| 摘要 |
PROBLEM TO BE SOLVED: To prevent a valve member from being contacted with the inner circumferential surface of a pipe installed and at the same time to enable an inter-surface clearance to become narrow even if a pipe diameter is increased.SOLUTION: The central part of a stopper plate 3 is provided with a communicating flow passage 25 having incomplete circular section and a restricting part 26 is arranged at the upper part of the communicating flow passage 25. The restricting part 26 is formed into a tapered shape extending in a flow passage central direction from the end surface abutted against an upstream side valve case 1 of the stopper plate 3 toward the end surface at the downstream side. The extremity end at the downstream side of the restricting part 26 is provided with an engaging part 27 abutted against an inner circumferential edge of the upper part of a disc part 13 of a valve body 2 under a full-opened state and restricting a degree of opening of a wafer type check valve. At this time, the upstream side of the engaging part 27 is formed with a clearance 34 between the restricting part 26 and the disc part 13. |
