High pressure packing cup

Claim 1

In combination with an elongate rigid mandrel that supports a circular collar of such diameter that the circumferential edge of said collar is radially spaced from the interior surface of a tubular member that is to be tested hydraulically, a packing cup formed from an elastomeric material, said cup being in the form of a cylinder that has a flat first end surface that abuts against a flat second end surface of said collar, said cup having a bore extending longitudinally therethrough that is engaged by said mandrel, said cup having first and second end portions, said first end portion partially defined by said first end surface and having substantially the same transverse cross section as that of said collar, with said second end portion being at least partially defined by an outwardly projecting circumferentially extending lip that has an outer ring-shaped surface that slidably contacts the interior surface of said tubular member and an oppositely positioned ring-shaped interior surface that is contacted by pressurized fluid used in testing said tubular member, said packing cup being characterized by: a. a rigid ring of substantial height that extends longitudinally into said first end portion from said first end face thereof and is intermediately positioned between said bore and the external surface of said first end portion, said ring dividing said first end portion into inner and outer annulusshaped sections, with pressurized fluid when discharged into said tubular member above said packing cup three dimensionally deforming the same towards said collar to longitudinally shorten said cup and radially expand the portion of said cup between said lip and said ring into sealing contact with the interior surface of said tubular member, and said longitudinally and radially deformed portion exerting longitudinal forces on said inner and outer sections to radially deform said inner section inwardly into sealing contact with said mandrel and said outer section outwardly towards said inner surface of said tubular member, but said outer section expanding radially but a fraction of the distance of the portion of said cup above said ring expands due to the lesser thickness of said outer section, and said outer section when radially expanded tending to fill the space that existed between it and the interior surface of said tubular member when said cup was not deformed rather than extruding downwardly as a circumferentially extending bead in the annulus-shaped space between the outer surface of said collar and the interior surface of said tubular member; and b. first means operatively associated with said second end portions for preventing said pressurized fluid from flowing longitudinally between said bore and mandrel towards said collar.