JPS6438514A - Leakage detection mechanism of dual cut-off valve in gas combustion apparatus - Google Patents

Abstract

PURPOSE:To easily detect whether or not there is a leakage of the dual cut-off valve by connecting a pressure raising means capable of raising pressure higher than a gas supply pressure and a pressure detecting means between upstream and downstream cut-off valves. CONSTITUTION:Pressure raising means 2 and pressure detecting means 3 are connected between upstream and downstream cut-off valves 1a and 1b. When the fire of a burner 4 is extinguished, an actuator 12 is operated to raise the pressure within a space 5 by a diaphragm 11. Pressure detecting means 3 sets a value lower than the pressure at the time of raising the pressure by approximately 50mm H2O as a set pressure. When the pressure is higher than the set value, the pressure detecting means 3 is turned on, and when the pressure is lower than the set value, the pressure detecting means 3 is turned off. In the case of conducting the ignition of the burner 4, when the pressure detecting means is turned on, it is determined that there is no leakage of the gas from the dual cut-off valve, and a predetermined ignition of the burner 4, when the pressure detecting means is turned on, it is determined that there is no leakage of the gas from the dual cut-off valve, and a predetermined ignition is carried out. Further, when the pressure detecting means 3 does not conduct the ignition of the burner, a predetermined operation in the case of detecting the leakage of the gas from the valve.