Expansion chamber for progressive sealing system

A progressive sealing system for a reciprocating machine, comprising:

• a pressure breaker positioned at a high pressure end of a packing case and configured to meter a flow of gas from a compression chamber of the reciprocating machine;
• an end plate configured to couple the progressive sealing system to a housing of a cylinder of the reciprocating machine;
• a plurality of seals through which the rod passes, each seal being positioned along the rod between the pressure breaker and a low pressure end of the packing case;
• a first seal housing configured to hold a first seal of the plurality of seals;
• and
• a second seal housing configured to hold a second seal of the plurality of seals;
• wherein the first seal housing comprises a bore comprising an inner surface, the inner surface of the bore of the first seal housing and an outer surface of the rod defining an intermediate pressure space when the rod is received in the bore,
• wherein the first seal housing comprises an expansion chamber comprising an annular groove formed in the inner surface of the first seal housing and in fluid communication with the intermediate pressure space between the pressure breaker and the first seal, the annular groove and the intermediate pressure space defining a first volume, and the annular groove comprises a first depth and a first width and is configured to reduce pressure on the first seal during reciprocation, and
• wherein a pressure space is defined between the first seal and the second seal and defines a second volume that is less than the first volume.

A method of sealing a combustion chamber of a reciprocating machine, the method comprising:

• positioning, within a packing case for a rod of the reciprocating machine, a housing that defines an expansion chamber in front of a stack of seals, each seal being positioned along the rod between a high pressure end and a low pressure end of the packing case, wherein the expansion chamber comprises an annular groove formed in an inner annular surface of the housing, wherein the annular groove comprises a first depth and a first width;
• positioning, within the packing case, a pressure breaker configured to meter a flow of gas from the compression chamber, the pressure breaker positioned at the high pressure end of the packing case in front of the housing to create an intermediate pressure space that includes the expansion chamber, wherein the expansion chamber is between the pressure breaker and a first seal of the stack of seals that is closest to the pressure breaker to define a first volume, wherein a pressure space is defined between the first seal and a second seal of the stack of seals and has a second volume that is less than the first volume;
• and
• coupling the packing case with the rod.

A method of reducing wear on seals of a packing case to extend reliability and useful life of the seals, the method comprising:

• forming an expansion chamber, wherein the expansion chamber comprises an annular groove formed in an inner surface of the packing case, wherein the annular groove comprises a first depth and a first width;
• positioning the seal housing in front a stack of seals of the packing case;
• and
• positioning a pressure breaker ring at a high pressure end of the packing case, the pressure breaker ring being configured to meter a flow of gas from a compression chamber to create an intermediate pressure space including the expansion chamber between the pressure breaker ring and a first seal of the stack of seals to define a first volume,
• wherein a pressure space is defined between the first seal and a second seal of the stack of seals and has a second volume that is less than the first volume, the second seal being closer to a low pressure end of the packing case than the first seal.