Gettin ready to plumb the new shop for air, and wanna do it right the first time. Went to check prices on copper pipe, and didn't realize that there were 2 different types. Lowes had type M and Type L. Only difference I could tell was wall thickness. Question is, will the thinner stuff be ok for running compressed air lines? Any other suggestions?
Copper pipe for compressor lines.
- Thread starter StinkBug
- Start date
bosskong
Well-known member
I can't see any reason why the thinner type M pipe wouldn't work fine and I've heard of plenty of people using it for compressed air. According to Lowes, the 1/2" Type M copper pipe that they sell is rated to 850 psi.
I'll agree that bigger is usually better and if money were no object, I'd get the thicker stuff. But money is tight atm, so I'm about to install type M piping in my garage unless I hear of a good reason not to. Has anyone actually had a failure while using compressed air in type M copper piping or are you all just being ****?
I'll agree that bigger is usually better and if money were no object, I'd get the thicker stuff. But money is tight atm, so I'm about to install type M piping in my garage unless I hear of a good reason not to. Has anyone actually had a failure while using compressed air in type M copper piping or are you all just being ****?
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GeorgiaHybrid
Well-known member
The 850 psi rating is for static liquid pressure, not compressed air pressure. When you heat copper pipe to solder it, the pipe properties will change (you are annealing it) and it will become softer and the pressure values will change.
Having said that, I used type "L" when I ran my lines but if you use type "M", the worse thing that will happen is the pipe will split. Unlike other line types (the white stuff), the line will not shatter and send out shards of metal. I prefer the thicker material as my compressor is on 24/7 (which is why I plumbed the shop....) and I did not want to have a failure in a line that would cause the compressor to run for 24 to 48 hours without me knowing about it.
Having said that, I used type "L" when I ran my lines but if you use type "M", the worse thing that will happen is the pipe will split. Unlike other line types (the white stuff), the line will not shatter and send out shards of metal. I prefer the thicker material as my compressor is on 24/7 (which is why I plumbed the shop....) and I did not want to have a failure in a line that would cause the compressor to run for 24 to 48 hours without me knowing about it.
Wingnut65
Well-known member
I just researched that yesterday and found info at copper.org. Go with Type L!
Here is a link to their online 'Copper Tube Handbook' for identification of copper tube. Clikc on the "(See Table 1)" blue link and a table will pop up with info on approved applications. They do not list Compressed Air for Type M copper, only Type L and Type K. http://www.copper.org/applications/plumbing/techref/cth/cth_1stand_id.html
If I use copper, I am going to follow their recommendation.
Here is a link to their online 'Copper Tube Handbook' for identification of copper tube. Clikc on the "(See Table 1)" blue link and a table will pop up with info on approved applications. They do not list Compressed Air for Type M copper, only Type L and Type K. http://www.copper.org/applications/plumbing/techref/cth/cth_1stand_id.html
If I use copper, I am going to follow their recommendation.
spongerich
Well-known member
Just use PVC. What's the worst that could happen?
1969
Well-known member
Devilbiss recommends black iron over copper. My shop is plumbed with black iron, the new stuff, plastic or aluminum with the special fittings looks easier to install, no threading or sweating of joints. More $$$$$$ though.
rburke65
Well-known member
PVC is good enough......kidding of course. This topic has been covered to death and back.
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Steve in Mi
Well-known member
The tables indicate all 3 will handle the pressure however the thicker wall may offer an added measure of protection from physical abuse.
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StingRay
Well-known member
Type M is fine. I have worked in many shops with plain old M. There has never been a pipe blow out. We've had regular solder joints get yanked off from abuse though. I'm talking 75,000 square foot shops that have been in operation for 20 years. Now if you are going to run 175 PSI or larger diameters than 3/4" then L would be appropriate. Use a silver bearing solder and away you go. Like said if it did let go then all it would do is split and you'd have a helluva noise. You will not get a brittle fracture with schrapnel like you would with some plastics. If you get a bargain on L go for it otherwise it's a waste of money. I'm about a **** as you get when it comes to safety and doing it right and am a Mech Eng Tech by profession. I researched all of this and yes I consulted the copper handbook. I plumbed my shop in M and I'm not losing any sleep.
Charles (in GA)
Well-known member
Go to the Copper Tube Handbook, by the Copper Development Association.
http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf
Page 9, lower RH corner will tell you to use either K, L, or M pipe for compressed air, depending on pressures.
Pages 25 and 26 will have charts of L and M pipe in various sizes and pressure ratings at various temps for both drawn and annealed condition.
The table on page 28 will show you that it is probably unsafe (due to pressure ratings of the joints) to solder with 50/50 Tin-Lead solder and that you should use 95/5 Tin-Antimony solder.
LOOK AGAIN!
Select the "select the right tube for the job" link
http://www.copper.org/applications/plumbing/techref/cth/cth_2select_recom.html
Then scroll to the bottom. Blue links there take you to the same tables I reference above in the complete handbook, pages 25 and 26.
Charles
http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf
Page 9, lower RH corner will tell you to use either K, L, or M pipe for compressed air, depending on pressures.
Pages 25 and 26 will have charts of L and M pipe in various sizes and pressure ratings at various temps for both drawn and annealed condition.
The table on page 28 will show you that it is probably unsafe (due to pressure ratings of the joints) to solder with 50/50 Tin-Lead solder and that you should use 95/5 Tin-Antimony solder.
LOOK AGAIN!
Select the "select the right tube for the job" link
http://www.copper.org/applications/plumbing/techref/cth/cth_2select_recom.html
Then scroll to the bottom. Blue links there take you to the same tables I reference above in the complete handbook, pages 25 and 26.
Charles
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trbomax
Well-known member
When I built my shop in ohio in 1973 I used "M" and 50/50 solder.I put all the lines in the walls.Never had a leak or failure,its still working now because my son is there useing it.
Wingnut65
Well-known member
Thanks Charles for the info on the copper selection table. When I first found that table, it was in Greek. Now, after research, I understand the difference in the Annealed VS Drawn pressure calcs. Looks like Type L or Type M would work for small DIY sized compressors.
jeff
jeff
Grumpy365
Well-known member
I am using ACR for my air lines. Go to your local refrigeration supply company for a price. Also refrigeration supply houses carry 20' sticks.
nehog
Well-known member
Years ago I used air-hose when I had no money but a few extra hoses. Lasted about 10 years before I ripped it out. Most of it was still 'good' when it came out, a couple of spots were swelled a bit.
Uh, no I'm not recommending that as a solution!
NewShockerGuy
Well-known member
EXCELLENT information.
I'm glad I found this so that I wouldn't buy/do the incorrect things! Now to price stuff out!
-Nigel
bixxjs
Well-known member
Why use copper pipe? I work in a heavy industrial environment and we use plastic pipe and pushfit fittings.Fabrication is easy as you only need a simple alligator type cutter for the pipe and various bends,adaptors and fittings are available.
If you need to move the pipe work it's just a matter of isolating the air and simply pulling the pipes/fittings apart.
If you need to move the pipe work it's just a matter of isolating the air and simply pulling the pipes/fittings apart.
matt_i
Well-known member
Box store is everywhere. Having 10' pipe lengths shipped & delivered residentially adds extra cost. Also, my guess is the system you use is sold on the benefit of requiring less labor (push pull tug etc) but is actually a higher material cost to balance.
pancho400cid
Well-known member
Get ready for a shock.
I used copper.... no threading, good for pressure and corrosion... but it ain't cheap.......
My set-up is quite small and I still spent like $300.00 or so.
73RR
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I'll stick to black iron.
Stuart in MN
Well-known member
I'm always curious about how seven year old threads get dug up.
MScott
Well-known member
Thread Shovels!
Something else to consider for those trying to decide between Type L and M, the M can bend and squirm as you try to attach a hose to an air fitting (plug in) while the type L doesn't seem to.
As for price, see if you know anyone with a discount, belonging to a car club can help greatly with that.
If you are serving or have served in the military Home Depot gives 10% off of most things.
Several others do as well, but as with most places, you have to ask for it.
Lets have a teachable moment.
Everybody who is nervous about soldering copper because it anneals, or because you heard from a guy who overheard in a bar that solder ain't strong enough for compressed air service, or you can't solder copper line well enough to hold water raise your hand.
If you live in NY City and are scared the Fire Department will burn your building to the ground because you didn't buy a License for your compressed air system just start digging yourself a Safe Spot with the thread shovel. Given the Daily STUPID **** I see, I'm with the IAFF on this.
OK, Anybody in the group with your hand up ever heard copper tubing can be glued together?
Products like Just for Copper have only been on the market for 10 years. Wallyworld, Sears, Homer Desperate, Blowes, Menards and Amazon all sell it.
Actually, it's a binary adhesive, not a glue, but we only cover that in the Advance Class for extra tuition. Plumbers and refrigeration guys hate this product because it works. It's one of those things taxpayers funded developing for NASA, back when they still went into space, and it WORKS well. It also adds no annealing to the joint, is vibration resistant, and offers little chance to set the surrounding structure on fire as you use it.
