輸氣管道用無縫管線管表面發(fā)紋的檢驗與判定

Inspection and Identification of Hair Cracks of Seamless Steel Gas Linepipes

摘要: 某油田多條輸氣管道投產運行一年之后探傷發(fā)現無縫管線管表面存在發(fā)紋。經過對無縫管線管表面發(fā)紋情況進行試驗分析后認為,此類發(fā)紋屬于折疊類缺陷,其深度沒有超過標準規(guī)定的公差范圍;該類缺陷是在制管廠產生的,在使用過程中沒有擴展;該批無縫管線管表面肉眼檢查未發(fā)現超標缺陷,經過打磨探傷才發(fā)現發(fā)紋,根據訂貨標準GB/T8163-1987規(guī)定,該批管線管質量符合訂貨技術要求。

Abstract: Through relevant NDT process, surface hair cracks are found with seamless steel linepipes as used for several gas pipelines that have been operating in a certain oil field for about one year. Based on test analysis of the hair cracks, it is identified that the hair cracks are of some kind of fold defect with depths within the tolerance range as specified in application specification, and that such defects are ex-works ones, and have not extended during the site operation. No defects beyond the application specification are found with the lot of seamless steel linepipes by relevant visual inspection, and only after undergoing surface grinding treatment, and then NDT check, are the said hair defects revealed. According to the applicable Specification GB/T 8163-1987 used for the order, this lot of linepipes are in compliance with relevant technical requirements.