Is 1/2" enough?

[I Lean]

For shop air plumbing--I have some 1/2" copper pipe and fittings already, I'm wondering if it's large enough that I won't see a pressure drop at the other end. It seems like most people are using larger diameter stuff.

It'd be going in a 26x32 building, so the furthest distance from the compressor would be maybe 75'-ish.

[Wyoming9]

Depends more on your CFM requirements Also how much your compressor puts out.

If you are sand blasting in a big way you might want larger pipe.

Then again you are most likely using 1/4 or at most 3/8 quick connect fittings

Bigger never hurt but it does take just that much longer for the compressor to recover.

[Shefron]

Originally Posted by I Lean

For shop air plumbing--I have some 1/2" copper pipe and fittings already, I'm wondering if it's large enough that I won't see a pressure drop at the other end. It seems like most people are using larger diameter stuff.

It'd be going in a 26x32 building, so the furthest distance from the compressor would be maybe 75'-ish.

I would use 3/4 or 1in to avoid pressure drop. I get some pressure drop when running air tools off a 25' hose reel.

[solarpower]

copper seems like pretty fancy stuff for air lines.

1/2 should be fine...but remember that using larger pipe adds to the volume of air over all. Your pressure will be the same no matter what size line you use. If it's 120 PSI at the tank..it will be 120 PSI in the lines unless you use a pressure regulator. but like they said it's all about the compressor recovering.

I would save the copper for a water line.

[I Lean]

Originally Posted by Wyoming9

Depends more on your CFM requirements Also how much your compressor puts out.

If you are sand blasting in a big way you might want larger pipe.

Then again you are most likely using 1/4 or at most 3/8 quick connect fittings

Bigger never hurt but it does take just that much longer for the compressor to recover.

No blaster, just normal air tools and a plasma cutter. Probably my greatest CFM user would be stupid little die grinders, my compressor gets it's ass handed to it by those.

It's a 60gallon Husky single-stage, claimed output 10.3CFM @ 90psi.

Originally Posted by Shefron

I would use 3/4 or 1in to avoid pressure drop. I get some pressure drop when running air tools off a 25' hose reel.

Me too, which is why I ask. I think my hose reel has 3/8" hose, plus the swivel fitting and whatever--so I know the 1/2" pipe won't drop as much as that does, but over a longer distance.

Any engineeer types know how to figure exactly what pressure drop I'd see over a given distance?

[trkklr77]

1/2" is enough for me to crush 14bff pinion sleaves over 100' away from the compressor.

[I Lean]

Originally Posted by solarpower

copper seems like pretty fancy stuff for air lines.

1/2 should be fine...but remember that using larger pipe adds to the volume of air over all. Your pressure will be the same no matter what size line you use. If it's 120 PSI at the tank..it will be 120 PSI in the lines unless you use a pressure regulator. but like they said it's all about the compressor recovering.

I would save the copper for a water line.

I've been looking at this little stack of copper for about 9 years, so I feel fine with using it.

[Shefron]

Originally Posted by I Lean

No blaster, just normal air tools and a plasma cutter. Probably my greatest CFM user would be stupid little die grinders, my compressor gets it's ass handed to it by those.

It's a 60gallon Husky single-stage, claimed output 10.3CFM @ 90psi.




Me too, which is why I ask. I think my hose reel has 3/8" hose, plus the swivel fitting and whatever--so I know the 1/2" pipe won't drop as much as that does, but over a longer distance.

Any engineeer types know how to figure exactly what pressure drop I'd see over a given distance?

I would scrap the copper line for air like the other guys are saying and get some gav pipe. Not to bad for pricing overall and can be cut to length. Dont forget to put a slope in the pipe and maybe a drain at the end.

edit: One or two water seperators would be nice also

[MQYJ]

I just ran 1" copper for mine as I never really had decent pressure with the 1/2" black iron pipe I had installed previously. I did this when I changed the compressor out to an 80 gal. 2 stage. It runs up to 175psi at the tank but with the one inch and my regulator wide open I'm only getting about 130 psi static pressure at one of the 3/4 branch lines. So with that I'm thinking that you do lose some pressure in the system depending on your air line size. I can't explain it right now and don't really care enough to look it up either.

As far as galv. pipe goes. This is from the TP tools website.

"We do not recommend galvanized metal pipe, as galvanization can come off the inside of the pipe, clogging separators and regulators."

[ChiScouter]

http://www.gates.com/industrial/pres...043#calculator

The 1/2" copper will outflow any of your quick connect fittings.

[Harold Phipps]

Some friends with a truck repair shop use 1/2" copper and have since 1962.
I'm guessing the copper will work just fine.
I think I would run it in a loop. All the way around and back to the compressor, I read that was the "best" way to do it, but don't remember the reason.
Weird thing about galv pipe, with air, it plugs up faster than black pipe with the condensation making rust. I REALLY have no idea why.
The new 1/2" aluminum tubing for air, claims to flow more than 1 1/2" black pipe. Also has really cool drop attachments, but it isn't cheap.
All that being said, I am starting to run 2" black around my shop, and will TRY to do it in a loop. To start it will just be like branches, but I will run it so it can be in a loop. The "drops" will start with a cross, drain only on the down port, and the "drop" will be off the top port of the cross, bushed down to 3/4" or 1" black pipe for the drop. Depends on what is available when I start buying drop stuff.
The air drop will also have a drain on it.
Drops every 10 feet will be plenty.

[bluesman2a]

I run 3/4" main lines with 1/2" drops. All copper. The best of both worlds. Everything in red is 3/4". It runs off an 80 gallon 2-stage at 175 PSI, and I use it for standard air-tools, blasting, etc.

In a perfect world it would be looped as mentioned above, but this works quite well.



As mentioned above, make sure you plumb your drops so they can be drained and don't accumulate water. I did mine like this:

[I Lean]

Thanks for the replies! ChiScouter, that calculator is exactly what I was looking for--but everything I found online wanted WAY more parameters that I didn't know/don't care about. It looks like I'll see less than a pound of pressure loss, which it completely acceptable.

If I don't have enough 1/2" to do the job, I like the idea of 3/4" runs with 1/2" drops. (if I have to buy anything....)

[Slowzuki]

Either your gauge or your regulator is fucked. There is no friction loss at static. Even flowing, you can move a lot of air in 1" pipe or tube without any serious pressure drop.

Originally Posted by MQYJ

I just ran 1" copper for mine as I never really had decent pressure with the 1/2" black iron pipe I had installed previously. I did this when I changed the compressor out to an 80 gal. 2 stage. It runs up to 175psi at the tank but with the one inch and my regulator wide open I'm only getting about 130 psi static pressure at one of the 3/4 branch lines. So with that I'm thinking that you do lose some pressure in the system depending on your air line size. I can't explain it right now and don't really care enough to look it up either.

As far as galv. pipe goes. This is from the TP tools website.

"We do not recommend galvanized metal pipe, as galvanization can come off the inside of the pipe, clogging separators and regulators."