Filter assembly especially for internal combustion engine fuel has additional filter for air passing from unfiltered side to filtered side

摘要

The filter assembly, containing a cartridge (12) and an inner neck (14) that acts as a nozzle for the filtered fluid, has a passage (22) in the neck for air passing from the unfiltered side (18) to the filtered side (20). The passage is fitted with a filter (32) on its upstream side, the surface area of the filter being greater than the narrowest section of the passage, which is preferably 0.35 mm in diameter. The additional filter, made from a fuel-resistant polymer, metal or ceramic, has pores that are preferably about 20 micrometres in diameter.