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1·Encl. : a telegram from my home.

附：拍来的电报一份。

2·This paper describes and analyses the reasons of the failure of dual-encl-face mechanical seal for hydrocarbon pump and proposes a reformation and design method.

本文阐述并分析了轻烃泵用双端面机械密封的特点，提出了改进方法和设计依据。