城市燃气管网安全性检测与评价

Measurement and Appraisal of the Corrosion of the Pipe Network of Urban Nature Gas

以北京市二高压线为例,介绍了城市管网安全性的检则和评价方法。对土壤环境性质、防腐层破损程度和管体腐蚀状况进行检测和评价的结果表明:土壤含水量偏高,呈弱碱性,土壤环境腐蚀性综合评价为中等。管线防腐层老化严重,厚度较薄且有破损点,保护性能比较差。管道的部分管体已经遭到破坏,003号探坑处已经不符合强度安全要求;其他探坑处管道在现在的服役条件下,剩余壁厚仍然可以提供足够的强度,但是管体已经发生腐蚀,建议加强检测或采用阴极保护。

Take the Er Gao ya line in Beijing as an example. The measuring and appraisal methods for the security of the urban pipe network were introduced. The results of measurement and appraisal of the soil environment, the protective coating and the pipeline corrosion indicate that the water content of soil is high, presenting a slight alkalinity. The corrosiveness of soil is rated medium. The relatively thin anti-corrosion coating of the pipeline is ageing seriously, and has some damaged parts with a poor protective performance. Part of pipeline has destroyed already. Pipes at the No. 003 trail hole do not meet the intensity safety demand. The surplus wall thickness of other trail holes can offer still enough intensity under present service states, but the pipeline has been corroded, so it is proposed to adopt strengthening measures for a check-up or for athodic protection.