安全阀弹簧失效原因分析与改进措施

Failure Analysis of Pressure Relief Valve in FCCU and Improving Measures

弹簧式安全阀是用于催化装置上的重要部件，在常温下露点腐蚀是弹簧式安全阀失效的重要原因。针对大连石化公司二催化装置T302解吸塔塔顶安全阀的失效，利用电子能谱（EDX）、SEM电镜扫描等手段对失效安全阀弹簧进行检测分析，得出安全阀弹簧失效的主要原因是安全阀接触的介质舍有H2S、SO2、H2O，这些介质在30—40℃，常压的务件下在安全阀弹簧的表面形成酸性露点而腐蚀表面形成点蚀坑，这些点蚀坑引起应力集中导致弹簧断裂，并针对具体情况提出解决方案。

Pressure relief valve are key equipments in FCCU and sulfur dew point corrosion is main reason of their failures. Aimed at the failure of pressure relief valve on top of tower T302 in FCC of Dalian Petrochemical Corporation, the analysis was performed by means of various techniques including EDX and SEM observation, the results show that the main reason of failure of pressure relief valve is that the media which pressure relief valve contacts are H2S, SO2 , H2O, and they form dew points holes on the surface of spring and corrode it under condition of temperature 30 - 40℃ and normal pressure. The holes cause stress concentration and the spring＇s rupture. According to operating condition some improving measures are suggested.