GB1345436A - Sagety device for a gas-fired water heater - Google Patents

Abstract

1345436 Controls for water heater burners ULGOR SCI 8 July 1971 [19 Oct 1970] 32203/71 Heading F4T [Also in Division F2] A safety device for a gas fired water heater to prevent over-rapid ignition of a gas burner comprises upper and lower chambers 4, 5 separated by a resilient diaphragm 3, the lower chamber leading to a tapered duet 7 for water flow therefrom or thereto, there also being a waterway 8 for water from the upper chamber 4 to the duct, the waterway being arranged to be partially obstructed by a resilient deformable element comprising a fixed part 10 and a movable part 12 when flow through waterway 8 is either initiated or sharply increased to restrict the rate of movement of the resilient diaphragm 3. Movement of part 12 is co-ordinated with movement of diaphragm 3 by having secured thereto a rod 9 controlling the gas valve of the burner. The waterway 8 comprises a passage 13 and a channel 14 such that when the former is closed a restricted passage is still available via channel 14. In a modification, (Fig. 4 (not shown) the element 11 may be detached from diaphragm 3 but remains held in position thereby. Two passages 18, 19 (Fig. 5) may be provided for the waterway 8 and channel 14. The restricted passage may be formed by an aperture(a) in the movable part and a rib across the passage may replace channel 14 so preventing part 12 from lying flat. The device may be used under high pressure flow when part 12 is pressed into channel 14 to create a greater restriction.