Air line question

[Iroc-Z]

So I scraped some money together to put an air system in my garage. I have a 60 Gallon 2 stage imc compressor from 1992 that I restored. Picked up a 3/4 regulator/water regulator. I went out an picked up 3/4 copper pipe for the whole garage. Here is my question. I picked up Type M copper before I read anything on it. Should I return it and get the thicker copper pipe? Or should I just go with it? I looked around my work at the copper lines and found both the red type copper and blue type copper lines. I have never had a problem with any of the air lines at my shop. What would you guys do?

 

[PT Doc]

What are the max pressures for each type?

 

[930dreamer]

From HD.

http://www.homedepot.com/buy/cerro-...er-straight-pipe-3/4-m-10.html#specifications

 

[Iroc-Z]

From HD.

http://www.homedepot.com/buy/cerro-...er-straight-pipe-3/4-m-10.html#specifications

See I have heard that water psi is different the air psi. Not sure if that is true.

 

[uncletater]

just go back and change it in for some PVC pipe and be done with it.

 

[930dreamer]

http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf



Compressed Air—Use copper
tube of Types K, L or M determined by
the rated internal working pressures as
shown in Table 3. Brazed joints are
recommended.

 

[Iroc-Z]

So I should be good. Its not like my garage is a high volume shop with lots of use and abuse.

 

[csp]

Brazed joints are recommended.

I find this recommendation interesting based on the idea solder melting in the joints of the copper during a fire, but what about that hose reel that so many have plumbed into their air line setups?

Call me crazy but I'm pretty sure that hose is the weak link in a fire. It's also probably safe to assume that not everybody has a shutoff in front of their hose reel, or if they do, that they shut it off after every use.

 

[Iroc-Z]

That is a good point on the hose reel

 

[akdiesel]

Most of these rulings / laws are set up for buisenesses via OSHA and other organizations, but they give good guidelines to follow for your own safety as well.
As for your type M copper pipe, it will be fine provided your psv and pressure switch are working correctly.

 

[Steevo]

Yeah, you can use type M, but you'll be limited to only 700psi working pressure . . . .

 

[Iroc-Z]

Awesome. I am going to get started this weekend.

 

[billsr4]

you can use 3/4 pvc rated a 350 psi and its a lot easier to work and a lot cheaper.

 

[Iroc-Z]

you can use 3/4 pvc rated a 350 psi and its a lot easier to work and a lot cheaper.

That is ok. I am not interested in taking a chance on pvc. At least if this copper blows out it will just crack and not explode.

 

[Angelfire]

The copper.org link was an interesting read. Seems there really is validity to having soldered joints being weaker than the pipe, particularly if a 50/50 type solder was used. At a temp of 150, which is highly conceiveable near the compressor, the max working pressure is 150. Compare that with brazing which is ~3 times that amount. Just interesting is all....

 

[darkk]

See I have heard that water psi is different the air psi. Not sure if that is true.

Pressure is pressure, 5 PSIG is 5 PSIG Air or water. If you used pex tubing it does not explode like rigid pvc....and it's cheap to buy, easy to install.

 

[larry_g]

See I have heard that water psi is different the air psi. Not sure if that is true.

What makes the difference is stored energy. Compressed air contains a lot of potential energy and that is what causes the 'explosion' when the line or tank ruptures. When a line or tank containing fluid under pressure ruptures the fluid flows out but since it contains no energy it does not 'explode' or more correctly expand at a high rate of speed. That is PART of the reason that PVC can handle water safely but not gasses.

lg
no neat sig line

 

[RCStocker]

I have used PVC pipe for 30 years in my own shop. I never had more than 120 psi.
PVC is not allowed at all in a commercial shop. When I went to a 2 stage compressor with 175 psi I changed to copper pipe.
If you have see all the pictures of blown PVC you would not use it. I have 2 cousins and an Uncle that are doctors. I should say were. They have all passed on now. They told me about people having the PVC lines blow. One patient lost an eye. PVC gets old and brittle. If it is in the sun it only takes several years until it snaps when you cut it.

For a small home compressor PVC is a great way to go but you did not hear it form me. Do not put it in a commercial shop of any kind. I don't think there is an insurance company that will honor their policy if you use PVC. It does not meet code. Remember code is a minimum standard you can always make things better.

 

[hidollartoys]

Pressure is pressure, 5 PSIG is 5 PSIG Air or water. If you used pex tubing it does not explode like rigid pvc....and it's cheap to buy, easy to install.

Not entirely true. Air is considered a "compressible" fluid and water is considered a "non-compressible" fluid. Each have different characteristics when under pressure. And thus the rupture reaction will be different. also there is the mechanical differences in each when flowing in a pipe, I.E. water hammer, weight, etc.

 

[GTO]

Why not go with Black Pipe,it's cheaper.

 

[BD1]

If you want a slick super CLEAN job, use PROPRESS Fittings . No soldering required.
http://www.pexsupply.com/Propress-Fittings-892000

 

[Iroc-Z]

I went with copper for the look. I am going to polish it up after its done and clear coat it.

 

[sands35]

Why not go with Black Pipe,it's cheaper.

Just put a dryer right after the compressor. Also need to have dirt legs (as on NG lines to a furnace) to catch water and/or contaminants.

 

[Iroc-Z]

If you want a slick super CLEAN job, use PROPRESS Fittings . No soldering required.
http://www.pexsupply.com/Propress-Fittings-892000

Those are nice. I don't have the tool to compress them.

 

[GreyOwl]

And the Rigid 18v crimper is ONLY $2500.00+ on sale. A little much just to do airlines

 

[ThreeJ97]

Some places rent the pro press tool for the day.

 

[BD1]

Some places rent the pro press tool for the day.

The local supplier by me use to rent it for $20.00 a day. Fab all the pieces, crimp when done.

 

[Bwana]

Why not go with Black Pipe,it's cheaper.

Apparently not anymore. I'm replacing my PVC system with copper. Prices yesterday at Lowe's had black pipe at about $2/foot, copper at about $1/foot. Really surprised me, what's up with that?

Edit: BTW, I had two sections of PVC splinter as I was cutting them out so I think it's a good idea to replace it

 

[akdiesel]

A side note about PVC or rather ABS. I know the two are different material but I was informed by a house inspector a month ago that referenced some ABS we had to replace in the house that was leaking. The pipe had about a two foot long split. Thought it was due to some of the Skin So Soft product the renter had been using, but he said that back in the late 80's the manufacture of the ABS had a known fault in the product where the seems were and simply sent it to Alaska (that other third world country) to pass it off. This was when the house was built. Sorry for long spew, but some tidbit of info and could also reflect PVC.