减压塔出口膨胀节泄漏失效分析及修复

对某石化公司二蒸馏装置减压塔馏出口管线上的覫Ф1100 mm膨胀节在蒸汽吹扫时的泄漏失效进行了分析。结果表明,由氯离子引起的应力腐蚀以及电化学腐蚀的共同作用是导致膨胀节泄漏的根本原因。另外,膨胀节不锈钢材料与碳钢之间的电位差加速了电化学腐蚀的速度。修复后跟踪观察表明,对整个焊口使用"贝尔佐纳"技术屏蔽隔离以避免氯离子的结聚是解决膨胀节泄漏的有效方法。

Failure Analysis and Repair of Expansion Joint in Outlet Pipe of Vacuum Tower

The failure analysis on the leaked 01 100 expansion joint placing in outlet pipe of vacuum tower in a second distillation plant was investigated. The resuhs indicated that, the combination effects of stress corrosion resulting from chlorine ions and electrochemical corrosion caused the leakage of the expansion joint. Moreover, certain potential difference between stainless steel of expansion joint and carbon steel accelerated the rate of electrochemical corrosion. The tracking observation after repair showed that using Belzona technology to prevent the welding line from chlorine ions was available method to solve the leakage problem of expansion joint.