The main difference between normally open (NO) and normally closed (NC) air solenoid valves lies in their default positions:
1. **Normally Open (NO) Valves**: These valves are open when not energized. Air flows through the valve until the solenoid is activated, closing the valve. They are ideal for applications where continuous airflow is needed until an action is taken.
2. **Normally Closed (NC) Valves**: These valves are closed when not energized, stopping airflow until the solenoid is activated. They are used when it's important to prevent air flow by default, allowing it only when the solenoid is triggered.
Choosing between them depends on the specific control needs of your application.
