At its core, a Normally Open Solenoid Valve operates on the principle of electromagnetism. In the "normally open" state, the valve is in the open position, allowing fluid to flow through. When the solenoid coil is energized, it generates a magnetic field that pulls the valve's internal plunger or armature. This action moves the valve into the closed position, blocking the fluid flow. Upon deactivation (when the power is turned off), the spring or other return mechanism ensures the valve automatically returns to its open state.

    The main difference between a Normally Open and a Normally Closed Solenoid Valve lies in their resting state. In a Normally Closed Solenoid Valve, the valve remains closed when there is no power applied, and it opens when the solenoid is activated. Conversely, a Normally Open Solenoid Valve stays open when unpowered and closes only when an electrical signal is applied.