The SUN DTDF-MCN is a high-performance, pilot-to-open check valve with a sealed pilot, designed for use in hydraulic circuits. This valve allows free flow from the valve port (port 2) to the cylinder port (port 1) while blocking flow in the opposite direction. By applying pressure to the pilot port (port 3), the valve opens to permit flow from port 1 to port 2. The sealed pilot piston design makes this valve exceptionally versatile, allowing it to be used in circuits where the pilot line is separate from the main line, such as in cross-over applications or systems involving different fluids.