Here you go.
Galvanized pipe according to tp tools is not a good idea, should stay with the black pipe.
They tell about it on there tips/technical section. tips is on the upper red bar at the top of the page, at the far right.
http://www.tptools.com/ < Go here first
Then click on tips/technical
Then click on air line hookup- metal piping diagram
Then click on minimize moisture in your air lines with metal piping
This company has been in the business for a long time
Rob
There are questions to be answered, and answers to be questioned"
Chassis, Body Jig, Trunk Pan Pics.
http://webpages.charter.net/2manitowoc