A solenoid valve is an electromechanical device that controls the flow of fluid (either gas or liquid) within a system. The normally open solenoid valve operates in such a way that it remains open when not energized, allowing the fluid to pass through freely. Once the solenoid coil is energized, the valve closes, stopping the flow. This functionality makes normally open solenoid valves ideal for systems where the default state should be open until an external signal is given to shut the valve, such as in irrigation systems, fire suppression systems, and fluid dispensing.