| 摘要 |
PROBLEM TO BE SOLVED: To prevent burst of a membrane sheet at the time of the operation of a safety valve.SOLUTION: A safety valve includes: a fitting shaft 3 protruding downward from a center hole of a membrane sheet 2 stretched below a valve body 1; a sheet support part 4 fixed at the fitting shaft 3 so as to support the membrane sheet 2 from below; and an extension member 26 fixed at the fitting shaft 3. The extension member 26 is made of a box nut for being inserted into a male screw part 18 formed on an outer diameter surface of the fitting shaft 3. A pressure intake port 29 formed on an outer diameter surface of the extension member 26 is located farther from the outer diameter of the fitting shaft 3 in a shaft diameter direction, and continues to a hollow hole 23 inside the fitting shaft 3. A pressure introduction passage introduces primary side pressure to space 5 between the valve body 1 and the membrane sheet 2 via the pressure intake port 29 and the hollow hole 23. When opening the valve, the space 5 is decompressed by the suction from the pressure intake port 29 by an ejector effect. |
