A solenoid valve is an electromechanically operated valve that controls the flow of fluids (liquids or gases) in a system. The term “Normally Open” refers to the valve’s default state—open—when no electrical current is supplied to the solenoid coil. In this state, the valve allows fluid to pass through without obstruction. When the solenoid coil is energized, a magnetic field is generated, causing the valve to close and stop the flow of fluid.

    The working principle behind Normally Open Solenoid Valves is relatively straightforward. The valve consists of a solenoid coil, a plunger or armature, a spring, and a valve body. The plunger is held in place by a spring when the solenoid is not energized, keeping the valve open. When electricity flows through the solenoid, the plunger is pulled toward the coil, closing the valve and preventing fluid from passing. Once the power is turned off, the spring restores the plunger to its original position, opening the valve once again.