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.

A system for controlling rain water flow includes a container having a top end and an opposite bottom end. A drain tube having a drain port is connected to the container. A cover tube slidably receives the drain tube. A magnetic latch is disposed between the drain tube and the cover tube. The system includes a fill configuration in which the magnetic latch is magnetically engaged and the cover tube covers and seals the drain port of the drain tube. The system also includes a drain configuration in which the magnetic latch is magnetically disengaged and the drain tube slides downward to expose the drain port.