Thermally insulated atmospheric expansion tank

摘要

An atmospheric expansion tank comprises two main sections consisting of a body and a lid. In each section, the space between an inner layer 3, 6 and an outer layer 1, 4 is uniformly injected with polyurethane foam 2, 5 so as to provide a uniform thermal resistance. A tight fit is provided between the tank body and the lid. The tank is designed to provide sufficient uniform insulation against heat transfer from the inside to the outside of the tank so that, in use, the insulated tank saves energy and consequently reduces fuel costs. The insulation thickness is calculated according to the temperature difference between a central heating system set point and the ambient temperature. Preferably, the tank is designed to keep a fluid temperature constant whilst maintaining atmospheric pressure by purging a fluid, such as water, through an overflow valve.