| 摘要 |
PROBLEM TO BE SOLVED: To provide a fixing structure of check valve and packing, in which a fastening force of a cap nut does not give any influence against action of a valving element or does not produce any problem in sealing characteristic, when a check valve is newly and additionally installed between a meter and a joint.SOLUTION: A check valve 25 includes a main body 26 inserted into a joint 11 and a flange 28 positioned in an enlarged diameter part, and an annular packing 35 having a circumferential groove at its inner circumference is mounted to cover the flange. A valve seat pressor 31 for pressing a valve seat is installed outside the flange 28. The outer circumference side of the valve seat pressor 31 is formed with a circumferential groove, an outer circumferential wall of the packing is stored in the circumferential groove and an inner circumferential wall is positioned inside the flange. In a free state, a clearance is provided between an inner circumference of the inner circumferential wall and an outer circumference of the main body 26 of a valve box. When a cap nut 21 is fastened, movement of the valve seat pressor 31 is restricted by a shoulder part 9 at an inner end of the enlarged diameter part 7, the packing 35 is compressed and the check valve 25 is fixed. |
