US Patent 11879447 Composite structures for reciprocating gas compressor systems

A packing case assembly includes a packing cup configured to be disposed along a piston rod of a reciprocating gas compressor system; and a packing ring set disposed in the packing cup, the packing ring set including multiple rings. The packing ring set is configured to be disposed circumferentially around a portion of the length of the piston rod. A backup packing ring of the packing ring set includes a first region including a polymer, and a second region including a metal.