关于防腐大修的讨论与建议

Discussion and Suggestion on Pipeline Old Coating Displacement

埋地长输油气管道的防腐绝缘层大修理是延长管道运营寿命的必要措施。介绍了秦皇岛输油公司所辖管道的防腐大修情况,分析并讨论了防腐大修中存在的问题,认为:第一,理论上认为沥青防腐绝缘层寿命为20a左右的观点并非合理,20a应是平均寿命,不能一概而论;第二,用现行的防腐绝缘层电阻率的测量方法得到的数据不能可靠地说明防腐层老化程度;第三,防腐大修现场施工困难,质量难以保证。建议:防腐大修方案应在加强管理和实际检测的基础上制定;防腐大修选段判定的主要依据应以检漏和开挖坑检为主,以测量管道防腐绝缘层电阻率及日常资料分析为辅;防腐大修与维修相结合;加强质量监督;选择适用的材料并利用新技术进行管道防腐层的维修和检测。

Old coatings displacement is a necessary measures taken for elongating the service life of buried oil/ gas pipeline. The analysis and discussion have been made on the problems existed during the displacement by Qinhuangdao Oil Transportation Company. It is concluded that the standpoint which the service life of asphalt coating was 20-year is not correct on thoery,but the year should be an average service life and not treated as the same;the resistivity data of coating measured according to the current measurement method can not instruct the ageing extent of the coating;the old coating displacement is difficult to conduct because of inconvenient construction in the field. It is suggested that the displacement program should be worked out on the base of inspection;the displacement program of coatings should be firstly based on the results of leakage detection and bellhole inspection, secondly on analysis of the inspection of coating resistivity and daily inspection records;the displacement should be combined with coating repair;the quality supervision must be strenghened;the proper materials and new methods have to be selected to conduct the renovation and inspection of pipeline coatings.