Patent GB-409946-A (GB)
Title: Improvements in or relating to diaphragm gas valves
IPC: F23N1/08
Filed: 1933-07-29
Abstract: 409,946. Valves. BOSCH AKT.- GES., R., 4, Militõrstrasse, Stuttgart, Germany. July 29, 1933, No. 21342. Convention date, Aug. 1, 1932. [Class 135.] A diaphragm gas valve in which the main valve 12, Fig. 1, is carried by a diaphragm 13 subject to the gas pressure in an inlet chamber 14 and that in a control chamber 15 has several controllers 52, 27, 22 controlling the flow of control gas and so influencing the main valve, arranged in series, at least one controller 22 or 27 being subject to external working conditions such as the heat of a room or of a liquid, water level, steam pressure, fluid velocity &c., and another controller 52 subject to internal working conditions for maintaining constant one variable factor of the main gas floor. Fig. 1 shows the application to a water heater in which the consumption pressure is kept constant by the valve 52, the actuating diaphragm 56 of which is subject to outlet pressure by means of a conduit 58 and to the pressure of a spring 62 in the breather chamber 59. The current of control gas is led by a passage 17 to a distributer chamber 18, past a wide throttle 24 into the control chamber 15 and thence past the valve 52 into a coaxial chamber 53 whence a conduit 25 leads past the controller 27, which in this case is a valve opened by the water flow in a pipe 34 acting on a vane 33, to a pipe 20 supplying the controller 22, which is a pilot lighter valve. A narrow byepass throttle 19 ensures a supply of gas to the pilot burner when either of the valves 52, 27 is closed. Igniting gas is supplied to the pilot burner by a pipe 63 past a spring-pressed valve 64. A spring 16 closes the valve 12 when the pressures in the chambers 14, 15 are equal. Fig. 2 shows a water heater with a diaphragm gas valve 112 in which the gas flow is maintained constant. The diaphragm 113 is contained in a removable unit 170, 173 mounted in the casing 300, 301, The control conduit opens into a chamber 171 communicating with the main gas chamber by a passage 188 and also into a chamber 174 leading through an opening 176 to the control chamber 115. The opening 176 is formed in a removable casing containing a non-return valve 178 which because of its throttle opening 179 promotes quick closing and slow opening of the main valve. The external controllers are the same as in Fig. 1. To ensure a constant flow of gas in spite of variations in mains pressure, the main gas chamber 114 has an intermediate chamber 181 divided off it by a partition 180 having openings 182 controlled by a sliding valve 183, and an open pocket 185 containing a spring- pressed disc 186 subject to the mains pressure and the throttled pressure in the intermediate chamber 181. An increase in mains pressure causes the disc 186 to throttle the opening 188 and so reduce the control gas pressure in the chamber 171, thus allowing the valve 112 to close slightly under its spring. The disc 186 may be arranged in a capsule screwed into the wall 170 and may be corrugated to provide point contact with the capsule walls. The inlet to the capsule from the chamber 114 has a filter and an adjustable slide valve. The openings 182 are of such shape that equal angular movements of the valve 183 produce equal changes in gas flow. A filter may be arranged over the partition 180. The valve 183 carries a toothed sector engaging a pinion operable from outside the casing, and in one form, capable of withdrawal to prevent unauthorized regulation. In a modified form, an additional passage in the partition 180 is controlled by a plate movable laterally from outside the casing.