 10X effort invested in them.
If I had to do it all over again would spend some time truly understanding demand and adequate supply, this includes the number of hydrants all of it.
I am for tailoring the situation and if I can really save work or money by piping and wiring including risk reduction I am on it like flies on ****. It would be a matter of walking to the shelf, don't even got to go to the store but,,,,,,,,,,,,,,,,, today I give further consideration to the end than I used to as I learned the hard way,,, go bolt off, get invested in 2x as much as I need. I have painted trucks with 100 ft of 3/8 hose screwed to the pipe and a single coupling. I know masters got a circuit or 2 general in their garage they added when they moved in and a 10 cable they use on occasion to a welder outlet.
Got another one has 20 tools, 2 circuits. I might have added another but the truth is he could get by with one. new don't think of 25 ft circuits as needing upsizing and I don't run 2 in a box every 4 ft. I have done this, got 4 where 2 would do, used way less demand than I originally thought and none of the future proof.
Found out in the end I shouldn't have piped for every possibility but got to a good location and put a hose reel on it. I ended up with a reel anyway and could have saved a lot on pipe.

 

[LS6 Tommy]

JMO but one of the most overdone things on this site is plumbing for air. In a large shop thats 100'+ on a side sure, it makes sense to build a distribution system. On smaller garages like the OPs it violates my two favorite rules of engineering/design/fabrication/construction - 1. keep it simple stupid and 2. if aint broke, dont fix it. Personally I'd simply recommend placing a 50' hose reel above the compressor fed by a short flexible whip and maybe a second whip leading to a blast cabinet if you've got one. My last 700'-odd shop I did similar, the compressor closet was located next to the main door and also held a 3-hose reel unit, one was water (and unused), the others were 3/8" for small jobs and 1/2" for the large. The filter/dryer hung off the reel and a simple bypass allowed me to cut in/out dried air as necessary for painting. With one unit next to the door I could go anywhere in the garage and most of the way down my driveway as well. I also didnt have an unsightly run of pipe getting in the way, and when I moved I didnt have money/time wasted nor the same unsightly pipe for buyers to question the purpose of.

That's pretty much what I have, minus the filter/dryer. I don't do any painting, but a filter/dryer is on my list.

30' reel on the left side of the back wall by the nose of the car/bench, 50' reel just inside the roll up door for driveway work and a 20' coilhose with a quick connect and a blow nozzle over the top of the bench attached to a self retracting cable reel.

Tommy

 

[sberry]

For the op, get 25 ft of hose, hook one end to the ball valve on the comp the other to a filter/regulator and a hose reel to that with a coupling on the user end of that. All screwed with the connector at the tool. I know several that worked for decades this way and never were short of air, made a living in garages working on cars.
I had a bud did this, 1 regulator cost about 30$ and a piece of hose and about 5$ in fittings. 30 years, every day. I probably would have tailored a bit but he didn't care and retired it eventually and now it doesn't matter.
My own case I have a larger shop, all the effort is accumulative and adds up and I am totally unpredictable. I have seen poor compressors and crappy long hoses and it isn't that they don't work or there is too much loss but its usually fugged up and totally inconvenient to do basic functions, wait for some **** to pump up to service a tire, a 20 minute ordeal, you cant do fleet **** that way. Had 2 guys fix a tire this morning, it ***** and is work but it helps if the wire wheel is plug and play and a valve to use the tire machine, 4 air processes on demand, impact, wire wheel, tire machine and inflation all served with 3/8 hose. The machine is plumbed but its 1 thing at a time. Never used more than a hose would provide.
I have done a shitload of sandblast with 3/8 hose.

 

[sberry]

I done painted trucks from 200 ft of 3/8. Stuck this gem in and used 25 hose to the gun.

 

[sberry]

I worked in a power plant where there were 1000's of air tools. They had all the hoses, welding leads and argon, 120V lights all strung and hung and you wouild find an air hoise and put in a T , never cared about what was down the line r where it came from, there was **** strung all over and could reach it all with a short piece or 2 of hose, 1000's of these fittings basically everywhere in reach, may be 3 or 4 hoses go thru a doorway just kind of all strung together and parasitic like a octy.
They had a manifold in a given area with a dozen or 2 of these teats on it and it started with sections of hose and T's. Same for argon, used screwed fittings for it though. Find a hose not being used at the moment, put a Y in it with another valve or section of hose to a flow meter. With welders they had banks, each side for polarity and ******** lead to resistor units you hooked on to an unused lead you could find in the area. The lower you set it the hotter it got. You could short circuit and cook off of them. I heard they use inverters now which would have been a ********* from a cost comparison but at that point I don't think anyone gave much of a shirt.

