输气管道高强度试压方法及其在X80管道上的实践

根据管道屈服强度的样本统计数据，利用概率方法，结合管道埋地时的双轴应力状态，并根据试压段高差，确定管道可接受的最高强度试压压力。基于管道弹性变形，提出考虑空气含量和水压缩性的压力-容积曲线理论表达式。在工程实践中，采用压力-容积曲线实时监控试压进程，应用霍尔元件记录泵冲程数确定管道进水量，以此获得实际压力-容积曲线。在伊宁-霍尔果斯管道工程中，根据该方法确定管道试压强度为试压段高点不低于96% SMYS，实际监测所得的压力-容积曲线与理论曲线吻合较好，管道未发生泄漏。

A new method for high-strength pressure testing in gas pipelines and its application to the X80 gas pipeline in China

According to statistical data of pipeline yield strength samples, the acceptable maximum test pressure was determined using a probabilistic method while the elevation difference of the test segment and the biaxial stress of an undermined pipeline were fully considered. A mathematical expression of P-V curves, which takes the effect of residual air and compressibility of water into account, was proposed based on the elastic deformation of pipelines. In its engineering applications, a real-time control of the P-V curves was adopted during the pressure testing and the Hall element which can record pump strokes was used to determine the water volume pumped into pipelines, thus, the real P-V curves could be obtained. In the pressure testing of the Yining-Khorgos X80 gas pipeline, the hoop stress derived from this method was no less than 0.96 SMYS at the highest point of the test segment. The P-V plot recorded by pressure sensor and Hall element was well consistent with the theoretical P-V curves proposed with this method, and no leak was found during the test period.