Skip to content

Double Wall Storage Tanks

Double wall tanks are ideal for storing corrosive, environmentally hazardous, chemical and other dangerous substances that could potentially endanger the health and safety of workers or damage the environment and threaten public health in the event of spillage.

Use of double walled tanks is being increasingly required by local and federal government regulations as a precaution against accidents, particularly during the transport of dangerous, hazardous and other products, as well as for underground storage purposes.

All of ACO’s durable, double wall tanks come with both an inner tank and a secondary outer tank that has 120% the capacity of the inner tank and serves for containment purposes in the event of spillage.

In addition, the dome of the inside tank overlaps the sidewalls of the outer tank and so prevents the entrance of debris into con, rain, and snow from getting into the containment area.


ACO’s seamless, one-piece, double wall tanks are manufactured out of high grade HDPE or XHDPE/XLPE polyethylene and are, in fact, tough enough to resist chemical erosion even better than mild steel, stainless steel or FDP.

Moreover, like all ACO’s polyethylene products, ACO double wall tanks are fabricated to ASTM specifications. These one-piece tanks are extremely rugged, durable and stabilized against damage by the sun’s ultraviolet radiation. They are also designed to resist low temperature impacts and so are ideal for cold storage areas.

ACO’s wide selection of double wall tanks have different capacities and specifications that make them suitable for storing and transporting liquids with specific gravities (densities) of less than 1.5, less than 1.9, and less than 2.2.

Upper fitting flats come as standard on all ACO’s double wall tanks. Large tanks have lifting lugs and lower fitting flats molded into the bottom section in such a way as to permit the entry of the sturdy bottom outlet (optional).

ACO’s closed top double wall storage tanks have an extensive range of optional accessories, including different fittings and manway lids to meet with your requirements. Please contact us for more information about your needs and particular specifications.

ACO’s entire range of double wall tanks are ideal for storage uses where a double shell and secondary containment facility are paramount for safety and security purposes.

  • Very corrosion resistant
  • Very chemical resistant
  • Withstands low temperatures
  • Very durable, seamless one-piece construction
  • Complies with ASTM specifications
  • HDPE resin construction is stabilized against UV damage
  • Space-saving design due to narrow diameters so easy to store in plant
  • Suitable for liquid density (specific gravity) ratings of:
    • less than 1.5
    • less than 1.9 and
    • less than 2.2
  • Fabricated out of HDPE or cross-linked polyethylene (XHDPE/XLPE)
  • Suitable for potable water uses (HDPE resin listed NSF 61 and so complies with FDA)
  • Fittings supplied separately (on request)
  • Optional device to detect leaks available
  • