螺纹公差带对偏梯形螺纹密封性的影响分析

摘要

For the reason of the influence of the tolerance zone,there exist a gap between the API buttress casing thread,and the formation of spiral shape space gap.This gap is influenced by the height of thread tolerance zone,tooth type angle tolerance zone,taper tolerance zone and the tip of thread,thread root arc radius tolerance zone.From the view of the gap area caused by the toler-ance zone,the effect on the sealing of the buttress thread is analyzed,and the calculation results show that the high tolerance zone effect the most,the second is the tooth,tooth bottom arc radius tolerance zone effect,and the tooth type angle tolerance effect is the least,the effect of the taper tolerance zone is controlled by the button on the site.At last,some reasonable measures are pro-posed to improve the connection sealing.The results provide the technical supports for the de-sign,machining,and on-site evaluation of fit-for-service of buttress thread casing.%API 套管偏梯形螺纹由于公差带的影响，使螺纹牙之间存在间隙，形成螺旋状的空间间隙带，并受到螺纹牙高公差带、牙型角公差带、锥度公差带和牙顶、牙底弧半径公差带的影响。依据公差带产生的最大间隙，分析了4个公差带对螺纹密封性的影响大小。计算结果表明：牙高公差带影响最大，牙顶、牙底弧半径公差带影响次之，牙型角公差带影响最小，锥度公差带的影响受现场上扣情况的控制。提出了合理改善密封性的措施，有助于优化偏梯形螺纹设计和加工控制，为现场检查判断偏梯形螺纹的适用性提供了依据。