长庆至呼和浩特原油管道维修工艺

Maintenance Technologies for Chang- Hu Crude Oil Pipeline

根据长庆至呼和浩特(长呼)原油管道内检测报告,分析了管道缺陷类型和管道缺陷形成的原因,介绍了常用管体缺陷修复方式。针对长呼原油管道的特点,当腐蚀处的打磨深度小于12.5%,且无应力集中或金相异常现象时,不进行额外处理,当管道腐蚀处的打磨深度不小于12.5%,或腐蚀损失位于焊缝处时,需采用B型套筒进行修复。对比分析了常用的防腐补口、保温层和外防护层修复方式。长呼原油管道防腐补口采用防水型高温型粘弹体防腐胶带+双层聚乙烯冷缠带的修复方式,保温层采用现场聚氨酯发泡的修复方式,外护层采用防水型高温型粘弹体防腐胶带+压敏胶型热收缩带的修复方式。另外,还提出了管体缺陷修复工艺、防腐保温层修复工艺和外防护层修复工艺的技术要求和施工注意要点。

The defects classification and the causes to these defects of Chang-Hu crude oil pipeline were analyzed according to the internal inspection report. The common repairing methods of defects on pipe body were introduced. As per Chang-Hu crude oil pipeline characteristics, if the polishing depth is less than 12.5% and no stress concentration or abnormal metallographic phase exists, the extra measures are not needed. If the polishing depth is greater than 12.5% or the corrosion is on the weld, B sleeve was recommended in the repair. The common repair methods for joint coating, insulating layer and outer protective layer were compared. The water-proof, high-temperature type adhesive tape ＋ 2 layer polyethylene cold wrapping tape was adopted for joint coating repair, the field polyurethane foam was adopted for insulating layer repair and the water proof, high-temperature type adhesive tape ＋ pressure sensitive HSS was applied for external protective layer. In addition, the repair processes and precautions for the repair of the defects of pipelines, the corrosion-resistant insulation and external protection layer were presented.