running compressed air lines underground to my detached garage (help needed)

[dexter-]

Running electricity to my new garage(subpanel) and hopefully an air line for compressed air from my 60 gal compressor in my basement. Will be burying the electric wire and air line in an 18" deep trench in seperate PVC conduits. I figured if I had any issues with the air line in the future I can pull it and replace it easily that way. Will be using a reinforced nylon air line made by RapidAir Inc. and tapping into the last main run I have in my basement air lines. I want to slope the air line downward a bit towards the garage so any condensation that might form in the line can run with the airflow. My question is how do I drain the condensation at this point? The low point underground might possibly be 24" deep underground, so I am planning on having some sort of box or container in the ground to contain any sort of drain valves or tanks that I will need. Any ideas from someone that has already done this?

 

[larry_g]

http://www.garagejournal.com/forum/showthread.php?t=109062

See my reply in the above thread.

lg
no neat sig lien

 

[dexter-]

Thanks Larry but Im not sure I completely understand what you are describing. The T fitting would be facing upward? Then the line coming out of the top of the T would be the actual air supply to the garage, and the part of the T that continues straight would be the blow off? I wouyld have to elbow up about 2 or 3 ft to get above ground to a ball valve, would the air pressure be enough to blow any water up 3 ft and out the ball valve? Sounds like a nice easy solution if I am understanding you correctly. You have any pics?

 

[BillK]

Dexter,
I dont know your exact layout, but the preferred thing would be to have the line slope back towards the compressor, not the other way around. That way all you do is drain the compressor tank. That is the traditional way of doing it.

 

[larry_g]

Thanks Larry but Im not sure I completely understand what you are describing. The T fitting would be facing upward? Then the line coming out of the top of the T would be the actual air supply to the garage, and the part of the T that continues straight would be the blow off? I wouyld have to elbow up about 2 or 3 ft to get above ground to a ball valve, would the air pressure be enough to blow any water up 3 ft and out the ball valve? Sounds like a nice easy solution if I am understanding you correctly. You have any pics?

No pictures but you have the idea correct. You will have some high velocity at the blow off port and any fluid in the line will be carried out. The air going to the system will have to make the corner and up the tee and any H2O in that stream will tend to not make the corner and fall out into the end of the pipe. Usage and accumlation rate will dictate how often you will have to blow out.

I also agree that BillK has the correct answer also. Either way will work but I believe that you would want a fairly good sized pipe if you want it to drain back in a high use situation. Another option is to put a pressure tank in the shop to allow the air to slow down and the H2O fall out of suspension. Then you have a drain on that tank.

lg
no neat sig line

 

[BADSIX]

larry g's idea will work perfectly, you'll probibly want to install a water trap in your new garage also.