A compressor running in a "start-stop" mode operates more efficiently if the pressure trapped in the compressor head and discharge line is released after each pump-up cycle. This allows smoother starts and the use of a motor with lower starting torque. The most convenient way to release this trapped pressure is to use a Load Genie combination check and unloader valve, available only from Contol Devices. Simply install this unique valve in the compressor discharge line, and the Load Genie does the rest! The Load Genie senses air flow when the compressor is running and closes an unloading orifice port. when airflow stops (such as when the pressure switch turn off the motor), the Load Genie opens the unloading orifice to release head pressure, and a built-in check valve keeps receiver air from leaking back into the discharge line and compressor head. Alterniative methods rely on external unloading valves mounted on the pressure switch or compressor. These external unloading valves are connected with appropriate tubing and fittings to the compressor discharge line or compressor head. A tank check valve is also required. These systms, then, consist of the unloading valve, connecing tubing with appropriate fittings, a thank check valve, and the labor to install it all. Compare this to the single compnenet installation of a Load Genie, and the advantages are apparent.