Copper air line question / drain valve

[Firefyter_Emt]

Guys, I am just getting started to run the copper piping up to my shop. I am working on the drop for my air reel. The piping will run up inside the wall from my cellar (compressor is in a room down there) and drop drwn from the attic on the outside of the wall using those round based wall stand off pipe clamp things. Right now I want my air fitting to point down for the air reel and a second fitting with a spare chuck on it. Two questions, does this set up look ok? That and mostly I want to know what you think about my air drain. I want to shy away from the 1/4 turn ball valve so that it does not bet bumped and leak air. I was thinking about using this valve for a sink fitting. This has an easy screw knob and is less bulky than a garden hose type valve. The problem is that this stuff is not really made for air PSI but water. However, the 1/2" copper ball valves are to! So, do you think this valve will work? I will have a longer down pipe on it, it is just a used valve with a stub of pipe on it I need to remove. The air reel will be a thread to thread fitting for a cleaner install and I am putting in a 1/4 turn fitting at the ceiling to shut the entire line off in case I need to kill a line quick.

The air inlet is at the "T" where valve is and and the "T" under the air chuck will be a threaded outlet for the air reel.
http://www.yankeetoys.org/lee/11301.jpg

[BumpyDodge]

I'd use a ball valve or reservoir and petcock, closet shutoffs aren't really designed to hold up to frequent use.

The nicest air line plumbing I've ever seen is govt. contract work done on military bases.

They are all set up pretty much the same. The vertical down run terminates to a 4" copper water trap about a foot long with a petcock drain or ball valve on the bottom. The water trap is fastened to the wall with a fabricated steel bracket or section of lumber. Every air hookup off that drop comes from a Tee at the top of the water trap and each will have it's own ball valve shutoff so the coupling isn't always pressurized and to shut off air in an emergency. The air coupling will come directly off the wall from a brass "drop elbow" - they're cast fittings with ears on them to fasten to the wall. Much more durable too (you're asking for trouble using a standard elbow). Sometimes there will be a regulator and filter/drier on one drop for painting. Keeping the air lines high reduces the chances of them getting accidentally crunched, and you'll always know where your low points are. Your compresser tank is essentially the "water trap" at the other end of the line, so keep the shutoff valve at the compressor tank open and don't forget to drain it.

It'll cost a bit more initially, but you'll probably never have to worry about it again.

[pmurf1]

I won't even put those in people's houses in a water application, let alone 125+ psi of air. They're junk. Plastic stems and chrome or brass colored plastic handles like to snap off, often when you need them most. I'd stick with good full port 1/2" ball valves. If you're worried about bumping the handles, just pull them off. Keep them in a pile if you ever have to shut them off, or drill a small hole through the handle and bailing wire it around the pipe so it's nearby.

[MT4Runner]

You're also making your reel a low point. Put the Tees inline.

Let's see if I can do some ASCII art...ignore the periods.

Ball Valve T short pipe T drop pipe
.........reel.......coupler

floor to the left, attic to the right...tilt your head to the right! ;)

[EMG7895]

http://www.conbraco.com/products/ball/barstock1.asp?section=C
I wouldnt use that valve. What about one of these?