Preferred Construction Products

ASME Thermal Expansion Tanks

BigGuy® through Calefactio offers a wide variety of thermal expansion tanks designs with fixed bladders and removeable bladders that range in capacity from less than two gallons to over 1,800 gallons. Both ASME and Non ASME tanks are offered and some tanks offer ExpanView indicator which changes color if a leak is detected


  • Water remains permanently separated from air.
  • Conforms to ASME, Section VII.
  • Bottom & Top connection available.

ASME Thermal Expansion Tanks

ModelDescriptionASMEConnectionGallonsMax TemperatureMax PSI
AL SeriesReplaceable BladderASMEBottom10-1320240° F150/175/250/300
ALT SeriesReplaceable BladderASME Top10-1981240° F150/175/250/300
OT SeriesFixed BladderASMETop7-211240° F150/250/300
NA SeriesNo BladderASME-15-525 450° F125/150