法兰密封系统螺栓加载方式试验研究

均匀的螺栓载荷对法兰密封性能有极为重要的意义，由于螺栓间存在弹性交互作用，采用扭矩增量控制法按一定加载顺序加载才能降低螺栓载荷离散程度。试验研究了ASMEPCC-1传统的加载方法（LEGACY方法）和JISB2251加载方法在DNl00法兰8螺栓结构中的加载规律，以及载荷渐增顺次螺栓加载方法。采用应变片和应变仪实时监测螺栓载荷，采用力矩扳手加载。结果表明，ASME传统加载方法较为繁琐，JISB2251加载方法效率高且不易出错；以扭矩增量控制法顺次加载也能获得均匀的螺栓载荷；在保证充足预紧轮次的情况下，加载方式对最终螺栓载荷的离散程度影响不大，最后以目标载荷顺次加载几轮非常有必要。

Experimental Study of Bolt Tightening Method in Bolted Flange Sealing Connections

The uniform bolt preload has a significant effect on the flange sealing performance. The specific bolt tightening order must be taken to reduce the degree of dispersion in bolt preload because of the elas- tic interaction between bolts. An experimental study was presented in order to determine the tightening rules between the ASME PCC - 1 tightening method （LEGACY） and JIS B 2251 tightening method in the DN100 flange joint with 8 bolts. And the clockwise tightening method was also studied. The results indi- cate that the Legacy method is more tedious, while the JIS B 2251 method meets the requirement of practi- cal assembly to reduce the assembly cost and avoid human error. The uniform bolt preload can also be ob- tained in the end round by increasing tightening torque stepwise in the clockwise rotation. Tightening method （ clockwise pattern or cross pattern） has slight influence on the final bolt load in the case of ensu- ring adequate tightening rounds and it is necessary to tighten all bolts in the clockwise rotation for a few rounds in the end.