| 摘要 |
PROBLEM TO BE SOLVED: To reduce irregularity in operation pressure range of a safety valve and to keep a sealed state even when flaws or foreign matters are adhered to a contact surface between the safety valve and a safety valve cylinder, by providing a plurality of ring-like projecting parts on the inside surface in contact with the safety valve cylinder of the safety valve. SOLUTION: Three ring-like projecting parts 6, for example, are provided on the cylindrical inside surface in contact with a safety valve cylinder of a cap-shaped safety valve 1 that is covered over the cylindrical safety valve cylinder, using a black chloroprene rubber. Area of these ring-like projecting parts 6, namely, total area of three ring-like projecting parts 6 where the safety valve 1 comes into contact with the safety valve cylinder is 40-50% of total inside area. Since the safety valve 1 comes into contact with the safety valve cylinder at the ring-like projecting parts 6, adhesion of both can be prevented, and difference between maximum and minimum of operation pressure, namely, irregularity in the operation pressure can be reduced. Even when flaws or foreign matters are adhered to a contact surface between the safety valve 1 and the safety valve cylinder, the plurality of ring-like projecting parts 6 are provided, so that a sealed state can be kept. |
