Abstract: A filter cartridge has a keyed end cap which is configured and shaped for unlocking an associated valve mechanism that comprises a latch device and a valve. In this manner, when the fuel filter cartridge is placed into a fuel filter housing having such a latch and valve mechanism, the fuel filter cartridge is operable therein to filter fluid and pass the fluid into a standpipe contained within the fuel filter housing. The fuel filter cartridge of this type generally includes pleated filter paper which is disposed between two opposed end caps. The keys may be provided along the bottom end cap.