GAS VALVE

PURPOSE:To increase a proportional area without worsening the igniting property of a burner by a constitution wherein the flow rate of fuel gas becomes to the slow igniting flow rate at first, subsequently, it is decreased to the minimum flow rate and, thereafter, it is increased again, by only moving a valve rod into one direction. CONSTITUTION:When a rod 51 is moved downwardly, a second valve 55 is moved together with the rod 51 so as to separate a valve 55 from a valve seat 52b leaving a first valve 52 in closed condition and the fuel gas in a path 42 is flowed into a path 43 from a clearance between the valve 55 and the seat 52b through openings 52a, 53b, 54b and the clearance between the bottom wall of an inner tube 54 and a third valve 59 (slow ingiting flow rate). When the rod 51 is further moved downwardly and the third valve 59 contacts with the bottom wall of the inner tube 54, the opening 54b is closed and the gas flows from the opening 54C smaller than the same 54b (the minimum flow rate). When the rod 51 is moved downwardly further, the first valve 52 and outer tubes 53, 54 are moved downwardly together with the rod 51, the first valve 52 is separated from the valve seat 52b and one end of the opening 53a of the outer tube 53 appears at the lower part of the valve seat 48, then, the gas flows through the openings 53a, 54a. The amount of flow of gas is depending upon the positional relation between the outer tube 53 and the inner tube 54, which is determined by the position of the rod 51.