| 摘要 |
<p>PURPOSE:To connect a branch connection body easily with a main tube maintaining a secure sealability by composing to apply a pressure head part to a pressure receiving seat surface enlarged and opened along the circumference of the main tube for engagement. CONSTITUTION:A through hole 3 is formed in a flow passage 2 of a main tube l, and a conical pressure receiving seat surface 3' having a symmetric curvature to the axis of the through hole 3 expanded and opened along the outer circumferential surface of the main tube 1 is formed at its end. A joint metal 4 is provided surrounding the pressure receiving seat surface 3', and a screw hole 16 is formed in it. A pressure head part 6 is formed at an end of a branch tube 5, its forward end is formed spherical to be a pressure seat surface 18, and a circular protruding part 20a is formed at an upper part. The circular protruding part 20a is pushed by a nut 7 through a sleeve 20c. A distance l to an inner circumferential surface of the main tube 1 at an intersection of a contact line P of the pressure receiving seat surface 18 and the pressure receiving seat surface 3' and a parallel surface to the axis of the main tube 1 through the axis X of the through hole 3 is set, for a thickness T of the main tube 1, to satisfy a/5T<l<3/4T.</p> |
