Patent ID: 7442292

Claim:
A display for indicating the pressure differential across a filter element in a filter assembly defining a fluid inlet passage delivering unfiltered fluid to a filter element and a fluid outlet passage for fluid having passed through the filter element, said display comprising: a container defining an interior space and through which a level of fluid in said container is visually apparent; a first passage communicating between the fuel inlet of the filter assembly and said interior space; a second passage communicating between the fuel outlet of the filter assembly and said interior space, said second passage defining a valve seat; a valve carrying a sealing member movable between a seated position in which said sealing member is sealingly engaged with said valve seat to interrupt communication between said interior space and said fluid outlet and an unseated position in which said sealing member is moved away from said valve seat permitting communication between said interior space and said fluid outlet; a float positioned in said interior space and responsive to a fluid level therein to generate a first biasing force; and wherein said first biasing force biases said valve toward said seated position until a pressure differential between said inlet passage and said outlet passage is sufficient to overcome said first biasing force and unseat said valve, permitting fluid from said inlet passage to enter said interior space from said first passage, said fluid acting on said float to increase said first biasing force.