摘要 |
PURPOSE:To provide a coupling device which is not removed easily, and has also a sealing property. CONSTITUTION:Between a screw tube 5 and a union nut 6 screwed to the screw tube 5, a metal ring 11 with a cut circular form to be inserted to a copper pipe 4 is provided. Taper form inner end edges 9 and 10 to which the metal ring 11 is engaged so as to contract its diameter are formed to the screw tube 5 and the union nut 6. Furthermore, a locking groove 7 to surround the copper pipe 4 at an adequate position on the inner surface of the screw tube 5 is formed, and a seal ring 8 to pressure contact to the outer peripheral surface of the copper pipe is fitted and locked to the locking groove 7. |