US Patent 10226722 Overpressure leak detection lug

A filter cartridge with a longitudinal axis has mounting lugs engaging mating manifold flanges in an appliance to hold the cartridge in the appliance with fluid flowing through the cartridge at a line pressure of X psi while the lugs are designed for a greater, rated pressure Y. Each lug has a deformable portion and an aligned stop portion that are axially aligned. A distance d separates each stop portion from the axially aligned deformable portion. The deformable portion is below the stop portion and located to contact the manifold flange during use. The deformable portion permanently deforms above the rated pressure Y and below a qualification pressure Z that is at least twice the pressure X.