The pressure switch may also incorporate an unloader valve that reduces tank pressure when the compressor is turned off. Many articulated-piston compressors are oil lubricated.

The air is then exhausted through the discharge reed valve to build system air pressure. In the “unloaded” mode, the ESS piston is up, opening the cylinder to the compressor inlet.

Slow pressure buildup If it takes an abnormally long time to build system pressure, check for restrictions in the intake or discharge lines, watching for other symptoms. Check for system leaks, an ...