某采用外加电流阴极保护与牺牲阳极联合保护管线外腐蚀因素及控制措施

A pipeline Was Protected By Impressed Current Cathodic Protection and Sacrificial Anode External Corrosion Factors and Control Measures

管道外防腐多采用防腐层外加电流阴极保护或牺牲阳极保护。有些管线由于建设时间早,或局部保护电位不达标等原因,采用外加电流阴极保护加牺牲阳极联合保护。但实际使用中发现,失效牺牲阳极的工作状态会影响到外加电流阴保系统的正常运行。本文针对某采用联合阴保的管线外腐蚀现状,分析了外腐蚀因素;提出了初步控制措施:拆除失效牺牲阳极(含阴保机附近牺牲阳极)、修复破损绝缘层、合理提高保护电位等。

The external anticorrosion of pipeline is mainly protected by impressed current cathodic protection or sacrificial anode protection.In some pipelines,impressed current cathodic protection combined with sacrificial anode protection is adopted because of early construction or local protection potential is not up to standard.But in practice,it is found that the working state of the failed sacrificial anode will affect the normal operation of the impressed current cathodic protection system.In this paper,the external corrosion factors of a pipeline with combined cathodic protection are analyzed.The preliminary solutions are presented as follows:removing the failed sacrificial anode(including the sacrificial anode near the cathodic protection machine),repairing the damaged insulation layer,reasonably increasing the protection potential,etc.