Protected, thermally insulated secondary containment tank

FIREGUARD® double‐wall fire‐protected aboveground storage tank features an inner and outer steel tank with a unique lightweight thermal insulation material that exceeds the UL 2‐hour fire test. Insulating material is 75% lighter than concrete, reducing shipping, installation and relocation costs.


  • Insulates product in tank from ambient temperature variations, reducing emissions to the environment
  • Primary and secondary tank can be tightness tested on site with standard testing procedures, unlike other designs
  • Steel outer wall provides low cost maintenance and protection from weathering
  • Primary storage tank and secondary containment compatible with a wide range of fuels and chemicals, including biodiesel and ethanol
  • Support designs available for all seismic requirements
  • Interstitial space can be monitored for leak detection
  • Meets temperature requirements when the furnace test was extended to 4 hours (when the tank is constructed with 6 inches of insulating material)

FIREGUARD® is the only tank to meet the following standards:

  • UL 2085 Listed “Protected” tank
  • Ballistics and Impact protection per UL 2085
  • Both the inner and outer steel tanks are built to UL standards
  • National Fire Protection Association (NFPA) 30 & 30A
  • International Fire Code (IFC)
  • California Air Resources Board (CARB) Standing Loss Control testing requirements for air emissions
  • Steel Tank Institute (STI) Standard F941 for Protected Aboveground Storage Tanks

Additional Features

  • Capacities range up to 75,000 gallons
  • Steel construction allows for recycling
  • Low cost compartments and customization
  • Built to nationally‐recognized STI standards with strict third‐party quality control inspection program

FIREGUARD® is available from an extensive group of Steel Tank Institute fabricators who participate in the STI Quality Control Program. Under the program, independent quality control inspectors make unannounced visits to STI members, ensuring fabrication to the highest possible standards.

FIREGUARD® Publications

STI Tank Technologies

Aboveground Storage Tanks (AST)

Protected, thermally insulated secondary containment tank
Fire-tested, double-wall tank
Double-wall steel tank
Safe and sturdy support for your backup or emergency power
Open-top diked system

Underground Storage Tanks (UST)

Cathodically protected steel tank
Steel/FRP composite tank
Steel tank with an external urethane coating

Double‐wall jacketed underground storage tank

Gravity Oil Water Separators

Featured Affiliate

Commercial Metal Forming

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“STI provides a platform for collaboration between fabricators to improve upon technologies and help push the industry into the new century.”

Garrick Mullen
Watco Tanks, Inc.

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