Plumbing in air compressor lines... tips? tricks?

[Andy Perreault]

Hi All, I just bought a 7. 5 hp 230v air compressor. I have a concrete pad on the side of the garage to mount it on, and I will build a shed around it. So... I will be plumbing in the lines to various places in the garage where I will have quick disconnects. What do you guys think, should I use heavy gauge PVC pipe, should I solder together copper pipe, or go with 'black pipe' that is used for natural gas? The maximum pressure rating on the compressor is 140 psi.

Any "make sure you do this" or "never do that" advice or "here's what I did" advice?

Thanks in advance.

Andy

 

[Oil Burner]

Andy,

I can tell you what we do at work, as it is an industrial environment. You can find plastic pipe to hold those pressures, but they may not stand up to impacts. We use black pipe with threaded ends. Problem is, without a threader, you can't cut the lenghts easily and thread them. One guy here just did his line at home with copper and it turned out real nice. I think that is the best for home use. it is durable and easy to work with. I made him a dryer with dessicant inside to keep his air nice and dry. that would be my only suggestion. have fun and enjoy your new shop air!

~Jason

 

[BV]

I have heard of plastic bursting and sending fragments flying so when I do mine it will be black pipe or copper. I'm thinking the copper would be better since it would not rust if moisture was present.

 

[emarsh]

another thing you can do to prevent excess moisture in the tank is to connect a timed electric solenoid valve on the bottom of the tank. Cost is about $115 and run the drain line into a 5 gallon plastic fuel can with a valve at the end partially shut off and weighted. If you start with 2 gallons in the can, the moisture accumulated in the tank will keep the can full enough so that all you will hear is bubbles when the solenoid goes off. Adjust the timer as needed and you will save a bundle of dessicate or whatever type of AFTER dryer that you intend to use. I did this on all of our compressors at the plant and won a good idea award and some cash.

 

[Oil Burner]

you can also get a condensate separator for about $80 or so. just make sure you have a good installation on all lines and fittings as vapor pressure is different from air pressure. if there is a leak, moisture will get in.



-Jason



emarsh, great idea on your plant air system. we just installed 3 new sullair compressors with plc controls here and they are lightyears ahead of our old equipment.

 

[Philip]

I used 3/4" copper for my air lines. I used electrical conduct hangers to attach it to the walls.

 

[Paul Herioux]

Andy,

I went through this about two and a half years ago when we were opening the new shop. We ran it in 1" copper from the tank out around the perimeter and down the center of the shop.



Heres my list of suggestion:



1) Make sure the the enclosure around the compressor is well ventilated. You need to keep this room below 90*F if at all possible. Higher temps will lead to excessive condensate in the air supply.



2) Get a good water seperator. Make sure it is rated for a sufficient amount of flow for your application. It also needs to be mounted a minumum of 5' from the compressor to allow the compressed air to cool so it will work properly. If running copper I would suggest running the section from the compressor to the seperator with fin tubing like they use for base board radiant heat. A good heating supply shop can get in up to 2".



3) Have a rubber hydraulic hose made to run from the compressor to the shop manifold. If you run the copper right to the compressor it will eventually crack from vibration.



4) Bring the manifold into the shop high and run the perimeter with a drop of 1-2" per 10'. At the locations you want hoses run a drop leg straight down. Drop legs should be 1/4" larger than the largest impact you plan on using. 1/2" gets 3/4" line, 3/4" gets 1" line, etc. . With 3 of us working in the shop and myself owning the only 3/4" impact, the 1" manifold is adaquit. When we bumped up to 4 techs for about 9 months I wish we had ran 1 1/2" instead. With the other 3 techs using their 1/2" guns if I pulled the trigger on my 3/4" theirs would nearly stop. Of course I am running an IR 261 off of a 1/2" hose off of the manifold. 1100 ft. lbs. feels real good, just make sure you are holding on with both hands.



5) Each of these drop legs need to extend 6-12" below the port for the hose and terminate with a valve. This will act as a water trap. In a commercial shop enviroment I would drain these daily.



6) For quick couplers I would suggest the Milton H-style for increased airflow. These are harder to find but the A-style and M-style connectors found in most shops will drop through the center of an H. If the dealer I used to work for would have let me use them I wouldn't have needed to buy my 3/4" impact.



