L or M copper pipe for air lines?
- Thread starter 49chevys
- Start date
malibu101
Well-known member
L is a thicker wall than M.
I don't know much else about the differences.
In this case I'd think bigger is better.
I don't know much else about the differences.
In this case I'd think bigger is better.
snorky18
Well-known member
bigger is not always better.
thicker walls=smaller ID=more flow resistance
also thicker walls=higher costs (~50% more IIRC)
also thicker walls=takes a bit longer to heat up for sweating
take a look here:
http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf
as long as type M meets your pressure specs, and it should, there is no reason I can think of to go type L. Stick with M.
thicker walls=smaller ID=more flow resistance
also thicker walls=higher costs (~50% more IIRC)
also thicker walls=takes a bit longer to heat up for sweating
take a look here:
http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf
as long as type M meets your pressure specs, and it should, there is no reason I can think of to go type L. Stick with M.
djjsr
Well-known member
Another "M" user here. No problems.
t4runner
Well-known member
Why copper? Every shop I worked in used iron pipe just make sure you use a water separator. I guess I should ask this is for shop air lines right
Givl Reggin
Banned
*Actually* I think most use schedule 40 galvanized pipe and threaded fittings.
If you're intent on using copper you'll want Type K, hard drawn - it has a much higher burst rating.
Galvanized?
Never seen it used.
Been told to avoid galvanized as pieces of zinc get into stuff.....
Mastermind
Well-known member
all galvanized at the last couple places i've been. only place i've seen copper is buddies dad's shop, but his son in law is a plumber and it was in the truck.
Isn't pipe diameter standard so a thicker wall copper pipe would have a larger od but the same id? No?
foolishpride
Well-known member
I believe the OD is standard on the different types of copper pipe. Which makes the ID different for the 3 types. This way, copper fittings can be used for all the types of pipe.
snorky18
Well-known member
^^correct
gmwelder86
Well-known member
For air lines silver soldered type l or k to be by the ca plumbing code. Think compressed are in a fire. Typical soft soldered joints will melt around 500 deg. Have that let go and a massive amount of oxygen gets released.
Shootingblanks
Well-known member
I just completed this task this past weekend:
black iron
I was contemplating copper but because of price I opted for the ole and reliable black iron pipe.
This layout provided here was very helpful:
http://www.tptools.com/StaticText/airline-piping-diagram.pdf
My main line is 3/4" inch black pipe and my drop lines are 1/2".
Ordered a regulator, air filter and water separator to install on my two drops.
Next project will be installing a phase panel and running better electric to the garage. Hope to upgrade to a much larger compressor next year. Maybe a Quincy, Eaton or IR.
I was contemplating copper but because of price I opted for the ole and reliable black iron pipe.
This layout provided here was very helpful:
http://www.tptools.com/StaticText/airline-piping-diagram.pdf
My main line is 3/4" inch black pipe and my drop lines are 1/2".
Ordered a regulator, air filter and water separator to install on my two drops.
Next project will be installing a phase panel and running better electric to the garage. Hope to upgrade to a much larger compressor next year. Maybe a Quincy, Eaton or IR.
mrobins297aaa
Well-known member
I just completed this task this past weekend:
black iron
I was contemplating copper but because of price I opted for the ole and reliable black iron pipe.
This layout provided here was very helpful:
http://www.tptools.com/StaticText/airline-piping-diagram.pdf
My main line is 3/4" inch black pipe and my drop lines are 1/2".
Ordered a regulator, air filter and water separator to install on my two drops.
Next project will be installing a phase panel and running better electric to the garage. Hope to upgrade to a much larger compressor next year. Maybe a Quincy, Eaton or IR.
nice job
mrobins297aaa
Well-known member
normally copper water pipe is ID and copper refrigeration pipe is measured OD, thats why a lot of the sizes the fittings are not interchangable.
rlitman
Well-known member
Actually, you've described the difference between "pipe" and "tube".
Pipe is measured on a nominal OD.
Tube is measured by an actual ID.
rslaback
Well-known member
The way I learned it (and teach it) is that pipe is based off ID and tube is off OD.
RECox286
Well-known member
Politics and Religion...
My two scents:
I use sched 40 galvanized. If you want to use copper, I would get the
heaviest wall I could. OD of k,l,m is all the same, they use the same
size fittings. ID is the one that is different, but it is such a small
difference that it won't make any difference. You can always go up
one size of pipe, from 1/2" to 3/4" if you are that paranoid, but when
you get down to the quick couplers, well, the air is going thru a 1/4"
hole. I would try to get all brass fittings, rather than rely on the
cheaper copper fittings.
