1/2" copper for air lines

[Jason280]

I found a local deal on 110' of 3/4" copper, which I planned on using to run air lines in my shop. Unfortunately, it turned out to actually be 1/2" type L copper. Any reason I should hold out for 3/4"? The compressor in this shop is a 135psi 60gal, and the longest run will likely be less than 30-40' from the compressor itself (shop is 24x32').

Plan is to run drops for two hose reels, and two other drops for extra hook ups. I'll probably end up with less than 75-80' of actual copper air line, any reason 1/2" copper wouldn't be fine?

 

[matt_i]

Imo unless you have a very heavy useage or constant draw, the 1/2" will be fine.

I've got probably 8 sticks of same diameter squirreled away for an eventual airline project.

Take a look at JW Harris Stay Brite #8 solder and Stay-Clean flux. Its more expensive, but is silver-bearing, it flows like the old leaded solder, and is also safe for potable water. If you were using big box "lead-free" before you'll kick yourself for not switching sooner

 

[ForceFed70]

Agreed. 1/2" is generally more than enough for a home shop unless you have some weird abnormally high requirement. Typically only need larger than 1/2" when you've got multiple workers in the shop - and even then, 1/2" is good enough for 2 or 3 workers with typical air requirements.

 

[zmotorsports]

I think 1/2" would be fine seeing as how you have that much volume with your compressor, if much smaller compressor I may think otherwise.

In my last shop I had 3/4" run along the ceiling with 1/2" drops and it worked perfectly fine for the 26+ years in that shop. My air compressor is also a 60-gallon but I went with 1" in my new shop just to add a bit of volume to my system but I think you will be just fine as my last one had no issues.

 

[Copymutt]

You'll get a kick out of this one.
Talk about increasing volume. Buddy in Cave Creek, Az. Was on a local private water system. The city of Scottsdale took it over due to growth. They abandoned the existing system and ran new lines. Sly fox managed to coordinate capping all feeds. Now has his own underground storage of miles of air reserve. Amazing it doesn't leak down. This one got by all the inspectors, regulations. Nothing in the books about it.
Jim

 

[Firebrick43]

If you can make a full loop. It will provide more flow than a single run of 3/4 at the far corner with high demand.

 

[bullnerd]

Didn't someone on here mention that his air gun never really had full power until he upped the line size?

I don't remember if it was the line or the hose.

 

[sberry]

1/2 will drain that comp in a hurry. There really is not much "far side" here. All this would be different in a 100 ft building with tall ceilings. Same for loops and in fact really like a single run to drive any water down to a collector. I don't even have legs on some of them, use the filter/trap.

 

[ddawg16]

Don't forget, most flexible air hoses are 3/8".

If it's a really good deal....go for it. 1/2" Will be easier to run than 3/4".

Worse case, you could always add a small buffer tank near the longest leg. Personally, I don't think you will need it.

 

[ForceFed70]

Here's a good calculator to play with.
https://www.engineeringtoolbox.com/pressure-drop-compressed-air-pipes-d_852.html


20cfm through 100' of 1/2" = approx 5 PSI pressure drop.

Even at 35cfm and 330' of pipe, your pressure loss is only 15PSI. Up the regulated pressure to compensate if required.

 

[nadogail]

I have installed 1/2" copper in an industrial shop using a propane torch, 50-50 solder, and liquid flux.
Looked good, worked fine, lower cost than iron pipe, quick and easy. What was there not to like?

 

[Bob P1]

I'd say 1/2 would be OK for a home type shop. An industrial shop would benefit with a much larger line. The farther you get away from the compressor the line could be reduced, but not from the get go.

 

[teamextreme]

What was the question? Sorry, totally distracted by avatar...

 

[Need more space]

What was the question? Sorry, totally distracted by avatar...

Agree, alway love his post lol. Anyways I'm about to run mine and I plan to run 1/2 after talking to a local installer for a large compressor company.

 

[Buckgnarly]

Ran 1/2" in my 24x32, no problems with pressure drop.

 

[NUTTSGT]

What was the question? Sorry, totally distracted by avatar...

Agree, alway love his post lol. Anyways I'm about to run mine and I plan to run 1/2 after talking to a local installer for a large compressor company.

This one time, he posted. . . . um nevermind. . . .



When I went from 3/4" PVC to 1/2" black pipe, I saw no issues for my own personal garage. I doubt you will have any issues.

I've never met Jason but I think he got a keeper and I'd like to think he is probably a pretty damn good guy.

 

[Jason280]

Thanks for the compliments!

What are the requirements on solder for air lines with copper, I seem to remember there was a different recommendation for air vs water lines.

 

[rlitman]

Thanks for the compliments!

What are the requirements on solder for air lines with copper, I seem to remember there was a different recommendation for air vs water lines.

No difference. Just use regular lead free solder.

Some here will tell you that you need to braze, but that’s not necessary.

 

[Fix Until Broke]

If you've got extra left over, you could run parallel 1/2 lines as far as you can - unless you have another use for the material?

 

[Jason280]

Now, I need to figure out how to fab up a cooler/water trap. The shop is attached to a 32x36' 3-bay barn, with the compressor mounted in the rear corner of the barn (but just on the other side of shop). I mounted it this way to keep the noise level down, and to free up space in the shop. I'll probably be better off mounting the cooler/trap inside the actual shop, as the temps are cooler there during the summer months.

 

[Fix Until Broke]

Since you're using copper, you can find an old home air conditioning condenser or evaporator and just plumb it in series after your air compressor, before the shop. It's relatively huge so it will cool with convection, no fans needed and can be found relatively cheap.

