| 摘要 |
PROBLEM TO BE SOLVED: To provide a pipeline blocking-up gas expanding seal structure capable of preventing damage of a fluid expanding seal member caused by clearance generated between the peripheral edge of a joining seat of a valve connector and an outer peripheral surface of a plug body. SOLUTION: The valve connector 30 having a boss 32 protrusively formed on one side in the center of the disk-like joining seat 31 having the prescribed plate thickness and a prescribed diameter is arranged in a valve part of a gas expanding seal 20 inserted and installed around the outer periphery of a closing plug body 10. The joining seat 31 of this valve connector 30 is formed in a circular arc shape corresponding to a circular arc of the outer peripheral surface 11 of the closing plug body 10. |