Hope I have ruined your day by giving you another something to think
about.
Oh, BTW: I have never experienced any problems with my 1/2" galv
plumbing. I did put in water traps just before the quick couplers,
and have never gotten anything but water out of them in the 30 years
or so that I've been using the setup. Also, never had any air tools
falter b/c of the 1/4" couplers that are available most everywhere.
The other good things; no rusty pipes, inside or out, and I would have
to check prices, but the cost was comparable to copper at the time.
I have experienced pinhole leaks in some of the copper water pipes
in the walls, and basement of my home, where as, I have never had
an air leak, or NG leak, for that matter with the galv piping.
Uncle Bob
My two scents:
I use sched 40 galvanized. If you want to use copper, I would get the
heaviest wall I could. OD of k,l,m is all the same, they use the same
size fittings. ID is the one that is different, but it is such a small
difference that it won't make any difference. You can always go up
one size of pipe, from 1/2" to 3/4" if you are that paranoid, but when
you get down to the quick couplers, well, the air is going thru a 1/4"
hole. I would try to get all brass fittings, rather than rely on the
cheaper copper fittings.
Hope I have ruined your day by giving you another something to think
about.
Oh, BTW: I have never experienced any problems with my 1/2" galv
plumbing. I did put in water traps just before the quick couplers,
and have never gotten anything but water out of them in the 30 years
or so that I've been using the setup. Also, never had any air tools
falter b/c of the 1/4" couplers that are available most everywhere.
The other good things; no rusty pipes, inside or out, and I would have
to check prices, but the cost was comparable to copper at the time.
I have experienced pinhole leaks in some of the copper water pipes
in the walls, and basement of my home, where as, I have never had
an air leak, or NG leak, for that matter with the galv piping.
Uncle Bob
djjsr
Well-known member
Yup.
Go buy a fitting for 1/2" tubing and you can use it on any 1/2" tube. The wall thickness changes the inside diameter. Go to the Copper.org website and you'll see the difference in the wall thickness between K,L and M.
The fittings not interchangable size to size. But the fitting are all the same. If you are at a plumbing supply house and need a long turn 90* for 1/2" ID copper pipe you ask for a 1/2" 90. Go up the street to the Refrigeration supply house and you need to ask for a 5/8" 90. For some reason one trade does it by ID the other by OD. 3/4" plumbing is the same size as 7/8" ACR, 1" plumbing is the same as 1-1/8"ACR and so on. 3/4" ACR would technically be 5/8" plumbing, but I don't believe that term actually exists.
Last edited:
bob15
Well-known member
Be careful when using "tubing". I understand you're talking about copper pipe and I will also call it tubing; however, some people might get your message confused with soft copper refrigerant line, the flare-able copper tubing, which is outer diameter measured.
bob
mrobins297aaa
Well-known member
Mike your probably right but if I remember right 3/4" water pipe was interchangeable with 7/8" ACR and that was the only size were the fittings were actually the same below 1".
its been a while since I did any of that work but I do have a 5 gallon bucket of ACR fittings in the barn, I'll have to go out there and check them against plumbing fittings. I just don't think you can put a 5/8" ACR elbow on to a 1/2" plumbing pipe and it will fit............I'll let you know if I'm wrong.....lol
djjsr
Well-known member
mrobins297aaa
Well-known member
I was wrong, your right, its that 3/4" ACR that can cause you problems because there is no 5/8" plumbing..........when I matched up the different sizes it came back to me. if your running 3/4" ACR and need a 90 your not going to find one at HD. Thats why I always had some 3/4" ACR 90's on hand.
jvitez
Well-known member
I tried pipe dope once on a water plumbing project with copper NPT fittings, and everything leaked. I took it all apart and used Teflon tape: good for 4 years so far.
So many people on GJ talk about black pipe. No one around here sells any actual pipe, at least not in easily accessible stores. An HVAC gent told me to go to a pro HVAC supply store. Home Depot and Princess Auto sell the fittings but not the pipe.
Where do you guys get your black pipe?Provincial
Well-known member
I got my black iron pipe from a commercial plumbing supply company. Not a wholesale supply, but one that caters to professionals. It is commonly used for natural gas piping and fire sprinkler piping. Another use is to make stair railings.
I used 1" for my air lines and 1-1/4" to make stair railings in my shop.
I used 1" for my air lines and 1-1/4" to make stair railings in my shop.