Originally Posted by MARTINSR
Yes and you want galvanized not black. Black is for gas not water, unfortunately compressed air is full of water so it shouldn't be used.
Galvanized is not commonly recommended for air delivery. Black iron (steel) is preferred over galvanized due to the fact that when the moisture breaks down the galvanized it tends to peel off and provides greater opportunity for contamination/ obstruction. However, Stainless, copper, and aluminum are better choices.