Compressed air supply in workshop.

[cwarrix]

I want to put my air compressor in the back of my shop, but would like to have outlets in the front and maybe a couple of hanging coil type hoses hanging from above.

What would be a safe pipe type to use? My neighbor used copper to do his small shop, is that safe? What about PVC? Also, what size pipe should I use, 1/2, 3/4, etc.?

The total run will be about 40 feet or so, plus whatever hose I plug into it.

Thanks in advance!
Chuck

[twstanley]

I have seen pvc used, just make sure your don't exceed the psi rating on it. Make sure you brace it well so you don't flex and break the fitting on the end when you tug on the air hose, etc.

[Bird]

Iron pipe is probably best, copper second, and PVC is a no-no according to all the experts because of the possibility of it shattering and blowing pieces everywhere. However, I used PVC and never had a problem. Most larger compressors come with some instructions for plumbing. Don't forget to put a drop leg somewhere to drain condensation from the lines.

[cwarrix]

Thanks for the quick reply. I hadn't thought about the bracing issue. I think I may go with something a little stronger. Thanks!

[cwarrix]

Thanks for the quick reply Bird. Not sure about cost on iron, I'll compare to copper and see what works. I don't have a lot of stuff going on in this shop, just looking for convenience more than anything. Trying to get the compressor in the back out of the way and a reel with the hose towards the front where it is easy to get to. Thanks for the tip about drainage also, didn't think of that.

Do you guys know what size pipe I should use? Is bigger better?

Thanks!

[Bird]

Personally, I'd recommend 3/4" although half inch is probably adequate for most purposes. It depends on how much compressor you have and what tools you want to run on it. Sandblasters, sanders, grinders, and 3/4" or larger impact tools need a large volume of air. Many other uses don't need so much.

[cwarrix]

It's an old compressor, all I know is it is 220V and has a 60 Gal tank. I know that doesn't tell much, but that's all I remember about it. It's about 15 years old. All I need to run is an impact now and then, ratchet, die grinder, and a tire chuck to pump up tires of course [img]/forums/images/icons/smile.gif[/img] I'm not running a body shop or doing any heavy duty work, but I don't want to have to redo it down the road either.

I noticed most of the hoses that come on reels are 3/8", but some are 1/2" I was thinking of getting a 25' hose/reel to hang from the ceiling towards the front of the shop. I think I remember somebody saying you lose pressure the longer you go... But if I use bigger pipe to feed the reel, will that help keep the pressure up?

Thanks again for the help!

[Bird]

</font><blockquote><font class="small">In reply to:</font><hr />
if I use bigger pipe to feed the reel, will that help keep the pressure up?

[/ QUOTE ]

Yes, but I don't think you need to worry about pressure, it's the volume of air moved that can be a problem. However, I don't think you'll have any problems. The compressor I had in my shop was also a 220 volt, 60 gallon tank, and I used half inch pipe, although it was only about a 25' run to my farthest coupler and less than 10' to the closest ones, and I sometimes hooked three 3/8" 50' hoses together. I had the three 50' hoses in 3/8" size, one 15' hose, and two 10' coiled hoses in 1/4" size. I'd still recommend 3/4" pipe, but for what you intend to do, half inch will work just fine.

I was repairing/rebuilding mechanics' air tools. With a 3/4" impact wrench, I could test it with a quarter inch air hose to see if it was working right, but the tool could not develop its full power because, even though I had enough pressure, you cannot get enough volume through a quarter inch hose (or even a 3/8" hose) for that kind of tool. A 3/8" hose is usually quite adequate for a 1/2" impact or smaller tool.

[Pat]

I agree with all of Bird's recommendatons. Pipe just isn't that expensive and the savings from going with 1/2 inch are not enough to warrant any possible dificulty.

Although I agree with all Bird's suggestions I want to disagree with a small part of his comments (very small part.) The problem with small and or long lines IS PRESSURE. Not static pressure but the dynamic pressure.. Your compressor may pump up top 125 - 150 PSI and you will measure that (STATIC) pressure at the end of a very long and very small diameter line WHEN THERE IS NO APPRECIABLE FLOW! The problem is that there are dynamic losses caused by flow. There is "friction" in the lines. The larger diameter the lines (and fewer elbos) the less friction is involved when air is flowing.

Do your loved ones a favor. Don't take a chance on PVC. A few bucks saved is NOT WORTH IT.

In addition to the drainable water trap, out at the delivery end you might want to consider a filter to keep anything from anywhere from getting into anyplace it doesn't belong.

A regulator as close to the point of usage as practical is far better than regulating at the compressor. A regulator at the end of the distribution line can maintain say 90 PSI over a significant range of tank pressures, even with line losses. If you depend on the regulator at the tank, the line losses will cause you grief.

My new gravity feed spray guns have regulators and pressure gauges right at the handles. For all situations with air tools that I know of the pressure will be regulated much much better with a regulator near where the air is used as opposed to the compressor if there is an appreciable length of run to the using tool. If you turn the tank pressure down to avoid over pressuring a tool then when air is being consumed the line losses will give you poor performance. If you adjust to get a good air supply at high flow rates then when you stop the tool the pressure will rise to the value at the tank which may not be safe for your tool.

I am getting ready to install my new compressor. It too is a 240VAC 60 gal. I will be installing it under a shed roof on the other side of the shops outer wall so it won't be so noisy and not take up any shop space. I was all ready to start gluing up the distribution system lnes but was advised by those with much more experienced than I to NOT USE PVC. I was told that there is plastic pipe suited to air lines but PVC isn't it and that iron is the recommended way to go. Copper was not discussed. I see no reason why copper wouldn't work but I'd think it would be cost prohibitive compared to iron, especially in 1/2 inch.

Be safe,

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[cwarrix]

Hi Pat, thanks for the input. I decided to go with 3/4 copper for three reasons, safety, it was actually cheaper than iron at Lowe's, and at least for me, it is easier to work with. I soldered many a mile of the copper stuff when I did the laundry room project.

Anyway, I have a regulator on the compressor end now and thought it might be a problem since it is the smaller 1/4" connection. It looks like they have a reducer that takes it down right out of the compressor, then into the regulator, then into the quick connect. It seemed to me like this would be a area of resistance??? In electrical terms it would be like having a circuit wired with 6GA wire all the way except for one little 6" run that is 22GA. Just my twisted way of looking at something I don't fully understand... yet!

So, the plan is to come out of the compressor with as big a pipe as I can, somehow tie into the 3/4" copper, have the water trap close to the compressor, then try to reduce bends as much as possible getting to the other end of the shop.

This water trap you and Bird mentioned, I thought it was just a valve to drain water out of the copper line, is it more than that? Is it like the little 6" section of pipe you put in a gas line to catch dirt, only with a valve at the bottom to drain the water? If that's the case, I could come out of the compressor, into a tee, a short section of pipe goes down towards the floor and into the drain vavle, and another section goes up and across the rafters to the other end of the barn/shop?

Now I have to figure out where the regulator goes... the plan was to feed a reel with 50' of 3/8" hose mounted overhead in a convenient spot in the front of the shop where most of the activity is. And with enough reach to get outside to pump up car tires, etc. If I stick with that plan, the regulator would be in the rafters with the reel... guess it isn't too bad to have to use a ladder to adjust it, shouldn't need adjusting too often. I may add a couple of additional outlets and could add individual regulators for them.

Thanks for the tips and ideas guys! This site has been a big help for all of my recent projects.

Chuck