Compressed air lines in garage

[DonS]

Does anyone have any tips on installing compressed air lines in a garage? I have a craftsman 150 psi vertical compressor and would like to put it outside. Make a little shed for it to keep the noise down. A buddy of mine used PVC and never had any problems with it breaking...usually he keeps it at 100 psi and a inside gauge to monitor pressure. It will mainly be used for cleaning things off and filling.

 

[Glenn9643]

I've read many questions similar to yours regarding PVC, and almost every response indicated the dangers of the PVC bursting eventually. I'm looking into plumbing my shop for air and plan to use 3/4" black steel pipe or copper. My unresolved questions relate to where to put the drops and drains in the shop rather than what material to use.

 

[BillyP]

The use of PVC for a compressed air line has been discussed here before. If memory serves me correctly, most wouldn't use PVC, due to the fact it could burst.

Myself, I wouldn't be afraid to use it for that purpose. You'd need to run some type of flex line or rubber hose from the compressor to the PVC, due to vibration and movement of the air compressor. In areas that the PVC could accidentally be hit, you could use black pipe.

You could also run the PVC up high and T off and come down with metal. This way you could have several air sources throughout the building.

 

[Henro]

<font color="blue"> You'd need to run some type of flex line or rubber hose from the compressor to the PVC, due to vibration and movement of the air compressor. </font>

I found a piece of hydraulic line I picked up at TSC works well and is not too expensive. Comes with NPT ends on it that screw right into normal pipe threads...

Myself I decided to go with copper tubing. One advantage of copper is that it transfers heat best, and causes water to drop out of the air faster than plastic does. You can set up an initial vertical run, and use it as a course water separator, if you put a drain valve at the bottom...

 

[BillyP]

Henro, you could be right about the water thing. But couldn't you put a water separator right off the compressor?

By the way 1/2" schedule 80 PVC is rated at 850 PSI and 3/4" at 690.

 

[Junkman]

I would run 1" around the shop from the compressor and make the drops 3/4". Put a tee in the drop pipe for the air take off and a drain at the bottom of each drop pipe. That will be the best for eliminating moisture problems. The water filter at the compressor gets most of the moisture, but not all the moisture, unless it is big and expensive.

 

[OkeeDon]

I too have read many similar inquiries both here and on a sports car racing forum in which I participate. In every case, someone warns of the dangers of PVC bursting and shattering, but no one knows of any actual cases of that happening. On the other hand, I've been using PVC for that purpose for more than 30 years, the latest in a shop that I've had for almost 15 years, with no problems. The only thing I try to avoid is exposure to the South Florida sun. I have bumped my airlines with equipment a couple of times and broken it. In each case, it broke and the air leaked out quickly, but it never shattered or exploded, and I'm not sure I understand how it could -- even if the pressure discovered a weak spot, once that weak spot is breached, the air leaks out, and no further pressure exists.

In any case, all I'm doing is relating my personal experience, so if you do what I did and it explodes, don't blame me. /forums/images/graemlins/grin.gif

In my experience, Junkman is exactly correct in his recommendations for size and configuration. I used PVC ball valves at the bottom of each vertical drop for drainage. Just remember to keep your overhead lines at a slight slope leading to the vertical drops. Periodically let all the pressure out of the tank so any moisture in your first rising pipe/hose drains back in the tank, and keep the tank drained. I also used a pressure regulator that was combined with a water filter. If you use the air for painting, don't use a line oiler for the air tools -- the oil will get in the paint. Instead, oil each tool manually or install an oiler on the lines that are not used for painting.

 

[em14]

Here is a site that has some very good help in laying out your air system:www.tptools.com. Here is a site that has a great but very expensive alum air line tubing and fittings for the tubing. This is very nice stuff but ... it is very expensive!
Leo

 

[Keoke]

Don, I agree with you on the use of PVC, schedule 40 grey (elec) is what I use.
On the top horizontal run, consider turning the drop tee's upward and make the drop down run using two elbows
(180 deg's.). Make both ell's street type, all slip (male & female).
This will keep whatever water in your top lateral run from simply gravity dropping down the tees on your vertical drop down runs.

 

[Junkman]

The moisture is carried in the warm compressed air and only condenses when the air cools. It will still accumulate in the down pipe if you don't have drains.

