| 摘要 |
PURPOSE: To certainly discover tightening failure by water (air) leakage. CONSTITUTION: A ring groove 3 bulged outward is provided on the inner peripheral side in the middle of a socket part 2 of a connecting pipe 1, an O ring 13 is installed in the ring groove 3, an outside diameter of the O ring 13 is made substantially equal to an inside diameter of the bottom of the ring groove and an inside diameter is made substantially equal to an outside diameter of a connecting pipe inserted into the socket part 2. Thereafter, a recessed part formed with a clearance flow passage between itself and the bottom of the ring groove and between itself and an outer surface of the connecting pipe into which it is inserted and a protruded part collapsed by installation to the ring groove on its both sides and collapsed by the connecting pipe into which it is inserted are provided on a part of an outer peripheral edge and an inner peripheral edge, a section outside shape of the protruded part is made substantially triangle so as follow a section inside shape of the ring groove, and when the socket part and the connecting pipe are simultaneously tightened and connected to each other by a press tool at two points of both sides of the O ring, the clearance flow passage is lost. |
