Deep filter element suitable for replacing a shallow filter element and having a support frame made from thin stock

摘要

A deep format filter element has a peripheral frame with outwardly protruding mounting flanges. The mounting flanges simulate the periphery of a shallow format filter element to allow the deep format filter element to replace the shallow format filter element in many situations. The frame design allows the entire frame to be formed of cardboard and still provide adequate rigidity and strength. The frame includes at least a first cardboard sheet forming individual sides of the frame and panels of the mounting flange. The first cardboard sheet includes for each mounting flange at least two inside folds defining edges of the mounting flange's end panel and first and second side panels. An outside fold defines the second side panel of the mounting flange.