Many systems have the need for liquids to be drained from gas systems.  The most typical application would be draining water from compressed air tanks.  Ambient water vapor gets compressed along with air as it passes through an air compressor, but as the pressure of air rises its ability to hold moisture decreases.  This results in liquid water literally being squeezed out of the compressed air.  This water collects in low spots in compressed air piping system.  Water also gets carried along with the compressed air through the piping as it travels to air tools and paint booths.  Because water is corrosive to most air piping systems, and because water can damage air tools, air cylinders and other equipment, draining water from air compressor tanks is a constant requirement.  Since steam traps perform a similar function draining condensate from steam systems, they are commonly used, with slight modifications, as liquid drain traps.

Watson McDaniel manufactures a broad range of liquid drain traps suitable across a wide array of applications.