FIREGUARD® and FLAMESHIELD® tanks are both STI/SPFA aboveground steel storage tank technologies used for flammable and combustible liquid storage. Both are double-wall tanks that can provide secondary containment and interstitial monitoring capability, and both are available through STI/SPFA licensed fabricators.
The main difference is the level and type of fire protection.
FIREGUARD® is a UL 2085 listed protected aboveground storage tank. It includes an inner and outer steel tank with a lightweight thermal insulation material between the walls. It is designed as a protected tank to limit heat transfer from the tank exterior to the tank interior and includes features such as thermal insulation between the primary and secondary tank, integral secondary containment, interstitial monitoring, and impact and ballistics protection per UL 2085.
FLAMESHIELD® is a fire-tested, double-wall aboveground steel storage tank. It uses a tight-wrap double-wall design and is tested to meet the 2-hour, 2,000°F fire test requirements of Southwest Research Institute Standard SwRI 97-04. This heat exposure test is similar to the one used in the UL 2085 certification process. A FLAMESHIELD® tank provides built-in secondary containment and interstitial monitoring capability, but it does not use thermal insulation and is not the same as a UL 2085 listed protected tank.
Quick Comparison Table
| Topic | FIREGUARD® | FLAMESHIELD® |
|---|---|---|
| Basic description | Protected, thermally insulated, double-wall aboveground storage tank | Fire-tested, tight-wrap, double-wall aboveground storage tank |
| Primary standard/listing context | UL 2085 listed protected tank | UL 142 double-wall tank with SwRI 97-04 fire-tested performance |
| Fire protection approach | Uses lightweight thermal insulation between the inner and outer steel tanks to limit heat transfer | Uses a non-insulated tight-wrap double-wall design that has passed a 2-hour, 2,000°F fire test |
| Protected tank status | Yes, UL 2085 listed protected tank | No, fire-tested double-wall tank, but not the same as a UL 2085 protected tank |
| Impact and ballistics protection | Includes ballistics and impact protection per UL 2085 | Not positioned as a UL 2085 impact- and ballistics-protected tank |
| Secondary containment | Built into the protected tank system | Built into the double-wall tank system |
| Interstitial monitoring | Interstitial space can be monitored for leak detection | Interstitial space can be monitored for leak detection |
| Insulation | Includes lightweight thermal insulation material | Non-insulated tank design |
| Common applications | Projects requiring or preferring UL 2085 protected tanks, enhanced fire resistance, impact protection, or AHJ/code-driven protection | Projects requiring a fire-tested double-wall tank where UL 2085 protected tank status is not required |
| Typical decision question | Does the project require a UL 2085 protected aboveground tank? | Is a fire-tested double-wall UL 142 tank acceptable for the application? |
What Is a FIREGUARD® Tank?
A FIREGUARD® tank is an STI/SPFA protected, thermally insulated, double-wall aboveground storage tank. It features an inner and outer steel tank with a lightweight thermal insulation material between the walls.
FIREGUARD® tanks are UL 2085 listed protected tanks. They are designed to provide enhanced thermal protection of the primary tank, and the tanks contents, from exterior heat sources like fire, as well as integral secondary containment, interstitial monitoring capability, and ballistics and impact protection per UL 2085.
FIREGUARD® tanks are used for aboveground storage of compatible flammable and combustible liquids, including common fuel storage applications such as gasoline, diesel, biodiesel, ethanol blends, aviation fuel, and generator fuel. Final suitability depends on the stored product, tank design, project specification, applicable codes, and authority having jurisdiction.
What Is a FLAMESHIELD® Tank?
A FLAMESHIELD® tank is an STI/SPFA fire-tested, double-wall aboveground steel storage tank. It uses a tight-wrap double-wall design with built-in secondary containment and interstitial monitoring capability.
FLAMESHIELD® tanks are tested to the 2-hour, 2,000°F fire test requirements of Southwest Research Institute Standard SwRI 97-04. The fire test validates the performance of non-insulated tanks and confirms it can withstand the heat exposure without compromising the tank’s integrity.
FLAMESHIELD® tanks are commonly used when a project needs a fire-tested, double-wall aboveground storage tank, but the application does not require a UL 2085 listed protected tank.
Key Differences Between FIREGUARD® and FLAMESHIELD® Tanks
Protected Tank vs. Fire-Tested Tank
The most important difference is classification.
FIREGUARD® is a UL 2085 listed protected aboveground storage tank. UL 2085 protected tanks include additional protection features such as enhanced thermal protection of the stored contents, integral secondary containment, and impact protection.
