GB582015A - Improved method of and means for controlling the supply of gas to the burners of water boilers - Google Patents

Abstract

582,015. Fluid-pressure servomotorcontrol systems. STOTT & CO. (ENGINEERS), Ltd., J., and JONES, A. April 15, 1944, No. 6966. [Class 135] A gas-operated diaphragm valve 12, Fig. 8, for controlling the supply of gas to the burners of a water heater 41 is adapted to be actuated by a thermostatic device 40, responsive to the temperature of the water and also by the operation of the water draw-off taps 33 or 34. The valve 12 as shown in Fig. 1 comprises a valve member 13 supported by a diaphragm 14 and co-operating with a seating 15. A chamber 17 behind the diaphragm is supplied with gas through a restricted passage 18 and has an outlet 19 to which a pipe 38, Fig. 8, is connected which leads to a thermostatically operated cock 40x and to cooks operated simultaneously with the draw-off taps 33, 34. Fig. 4 shows an arrangement of draw-off tap for drawing off water from a boiler 12b through a valve 22, a gas cock 21, in the pipe 38, being opened simultaneously by a tongue and slot connection 24, 25 to relieve the pressure in chamber 17 of the diaphragm valve to allow the valve to open fully. Fig. 6 shows another arrangement in which the gas relief valve is a lift member 28, which is actuated by a cam 29 on the water cock 22. Thus the thermostatically-operated cock 40x controls the pressure in chamber 17 to adjust the opening of gas valve 12 in accordance with the temperature of the water in the boiler whilst the opening of the draw-off cocks effects full opening of the gas valve independently. The gas passing from cock 40x and the gas cocks associated with the draw-off taps is led by pipe 39 to be burnt adjacent the main burners. The valve member 13 of the gas valve 12 is prevented from closing completely by an adjustable stop screw 16 to allow sufficient gas to pass to keep the burners alight.