A 2/2 solenoid valve is a directional control valve with two ports and two switching positions. It is commonly used to control the starting and stopping of air, water, oil, and other compatible fluids.

Use the interactive animation below to understand how a normally closed (NC), spring-return 2/2 solenoid valve works. Click Open to energize the solenoid and allow air to flow from the pressure supply to the receiver. Click Close to de-energize the solenoid and let the spring return the valve to its normally closed position.

How Does a 2/2 Solenoid Valve Work?

A 2/2 solenoid valve has two ports:

• P – Pressure/Supply: The inlet for compressed air or fluid.
• A – Outlet: The outlet connected to the receiver or downstream equipment.

It has two operating positions:

1. Valve Closed – Solenoid OFF

When the solenoid coil is de-energized, the return spring moves the valve mechanism to its normal position. In this normally closed configuration, the supply port is blocked, stopping further flow into the receiver.

2. Valve Open – Solenoid ON

When electrical power energizes the solenoid coil, the magnetic force moves the valve mechanism against the spring. The supply port connects to the outlet, allowing compressed air or fluid to flow into the receiver.

When power is removed, the spring returns the valve to its normally closed position.

Common Applications of 2/2 Solenoid Valves

• Compressed-air supply isolation
• Air receiver and pneumatic system charging
• Water and fluid flow control
• Automatic process lines
• Equipment isolation and utility control
• On/off control in industrial automation systems

Normally Closed vs Normally Open

A normally closed (NC) valve blocks flow when the coil is de-energized. A normally open (NO) valve allows flow in its normal, de-energized position. The correct type depends on the required operating sequence and the consequences of electrical power loss.

Key Takeaway

A 2/2 solenoid valve provides simple ON/OFF flow control using two ports and two positions. The animation demonstrates the operating principle of a normally closed, spring-return valve.

Note: This interactive animation is an educational illustration. Actual valve operation depends on its design, fluid, pressure rating, electrical specification, and manufacturer documentation. It is not a substitute for equipment datasheets or safety procedures.