GAS SHUTOFF DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent mischief using a forced shutoff function. SOLUTION: A flow rate deciding part 2 calculates gas flow rate value from a flow rate pulse signal A that is generated when a fixed amount of gas passes through a gas channel from a flow rate sensor part 1 and outputs a closing valve signal B when the gas flow rate exceeds preliminarily stored prescribed value. A forced shutoff deciding part 6 receives a forced shutoff signal D generated by a forced shutoff inputting means 5 when the means 5 detects a forced shutoff request from the outside and outputs a forced closing valve signal E when the signal A of the part 1 is inputted in an interval that is equal to or more than a preliminarily stored fixed interval. A valve driving part 3 outputs a valve closing drive signal C when it receives the signal B of the part 2 or receives the signal E of the part 6. The valve 4 closes the gas channel when it receives the signal C of the part 3.