7) For hoses I suggest 3/8" with 3/8" fittings if using up to 1/2" impacts. For 3/4" imacts use 1/2" hose with 3/8" fitting on the tool end and 1/2" fitting screwed directly into supply manifold.



Sorry it was so long, this should cover the basics.

Feel free to PM if you have any questions.

Later,

Paul

 

[LSMITH]

I have put together a couple shops (industrial) and Paul has it pretty well nailed down. The only thing I would add is use pipe dope on any threaded connections, it won't let you down.

 

[Andy Perreault]

Thanks for all the replies, guys. The biggest air tool I have is a 1/2" impact wrench. This won't be for a commercial shop, it's just lil' ol' bald-headed me futzing around in my shop. But I want the system to be set up in a quality manner. It'll be a while before I start with the plumbing. I spent the day planning out how the shed around the compressor will be built, as well as going to Lowe's and Home Depot to buy the lumber, plywood, etc.

Thank you Paul for all of your advice. In the instructions that came with the compressor, they recommended setting up a fresh air supply from the outside of an enclosure to ensure a cooler intake. I think I might do that. The compressor is on the east-facing side of the garage, and there are many tall trees just behind (south) of the garage, so the compressor shed will only be in the sun for the early part of the day in the summer, and it probably won't get much sun at all from lmid-fall to mid-spring. But I still might rig up an outside air source, maybe an automotive type air filter mounted on the side of the shed, enclosed in a hood to keep the rain off.

The instructions also mention using a flexible line because of vibrations, as Paul noted. I guess the next thing will be to look in the yellow pages for a company in the Seattle area that supplies such things as commercial size water separators, etc. The stuff I saw at Lowe's looked pretty cheezy.

One thing I will do is get some water drain valves that are standard on most newer semi-tractor and trailer air tanks. Instead of turning a valve, they're spring loaded and have a lanyard attached to them that runs to a convenient location. Just tug on them and they let air out. When you let go, they spring closed again, a lot like honking an air horn. By using one of these at each water trap and at the bottom of the compressor tank, draining the water off will be convenient and will only take a few seconds. That'll be better than having to go around back in the rain, opening the shed, and reaching down into the spider webs to open a drain cock.

Thanks again, Andy

 

[Sled Puller]

You definately want a metal pipe, to draw the moisture out of the air.

For painting, run your drops, straight up, then elbow them down with a regulator and water seperator at each one.

Depends on how serious you want to get.

TiP Tool, a paiting/sandblasting outfit, in Ohio has diagrams for air lines.



I did mine in black pipe, threaded by hand, have seen copper.

 

[Paul Herioux]

LSMITH, thanks for catching the pipe dope for any threaded fittings, its one point I forgot. Make sure it is the paste style and not the tape. If a piece of teflon tape gets inside the line then get blown through into an impact it will tear it up.



Andy, when you plumb the outside air intake make it easy to dismantle or reroute to inside air. If the outside temp gets down to 25*F or lower you will want to reroute to inside air. One of the dealers I worked for tried pulling in outside air all year. Any time the temps dropped below freezing we actually started getting more water and were having problems with the valves in the compressor head. Don't really know why this happened, just know it did.



Later,

Paul

 

[QRTRHRS]

One thing I did not see mentioned is the mounting pads for the compressor. There are rubber pads available that are placed on the floor for the compressor to sit on when you bolt it down. What they do is dampen the vibration to minimize the chances of the legs starting to crack where they get welded to the body. The material is a special composition not just a hunk of rubber so get the correct product. I called up Campbell Hausfield to order mine.



Did you get the regulator yet? Make your you get one rated for your max air pressure.

 

[Scot]

I built a fairly efficient drier.

3/4" flex from compressor to drier. Drier is made of 3" PVC. Build an inverted 3" U as tall as you have available space. Mine is 8'. Put a T on the bottom on both ends. Reduce the horzontal legs of T to inlet and outlet size. Run outlet back up to ceiling or purlin. Reduce bottom of T with bell reducers to 1/4" NPT and add a drain valve.



Branch lines end in a T that acts as a trap also. I have only gotten a bit of water to the secondary traps once after blasting about 500 lbs of sand.

