外载作用下小口径设备管口法兰校核方法的探讨

ON CHECKING METHOD FOR EQUIPMENT NOZZLE FLANGE WITH SMALL DIAMETER UNDER EXTERNAL LOAD

法兰按其在工程上所对应的专业可划分为设备用法兰、管道用法兰及设备与管道相接的管口法兰。文章简要说明了这三类法兰的设计特点,同时介绍了设备和配管两专业在法兰校核上所侧重的方法。通过有代表性的工程实例,得出外载作用下采用各专业不同侧重的管口法兰校核方法计算产生的不同结果,并在此基础上详细阐述了当量压力法,NC3658.3、ASME SectionⅧ法兰应力计算方法及EN1591法兰校核方法的计算原理、各自特点及存在的问题,最后结合计算结果的对比、分析,提出了外载作用下小口径管口法兰校核方法的选择建议。

Flanges can be divided into equipment flanges,pipeline flanges and nozzle flanges for equipment and pipeline connections according to the disciplines they correspond to in engineering.This paper briefly explains the design features of these three types of flanges,and introduces the preferred checking methods for equipment and piping disciplines.Different calculation results were obtained from adopting different checking methods under external load preferred by each discipline through a representative engineering example.On this basis,the paper further elaborates the calculation principles,respective characteristics,and existing problems of equivalent pressure method,NC3658.3,ASME SectionⅧand EN1591.Finally,combining with the comparison and analysis of the calculation results,suggestions for the selection of appropriate checking methods for small-diameter nozzle flanges under external load are made.