Abstract: Combined with the engineering design experience of domestic large-scale oil refining and chemical engineering projects in recent years, the methods used in the design of large diameter carbon steel pipeline for flare system are introduced. Calculate the wall thickness and check the stiffness conditions of the pipe in combination with SH/T 3059—2012 or ASME b31.3—2020; large diameter steel pipes are recommended to be welded with normalized steel plates and supplied after overall stress relief heat treatment; the connection between the main pipe and the branch pipe generally adopts the combination of local opening reinforcement (the outer diameter of the branch pipe is less than half of the main pipe) and tee pipe fittings (the outer diameter of the branch pipe is greater than or equal to half of the main pipe); the tee is recommended to adopt the hot extrusion flanging hot forming butt welding process, and 100% radiographic inspection shall be conducted for the weld, and plug welding connection is not suitable; the flange design shall be matched with the equipment and valve; the large diameter blind plate is designed by GB 50316—2000(2008) or ASME B31.3—2020, and the split structure is recommended; large diameter non-standard valves should be selected according to the standard of conventional size valves for manufacturing, nondestructive testing and testing, but attention should be paid to valve end flange matching with pipe or equipment ends. The limitations of the current codes are summarized, and it is pointed out that attention should be paid attention to the material design, flexibility analysis and pressure test of large diameter pipeline under wet hydrogen sulfide condition.

Key words: refining and chemical industry, large diameter, flare system piping, piping, fitting, flange, blank, valve

摘要： 结合近年来国内大型炼油化工项目工程设计经验,阐述了炼油化工企业火炬系统大口径碳钢管道的设计思路。设计原则:结合SH/T 3059—2012或ASME B31.3—2020计算管子壁厚并校核刚度条件;大口径钢管建议采用正火处理的钢板焊接,经整体应力消除热处理后供货;主管与支管的连接一般采用局部开口补强(支管外径小于主管一半)和三通管件(支管外径大于等于主管一半)结合的方式;三通推荐采用钢板热挤压翻边热成型对接焊工艺,并对焊缝进行100%射线探伤,不宜采用插焊连接;法兰设计应注意与设备和阀门端匹配;大口径盲板采用GB 50316—2000(2008)或ASME B31.3—2020进行厚度设计,推荐采用分体式结构;大口径非标阀门建议参照常规尺寸阀门的标准进行选材、制造、无损检测和试验,但应注意阀门端法兰与管道或设备端匹配。总结了当前规范存在的局限性,指出应关注湿硫化氢工况下的材料设计、大口径管道柔性分析及试压等内容。

关键词: 炼油化工企业, 大口径, 火炬管道, 管子, 管件, 法兰, 盲板, 阀门