| 摘要 |
PURPOSE:To enable to facilitate ensuring of gas under the use, by a method wherein one end of a connection pipe containing an incombustible liquid is connected to a gas feeder, and when starting to feed gas, an electric contact installed to the other end of the connection pipe is closed through the medium of the incombustible liquid by a gas pressure. CONSTITUTION:If, on operation of a gas device, a gas plug 5 in a gas pipe 21 is opened, a balance of a gas pressure between parts A and B connected to each other through an orifice-shaped feed port 2 is broken, and a moving valve 3 is pressed downward against buoyancy of liquid 6 through the force of the gas pressure of the part A joined to a gas source. As a result, a level of a liquid surface at other end 7 side of a connection pipe 1 is raised, and a float 8 is also raised. The float 8 is formed of a conductor, and thereby electric contacts 9a and 9b are connected together through the float 8 to light a lamp 11. Lighting of the lamp 11 ensures that gas is under the use. |
