Fuel oil filter cartridge

Abstract

A refill filter cartridge for a liquid fuel filter includes a semi-rigid plastic 'blister' having an open end closed by a cover member to define a fluid receiving compartment. A pleated paper filter medium in the compartment divides the latter into inlet and outlet portions which communicate with openings in the cover member. The filter housing includes a base and a cup-shaped glass housing that cooperates with the base to define a chamber which receives the plastic blister when the refill cartridge is installed in the filter. The cover member defines cooperating surfaces which engage the base and the glass housing so that the glass housing clamps the cover member between the glass housing and the filter base. The plastic blister is shaped to conform to the inner walls of the housing so that the housing engages the walls of the blister throughout their entire area. Accordingly, the glass housing serves as a support for the blister, so that the latter can withstand fluid pressure forces that would normally rupture the blister. In this way, a relatively inexpensive plastic blister can be used instead of a glass housing in the refill, and the filtering medium can be sealed to the sides of the blister instead of being sealed directly to the housing. Accordingly, the glass housing can be used over and over again, and need not be thrown away when the filter is changed.