Expansion vessels are small tanks used to protect closed water heating systems and domestic hot water systems from excessive pressure which can become hazardous otherwise. Without an expansion vessel, the water system cannot allow cold water to expand as it is heated therefore creating a dangerous environment.
As water is heated, the pressure can increase by up to 4.5%. An expansion tank allows for this increased pressure which means it is a vital part of any sealed system. The boiler expansion vessel contains a certain amount of air within it; this absorbs excess water pressure caused by thermal expansion as air can be partially compressed. The air that is present within the tank acts to maintain and provide sufficient pressure in the system when water levels are lower.
These tanks are wide-ranging in size and shape to accommodate the large selection of boilers available today. Whether you require an individual item or an expansion vessel kit, each product is manufactured from high strength steel to provide a shell that can withstand high pressure.