| 摘要 |
<p>PURPOSE:To facilitate main pipe excavating work in the case where the main and branch pipes are connected using a Y-bend in a riser piping formula by adding only one bend to reduce a difference in height between the main and branch pipes. CONSTITUTION:A turning angle at which a Y-bend 2 is rotated centering around the central axis 2C of a main connection 2A and the bending angle gamma of a bend 7 are determined from each of formulas which express a plane projecting angle alpha formed of the main connection 2A of the Y bend 2 and a branch pipe connection 2B, a angle beta formed of a horizontal plane F1 and the central axis 2c2 of the above branch pipe joint 2B, and a plane crossing angle delta between the main pipe 3 and the branch pipe 4, and the branch pipe connecting side of the bend is established to be parallel to the horizontal plane FL and to incline at a plane crossing angle delta for piping the main and branch pipes.</p> |
