低温绝热容器是指用于存储液氧、液氮、液氩、液化天然气等低温液体的压力容器~[1]。低温绝热技术是通过限制热传导、热对流和热辐射三种传热途径减小热量传递方法的手段。目前常用的绝热技术有普通堆积绝热、高真空绝热、真空粉末绝热、真空多层绝热~[2]。为获得良好的绝热效果,绝热层往往工作于真空环境中,其真空度的大小对绝热效果起关键作用。因此,TSG R7001—2004《压力容器定期检验规则》规定 Low-temperature insulated container is used to store liquid oxygen, liquid nitrogen, liquid argon, liquefied natural gas and other cryogenic liquid pressure vessel ~ [1]. Cryogenic insulation is a means of reducing the heat transfer by limiting the heat transfer, thermal convection and thermal radiation. At present, the commonly used adiabatic technology has ordinary stacking insulation, high vacuum insulation, vacuum powder insulation, vacuum multi-layer insulation ~ [2]. In order to obtain a good adiabatic effect, the insulating layer often works in a vacuum environment, and the degree of vacuum plays a key role in adiabatic effect. Therefore, TSG R7001-2004 “Pressure Vessels Regular Inspection Rules” provides