 

[OkeeDon]

<font color="blue"> "This will keep whatever water in your top lateral run from simply gravity dropping down the tees on your vertical drop down runs." </font>

Well, actually, I prefer to have to water from the lateral run drop down the tee to the vertical drop down run. Like Junkman said, I use another tee in the vertical line for the air fittings and extend the drop down run past the air outlet, to a ball valve, so the water can drop down the vertical, go past the ait outlet, accumulate in the bottom of the vertical run, and be exhausted when I come along and open the ball valves. Like this:

_______
|
|
|
|
}---= (outlet)
|
|
@ (ball valve)
|

 

[Keoke]

Don, I did mine the same as you on the used drop lines, that is chuck first followed by water drain valve at bottom. However, I find the "up and then down" on the horizental helps to keep water out of the used down lines. The last down pipe is run with the tee facing down. This is where most of the water ends up has a drain valve with a bucket.

cheers,

 

[Boondox]

</font><font color="blue" class="small">( Myself I decided to go with copper tubing. One advantage of copper is that it transfers heat best, and causes water to drop out of the air faster than plastic does. You can set up an initial vertical run, and use it as a course water separator, if you put a drain valve at the bottom... )</font>

Henro -- I used iron pipe in my shop, but have since converted the shop to wood and moved the compressor to the garage, but have not yet connected it. Tell me more about using copper. Seems like it would be a lot more versatile and easy to plumb that way. Any tricks or advice you'd offer someone thinking of going that way?

TIA, Pete

 

[MadReferee]

I used copper for my compressor lines. Cold garage with one drop to to warm basement with 2 drops. 3/4" for the main run and 1/2" for the drops. I think the copper tubing was type L. All joints were soldered. Put a manifold on each drop for 3 lines and a drain valve after each manifold. Works like a champ.

 

[DonS]

Thanks for all the great information. Why not have 2 valves, put the other one on the top side of the outlet. This way you could shut off the pressure and drain the water without a big blast or having to take the pressure all the way out of the line in order to drain it. Does this make any sense?

 

[hobbyfarm]

Don,
We've had PVC for years with zero problems. Even with the pressures of a two stage compressor (175psi) occasionally just to test and try to check the pipes for weaknesses. Never had a failure. Besides, if you do, PVC is very cheap and quick to repair. For me, the worst thing about the plastic pipe is keeping your PVC cement fresh. It doesn't have a very long shelf life.
And as Henro said, don't forget to install a hose or other flexible couplng from compressor to plumbing.
Good luck!
phil

 

[Henro]

<font color="blue"> Tell me more about using copper. Seems like it would be a lot more versatile and easy to plumb that way. Any tricks or advice you'd offer someone thinking of going that way? </font>

Pete, seems like black pipe, PVC or copper tubing all would work fine. The Black pipe would likely be the strongest and the PVC the cheapest...

Like MadRef said, using copper for air is no different than using it for water. You just solder it together. One would follow the same precedures as far as running the piping regardless of what material he used I would think.

My understanding of the advantage of copper is that it allows the air being transported through the pipe to cool quicker and when the air cools it drops out moisture. This is the theory and I am sure it is sound, but how practical it is in the home shop is another thing. It could be that the air, especially if tools requiring high cfm are being used, travels from compressor tank to the tool so fast that there is little difference in the amount of moisture that drops out, whatever the pipe material is. Now if one were using an air brush, the story might be different...

For me, copper offered a little more mechanical strength than PVC (could be just in my mind though) and was easier to work with, and cheaper, than black pipe.

I have no regrets using copper, just as others who have used PVC or iron pipe have no regrets either... /forums/images/graemlins/smile.gif

 

[v8dave]

Depending on your access to tools and soldering ability, copper is quicker to assemble than black pipe and its threaded junctions. I've always had to have the hardware store cut my pipes and thread them. If you have a power saw and threader, maybe black pipe wouldn't be so bad.

Maybe it's me but, I never get black pipe gas lines or galvanized water lines to come out to the correct length. Then there is the assembly order of putting together threaded pipe. I tried unions, but they are their own little ****. Then I gave up and used copper and PVC on water lines.

Changing the layout of copper is easier than black pipe. If you want to add on to a threaded system, you end up with the dreaded unions.

Of course PVC is the easiest to install and change. But, given the amount of PVC sprinkler lines I've repaired, I'll probably use copper, instead of PVC, for my shop air simply because of its greater durability to physical abuse.

 

[Jeff396]

Keoke,

The article that I used to install my lines at my last two houses said to do it just as you say. Take the pipe up and out of the horizontal line, put a drain at each drop and a final drop and drain at the end of the horizontal to drain the main line. I also put a drain on the riser up to the ceiling. One thing that wasn't said was to be sure to pitch the main horizontal slightly down so all of the water accumulated will actually go to that final drain drop. Another thing they said was important was to have at least 50' of line before you have any drops. They said this was to give a good bit of the water time to condense out of the air before you used it.

I still need to put lines in my current house. I sure would like to use something other than black pipe this time!

Jeff

 

[MadReferee]

</font><font color="blue" class="small">( Another thing they said was important was to have at least 50' of line before you have any drops. They said this was to give a good bit of the water time to condense out of the air before you used it.)</font>

This is not really practical for the average basement or garage shop. A water filter just after the tank and a drain port at the end of each drop will be more than sufficient.