A Spin-on filter assembly that can be used with both suction-side and pressure-side filtration systems is described. The filter assembly screws onto a filter mounting head. The filter mounting head is part of a filtration system that provides fluid to be filtered to the filter assembly. The filter assembly filters the fluid to be filtered through a filter media contained within the filter assembly and provides the filtered fluid back to the filter mounting head. The filter assembly includes an upper seal that seals the clean side of the filter media from the dirty side of the filter media when the filter assembly is connected to the filter mounting head in an installed position. The upper seal includes a sealing ridge that has an elongated shape and is flexible such that the filter assembly can be used on both pressure-side and suction side applications in filtration systems.