Abstract:Rotation angle is very important for pipe precasting and site erection. However, it is difficult to determine the right rotation angle. By analyzing rotation angle hidden in pipe of different structure, the author claimed that the rotation angle is the dihedral angle of pipe section rotated before and after. Two calculation methods were provided. By comparison,CAD based calculation is more accurate than trigonometric function.

Keywords:power plant distribution design, pipe section, rotation angle, dihedral angle, calculation method