Abstract
Generally, a bolt axial tension is applied by the torque control method for the bolted flange connection. The torque control method does not allow an accurate control of the bolt axial tension due to the problems related to friction. Another cause is that the axial tensions of bolts often do not become uniform because tightening of bolts causes elastic interaction among bolts, when more than one bolts are used. In order to obtain uniform bolt loads and to prevent accidents, a guideline of the pipe flange tightening was proposed by ASME PPC-1. However, the easier tightening method is desired for more than it. In this study, FEM analyses and correspond experiments were examined, and the authors propose to tighten two bolts simultaneously in the bolted flange connection sequence.