 

[coljar]

I won't even try to use EMT for air. I've got black iron in my garages and in 2 years, some of the black iron pipe in the older garage will have been in air service for 90 years, which is when my grandfather opened the business. With that said, at the plant I work at, there are miles of galvanized air lines, some of which are supplying instrument air to millions of dollars worth of machinery, but with filters at each machine.

 

[sberry]

Hundreds of grinders, a few at a time ran constant, no one gave a **** what pressure drop was or what the voltage loss was by a bunch of engineers building a nuke. We has welding rod heaters too. If you needed sticks with your work order you went and collected it from an oven and in to a hot box that was in a semi trailer, full of these things, had a cord to them all, hundred maybe 150 of them on shelves plugged in to the wall. They put hot rod in it and you carried it to your work area and plugged it in to any place you could find, I never thought it at the time I guess but these Y connections for electric we plugged them in to, they may have had a 30 twist on them, its been so long I don't recall but it was a bunch of cord hung with 2 way or Y as I remember. There is a guy on SFT forum I worked with in passing there at the same time.
.

 

[sberry]

It had 2 shifts for a while. It wasn't 2 continuous shifts but everyone worked on a separate set of projects so there were toolboxes like foot lockers all over the place. They issued air grinders from a tool crib inside the plant itself and anything else was issued from a window, just went up and asked for a tool. Need a hammer, a drill bit, a wrench and 3 grinding wheels go get them, had a crib with guys handing **** out.
Had pre sharpened tungsten.

 

[padroo]

I worked in a steel mill for 40 years, all air, gas and oxygen was black pipe. Black pipe is cheap and easy to work with.

 

[Ironhorse74]

JMO PersonallyI'd simply recommend placing a 50' hose reel above the compressor fed by a short flexible whip and maybe a second whip leading to a blast cabinet if you've got one. My last 700'-odd shop I did similar, the compressor closet was located next to the main door and also held a 3-hose reel

I have three hose reels mounted and hard plumbed for 1500 square feet. There are other air outlets available. I try to keep tye hose reels near where I am working. I think air hoses laying all over the shop floor are a tripping hazard and not safe.

Just my .02

 

[MushCreek]

I think the distribution depends upon the usage. I'm putting together a machine shop in my barn, and you need air at each machine, sometimes multiple ones. For example, a milling machine with a power drawbar and pneumatic mist coolant system will need three, with the third one being for an air hose to blow out chips. It would be a PITA to constantly be detaching 'the' air hose and dragging it over to another machine. It would be like having one outlet, and using an extension cord for each machine. I'm not gonna go crazy, but I'll have a drop at or near each major machine, and an overhead reel for car work.

 

[jubilee]

I have a 2' x 3/4" braided hose coming off compressor going into 3/4" copper. Copper goes vertical for 10', then turns and goes horizontal for 15' (with 6" drop), then turns vertical again and goes down 6' where it terminates with a manifold and 50' hose reel. I have valves/traps on both lower ends of verticals to drain moisture and junk. Works very well. Don't use any filters other than screw on for paint guns and I probably don't need to use those. 30 years and many many hours of running air tools with no problems.

 

[engineer2]

I like copper because it is so easy to work with and doesn't corrode.

 

[4EyedTurd]

While we're asking... if you had a 20x30 shop with an 80gal compressor in the far corner of it and two hose reels. Where would you mount your hose reel(s)?

 

[sanddan]

I hung one reel near my weld table. It's a 50'er so it will easily reach 1/2 of the shop. The second one I hung at the opposite end near my lift. I also have several spots I can hook up a hose if needed.

 

[maintenancemike]

EMT or PVC is not recommended for air pressure, the PVC has been known to cause damage when it explodes. Harbor Freight has hoses for cheap, but my personal preference is 1/2" American galvanized pipe, which is less prone to rusting than black pipe, which is why they don't use black pipe for water. Black pipe was originally designed for low pressure natural gas, I'm told.

I won't knock you, but it's not recommended to use galvanized pipe for compressed air, due to flaking that ends up in your tools and paint.
Copper, black pipe, and now the new systems use aluminum tubing in some really nice systems. I recently did a 125h.p. system in 2" copper. Very pricey.

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