Spool, 3-Way, 2-Position Hydraulic Solenoid Valve

The main difference between 2-position and 3-position solenoid valves lies in the number of distinct positions or states they can assume. A 2-position solenoid valve has two distinct positions—typically referred to as "normally open" (NO) and "normally closed" (NC). In the NO position, the valve allows fluid flow when the solenoid is de-energized or not powered. In the NC position, the valve blocks fluid flow when the solenoid is de-energized. When the solenoid is energized, it switches the valve from one position to the other. Essentially, a 2-position solenoid valve provides an on/off control of fluid flow. A 3-position solenoid valve has three distinct positions—often referred to as "center," "normally open," and "normally closed." In addition to the NO and NC positions, it has a central position. In the center position, the valve may either block the fluid flow or allow flow through a separate pathway, depending on the specific design and application. The center position is typically used for diverting flow or providing a neutral state.