A solenoid valve can be direct acting or what type of operated valve?

A solenoid valve can be direct acting or pilot operated. In a pilot-operated solenoid valve, a small amount of fluid is used to control the larger flow of fluid through the valve. This is achieved through a secondary mechanism that relies on the pressure differential created by the incoming fluid. When the solenoid is energized, it opens a small orifice that allows fluid to flow into the pilot chamber, which then opens the main valve.

This type of valve is advantageous in applications where larger flow rates or higher pressures are involved because it can effectively control a significant flow with a relatively small electric current. Additionally, pilot-operated valves can achieve a fail-safe position more easily than purely direct-acting valves, which makes them suitable for various applications in refrigeration and air conditioning systems.

Direct acting solenoids, on the other hand, do not rely on additional fluid pressure for their operation and instead use the magnetic force generated by the energized coil to directly move the valve plunger. However, in larger systems, the pilot-operated solenoid is often preferred for its efficiency and effectiveness in managing higher flow scenarios.