 

[Andy Perreault]

Originally posted by QRTRHRS

One thing I did not see mentioned is the mounting pads for the compressor. There are rubber pads available that are placed on the floor for the compressor to sit on when you bolt it down. What they do is dampen the vibration to minimize the chances of the legs starting to crack where they get welded to the body. The material is a special composition not just a hunk of rubber so get the correct product. I called up Campbell Hausfield to order mine.

Did you get the regulator yet? Make your you get one rated for your max air pressure.

My compressor (Campbell Hausfield) came with rubber mounting pads.

With the help of my Dad who is visiting here, the shed is now complete and painted, the 230v wiring is done, and the compressor is anchored to the floor. We're even putting a 120v outlet and a light in the shed. My Mom says, "If you keep going, you're gonna end up putting a wet bar and a TV in there!"

Next is the plumbing, regulator, etc. Dad found 6 ten foot lengths of 'Schedule 40, 450 psi' 3/4" PVC pipe behind the garage. They were leftover from a plumbing project last year and I had forgotten about them. I think I'll go ahead and use them.



Interesting idea, Scot. Trying to visualize what you're describing, I figure you have the supply from the compressor being input at the bottom of one of the legs of the upside down "U", and the line running into the shop coming up from the bottom of the other leg? And you have Tee's with drain valves on each leg? I would be able to duplicate that, because the back wall of the shed is almost 8 feet high. The shed is a little too big, because the previous owner of this house had a horizontal tank compressor, and mine has a vertical tank. The concrete pad was already there, so we built the shed to the same width and depth, only taller than the original (the original shed was gone, but I could see the outline of it in the paint on the garage wall). So, I will have a some storage space in the shed for whatever. Don't worry, I won't keep any flammables or dangerous items in there. I was thinking about standing up the wheelbarrow in there.

Thanks for all the ideas, everyone.

BTW, I just noticed that in my original post, I said I bought a 7. 5 hp. I realized when looking at it today that it's a 7. 0 hp.

Andy

 

[DaveN]

Don't cheat on the pipe size

Make sure you use large enough pipe. Most of the time you'll never notice it, but if you ever start using two tools at once, you'll want the larger size, i. e. 3/4" or 1". it's always better to go a little big, the larger pipe acts as storage as well, so it makes your tank a little larger.

 

[PHuckleberry]

My compressor sits in a shed outside of my shop as well. I ran 3/4 inch flex copper tubing from the compressor, through the wall into the shop and connecting to hard copper pipe on the wall. Same stuff after that, drains, chucks and so on. In the summer I open the door to the shed and turn a fan on to keep the 'pressor cool.

 

[illflem]

I built a drier similar to what Scot described, all it really is is large pee trap, the large pipe slows the air velocity so moisture doesn't get pushed though into the lines but rather ends up at the bottom. Connected the bottom up to a solenoid valve with a timer that is adjustable from one to sixty seconds on every one to twenty-four hours, three seconds twice day seems to be plenty. The drain at the tank bottom is plumbed to the same valve. Cost less than $50 from Grainger. Filter water separator/pressure regulator is next in line.



The door to the insulated for sound plywood compressor housing has several 3'' holes in it with a furnace filter behind it, never have had to clean the compressor's filter.



On the 3/4'' and 1'' black steel supply lines I drilled and tapped 3/8'' ports for the quick connects and extension hoses rather than fool around with a bunch of tees and bushings. This way you can also install the connectors exactly where you want without cutting and threading pipe. The same can be done with PVC. If you do want to use a tee drill and tap either slip or threaded PVC plugs to the desired outlet size.



At the work benches the quick connects are under the benchtop, no hoses running on top of the work area, same goes for electrical outlets.

 

[merryman]

I too have heard of PVC shattering and sending schards of PVC all over a guys shop. I used 3/4 copper, but sure wish I had heard some of these suggestions befor putting my system in. Now with 3/4 copper all the way around a 40 X 60 shop with quick connects every 15 feet, I don't want to start redoing it.



Vaughn

 

[Scot]

Andy, I will try and send you a picture of my drier this weekend.

 

[merryman]

Scott;

If it is convenient, I would appreciate a picture of your dryer also.

Thanks

Vaughn