The Ideal expansion vessel is a device to handle the expansion of water in a heating system or hot water system due to increases in temperature. When water rises in temperature, it expands, particularly when it is placed under pressure, such as in a sealed heating system or an unvented hot water cylinder. Expansion tanks typically consist of a storage container or disc which is divided inside into two compartments separated by a rubber sheet known as the diaphragm.

Brand Name	Ideal Heating