基于SINTAP标准的海底外输管线安全评定

SAFETY ASSESSMENT USED FOR WELDED PIPELINE BASED ON SBSTAP

采用欧共体提出的结构完整性评定方法SINTAP(StructuralIntegrityAssessmentProcedure)对海底外输管线API5LX56焊接接头埋藏裂纹进行了安全评定。根据母材和全焊缝拉伸试验结果建立评定曲线;根据BS7448:Part4标准采用多试样方法进行了低温断裂韧性试验,建立了焊缝和HAZ的CTOD—R阻力曲线,从而确定了启裂CTOD值δ0.2。在评定计算中取不同水深的应力最大值,考虑残余应力的影响,针对由DNVOS—F101中规定的最大错位情况,给出了在铺设条件下的容许埋藏裂纹尺寸。为管线铺设工程中的焊接缺陷验收和拒收提供了依据。

Structure Integrity Assessment Procedure （SINTAP） put forward by the European Commission was applied in safety assessment for welded joints of the API 5LX56 pipe line steel with embedded flaw. Assessment curves derived from the tensile test results of parent materials and welded seam were obtained. Based on BS 7448 standard, CTOD-R resistance curve of welded seam and HAZ derived from low temperature fracture toughness test was obtained, from which CTOD value leading to crack was determined. The assessment was carried out using the maximum stress at different water depth considering residual stress. The tolerable embedded flaw sizes were achieved in maximum allowable misalignment, which supply standard to evaluate the acceptability of flaws in pipe line paving engineering.