摘要
Abstract
A comparison of flange design calculation methods and flange standards specified in the design specifications for gas pipelines,process pipelines,and pressure vessels in the United States reveals that only the design specifications for gas pipelines simultaneously adopt the pipe flange standards ASME B16.5 Pipe flanges and flanged fittings:NPS 1/2 through NPS 24,Metric/lnch Standard(hereinafter referred to as ASME B16.5),ASME B16.47 Large diameter steel flanges:NPS 26 through NPS 60,Metric/inch standard(hereinafter referred to as ASME B16.47),and the pipeline flange standard ANSI/MSS SP-44 Steel pipeline flanges(hereinafter referred to as ANSI/MSS SP-44).To investigate the cause of these differences,through a brief review of the Taylor-Waters method for flange design calculation,the compilation history of pipe flange standards ASME B16.5,ASME B16.47,and pipeline flange standard ANSI/MSS SP-44,as well as an analysis of ANSI/MSS SP-44′s provisions on pipeline flange materials,heat treatment,and flange design,it is clarified that the minimum yield strength and wall thickness of pipeline flange welding ends in gas pipelines and the pipes connected to them have a mutually related impact,which may affect the structural dimensions of pipeline flanges and the selection of flange body materials.Especially when the pipes connected to the pipeline flange welding ends are high-strength,cold-worked,and thin-walled,more attention should be paid to the selection of pipeline flange body material and its impact on the sealing performance of flange gaskets.This is a distinctive feature of pipeline flanges compared to pipe flanges.Based on an analysis of the design and selection of pipeline flanges in China's gas pipeline projects,as well as the current status of pipeline flange standard compilation,suggestions are made to revise and supplement the technical provisions related to pipeline flanges and pipe flanges in the design specifications for gas pipeline engineering.These suggestions include compiling pipeline flange standards and pipeline flange steel standards and systematically replacing non-compliant flanges on in-service gas pipelines to ensure the sealing performance of in-service pipeline flanges and achieve long-term safe operation.关键词
管法兰/管线法兰/法兰设计/泰勒—华脱尔斯法/垫片密封性能/管子最小屈服强度/管子壁厚/法兰焊接端Key words
Pipe flange/Pipeline flange/Flange design/Taylor-Waters method/Gasket sealing performance/Minimum yield strength of pipe/Pipe wall thickness/Flange welding end
