The SPIDER in-vessel actively cooled components shall be drained in case of major maintenance to limit, as much as possible, atmospheric corrosion inside the circuits, to prevent water spreading, and finally to allow the execution of vacuum leak tests of the components before re-installation of the SPIDER Beam Source (SBS) inside the Vacuum Vessel. Draining of hydraulic circuits is first foreseen by gravity after opening the end connections of hydraulic circuits and then by blowing out with nitrogen. Injection of pressurized nitrogen is simulated by means of one-dimensional and three-dimensional models to perform transient two-phases analyses in order to calculate the minimum required inlet pressure and estimate the process time.

进行大维护时，应排空SPIDER船上主动冷却的组件，以最大程度地限制电路内部的大气腐蚀，以防止水扩散，并最终允许在重新安装之前执行组件的真空泄漏测试将SPIDER光束源（SBS）安装在真空容器内。在打开液压回路的末端连接之后，首先要通过重力预见液压回路的排空，然后再吹氮气。借助一维和三维模型对加压氮气的注入进行模拟，以执行瞬态两相分析，从而计算所需的最小入口压力并估算过程时间。