Composite structures for reciprocating gas compressor systems

1. A packing case assembly comprising:

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 comprising multiple rings, wherein the packing ring set is configured to be disposed circumferentially around a portion of a length of the piston rod,

wherein a composite backup packing ring of the packing ring set comprises:

a first region comprising a polymer, and

a second region comprising a metal,

wherein an inner surface of the composite backup packing ring is configured to face the piston rod;

the first region extends along at least a portion of the inner surface; and

the second region is disposed circumferentially around at least a portion of the first region.

2. The packing case assembly of claim 1 , wherein the first region comprising the polymer extends along a first side surface of the composite backup packing ring, wherein the first side surface is perpendicular to an inner surface of the composite backup packing ring and is configured to face toward a high-pressure end of the piston rod.

3. The packing case assembly of claim 2 , wherein the first region comprising the polymer extends along the entire first side surface of the composite backup packing ring.

4. The packing case assembly of claim 2 , wherein the first region comprising the polymer extends along a second side surface of the composite backup packing ring, wherein the second side surface is perpendicular to the inner surface of the composite backup packing ring and is configured to face toward a low-pressure end of the piston rod.

5. The packing case assembly of claim 4 , wherein the first region comprising the polymer extends along the entire second side surface of the composite backup packing ring.

6. The packing case assembly of claim 1 , wherein the first region comprising the polymer contacts the second region comprising the metal.

7. The packing case assembly of claim 1 , wherein the composite backup packing ring comprises an interlayer region disposed between the first region comprising the polymer and the second region comprising the metal.

8. The packing case assembly of claim 1 , wherein the composite backup packing ring comprises a pin configured to inhibit rotation of the first region relative to the second region.

9. The packing case assembly of claim 1 , wherein a thermal conductivity of the metal of the second region is higher than a thermal conductivity of the polymer of the first region.

10. The packing case assembly of claim 1 , wherein a strength of the metal of the second region is higher than a strength of the polymer of the first region.

11. The packing case assembly of claim 1 , wherein a coefficient of friction between the piston rod and the polymer of the first region is less than a coefficient of friction between the piston rod and the metal of the second region.

12. The packing case assembly of claim 1 , wherein a wear resistance of the polymer of the first region is greater than a wear resistance of the metal of the second region.

13. The packing case assembly of claim 1 , wherein the metal comprises one or more of cast iron, bronze, aluminum, an aluminum alloy, or steel.

14. The packing case assembly of claim 1 , wherein the polymer comprises one or more of polyether ether ketone, polytetrafluoroethylene, nylon, or an aromatic thermosetting copolyester.

15. The packing case assembly of claim 1 , wherein the first region comprises multiple layers.

16. The packing case assembly of claim 1 , wherein the first region comprises a metallic filler.

17. The packing case assembly of claim 1 , wherein the first region comprises a non-metallic filler.

18. A reciprocating gas compressor system comprising:

a piston rod movable from a first end to a second end of the compressor system, and wherein a gas compressor system is defined at the second end of the compressor system; and

a packing case assembly comprising:

a packing cup disposed along the piston rod; and

a packing ring set disposed in the packing cup, the packing ring set comprising multiple rings, wherein the packing ring set is disposed circumferentially around a portion of a length of the piston rod,

wherein a composite backup packing ring of the packing ring set comprises:

a first region comprising a polymer; and

a second region comprising a metal,

wherein an inner surface of the composite backup packing ring is configured to face the piston rod;

the first region extends along at least a portion of the inner surface; and

the second region is disposed circumferentially around at least a portion of the first region.

19. A reciprocating machine, comprising:

a reciprocating component comprising an outer surface;

two or more rings configured to receive a portion of the reciprocating component, wherein at least one of the two or more rings comprises:

a first region comprising a polymer;

a second region comprising a metal;

an inner surface configured to couple with the outer surface of the reciprocating component; and

opposing side surfaces adjoining the inner surface,

wherein the first region comprising the polymer forms the inner surface and at least a portion of at least one of the side surfaces, and

the second region is disposed circumferentially around at least a portion of the first region.

20. The reciprocating machine of claim 19 , wherein the first region comprising the polymer forms the inner surface and at least a portion of each of the opposing side surfaces.

21. The reciprocating machine of claim 19 , wherein the at least one of the two or more rings comprises a pressure breaker, wherein the pressure breaker is the ring of the two or more rings that is nearest a compression cylinder of the reciprocating machine.