A 3-way solenoid valve is an electromechanically operated fluid control component with three ports (typically an inlet, an outlet, and an exhaust port), designed to control the flow path, mix or divert media (including fluids, air, gases, and other process liquids/gases) in automated systems. It is actuated by an electric current passing through the internal solenoid coil, which generates magnetic force to move the internal spool or piston and switch the flow path among the three ports.
Basic Classification
Based on the initial state when de-energized, it is mainly divided into two types:
Normally Closed (NC) 3-way Solenoid Valve: The valve blocks the flow path between the inlet and outlet when de-energized, and opens the path to allow media to flow when energized. It is widely used in scenarios where the default state is to cut off the flow.
Normally Open (NO) 3-way Solenoid Valve: The valve allows media to flow between the inlet and outlet when de-energized, and closes the path to block the flow when energized. It is suitable for applications such as emergency exhaust, fail-safe circuits, or scenarios where the default state is to maintain flow.
Working Principle
When the solenoid coil is energized, the generated electromagnetic force moves the internal piston or spool, redirecting the media flow path. For example, in a center-exhaust type 3-way solenoid valve, energizing the coil may direct the media from the inlet to the outlet, while de-energizing it vents the pressure from the outlet to the exhaust port. When the power is cut off, the electromagnetic force disappears, and the spring reset mechanism pushes the piston or spool back to the original position, restoring the default flow path.
