| 摘要 |
PURPOSE:To make leak as well as the regulation of the leak unnecessary and obtain the merits of both of proportional type and ON.OFF type by a method wherein an auxiliary passageway secures a given amount of gas after a main valve is closed while the auxiliary passageway is closed instantaneously by an auxiliary valve. CONSTITUTION:A heat sensitive tube 38 detects a temperature rise, liquid therein is evaporated and a vapor pressure is increased to expand a bellows 33 through a capillary tube 37, a lever 23 is rotated clockwise and a main valve 15 is elevated. The pressure of gas in the upstream side of a passageway is increased by the closing of the main valve 15 and a small diaphragm 42 is operated downwardly together with a rod 43 and another diaphragm 41. Accordingly, an auxiliary valve 45 is descended by the pushing force of a coil spring 46 and a slit 47 or an auxiliary passageway is intercepted instantaneously. The diaphragm 41 descends further by the closing of the auxiliary valve 45 and is abutted against a valve seat 44. According to this operation, the passageway of the gas upon a high temperature is intercepted double by the main valve 15 and the diaphragm 41. The opening and closing of the main valve 15 is effected in a proportional style while the opening and closing of the auxiliary valve 45 is effected by ON. OFF style. |
