Self-sealing flange and method of installation thereof

Abstract

A self-sealing flange assembly includes an elliptical shaped hole in a blind wall, the greatest diameter of which is larger than the smallest diameter of an elliptical shaped inner flange. Attached at a right angle to the surface of the flange is an internally or externally threaded nipple, bushing, stud or fastener. An annular groove located on the circumference of the flange contains a sealing means. At least one dimple at an apex of the elliptical flange locates the flange in situ when it is inserted through the wall opening and positioned thereon. An outer elliptical washer type element is tightened against the outer wall by rotation of a nut on the threads of the nipple, bushing, stud or rotating the bolt in the fastener, compressing the elliptical inner flange and sealing means against the inner wall forming a one piece leak proof assembly. The dimple used to locate the flange in situ also prevents rotation of the inner flange during the tightening process. A method of drilling a generally elliptical hole in blind walls to accommodate the claimed elliptical flange in which two holes are drilled with a drill bit with a diameter equal to twice the sum of the minimum diameter of the flange plus 1/6 the minimum divided by two and one hole is drilled with a drill bit with a diameter of the smaller drill bit plus a distance equal to one-third the minimum diameter of the flange. Both drill bits are centered on a single line. The larger hole is drilled at the center of that line and a smaller hole is drilled on each side proportionately located to achieve a general elliptical shape.