Overview of 2-way Solenoid Valve

A 2-way solenoid valve is an electromechanically operated fluid control component that features one inlet port and one outlet port, designed to start, stop, or regulate the flow of media (including fluids, air, gases, and other process liquids/gases) in automated systems. It is controlled by an electric current passing through the internal solenoid coil, which generates magnetic force to actuate the valve spool or poppet and switch the flow path.

Basic Classification

Based on the initial state when de-energized, it is mainly divided into two types:

1. Normally Closed (NC) 2-way Solenoid Valve: Flow from the inlet to the outlet is completely blocked when the power is off, and the valve opens to allow flow only after it is energized. It is the most common type for general process control scenarios.
2. Normally Open (NO) 2-way Solenoid Valve: The valve remains open and allows flow when the power is off, and closes to block flow after energization, which is suitable for emergency cut-off or special energy-saving applications.

Working Principle

When the solenoid coil is energized, the generated electromagnetic force lifts or moves the internal closing member (poppet/spool), opening the orifice to allow media to flow through the valve from the inlet to the outlet. When the power is cut off, the electromagnetic force disappears, and the spring reset mechanism pushes the closing member back to the original position, closing the orifice and blocking the flow. For pilot-operated 2-way solenoid valves, a minimum differential pressure across the valve ports is required for operation, and it can achieve higher flow capacity with smaller overall dimensions.