#steam_boiler__steamboiler__boiler  sealed vessel where water is converted to steam
  supertype:  vessel  an object used as a container (especially for liquids)
  subtype:  auxiliary_boiler  an extra boiler (as a ship's boiler that is used while the ship is in port)
  member:  boilerplate
  part of:  heating_system  steam_engine
  part:  steam_whistle__steamwhistle  a whistle in which the sound is produced by steam; usually attached to a steam boiler

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