The pipe ball joint includes a casing having a socket portion with a substantially spherical interior surface and a first pipe segment extending from the socket portion. The socket portion has an annular groove disposed adjacent the partially spherical interior surface. A ball pipe section includes a ball segment received in the socket portion of the casing and a second pipe segment extending from the ball segment. A seal assembly is received in the annular groove of the casing and is disposed against the ball segment of the ball pipe section. The seal assembly includes a plurality of nested seal rings that each include a concave face and a convex face.

A first peripheral wall end portion of a conversion adapter is connected to a tubular body across a gasket, and has either an annular protrusion to be pressed into an annular groove on a side surface of the gasket, or an annular groove to allow an annular protrusion projecting from a side surface of the gasket to be pressed thereinto. The first peripheral wall end portion has either an internally threaded portion to allow an externally threaded portion of the tubular body to be screwed thereinto, or an externally threaded portion to allow a nut to be screwed thereonto. The nut also allows an externally threaded portion of the tubular body to be screwed thereinto. A second peripheral wall end portion of the conversion adapter has an externally threaded portion to allow another nut to be screwed thereonto, and then, to allow the sleeve to make contact with the inside.

The pipe ball joint includes a casing having a socket portion with a substantially spherical interior surface and a first pipe segment extending from the socket portion. The socket portion has an annular groove disposed adjacent the partially spherical interior surface. A ball pipe section includes a ball segment received in the socket portion of the casing and a second pipe segment extending from the ball segment. A seal assembly is received in the annular groove of the casing and is disposed against the ball segment of the ball pipe section. The seal assembly includes a plurality of nested seal rings that each include a concave face and a convex face.

A fluid seal may comprise an external sealing body, and an internal sealing body disposed within the external sealing body. The internal sealing body may be radially connected to the external sealing body by a webbing. Further, the external sealing body may hermetically seal a fluid path from the exterior of the fluid path, while the internal sealing body may hermetically seal the fluid path from within the interior of the fluid path.

A reciprocating compressor and a method of manufacturing a reciprocating compressor. The reciprocating compressor may include a discharge muffler forming a discharge chamber in which refrigerant compressed in a compression chamber flows and a discharge hose that extends from the discharge muffler to guide discharge of the refrigerant and coupled to the discharge pipe. At least a portion of the discharge muffler and the discharge hose are integrally formed using injection molding.