核电厂主蒸汽安全阀内漏原因分析及处理

NPP Main Steam Safety Valve Inner-leakage Analysis and Solution

核电厂主蒸汽安全阀直接保护主蒸汽系统的安全,阀门密封面如果出现明显的蒸汽泄漏现象,将导致机组停堆,提高安全阀的密封可靠性尤其重要。通过分析,发现引起主蒸汽安全阀内漏的主要原因有:安全阀使用过程中整定压力逐渐变低、安全阀密封面逐渐变宽等。针对以上原因,探索了安全阀碟簧调整、安全阀阀芯机加工及更换、安全阀阀座研磨等方法,提高了主蒸汽安全阀的密封可靠性和长期运行的稳定性。

NPP Main Steam Safety Valves protect the safety of Main Steam System.If there is obvious steam leakage from the trim,the Unit shall be shut down.It is very important to improve the valve seat tightness reliability.Through analyzing,we found the causes of the safety valve inner leakage:the set pressure of the safety valve changed lower along with using,the seal surface changed wider,etc.For the upper causes,we had tried adjusted the belleville spring,machined the disc or replace it,machined the seat,etc.Through the upper actions,we had increased the valve seat tightness reliability and improved the valve long-term reliability.