Cryogenic ball valve for 2k helium temperature range

Abstract

This invention discloses a cryogenic ball valve for the 2K helium temperature range, relating to the field of cryogenic valve technology. The cryogenic ball valve for the 2K helium temperature range includes a lower valve body, a ball, a valve stem, and an upper valve body. The upper valve body is mounted on the lower valve body, and the valve stem passes through the lower valve body and connects to the ball. Multiple sealing structures are spaced apart between the outer periphery of the valve stem and the upper valve body. A protective gas chamber is formed between adjacent sealing structures, and the protective gas chamber has a protective gas inlet for introducing protective gas to form a positive pressure barrier around the valve stem, preventing helium leakage and air backflow. The valve stem includes an extended section made of a low thermal conductivity material to increase thermal resistance and reduce conductive heat leakage. Multiple vibration damping rings are provided between the valve stem and the lower valve body to suppress thermoacoustic oscillations by disrupting airflow and sound field coupling. An internal sealing structure made of PCTFE is provided between the ball and the upper valve body to ensure the reliability of the cryogenic seal. This invention is suitable for 2K helium temperature conditions and systematically solves the problems of helium leakage, contamination, heat leakage, and thermoacoustic oscillations.

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