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Above Ground UL 142 Double Wall Storage Tanks

Fire codes, environmental policies and SPCC (spill prevention, control and countermeasure) regulations have a secondary containment requirement for aboveground storage tanks. To meet this requirement, UL 142 double wall tanks are commonly used. Double wall storage tanks feature an inner tank tightly wrapped within an outer tank. This provides a convenient secondary containment solution in one unit.

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The UL 142 Standard

The UL 142 Standard for Steel Aboveground Tanks for Flammable and Combustible Liquids is one of the most common construction standards for the tank industry. One type of tank covered under this standard is the double wall storage tank. Underwriters Laboratories (UL) is an accredited developer of standards for product safety and performance. UL standards are widely recognized in the United States and Canada across many industries. UL Certified or listed means that UL has tested product samples and determined that it meets UL's nationally recognized Standards for Safety. A UL product listing or certification demonstrates the manufacturer’s experience in the industry, the commitment it makes to quality and steps it has taken to ensure its products can be safely used. There is no legal requirement that all tanks must be UL certified or listed. However, the regulating authority or fire marshal may set such requirements in their jurisdiction.


Double wall storage tanks are usually preferred over single wall tanks, not only due to requirements, but also due to costs. The drawbacks of single wall tanks VS double wall storage tanks are the costs involved with owning and installing a single wall tank. Relocating single wall storage tanks within a concrete dike can be an issue, as concrete dikes are permanent structures. Double wall storage tanks are a complete unit, so no separate dike is required and relocation is easy.


We offer double wall storage tanks in sizes ranging from 150 gallons to 30,000 gallons, in both single and multiple compartment systems. They can be constructed of mild carbon steel or stainless steel. Interior coatings are available when additional corrosion resistance is needed. Exteriors come standard with red oxide primer. We have a selection of colors customers can choose from if a painted topcoat is desired. We offer a full line of safety accessories, such as stairs and ladders for our storage tanks. We have many options for spill prevention. Tank equipment packages are available for customers who prefer a turn key job. With this option, pumps and equipment are pre-mounted to the tank and plumbing is pre-installed prior to shipment. Our double wall storage tanks are suitable for the storage of a variety of products including gasoline, diesel fuels, antifreeze, oils, lubricants, waste oil, biodiesel, chemicals, water storage and more.


For bottom anti-roll support and ground clearance, we offer a variety of supports for our single wall storage tanks. These include saddles, leg supports, light duty skids, box skids, heavy duty skids, pipe skids and super heavy duty WF beam skids.

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Leg Supports (Up to 4,000 gal.)

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Light Duty Skids (Up to 1,100 gal.)

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Heavy Channel Iron Skids (Up to 1,100 gal.)

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Box Skids (Up to 2,000 gallons)

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Saddles (All sizes)

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Heavy Duty Beam Skids (All sizes)