Abstract: A safety device for controlling the excess flow of gas adapted to shut off the flow of gas when the flow of gas exceeds a predetermined level. The device comprises a cylinder having in one end a throat member through which the gas flows, and a plurality of orifices formed around the cylinder through which orifices the gas is delivered to the throat member and then to a burner; a ball disposed at the other end of the cylinder, the ball having one side subject to the supply pressure of the gas and the opposite side subject to the delivery pressure of the gas. When the flow or delivery rate of the gas exceeds the predetermined level that is determined by the flow capacity of the orifices, the delivery pressure of the gas decreases to allow the ball to be pushed by the supply pressure of the gas so as to close the throat member, thus shutting off the flow of the gas.