Patent ID: 8684036

Claim:
A cryogenic valve comprising: a first port and a second port; a valve body comprising a valve seat defining a fluid orifice in fluid communication with the first port; a valve stem configured to engage with the valve body, wherein the valve stem comprises a first end and an opposite second end with a longitudinal axis extending through the first end and second end, wherein the valve stem forms a first channel extending substantially along the longitudinal axis, the first channel configured to allow fluid flow through the valve stem, wherein the valve stem is configured to engage with the valve body along a first engagement perimeter; a first weld configured to hermetically seal the first engagement perimeter; a sealing member; a valve element positioned within at least a portion of the first channel, the valve element configured to bias the sealing member against the orifice to substantially block flow through the orifice and the first port, wherein the bias is controlled in response to control of the position of the valve element by a valve actuator; a housing configured to substantially seal and enclose at least an engagement portion of the valve body and valve stem along a second engagement perimeter, and form an inner housing cavity configured to substantially enclose the valve stem and thermally isolate at least a portion of the valve body and valve stem, including said engagement portion, from the housing; a second weld configured to hermetically seal the second engagement perimeter; an electrical connector configured to engage the housing along a third engagement perimeter, and to allow electrical communication through the housing; and a third weld configured to hermetically seal the third engagement perimeter.