This category covers steel tank constructions intended for aboveground storage of flammable and combustible liquids at atmospheric pressure. these tanks are intended for stationary installation and use in accordance with the Flammable and Combustible Liquids Cod, NFPA 30, the Standard for Installation of Oil Burning Equipment, NFPA 31, and the Automotive and Marine Service Station Code, NFPA 30A, of the National Fire Protection Association. the following types of steel tank constructions as indicated in the individual Listings.

Aboveground Tank for Flammable Liquids:
Single-wall steel primary containment tank.

Aboveground Tank for Flammable Liquids on Supports:
Aboveground Tank with integral welded steel supports.

*Secondary Containment Aboveground Tank for Flammable Liquids:
Steel primary containment tank contained within a steel secondary containment shell forming an interstitial (annular) space which is capable of being monitored for leakage.

*Secondary Containment Aboveground Tank for Flammable Liquids on Supports:
Secondary Containment Aboveground Tank for Flammable Liquids with integral welded steel supports.

Open Top Diked Aboveground Tank for Flammable Liquids:
An aboveground Tank for Flammable Liquids with an integral steel open top dike intended to contain liquids resulting from a spill, tank leak or rupture.

Open Top Diked Secondary Containment Aboveground Tank for Flammable Liquids:
Secondary Containment Aboveground Tanks for Flammable Liquids with an integral steel open dike intended to contain liquids resulting from a spill, tank leak or rupture.

*Closed Top Diked Aboveground Tank for Flammable Liquids:
Aboveground Tank for Flammable Liquids with an integral steel dike intended to contain liquids resulting from a spill, tank leak or rupture. The dike has integral protection on the top to prevent precipitation, debris, or other elements from entering the diked area.

*Closed Top Diked Secondary Containment Aboveground Tank for Flammable Liquids:
Secondary Containment Aboveground Tank for Flammable liquids with an integral steel dike intended to contain liquids resulting from a spill, tank leak or rupture. The dike has integral protection on the top to prevent precipitation, debris or other elements from entering the diked area.

The basic standard used to investigate products in this category is UL 142, ‘Steel Aboveground Tanks for Flammable and Combustible Liquids’.
The Listing mark of Underwriters laboratories, Inc. on the product is the only method provided by UL to identify products manufactured under its Listing and Follow-Up Service. The Listing mark for these products includes the name and/or symbol of Underwriters laboratories, inc. together with the word ‘LISTED’, a control number, and the appropriate tank construction as indicated in the individual Listing.

* Note: The Myers tank system is listed in one or more of the above categories under UL 142.

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