Since I lean to Socratic teaching, Google is your friend, pick your brand, and give it a try, unless the tube system will be carrying the 400 class of refrigerant gases.
Everybody who is nervous about soldering copper because it anneals, or because you heard from a guy who overheard in a bar that solder ain't strong enough for compressed air service, or you can't solder copper line well enough to hold water raise your hand.
If you live in NY City and are scared the Fire Department will burn your building to the ground because you didn't buy a License for your compressed air system just start digging yourself a Safe Spot with the thread shovel. Given the Daily STUPID **** I see, I'm with the IAFF on this.
OK, Anybody in the group with your hand up ever heard copper tubing can be glued together?
Products like Just for Copper have only been on the market for 10 years. Wallyworld, Sears, Homer Desperate, Blowes, Menards and Amazon all sell it.
Actually, it's a binary adhesive, not a glue, but we only cover that in the Advance Class for extra tuition. Plumbers and refrigeration guys hate this product because it works. It's one of those things taxpayers funded developing for NASA, back when they still went into space, and it WORKS well. It also adds no annealing to the joint, is vibration resistant, and offers little chance to set the surrounding structure on fire as you use it.
Since I lean to Socratic teaching, Google is your friend, pick your brand, and give it a try, unless the tube system will be carrying the 400 class of refrigerant gases.
tlmartin84
Well-known member
I'm using HVAC Refrigerant grade copper for my condenser coil at 150psi. HVAC lines are charged with gas well above 150psi............
Don't see why it would matter.
Don't see why it would matter.
Spareparts
Well-known member
My system was installed 30 yrs ago, my trunk line is 3/4" L why, because I had it, all "T" and 1/2" drops are M and all tubing is anchored about every 6' except where there is a joint and it is clamped there. I added about 40' to the trunk line to make it a loop system and that was also type M. I run 175 psi and have never had a single leak. I think the biggest reason for me not having problems is that the system is mounted securely to eliminate vibration and not hanging anything on it.
What type of plastic pipe (not pvc..obviously )...lol
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73RR
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It might have been started a long ago but the information is still good for the many new guys who actually bother to use the search button.
New shops get built every day and having air is a good thing.
For those interested, PEX can also be used for air lines.
Odd thing I've observed over the last 40 years; Just about every tractor trailer rig going down the road has plastic air lines for the brakes. They got red ones and blue ones, and even plastic hoses from the tractor to the trailer.
Most building air operated valves for the heating system have had plastic tubing instead of copper for 30 years too.
You too can buy it, be prepared to spend the money you saved on tubing for the fittings, and unlike copper, you can't assemble the system with adhesive.
Most building air operated valves for the heating system have had plastic tubing instead of copper for 30 years too.
You too can buy it, be prepared to spend the money you saved on tubing for the fittings, and unlike copper, you can't assemble the system with adhesive.
simpler=better
Well-known member
I use PVC 1/2" hoses almost every day-they're great!
tlmartin84
Well-known member
One other thing...........
Have you guys notice a lot of the tubing from the compressor to the tanks is "tube" and not "pipe"?
Have you guys notice a lot of the tubing from the compressor to the tanks is "tube" and not "pipe"?
NewShockerGuy
Well-known member
Yep, I search and then the topic comes up. Still very valid information and it get's annoying when you have people asking the same question over and over and it's there many times over. It's funny, no matter which forum I'm on some get annoyed at old threads being revived, and they insist on making a new topic of the same questions. While other forums give you a beating if you don't search first and ask a question that has already been asked/answered.
On my smaller 30 gallon the pipe from the compressor to the tank is copper.... is that what you mean? I'm not sure I follow you on the tube/pipe difference?
If you bend the copper pipe is it not a tube?
-Nigel
tlmartin84
Well-known member
Yeah, most of them have a copper tube that is flared. And it is not the Schedule M or L listed.
Another thing I have noticed is most box store black pipe that everyone refers you to, is only rated at 150 psi @ 72F for air.
Another thing I have noticed is most box store black pipe that everyone refers you to, is only rated at 150 psi @ 72F for air.
technically speaking, tube is measured OD, pipe is measured ID and is usually nominal
AND
Tubing used in plumbing is specd as ½ or 3/4 and the same OD tube for refrigeration is 5/8 and 7/8 and stainless tubing is called out however the kid with the electronic crayon set drawing the multicolored pictures feels like.
Tain't easy knowing what people are talking about some days.
4cyclic
Well-known member
About to expand my system, I'm glad M is good enough. L type is quite expensive around here.