机坪管线外防腐对阴极保护影响的分析

Analysis of Hydrant Pipeline Outer Corrosion Prevention Influence on Cathodic Protection

某机场机坪加油管线扩建工程竣工验收阶段,在对牺牲阳极保护系统进行测试时,发现阴极保护电位没能达到规范要求的-850 m V。经过分析调查,造成此问题的原因可能是管线外防腐层的变化、旧机坪的杂散电流以及管线土壤电阻率的变化,重点从管线外防腐层自身性质和工艺计算两个方面分析了对牺牲阳极保护系统效果的影响情况。该工程牺牲阳极阴极保护系统管道保护电位不达标的原因主要是新旧机坪管线绝缘问题和牺牲阳极组数量不足,据此进行整顿后管道保护电位达标。

On the stage of the airport hydrant pipeline extension project complete acceptance,when taking a test on sacrificial anode protection system,it was found that the cathodic protection potential did not scratch- 850 m V which specified by standard. After analysis and investigation,the pipeline outer corrosion variation,stray current of old hydrant and soil resistivity variation were the probable cause,and the outer corrosion prevention features and process calculation were focused on to analyze influence of sacrificial anode protection system effect. The main reasons of this project sacrificial anode protection system pipeline protection potential which is unqualified were insulation problem of the new and old hydrant pipeline,and the insufficient scrificial anode amount. Accordingly,the pipeline protection potential was qualified after rectifying.