关键词: 止回阀, 事故, 失效, 风险控制

Abstract: In order to prevent the occurrence of check valve failure，aimed at control problems of check valves exposed by accidents，the failure mode and failure phenomenon of the check valve were summarized. The special analysis was made on the accidents caused in history by the check valve failure. The pertinent measures were suggested. Based on the failure mode of check valves，the deep-seated reasons such as design problems，quality problems and maintenance problems were analyzed. Comparing the design，maintenance and inspection standards of check valves，it is concluded that the main reasons for the poor reliability of the check valves during the process are the quality of manufacture，the selection of equipment，and the inspection and maintenance. Under the guidance of “the industrial valves-pressure testing （GB/T 13927-2008）”，the selection of the check valve must be on the basis of the leakage grade, which is of great guiding significance for improving the leakage grade and ensuring the quality of the purchase. At the same time，control measures for elimination of failure risk of check valves are suggested.

Key words: check valve, accident, invalid, risk management