JPH0369142B

PURPOSE:To make a safety valve to operate at a definite pressure, by placing the safety valve so as to seal an exhausting hole provided on the concave part of a cover giving compression, while placing an upper cover over the safety valve, and welding the cover and the upper cover together when the pressurizing force is elevated to a specified value. CONSTITUTION:The concave part 5 of cover 4 is set on a supporting table 13, and a safety valve 1 is placed on the concave part 5 so as to seal an exhausting hole 7 provided on the part 5, and then over which an upper cover 6' provided with an ejecting hole 8' is placed. Then a pressurizing rod 14 is applied on the upper cover 6', and the safety valve 1 is compressed by moving the said rod toward the direction of the arrow. Under the specified pressurizing force, the upper cover 6' ad the concave part 5 of the cover 4 is welded together by such as laser welding. Thereby safety valve operates accurately at the definite pressure without dispersion thereof.