Way to help minimize the amount of water reaching pneumatic devices is to properly orient all connections to the main air pipe (called a header ). Ideally, each instrument air tap coming off a header should do so on the top of the header, not the bottom. This way, collected condensation inside the header will not go directly to the points of use, but rather will drain downhill to the lowest point in the header where a drain valve may be placed.
This next photograph shows an incorrect installation, where air is drawn off the bottom of the
main header line:
Such an installation invites trouble, as every bit of water condensed inside the header is
guaranteed to find its way to the instruments connected to the underside of that header.
One good feature of this installation is the use of stainless steel as the piping material. Copper,
brass, plastic, and stainless steel are the preferred materials for instrument air piping, tubing, valves, and fittings, as standard (iron) pipe will inevitably rust in the presence of condensation. Particles of rust created inside an instrument air system plays havoc with the tiny ports, nozzles, and orifices of pneumatic instruments.
The proper way to make instrument air connections to the air header is as such:
In order to facilitate draining of the header, the header should be slightly inclined, with the drain
valve installed at the lowest point.