摘要 |
A spring loaded valve for use with a cryostat insert is provided for selectively directing liquid cryogen to the bottom or top of a supercoolable vessel. The spring loaded valve situated at the tip of the insert extends into a housing in the top of the supercoolable vessel. A slidably mounted sleeve extends inside a cryogen fill tube. The sleeve is spring loaded and when the valve is inserted in the housing the fill tube covers apertures in the sleeve allowing fluid to flow from the fill tube through the end of the housing past the valve head. When the spring loaded valve is partially retracted from the housing the holes in the sleeve are uncovered and liquid can flow from the fill tube to a passageway in the housing extending to the bottom of the supercoolable vessel. The valve closes the aperture leading to the upper portion of the vessel.
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