秦山第二核电厂安全厂用水系统D700止回阀不回座缺陷分析和处理

Analysis and Solution for Not Returning of DN700 Check Valve of Essential Service Water System in Qinshan Ⅱ

秦山第二核电厂3、4号机组安全厂用水系统DN700旋启式止回阀在机组运行期间,出现了不能自动回座的共性缺陷,并且故障频发,一度影响了系统的正常功能,对机组稳定运行造成了安全隐患。本文结合止回阀的结构对可能造成此缺陷的因素进行了一一分析,并找到了根本原因,最终顺利消除了此缺陷,保证了机组的安全运行。

During the operation period,the DN700 swing check valve of essential service water system in Unit 3 and 4 of Qinshan II did not automatically return,and the normal function of the system was once affected,which endangers the stable operation of the unit.The thesis analyzed the factors possibly causing the defect based on the structure of the check valve.The root cause was found out,and the defect was successfully eliminated,so that the safe operation of the unit was ensurd.