FLAMESHIELD® is a fire-tested, double-wall aboveground tank. It is tested under SwRI 97-04 and is manufactured as a double-wall UL 142 tank, but it is not the same as a UL 2085 listed protected tank.
This distinction matters because project specifications, fire codes, insurers, or the authority having jurisdiction may require one classification over the other.
Thermal Insulation
FIREGUARD® tanks include lightweight thermal insulation material between the inner and outer steel tanks. This insulation is intended to limit heat transfer to the primary tank and the tank’s contents during fire exposure.
FLAMESHIELD® tanks are non-insulated. Their fire-tested performance is based on a tight-wrap double-wall design that has been tested to withstand the required fire exposure.
Fire Test Context
Both tank technologies are related to fire performance, but they are evaluated in different specification contexts.
FIREGUARD® is tied to UL 2085 protected tank requirements. UL 2085 includes fire exposure performance and physical protection criteria. The tank is subjected to a 2-hour, 2,000°F heat exposure and the tank interior temperatures are monitored during the test to confirm that the test limits are not exceeded.
FLAMESHIELD® is tied to SwRI 97-04 fire-tested performance. A 2-hour, 2,000°F fire test validates the performance of properly designed non-insulated double-wall tanks.
Impact and Ballistics Protection
FIREGUARD® includes ballistics and impact protection per UL 2085. This is an important reason FIREGUARD® may be selected for sites where physical damage, vehicle traffic, public exposure, or AHJ requirements are a concern.
FLAMESHIELD® is not positioned as a UL 2085 impact- and ballistics-protected tank. Site-specific physical protection, such as barriers or bollards, may still be required depending on the installation and local code requirements.
Secondary Containment and Leak Detection
Both FIREGUARD® and FLAMESHIELD® are double-wall tank systems that can provide secondary containment and interstitial monitoring capability.
For both technologies, the interstitial space can be monitored for leak detection. This helps owners and operators detect a release from the primary tank before product reaches the environment.
Emergency Venting
Emergency venting is an important specification and inspection issue for aboveground storage tanks.
UL 2085 tanks, including FIREGUARD® tanks, are required to be shipped from the fabricator with UL listed emergency vents on the primary and interstitial vent openings. FLAMESHIELD® tanks should also be evaluated for proper normal and emergency venting based on the tank design, stored product, applicable codes, and AHJ requirements.
Because venting requirements are technical and code-sensitive, they should be reviewed early with the tank manufacturer, project engineer, vent manufacturer, and authority having jurisdiction.
Siting and Code Review
FIREGUARD® may be preferred where a protected tank classification helps address fire exposure, physical damage protection, site constraints, separation distances, or AHJ expectations.
FLAMESHIELD® may be appropriate where a fire-tested double-wall tank satisfies the project requirements and the installation does not require a UL 2085 protected tank.
The authority having jurisdiction should be involved early because code interpretation, required protection, setbacks, capacity limits, and installation conditions can vary by location.
When FIREGUARD® Tanks Are Typically Used
FIREGUARD® tanks are typically used when the project requires or benefits from a UL 2085 listed protected tank.
| Application Need | Why FIREGUARD® May Fit |
|---|---|
| UL 2085 protected tank requirement | FIREGUARD® is a UL 2085 listed protected tank |
| Enhanced fire resistance | The tank includes thermal insulation intended to limit heat transfer during fire exposure |
| Impact and ballistics protection | FIREGUARD® includes ballistics and impact protection per UL 2085 |
| Integrated secondary containment | The double-wall protected tank system includes secondary containment |
| Interstitial monitoring | The interstitial space can be monitored for leak detection |
| Constrained sites | A protected tank may help address code, AHJ, setback, or exposure concerns |
| Fuel storage applications | FIREGUARD® is commonly used for aboveground storage of compatible fuels and combustible liquids |
| Long-term flexibility | Steel construction supports compartments, customization, relocation, repair, and recycling |
When FLAMESHIELD® Tanks Are Typically Used
FLAMESHIELD® tanks are typically used when a fire-tested, double-wall aboveground storage tank is appropriate, and UL 2085 protected tank status is not required.
| Application Need | Why FLAMESHIELD® May Fit |
|---|---|
| Fire-tested double-wall tank | FLAMESHIELD® has 2-hour, 2,000°F fire-tested performance under SwRI 97-04 |
| Built-in secondary containment | The tight-wrap double-wall design provides secondary containment |
| Interstitial monitoring | The interstitial space can be monitored for leak detection |
| UL 142 double-wall tank context | The primary and secondary containment are manufactured and listed under UL 142 |
| Non-insulated design | The SwRI 97-04 fire test validates performance of non-insulated tanks |
| Fuel and chemical compatibility | The primary storage tank and secondary containment are compatible with a wide range of fuels and chemicals |
| Project cost and customization | Steel construction supports compartments, customization, relocation, and fabrication flexibility |
Why FIREGUARD® May Be Required or Preferred
FIREGUARD® may be required or preferred when the project calls for a UL 2085 listed protected aboveground tank. This can be driven by fire code requirements, AHJ interpretation, insurance requirements, owner standards, site constraints, proximity to property lines or buildings, vehicle traffic, or critical fuel storage needs.
