管道外径和壁厚是管道设计的重要参数,但由于现有工艺技术的限制,在制作过程中外径和壁厚必然存在一定的制造偏差,对管道可靠度会造成一定影响。为明确外径和壁厚的制造偏差对管道可靠度的影响,首先通过管道几何尺寸测量仪获得了管道的外径与壁厚数据,研究了管道外径和壁厚的分布规律；然后建立计算管道压力的极限状态函数,利用一次二阶矩法推导了考虑管道外径和壁厚制造偏差影响的管道可靠度计算公式；在此基础上,研究了管道外径和壁厚的平均值与标准差对管道失效概率的影响,并分析了管道失效概率对各个影响因素的敏感程度。研究表明,管道外径制造偏差对管道可靠度的影响较小,而壁厚制造偏差对管道可靠度的影响相对较大。因此，在管道加工制作过程中,应严格控制壁厚的制造偏差。

The outer diameter and wall thickness of pipeline are important parameters in pipeline design. But due to the limitation of the existing technology, there will be a deviation from manufacturing tolerances of the outer diameter and wall thickness in the pipeline production process, which will have certain impact on pipeline reliability. In order to study the influence of deviations from manufacturing tolerances of outer diameter and wall thickness on pipeline reliability, this paper obtained the data of pipe outer diameter and wall thickness by pipeline geometry dimension measuring instrument, and studied the distribution law of pipe outer diameter and wall thickness. The limit state-function for calculating pipeline pressure is established and the reliability calculation formula considering the influence of deviation from manufacturing tolerances of pipeline is derived by using first-order second-moment method. On this basis, the influence of average and standard deviation of pipe outer diameter and wall thickness on pipeline failure probability was studied, and the sensitivity of pipeline failure probability to the geometric parameters was analyzed. The results show that the deviation from manufacturing tolerances of outer diameter has little influence on pipeline reliability, while that deviation of wall thickness has relatively large influence on pipe reliability. Therefore, the deviation from manufacturing tolerances of wall thickness should be strictly controlled in the process of pipeline production.