A Leak Detection System for Valves Cooled to 20 K while Cooled with a GM Cryocooler

Abstract

Cryogenic valves are widely used in cryogenic systems such as aerospace propulsion systems and various cryostats. Under cryogenic temperatures, thermal shrinkage and sealing material hardening may dramatically enlarge the sealing gap of the valves, which leads to a serious leakage. Therefore, a detection system for cryogenic valves is badly needed. In this paper, a cryogenic leak detection system is established, which has the capability of detecting internal and external leakage of the valves at temperatures around 20 K. Compared with the traditional cryogenic leak detection system, this system, getting rid of threats from cryogenic liquid, successfully enhances the overall safety and is able to test five valves simultaneously to improve efficiency. This system optimizes the heat exchanger structure and shortens the cooling time.