An auto drain valve 100 comprises a valve body 222 wherein a piston 111 having a piston rod 08 with sealing disk 07 and sealing member 03 which is movable within said valve body 222 wherein air vent 30 and liquid outlet 40 and closes simultaneously. Further the valve body 222 is connected to the bowl 10; valve body 222 consisting of air vent 30, liquid inlet 40′ and liquid outlet 40; moveable piston 111, solenoid coil 9 surrounding the piston rod 08; spring 01 and spring 02 resiliently biasing on the Piston 111 seal air vent 30 and liquid outlet 40 in its de-energized condition; when the solenoid coil 09 is energized and Piston 111 moves away from air vent 30 and liquid outlet 40 simultaneously, liquid is drained form bowl 10 through liquid inlet 40′ into valve body 222 and drained out form liquid outlet 40.

An auto drain valve 100 comprises a valve body 222 wherein a piston 111 having a piston rod 08 with sealing disk 07 and sealing member 03 which is movable within said valve body 222 wherein air vent 30 and liquid outlet 40 and closes simultaneously. Further the valve body 222 is connected to the bowl 10; valve body 222 consisting of air vent 30, liquid inlet 40′ and liquid outlet 40; moveable piston 111, solenoid coil 9 surrounding the piston rod 08; spring 01 and spring 02 resiliently biasing on the Piston 111 seal air vent 30 and liquid outlet 40 in its de-energized condition; when the solenoid coil 09 is energized and Piston 111 moves away from air vent 30 and liquid outlet 40 simultaneously, liquid is drained form bowl 10 through liquid inlet 40′ into valve body 222 and drained out form liquid outlet 40.

According to one aspect of the present disclosure, a drain system, including a sensor in communication with a reservoir and controller, uses algorithmic control of a drain valve to adjust the interval and duration of actuation of the drain valve to regulate a fluid level within the reservoir. In embodiments applying the drain system to a gas compressor system, the disclosed control algorithm enables the controller to prevent the loss of compressed gas through an open path out the drain and further to prevent condensate generated by operation of the compressor system from backing up in the reservoir and reentering the flow of compressed gas. The control algorithm adjusts the interval and period of actuation of the drain valve such that as operating conditions change the drain valve opens more or less frequently for longer or shorter periods in response to varying condensate load.