What are the two types of solenoid valves?

Solenoid valves typically come in two main types based on their operation:

1. Normally Open (NO) Solenoid Valve: In this type, the valve remains open when the solenoid is not energized. When the solenoid is activated, it closes the valve. These valves are used when the flow of fluid is required to be uninterrupted until the solenoid is powered to stop it.

2. Normally Closed (NC) Solenoid Valve: In this type, the valve remains closed when the solenoid is not energized. When the solenoid is activated, it opens the valve to allow fluid to flow. These are used when the flow of fluid is required to be stopped by default until the solenoid is powered to allow it.

These types can also be combined in some valves to handle different flow scenarios, like 2-way or 3-way solenoid valves, which refer to the number of ports for fluid flow.