Abstract: An improved filter apparatus for a cryogenic fluid includes a filter and a support. The filter includes a mesh having an internal space and an open end. The support is associated with the mesh for maintaining a volume of the internal space above a predetermined value. In operation cryogenic fluid enters the internal space through the mesh and exits the open end thereof.

Abstract: A fluid storage and pressurizing assembly includes a storage receptacle and a pump assembly. The storage receptacle includes an inner vessel defining a cryogen space for storing a fluid at a storage pressure and a cryogenic temperature, an outer vessel surrounding the inner vessel, and an insulated space between the inner vessel and the outer vessel, and a pump assembly. The pump assembly includes a pump immersed in the cryogen space having an inlet for receiving a quantity of fluid from the cryogen space, and an outlet for delivering the fluid therefrom. The pump assembly further includes a pump drive unit for driving the immersed pump, the pump drive unit being at least partially disposed within a space defined by the storage receptacle.

Abstract: A piston arrangement comprises a circumferential piston groove that can accommodate a seal for sealing between the piston and the cylinder bore when the piston moves in a reciprocal movement. The piston arrangement comprises a first fluid flow passage, defined at least in part by the piston body that fluidly connects the forward side of the cylinder bore with a space within the piston groove underneath the seal and a second fluid flow passage, defined in part by the piston body, which fluidly connects the rear side of the cylinder bore with the space within the piston groove underneath the seal. The two fluid flow passages allow a controlled fluid flow around the piston seal and comprise a channel provided in a lateral wall of the piston groove or an orifice provided in the piston body.

Abstract: A fluid storage and pressurizing assembly includes a storage receptacle and a pump assembly. The storage receptacle includes an inner vessel defining a cryogen space for storing a fluid at a storage pressure and a cryogenic temperature, an outer vessel surrounding the inner vessel, and an insulated space between the inner vessel and the outer vessel, and a pump assembly. The pump assembly includes a pump immersed in the cryogen space having an inlet for receiving a quantity of fluid from the cryogen space, and an outlet for delivering the fluid therefrom. The pump assembly further includes a pump drive unit for driving the immersed pump, the pump drive unit being at least partially disposed within a space defined by the storage receptacle.

Abstract: An improved filter apparatus for a cryogenic fluid includes a filter and a support. The filter includes a mesh having an internal space and an open end. The support is associated with the mesh for maintaining a volume of the internal space above a predetermined value. In operation cryogenic fluid enters the internal space through the mesh and exits the open end thereof.

Abstract: A fluid storage and pressurizing assembly includes a storage receptacle and a pump assembly. The storage receptacle includes an inner vessel defining a cryogen space for storing a fluid at a storage pressure and a cryogenic temperature, an outer vessel surrounding the inner vessel, and an insulated space between the inner vessel and the outer vessel, and a pump assembly. The pump assembly includes a pump having an inlet disposed within the cryogen space for receiving a quantity of the fluid from the cryogen space, and an outlet for delivering the fluid therefrom, and a pump drive unit for driving the pump, the pump drive unit being at least partially disposed within a space defined by the storage receptacle.

Abstract: A piston seal for a reciprocating piston is disclosed having the shape of split ring comprising a first end segment and a second end segment overlapping along a split surface that extends from the inner circumferential surface to the outer circumferential surface of the seal and is transverse to the direction in which the 5 piston moves when reciprocating in a cylinder bore. The split surface is spaced further from the leading lateral surface of the seal that faces a compression chamber associated with the piston than it is spaced from said trailing lateral surface of the seal that is opposite to the leading lateral surface.

Abstract: A piston seal assembly is disclosed comprising a seal and a seal energizer which supports the seal. The piston seal assembly comprises one component that is designed to position the seal energizer in a fixed axial position within the piston groove. In one embodiment, the seal energizer has the shape of a split ring with at least one of its lateral surfaces shaped to position the energizer in a fixed position within a piston groove. In other embodiments the piston seal assembly comprises a spacer that is positioned next to the seal energizer within the piston groove and is designed to position the seal energizer in a fixed axial position. The piston seal assembly can comprise a seal that has a portion which protrudes between the seal energizer and the piston groove wall such that it positions the seal energizer in a fixed axial position within the piston groove.

Abstract: A fluid storage and pressurizing assembly includes a storage receptacle and a pump assembly. The storage receptacle includes an inner vessel defining a cryogen space for storing a fluid at a storage pressure and a cryogenic temperature, an outer vessel surrounding the inner vessel, and an insulated space between the inner vessel and the outer vessel, and a pump assembly.

Abstract: A piston arrangement comprises a circumferential piston groove that can accommodate a seal for sealing between the piston and the cylinder bore when the piston moves in a reciprocal movement. The piston arrangement comprises a first fluid flow passage, defined at least in part by the piston body that fluidly connects the forward side of the cylinder bore with a space within the piston groove underneath the seal and a second fluid flow passage, defined in part by the piston body, which fluidly connects the rear side of the cylinder bore with the space within the piston groove underneath the seal. The two fluid flow passages allow a controlled fluid flow around the piston seal and comprise a channel provided in a lateral wall of the piston groove or an orifice provided in the piston body.

Abstract: A piston seal assembly is disclosed comprising a seal and a seal energizer which supports the seal. The piston seal assembly comprises one component that is designed to position the seal energizer in a fixed axial position within the piston groove. In one embodiment, the seal energizer has the shape of a split ring with at least one of its lateral surfaces shaped to position the energizer in a fixed position within a piston groove. In other embodiments the piston seal assembly comprises a spacer that is positioned next to the seal energizer within the piston groove and is designed to position the seal energizer in a fixed axial position. The piston seal assembly can comprise a seal that has a portion which protrudes between the seal energizer and the piston groove wall such that it positions the seal energizer in a fixed axial position within the piston groove.

Abstract: A piston seal for a reciprocating piston is disclosed having the shape of split ring comprising a first end segment and a second end segment overlapping along a split surface that extends from the inner circumferential surface to the outer circumferential surface of the seal and is transverse to the direction in which the 5 piston moves when reciprocating in a cylinder bore. The split surface is spaced further from the leading lateral surface of the seal that faces a compression chamber associated with the piston than it is spaced from said trailing lateral surface of the seal that is opposite to the leading lateral surface.