The analysis and experimental research of ultrahigh vacuum ConFlat-type flange joints applied in accelerator and space technology

Finite element analysis (FEA) of ultrahigh vacuum ConFlat-type flange joints for both Wheeler's and CERN's models were carried out. These models differ in the angle of inclination between the two shelves of knife-edge. The main value of this research is a computer simulation for deformable flanges and gaskets because all analyses before this have been done for absolutely rigid flanges (non-deformable flanges) and deformable gaskets. The analysis variable parameters are the radius of rounding at the tip of the knife-edge (0.05 … 0.2 mm), the angle between the shelves forming the knife-edge (70° and 90°) and the material properties of the copper ring (annealed and 1/4 hard). The calculation of bolted connections for tightening the flanges was also carried out as the experience has shown that during the tightening of bolts, they reach the yield point and begin to deform plastically. That leads to incomplete tightening of the flanges and, therefore incomplete sealing of the joint. The experimental research of the flanges tightening and the comparison with computer simulation results were carried out.