 

[mrobins297aaa]

Imo unless you have a very heavy useage or constant draw, the 1/2" will be fine.

I've got probably 8 sticks of same diameter squirreled away for an eventual airline project.

Take a look at JW Harris Stay Brite #8 solder and Stay-Clean flux. Its more expensive, but is silver-bearing, it flows like the old leaded solder, and is also safe for potable water. If you were using big box "lead-free" before you'll kick yourself for not switching sooner

just another vote for stay brite #8, I used it for years on R-22 systems now that I'm retired I use it for everything.........it's real nice stuff, a little pricey but worth it.

 

[Jason280]

JW Harris Stay Brite #8 solder and Stay-Clean flux.

Are these sold in Lowe's, or will I need to check a plumbing/HVAC supply store?

 

[mrobins297aaa]

I don't think so, I always bought it at hvac supply house, you can find it on line, probably ebay.

it might be a little over kill for your needs but it's real nice to work with. make sure you get the stay clean flux

 

[mrobins297aaa]

ebay about $60

 

[On-Wheel]

$60 bucks might not be over kill for freon. The main thing for sweating copper is clean joints.Get a wire brush tool to go in fittings and around pipe,a few twists,4-5,is good.I use a wet rag to remove extra solder while it's hot.Always seems like the extra was a pain if one had to resolder.

 

[Jason280]

$60 does seem a little excessive, what benefit does this stuff provide over normal flux/solder that I can buy locally? I'm not trying to be a cheapskate, just trying to justify the expense.

 

[mrobins297aaa]

it's over kill for what your doing, it's a little easier to work with and it is a stronger joint.

 

[matt_i]

My thinking on the cost is that if one were to max out the pressure switch and run the tank and the trunk line up to 175psi then its more important. Eventually the lead-free solder will creep under load. I can't tell you specifically where though. I think JW Harris had some literature on the comparison that I read a long time ago. I worked in a plant where we had a 300psi refrigerant-delivery line that was some 1200 feet long. All the joints & repairs on that used the Stay Brite.

The other benefit is the ease of working with it down the road. I've spent more times than I'd like reworking copper joints where the solder didn't flow right and I had a pinhole, had to drain the water system again, etc. Never have had that problem with the stay-brite. For a new install where everything's new and perfect the lead-free is pretty easy to do.

 

[Jason280]

Here is the solder I have now...

 

[gtr1999]

I am following this since I am doing about the same thing in my home shop. I have access to some surplus 1/2" blk pipe and copper tubing so I am planning on using both. The copper tubing was used off a 400 gallon rec tank to the control panel and we never had a leak but I don't know what was used to solder it 17 years ago.

How does the Stay-Brite8 flow? I have sweat plenty of tubing over the years but never used this, will it flow with a propane or do you need ace?

My line pressure should never be over 145psi and most of the run will be regulated down to about 100psi.

 

[IowaDon]

Here is the solder I have now...

Here is the solder I have now...

If you have had good luck making watertight joints with that solder, there is no reason in the world not to use it for your air lines.

 

[mrobins297aaa]

I am following this since I am doing about the same thing in my home shop. I have access to some surplus 1/2" blk pipe and copper tubing so I am planning on using both. The copper tubing was used off a 400 gallon rec tank to the control panel and we never had a leak but I don't know what was used to solder it 17 years ago.

How does the Stay-Brite8 flow? I have sweat plenty of tubing over the years but never used this, will it flow with a propane or do you need ace?

My line pressure should never be over 145psi and most of the run will be regulated down to about 100psi.

just a regular propane tank

 

[jfitz]

I found this chart which will help you out. I used Type L with 95-5 solder

 

[gtr1999]

just a regular propane tank

Thank you. Do you still have the 67 vette?

 

[mineallmine]

1/2" is fine for what you are running. When I did mine (coincidentally same size shop...24x32) I was going to go 1/2" but after reading I went up to 3/4" (used rapidair maxline kit) because my one run was going to be close to 100'. At the distances you are going you will be fine. A loop would be great if practical, but the way my garage is set up and the way I ran my air lines the loop wasn't practical so this was my solution.

I have run major air tools from the furthest point with zero noticeable loss in power (over 100' away from compressor using a cutoff tool and an impact gun.)

 

[BillK]

Jason,
My entire business shop is plumbed with 1/2" copper. It works fine, including the bead blast cabinet which is an air hog.

I did mine with my stash of old school solder with lead. It has been fine for 16 years so far

 

[bczygan]

Here are the solders and pastes I have.

Any usable for this?

Bill

 

[ddawg16]

You are not drinking from it.....If you have lead solder....use it.

You want to use a regulator and dryer coming out of the compressor. I took mine off. I never have any moisture in my lines....but then again, I'm in dry California.
If you are really worried about moisture, add a drip leg at a convenient point...put a 1/2" ball valve on it for draining. A quick burp will let you know if you have moisture or not. Copper does a decent job of condensing out moisture.

A few key points....

Map gas with a good torch head. Yellow can....not the blue one. You spend too much time applying heat to get it hot enough....Map will heat it up quicker....

Get it clean. Besides the typical brush they sell at HD, I use 220 grit sand paper to make sure there is NO dirt.

De-bur the inside of the pipe. When you cut it, it leaves a little lip. De-bur it....It only makes a marginal difference on air flow....but really cuts down on the noise.

Make sure the pieces are snug...but not tight. Fittings should go on without force. If they are too tight, the solder has trouble wicking into the area.

 

[mrobins297aaa]

Thank you. Do you still have the 67 vette?

I do have a few older vettes but unfortunately that one belongs to Cindy Crawford and some lucky guy driving it, maybe her husband I don't know.