高压大口径在役输气管道带压开孔技术分析

Technical Analysis of Hot Tapping of In-service Natural Gas Transmission Pipeline with High Pressure and Large Diameter

结合国外某在役输气管道工程实例,依据国外标准,对设计压力为7.5 MPa、DN1 000 mm、开孔率为0.9的在役输气管道的不停输带压开孔技术要点进行分析,确定主要技术参数。技术要点包括开孔位置的选择、支管连接形式和材料的选择、焊接技术要点(管道允许带压施焊压力的确定,避免烧穿及裂纹的措施,对开三通的焊接要点)。

Combined with a foreign in-service gas transmission pipeline engineering, the technical key points of hot tapping of in-service gas transmission pipeline with 7.5 MPa design pressure, DNI 000 mm and 0.9 hole opening ratio are analyzed according to the foreign standards to determine the main technical parameters. The key technological points include the choice of hole opening location, the forms of branch pipe connections and material selection, the main points of welding technology （ determination of welding pressure with allowable pressure on pipeline, measures to prevent burn-through and cracks, and welding points on three/inks）.