Packing: PTFE or graphite packing protected from freezing by a column of insulating gas.
Packing: PTFE or graphite packing protected from freezing by a column of insulating gas.
填料：通过绝缘气体柱防止PTFE或石墨填料冻结凝固。
Packing: PTFE or graphite packing protected from freezing by a column of insulating gas.
填料：通过绝缘气体柱防止PTFE或石墨填料冻结凝固。