Biasi Expansion Vessels also sometimes called expansion tanks or pressure vessels are a component fitted internally to Biasi Combi type
and sealed system boilers and it's function is to compensate for the expansion of hot water, as water will expand when heated producing
a rise in pressure within the sealed or closed system. There is a menbrane or diaphragm within the vessel which separates the water from
the air and this allows the water to expand. All our Biasi Expansion Vessels are new and genuine manufacturer spares.