Drip leg for air line

[Moodster]

Hey guys,
I'm working on copper air lines for my compressor. I started brazing this weekend and due to the way everything is setup I don't have a very long drip leg. How much water actually gets stored in the drip leg? Would six inches of 3/4" copper pipe be enough to hold water or would I be draining it constantly?

Thanks,
David

 

[240sxguy]

You should definitely be draining it before you get 6" of water in the drip leg, seems fine to me.

 

[sammerdog]

You're golden. The industrial shops I worked in usually sported 6"-8" drops.

 

[64duece]

I wanted to get a clean way to drain. My buddy has a long leg and blows out on the floor and has big "splash stain" under it.

 

[sammerdog]

I wanted to get a clean way to drain. My buddy has a long leg and blows out on the floor and has big "splash stain" under it.

In paint booths, there'll be a length of garden hose coming off the leg. They use it to minimize getting contaminates in the air and on fresh paint, but it could also be used to direct your blow-off water.

...just to be sure, you are talking about a drip leg with a manual bleed off valve on it, aren't you?

 

[sharage71]

I'd like to see some pics of some you guys drip legs/drops etc.

Thx

 

[64duece]

In paint booths, there'll be a length of garden hose coming off the leg. They use it to minimize getting contaminates in the air and on fresh paint, but it could also be used to direct your blow-off water.

...just to be sure, you are talking about a drip leg with a manual bleed off valve on it, aren't you?

Yes, he has a manual ball valve on some of the legs that we use for specific things in the shop like plasma cutter, paint supply air. The drops work great but the stains look ugly.

I was thinking of some sort of "catch can/diffuser" that will allow the pressurized air/water to escape from the blow down and let the water evaporate. I didn't feel like plumbing them outside the building but I may just do that.

 

[sammerdog]

Yes, he has a manual ball valve on some of the legs that we use for specific things in the shop like plasma cutter, paint supply air. The drops work great but the stains look ugly.

I was thinking of some sort of "catch can/diffuser" that will allow the pressurized air/water to escape from the blow down and let the water evaporate. I didn't feel like plumbing them outside the building but I may just do that.

On drops by the overhead doors, we'd hang 5 gallon buckets on them in the winter time, just to help minimize icy spots. But you'd go to bleed off the air and the **** in the bucket would just explode all over if you weren't careful. Probably shoulda thrown a towel over the top of the bucket, huh?

 

[Moodster]

...just to be sure, you are talking about a drip leg with a manual bleed off valve on it, aren't you?

Yes, I'm using a ball valve.

David

 

[redsky49]

6" is typical industry standard length for drip/dirt leg. If you are operating compressor extensively, and are frequently blowing down the air piping, you may be in the market for a filter/dryer located upstream at the compressor.
Also depends on the ambient air humidity levels at your location.

Air tools like dry air, especially if spray painting.

Offered only as opinion

 

[e-tek]

I don't mean to seem contrary (or a know-all!) but I've worked in Body Shops shops, managed technical shops and visited industrial shops from Vancouver to Central Canada and have yet to see a shop that produces as much water as some of the examples eluded to above. As previously stated, if your system IS making/collecting so much moisture you'd fill a 6" drop in a week - then you have a serious problem!
If you live in a humid cimate, there are some excellent ways to rid your system of water: include making sure your flex line from the compressor to the main pipe is going steeply upwards, so that any moisture pulled in or condensed in the tank stays there, then adding a dryer (heated air) next to the compressor. After that, you may get mositure consdensing in your lines, which is why your main lines need to be agled from your tank. Here some like to angle back to tank, to get condensate to travel back, while some like to angle forward, to roll condensate towards a moisture trap. If you are painting or using a sandblaster (without a heat-dryer), then a dessicant mositure trap is a good idea.
WOuld love to see some pics of your shop and system - I had as much fun building mine as I do using it!

 

[64duece]

e-tek....that's great advise.

I'm planned on coming out of the compressor into a flex headed to the wall and straight up to the top plate. I'll make sure the flex is headed upward to a dessicant mositure trap mounted on the wall. Should keep a good bit of the water in the tank that way.