| 摘要 |
PURPOSE:To provide a simple-structured device which eliminates the need to regulate, by a method wherein two elastic members are located between both sides of an overpressure resisting diaphragm which separates a high-pressure side and a low-pressure side from each other and between end surfaces of a first and a second casing positioned facing and opposite to each other. CONSTITUTION:An overpressure resisting diaphragm, separating a first pressure chamber (high-pressure side) and a second pressure chamber (low-pressure side) from each other, is placed. Two elastic members, which control a volume change rate against the pressure of the diaphragm corresponding to displacement of the overpressure resisting diaphragm due to a differential pressure so that, if the differential pressure is within a detecting range, the volume change rate reduces, and if exceeding the detecting rate, the change rate increases, are located between the both sides of the diaphragm and between end surfaces of a first and a second casing positioned facing and opposite to each other. For example, umbrellar-type springs 42, 42' are concentrically secured to bottoms of concave parts 32a and 32'a of a first and a second casing, and forward ends of legs 42b and 42'b make contact with both sides of a diaphragm for preventing an overpressure resisting diaphragm. |
