GB196820A - Automatic safety gas cock - Google Patents

Abstract

196,820. Edmead, F., and Streete, A. May 4, 1922. Fluid-actuated valves. -An automatic safety gas cock for preventing accidental flow of gas when the gas supply is restored after temporary cessation comprises a valve, as 6, 11, Figs. 1 and 3, incorporated in the control cock 4, which valve can only be opened by the cooperation of pressures due to the normal supply at the inlet 2 and a pressure accumulator, as 10, supplied from the inlet, such pressures acting in the same direction on different parts of the valve member 6, 11. Fig. 1 shows the valve 6, 11 and the cock 4 in the position of normal supply, the valve 6, 11 being held open by the action of the gas. Should the supply fail the valve 6, 11 falls to the closed position and the restored gas supply acting under the conical valve part 11 is insufficient to reopen the valve; the cock 4 with the accumulator 10 is given a quarter turn to the position shown in Fig. 3, which allows a charge of gas to pass through the passage 7 into the accumulator. In this position also the supply pressure acting under the piston part 6 of the valve is insufficient to raise the valve. When, however, the cock is given a reverse quarter turn the two pressures act simultaneously under the valve 6, 11 and thereby raise and reopen the same, as shown in Fig. 1.