GB871872A - Improvements in or relating to thermostatically controlled gas fired water heaters - Google Patents

Abstract

871,872. Supply and delivery arrangements for water-heaters; temperatureresponsive actuating-elements. GAS COUNCIL. March 18, 1959 [March 18, 1958], No. 8705/58. Classes 64(1) and 64(2) [Also in Group XXIX] The gas flow to the burner 36 of a waterheater is controlled by the hot water flow by means of a diaphragm or by means of a valve having a stem 43 operated by a pivoted flap 42, and also at the outlet of the heater, before the hot water delivery pipe 24, there is a temperature-responsive element 18, acting as a water valve with a seat 28, and a manual water valve 38. When the valve 38 is open, a flow of water to open the gas valve under cold conditions is ensured by a by-pass 29 across the valve 18 or the valve is adjusted so as not to close completely. The element 18 has an elastic plug 11, with a bonded stainless steel facing 14, in a brass or stainless steel casing 10 which also contains wax 9. Embedded in the plug 11 is one end of a pin 15, the other end being adjustably fixed so that on heating and expansion of the wax the element 18 moves away from the seat 28 to open the valve. In another embodiment, Fig. 2 (not shown), the thermostatic element is positioned on the downstream side of the valve seat 28 and the manually operated valve 38 is disposed between the thermostatic valves and the heat exchanger 35, an outside by-pass pipe being provided. In a further embodiment, Fig 3 (not shown), the manually controlled water valve is on the cold water side of the heat exchanger 35. In other modifications, Figs. 4-8 (not shown), the form of the thermostatic valve seating 28 is varied and in some the facing 14 constitutes the valve closure surface. The by-pass may be provided with an adjustable restriction.