FIREGUARD® may be a strong choice when the project requires:
| Decision Factor | FIREGUARD® Advantage |
|---|---|
| Protected tank listing | FIREGUARD® is UL 2085 listed as a protected aboveground storage tank |
| Fire exposure performance | The insulated design is intended to limit heat transfer to the primary tank during fire exposure |
| Physical damage protection | FIREGUARD® includes impact and ballistics protection per UL 2085 |
| Secondary containment | The double-wall protected tank system includes secondary containment |
| Leak detection | The interstitial space can be monitored |
| Code and AHJ acceptance | FIREGUARD® may help address protected tank requirements in certain installations |
| Fuel compatibility | FIREGUARD® can be used with a wide range of compatible fuels and chemicals |
| Steel construction | Steel allows for sustainability, compartments, customization, repair, and relocation |
Why FLAMESHIELD® May Be Preferred
FLAMESHIELD® may be preferred when a project needs a fire-tested, double-wall aboveground tank but does not require a UL 2085 protected tank.
FLAMESHIELD® may be a strong choice when the project requires:
| Decision Factor | FLAMESHIELD® Advantage |
|---|---|
| Fire-tested performance | FLAMESHIELD® has 2-hour, 2,000°F fire-tested performance under SwRI 97-04 |
| Double-wall containment | The tight-wrap design provides built-in secondary containment |
| Leak detection | The interstitial space can be monitored |
| UL 142 tank context | The primary and secondary containment are manufactured and listed under UL 142 |
| Non-insulated configuration | Fire-tested performance is validated for a non-insulated tank design |
| Design flexibility | Available in horizontal, vertical, rectangular, and diked designs |
| Lower-weight fire-tested design | Because FLAMESHIELD® tanks weigh less than comparable UL 2085 listed protected tanks, they may be easier to ship, handle, and place while still providing fire-tested double-wall performance. |
| Steel construction | Steel supports sustainability, compartments, customization, repair, and relocation |
Common Confusion Points
Are FIREGUARD® and FLAMESHIELD® the same thing?
No. Both are STI/SPFA aboveground steel tank technologies, and both are related to fire performance, but they are not the same. FIREGUARD® is a UL 2085 listed protected tank. FLAMESHIELD® is a fire-tested, double-wall aboveground tank tested under SwRI 97-04.
Is FLAMESHIELD® a UL 2085 tank?
No. FLAMESHIELD® should not be described as a UL 2085 protected tank. It is a fire-tested, double-wall UL 142 aboveground tank with SwRI 97-04 fire-tested performance.
Is FIREGUARD® just a fire-tested tank?
No. FIREGUARD® is more specifically a UL 2085 listed protected tank. It includes thermal insulation and impact and ballistics protection per UL 2085.
Do both tanks provide secondary containment?
Yes. Both FIREGUARD® and FLAMESHIELD® are double-wall tank systems with secondary containment and interstitial monitoring capability.
Do both tanks have insulation?
No. FIREGUARD® includes lightweight thermal insulation between the inner and outer steel tanks. FLAMESHIELD® is a non-insulated tight-wrap double-wall tank.
Which tank should be specified?
The right tank depends on the stored liquid, capacity, site layout, fire exposure, impact exposure, separation distances, applicable codes, owner requirements, and AHJ interpretation. If the project requires a UL 2085 protected tank, FIREGUARD® is the appropriate STI/SPFA technology. If the project requires a fire-tested double-wall tank and UL 2085 protected tank status is not required, FLAMESHIELD® may be appropriate.
FAQs
Related Resources
FIREGUARD®
FLAMESHIELD®
UL 142 vs. UL 2085 Aboveground Storage Tanks
What Is UL 2085?
When Is UL 2085 Required for Aboveground Storage Tanks?
STI Technologies
STI Standards
Shop-Fabricated Tank Manufacturers
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STI/SPFA members fabricate aboveground steel storage tanks for fuel, petroleum, commercial, industrial, and regulated storage applications. Learn more about STI/SPFA tank technologies for your next project.
