在役双金属复合管失效后抢险试压方案优化

Optimization of Emergency Pressure Test After Failure of Bimetal Composite Pipe

对于焊缝频繁发生腐蚀穿孔失效的双金属复合管埋地集输管道,难以通过检测手段评价管道的剩余使用寿命,可以对管道进行试压,初步判断管道的安全性,但是对于已使用并存在较严重腐蚀的双金属复合管没有可以依据的相关试压标准规范。通过对标分析,新建集输管道的试压标准对于此类管道试压不可行,优化降低试压压力大于运行压力并且小于设计压力,在管道氮气置换合格后,利用装置自产天然气依据建压曲线逐步建压试压,稳压检漏合格后组织投产,确保管道在运行压力下并且在小范围内波动时的安全性。通过实践,证明此方法可行,达到预期目的,可在类似工程中推广应用。

For the buried double metal composite pipe with frequent weld corrosion perforation, it is difficult to evaluate the remaining life through detection.Preliminary judgment of pipeline safety can be performed upon pipeline pressure test.But for double metal composite pipes that are in service with serious corrosion, there are no related standard specifications for pressure test.Through analysis, standard for pressure test of newly-established pipeline is infeasible to this kind of pipeline.Test pressure shall be reduced to make it greater than the operating pressure and lower than the design pressure.After passing pipeline nitrogen replacement, pressure shall be gradually established and tested according to the curve.Start-up shall be conducted after passing leak detection to ensure the safety of pipeline under operation pressure and small range of fluctuation.It is proved that this method is feasible and can be promoted in similar projects.