Copper or steel on compressor before isolation hose?

[1320stang]

https://goo.io/nJwYmJ

The relationship of my Delta 80 gal., upright compressor to where the riser to the ceiling is would mean that if I put the drain leg on the end, it'll dump down onto the compressor, pretty close to the pump. The output on the compressor is from an aluminum 'head' that the switch is attached to, there is no bung on the side of the tank anywhere, so I have to come out there. I was going to come out about 10", tee with a 6" drip leg and a ball valve on the bottom. Up top I was going to a hydraulic hose over to the riser going up to the ceiling.

I put a 1/2" galv. ****** and a ball valve there and was going to upsize to 3/4" right there. I started to go with galv. pipe there over to the hose, but seeing some of the pipe sealing problems even with dope, I was thinking of going copper. I was going to weld up a bracket to attach to the motor/pump platform to help support the pipe, do you think copper would be okay if it's supported?

 

[kbs2244]

First, do not use galv. The reason they will not let you use it for gas lines is that they are afraid of the zinc flaking off and clogging thing up. If that is a problem to worry about at gas pressures and flow rates, think about it at compressed air pressures and flow rates.

Flow rates and restriction is the reason to go with as large a dia pipe as you can.

Second, vibration is the biggest problem for copper. The joints cannot take the mechanical stress as well a threaded fitting. So if you go copper, get you isolation hose as close to the compressor as possible.

 

[1320stang]

I understand the issues with galv. pipe, the ****** before the valve is 1 1/2" long. The rest of the system beyond the isolation hose will be copper. I will be using point of use particulate filters and regulators, I figure the drip leg should take care of some trash along with gravity.

I realize the problems associated with copper and vibration, but if the pipe is fully supported, maybe even attached to the point that there are no competing harmonics, do you think it will still fail? The main valve will be shut off and the lines decompressed after each use.

 

[fefarms]

If the isolation hose does its job, vibration is not a problem. I have had soldered copper working in shops for 10+ years.

It is not necessary to depressurize to save wear to the lines. In fact, it is better not to -- less wear on the compressor, less water in the tank, less stress/strain cycles in the lines. You can shut the valve off and trap the air in the tank, and let the lines bleed down at whatever rate, just to minimize run time.

If your main airlines are sized for less than 20 feet per second air velocity, the air will not carry zinc debris or condensed water past drip legs. One short galv ****** wont be a problem. (I wouldn't do a whole system out of galv, but you see it done all the time).

Read this article to learn how to size main and branch compressed air lines:
http://www.chemicalprocessing.com/articles/2005/12.html

 

[1320stang]

What I've decided to do is to go ahead and run the isolation hose directly off the valve and go over to the upright with it's drip leg. I'll put a npt to hose bibb on the other end of the valve and put a piece of garden hose to direct the drainage. The copper will go across the ceiling and down an opposing wall to another drip leg that is positioned over my laundry tube. If I want to drain the system of air, I'll do it from there, that will likely be where most of my condensate will be anyway as the piping drains away from the compressor.

 

[W-Cummins]

First, do not use galv. The reason they will not let you use it for gas lines is that they are afraid of the zinc flaking off and clogging thing up. If that is a problem to worry about at gas pressures and flow rates, think about it at compressed air pressures and flow rates.

Do you guys think that if you keep repeating this story it will some how become true ?? Some places may not allow you to use galvnized pipe on gas, but it's fine in lots of places, large and small. Infact all the large fitings on my meter ( including all the gas specfic valves are all galvanized. The riser pipes are also all galvnized pipe etc...


William....

 

[fefarms]

In my experience, most of the water will condense in the compressor tank. The next highest accumulation will be in the first drip leg right as the line turns to go up to the ceiling. The drip leg all the way across the shop will accumulate some, as the air continues to cool in the main header (that's why you put it there and slope the line down), but if there is appreciable water in that drip leg, there will be a lot more in the first two places. If you drain the legs daily, or even weekly, the drain leg near your laundry tubs will have just a few drips of water. The thing that makes lots of condensed water is a high continuous air draw in humid weather (like sandblasting). Impact wrenches and other burst uses don't generate significant water anywhere but the compressor tank.