If you run the air system hard, put an intercooler radiator between
the compressor output and the receiver tank, and a refrigerated air
dryer between the receiver tank and the shop piping system. Between
the two, they will catch most of the moisture before it gets into the
shop system air lines.

And if you've never been told, DO NOT use PVC plastic water pipe for
air line systems, EVER. Much bad mojo when the pipe shatters and
explodes like a grenade, which can land anybody unfortunate enough to
be nearby in the hospital - or worse, the morgue. They make special
plastic pipe that is rated for compressed air use in hazardous
(usually corrosive) industrial applications, but it costs more than
copper. Black iron pipe will eventually rust through and will put
rust scale into your air system, but it won't explode.

You need a drop leg on the air line from the overhead main trunk
line right before the outlet that will catch any condensed water in
the shop air lines, and a petcock or small ball valve to drain it
periodically. The tap off to the drop leg should come off the top of
the trunk line.

(And there should be another drop leg and drain valve at the far end
of the trunk line to drain it also. Belt and suspenders.)

Then a ball valve for servicing.

Then a coalescing air filter - bowl type to catch any oil, water,
and small bits that are in the air (varies from 5 to 1 micron
depending on the element). And check the air flow CFM rating. They
sell these at the Borg if you need it today - Home Depot, Lowe's, good
hardware stores.

Then a pressure regulator with a high enough flow rating to handle
the tool you want to run.

Then if you are running an air tool off that line, a mist
lubricator. And make sure that any air hoses used on this outlet are
ONLY used for air tools, as now they have air tool oil mist inside
them. Oil in painting air is very bad - fish-eyes everywhere.

You can use a different air coupler on those hoses, but it only
works for a one-person shop - there are dummies who will change the
connections and mix that oily tool hose in with your clean painting
hoses, or vice versa.

Or if you are painting, you want a final desiccant air dryer with an
indicator desiccant in it - when the indicator crystals in the
desiccant turn pink, it's time to replace and/or reclaim it in an
oven.

-- Bruce --

Holy Crap! You really messed up MY day! All I got is a two horse
compressor and some hose. I never suspected I needed all those things.

Oh, well, like I NEED a reason to go to the tool store.

Steve, who's going to be antsy knowing I need all this stuff, and most
stores closed tomorrow.