球阀工作密封投退问题的分析与处理

Analysis and treatment for seal cast back problem of ball valve

福建穆阳溪周宁水电站安装2台直径φ1 720 mm球阀,#2球阀刚投入时整体运行状况良好,后期出现影响自动开机的工作密封投退问题。经过分析,原因主要为密封损坏及先天设计不足。修改#2机组球阀开启流程,更换了新的D型密封,重新设计整套D型密封盘根,实施后未再出现类似问题。

Two ball valves with diameter φ1 720 mm were installed in Fujian Muyangxi Zhouning Hydropower Station. The overall operation of No. 2 ball valve run well when it was first putinto use,while seal cast back problem which affected automatic boot occurred at later stage. After analysis,the main reasons were seal damage and congenital design deficiency. The problems were solved by modifying the open process of No. 2 ball valve,replacing the three D type seal and redesigning the package D type sealing packing.