air compressor

[fred thomas <vafred@erols.com>]

Listers, just finished wiring my new work shed, my question is for the 
piping for the air compressor, is plastic pipe O/K or do I need metal, if 
so, should it be galvanized or the black pipe ?? The run is going to be 
rather long for attempting to keep all the water out, 1 in line filter & 
1 filter/regulator, total up & down configuration is about 20 feet. As 
usual you advice is valued.  Thanks  "FT"