Amtrol® EXTROL® 118-78 SX Series Vertical Floor-Standing Boiler System Expansion Tank, 20 gal Capacity, 0.57 Acceptance, 11.3 gal Acceptance, 100 psi Pressure, Heavy Duty Butyl/EPDM Diaphragm, 15 in Dia x 32 in H

  • Acceptance Capacity: 11.3 gal
  • Acceptance Factor: 0.57
  • Capacity: 20 gal
  • Country of Origin: US
  • Diameter: 15 in
  • Domestic/Import: Domestic
  • Finish: Urethane Topcoat
  • Height: 32 in
  • Manufacturer Name: Amtrol
  • Material: Steel Shell
  • Pressure Rating: 100 psi
  • Series: SX Series
  • Type: Vertical Floor-Standing
Amtrol® designed and patented the first Extrol diaphragm expansion tank in 1954 to control system pressure and help reduce energy consumption in heating and chilled water systems. Over six decades later, Extrol is still the world's leading expansion tank brand, setting the standard for quality, reliability and innovation. All Extrol tanks are made in the USA at our ISO registered facilities by American workers dedicated to producing the highest quality expansion tanks in the world.
  • Features and More


  • These non-ASME tanks are available in sizes up to 86 gallons and can be used with high output boilers up to 1,500,000 BTU's
  • Accepts expanded water as system temperature rises to reduce pressure build-up
  • 12 psig factory precharged
  • 1 in NPTF steel system connection
  • 1-13/16 in stand to connection
  • Projection welded air valve


  • Large Residential and Light Commercial Closed
  • Non-Potable
  • Hydronic Heating Systems


  • ISO 9001:2008