| 摘要 |
PURPOSE:To prevent the danger by a method wherein a bypass pipe, in which a flow differential pressure detector is interposed, is provided so as to normally detect the leakage and to utilize the pressure difference in case that excessive flow rate develops during gas is used. CONSTITUTION:If gas normally leaks in a piping, a solenoid valve is closed by a common gas leakage detector or the like. During a gas appliance is ignited and put in use, if the excessive amount of gas in use flows, a flow differential pressure detector 4 brings itself into actuation as a pressure detector, not as the flow rate detector as is the above-mentioned case. Concretely, though a valve 1' may be in a state throttled in response to the amount of gas in use so as to be able to use said state or the throttled portion may be provided at some other position to use the throttled state, the differential member 8 of the flow differential pressure detector 4 is shifted toward the low pressure side or in the downstream direction against a spring 9 by the pressure difference developed between the upstream side A and the downstream side C of a valve 1'. The excessive flow rate is detected by the length of the shifting of the member 8. If said shifting length exceeds the reference range, the excessive flow rate signal is issued from a meter 10 and sent through a control device 6 to a solenoid valve 1 so as to quickly close the valve 1' in order to contrive to establish safety. |
