COMBINATION VALVE FOR LIQUID FILTER

摘要

A liquid filter includes an annular filter cartridge and a combination anti-drain back and relief valve assembly. The combination valve (40) includes a valve seat (42) from which axially extending arms extend and a spring retainer (54) and spring (72) which holds a gasket (64) against the valve seat (42). The gasket (64) includes an anti-drainback portion which projects from the valve seat (42) and a relief valve portion which is supported on the valve seat (42). Upon assembly the combination valve (40) and filter element (18) in the housing (12), the filter assembly is supported by the spring retainer (54) and is forced into sealing engagement with the gasket (64), holding the latter against the valve seat (42) in a gasket engaging area (62) between the relief valve portion and the anti-drainback portion. This assembly process also removes the coil spring load from the barbs on the valve seat arms (48). The spring retainer (54) is designed such that the range of movement relative to the valve seat (42) is limited during handling before and during assembly of the liquid filter, thereby preventing over-compression of the spring (72) so that the spring force is consistent, thereby resulting in a consistent opening pressure of the relief valve.