Abstract: Tee is the important part indispensible for the oil and gas transmission pipeline system. With the energy demand becoming increasingly high, oil and gas pipelines develop in the direction of large diameter, high pressure and high steel grade. China's second West-East gas pipeline (with a diameter of 1219mm and a pressure of 12MPa) shows that tubular steel of Grade X80 has been put into application on a large scale. Therefore, it is inevitable to study straight tee of Grade X80 DN1200. China Petroleum Pipeline Machinery Manufacture Co Ltd successfully passed the appraisal on tee of Grade X80 organized by CNPC in December 2008, filling a blank in production of steel tubular of Grade X80 in the Chinese and foreign pipeline sector. This article briefs about the key technologies, such as the manufacturing process of the product, selection of welding materials, welding process, sizes of the structure, formation technology and thermal processing. Made under thermal pressure manufacture, this product has a strong anti-pressure capacity, a high dynamic function and a high safety property. It is used in large batches in the second West-East gas pipeline with a 100 percent qualification rate, satisfying the engineering demand.

Key words: straight tee, steel of Grade X80, large diameter, pipeline, key technology

摘要： 三通是油气输送管道系统中不可缺少的重要组成构件。随着对能源需求量的逐步升高,油气管道向着大口径、高压力、高钢级的方向发展^[1]。我国西气东输二线(管径φ1219mm,压力12MPa)的建设实现了X80钢级管线钢由试验到规模化应用的创举,从而也使X80钢级DN1200等径三通的研制势在必行。中油管道机械制造有限公司2008年12月成功通过由集团公司组织的X80三通管件产品鉴定会,填补了国内外油气管道X80钢级管件生产的空白。文章介绍了产品的制造工艺流程及焊材选取、焊接工艺、结构尺寸成型技术及热处理工艺等关键技术。该产品采用热压制造,具有承压能力强、力学性能高、安全性高等优点。在西气东输二线管道工程中获得批量应用,合格率达100%,满足了工程要求。

关键词: 等径三通, X80钢级, 大口径, 管道, 关键技术