expansion tank


Cars & Driving

  • noun an overflow container for gases or liquids subject to expansion, such as fuels or more particularly coolant which expands when heated, and when cool returns to the radiator


  • In a hot water system, the tank that provides for the increased volume of the water heated in the heating tank below it.
  • A device to control pressure in a fluid system by storing excess liquid.

Real Estate

  • noun a storage tank for domestic hot water that allows for the expansion of water owing to heating and reduces the risk of a dangerous build-up of water pressure