1, m-type solenoid valve: indicates "normally closed" or "closed". The M-type solenoid valve is closed when there is no power supply or it is not activated. When the solenoid valve is energized, it will open and allow fluid to pass through.

2.v-type solenoid valve: means "on" or "on". When there is no power supply or activation, the V-type solenoid valve is in the open state. When the solenoid valve is energized, it will close and prevent fluid from passing through.