GB967958A - Improvements in or relating to hot water circulation heating systems - Google Patents

Abstract

967,958. Central heating systems. WEATHERFOIL Ltd., and G. T. K. DEAN. June 17, 1963 [March 16, 1962], No. 10253/62. Heading F4U. A central heating system comprises a water heater 10 connected to heat distribution units 11 by flow and return conduits 12 and 13 respectively through which water is circulated by a pump 14; a feed tank and conduit 15 and 16 respectively, and an expansion pipe 18, 19; the system being made to retain pressure by the provision of a non-return valve 17 in the feed circuit, a pressure retaining valve 21 in the expansion pipe and a contractioncompensation vessel 20 located on the pressure side of the pressure-retaining valve, and bypassed by a conduit 23, of larger cross-sectional area than the expansion pipe. The contraction compensation vessel, which may be heated by an electric immersion heater 24, or by an oil heater, steam coil, or pipe direct from the water heater (not shown) is maintained at a temperature, which is controlled by a thermostat T4, sufficiently high above that of the remainder of the system to ensure that any steam formed due to a reduction in pressure is formed within the said vessel. If the pressure of the system rises, water is forced through the pressure retaining valve 21 which discharges into the feed water tank. In the form shown, the water heater 10 is oil-fired and electrically controlled by thermostats T2 and T3 (electrical circuit, Fig. 2, not shown) which, with thermostats T1 and T4 positioned in the vessel 20 prevent the water from being run at a temperature as great as that in the said contraction-compensation vessel.