| 摘要 |
PURPOSE:To enable to prevent the gas leak without fear of gas explosion caused by electric action by a structure wherein a semiconductor gas reaction element, which reacts only when organic gas reaches a certain concentration, is built- in and a sensing switch is turned ON by sensing the gas. CONSTITUTION:When gas leak occurs, the sensing switch 1a of a gas leak sensor 1 is turned ON and consequently a sensing relay 18 and a closing solenoid 2b are actuated in order to be able to close or shut off a gas shut-off valve 5 and to surely prevent the gas leak for the future. Moreover, because the gas shut-off valve 5 arranged in a gas distributing pipe system and a valve control box 2 to actuate the valve 5 are coupled with each other by means of insulative structure and at the same time a gas main line stop valve 8 arranged in the gas distributing pipe system and a main line stop valve switch 3 to put ON and OFF a switch in association with the valve 8 are arranged in a non-contacting state, the safety of the gas distributing passage in danger of explosion is secured. |
