抄録
In multi-bolt system, the scatter in axial bolt force is largely dependent on the method of tightening operation and elastic interaction due to the successive tightening of bolts. For tightening bolt operation, mainly two operations can be cited. It is JIS B 2251 and ASME PCC-1. In JIS B 2251, the range of application of gaskets is exclusive to Compressed Fiber Sheet Gasket and Spiral Wound Gasket. Because elastic modulus of Expanded PTFE Gasket is low value, there is a possibility of uneven gasket stress. Therefore Expanded PTFE Gasket is not applicable to JIS B 2251. In this study, focus is placed on elastic modulus of gasket. The present paper describes consideration of appropriate tightening round and scope application of JIS flange joint assembly guidelines by tightening test and three-dimensional finite element analysis in accordance with JIS B 2251. If elastic modulus of gasket is over 0.06, JIS B 2251 is effective procedure for flange joint assembly. Because average bolt force preload ratio to the target is more 85 percent on round three, appropriate the number of tightening round is three rounds.
