介绍干气密封的结构、工作原理、优越性，以及在离心泵轴封领域的应用情况和前景。
The paper introduces the structure, working principle, advantage of gas seal in centrifugal pump and its application and prospect.
阀门在试验过程中可翻转90度工作，特别适用气密封性能试验。
Valve can turn 90 degree working in testing course, especial suitable for property experiments of gas seal.
文章介绍了干气密封及其系统各部件的工作原理、结构、作用及其在乙烯冷泵中的应用情况。
This paper introduced dry seal and the working principle, structure and functions of its various parts, as well as its ap-plying situation in ethylene cold pumps.
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