ACT‐100® Steel/FRP composite tank features a strong steel tank for structural integrity, and a 100‐mil fiberglass outer coating for long‐lasting corrosion protection. Double‐wall design allows continuous interstitial leak detection and monitoring.

ACT-100 ® features:

Features the strength of steel with a 100-mil fiberglass outer coating

  • Meets UL 58, UL 1746 and ULC‐S603.1
  • A high‐voltage holiday test of the coating assures that the
    steel is isolated from corrosive soils
  • Can be used with a variety of leak detection systems
  • Steel provides complete compatibility with all blends of
    ethanol and biodiesel fuels
  • Impermeable to all petroleum products and vapors
  • No failures due to external corrosion in its history
  • Flat end design reduces the cost of installation and
    increases site layout flexibility

Additional features:

  • Steel tank provides structural strength, while its
    outer coating of fiberglass prevents corrosion
  • Various backfill options allow for money‐saving
  • Capacities range up to 60,000 gallons
  • Single or double‐wall construction

ACT-100 ® Benefits:

  • Steel construction allows for recycling
  • Low cost compartments and customization
  • Built to nationally‐recognized STI standards with
    strict third‐party quality control inspection program

Compatible with a wide range of fuels and chemicals, including biodiesel and ethanol

ACT-100® is available from a large network of STI Licensed Manufacturers •

ACT-100® Double-Wall Underground Steel Storage Tanks

  • Steel Tank Institute ACT-100® and UL Labeled
  • Compatible with alternative fuels
  • Low cost compartments and customization
  • Flat ends reduce installation costs
  • Provides safe and effective secondary containment
  • Capacities range up to 60,000 gallons

ACT‐100® Guideline Specification

A) General

1. Provide ACT‐100® external corrosion protected FRP composite steel underground storage tanks.


B) Labeling

1. Tanks shall bear the Steel Tank Institute ACT‐100® label.

2. Underground tanks shall bear the appropriate Listing label.


C) Product Description

1. Tanks shall be manufactured in accordance with Steel Tank Institute ACT‐100® Specification for External
Corrosion Protection of FRP Composite Steel Underground Storage Tanks.

2. Tanks shall be manufactured and listed in accordance with Underwriters Laboratories UL 58, Steel
Underground Storage Tanks for Flammable and Combustible Liquids and UL 1746, External Corrosion
Protection Systems for Steel Underground Storage Tanks or ULC‐S603.1, Standard for Corrosion Protection
for Steel Underground Tanks for Flammable and Combustible Liquids.

3. Double‐wall tanks shall provide testable secondary containment on site and access for interstitial leak
detection monitoring.

4. Tanks shall have a minimum 100‐mils of an approved FRP laminate on the tank exterior.

5. Tanks shall be factory tested with a high‐voltage holiday test.


D) Manufacturer

1. Manufacturer shall be a licensed member company of the Steel Tank Institute and subject to Steel Tank
Institute’s Quality Assurance program.

ACT-100® is available from an extensive group of Steel Tank Institute fabricators who participate in the STI Quality Assurance Program.
Under the program, independent quality control inspectors make unannounced visits to STI members, ensuring fabrication to the highest possible standards.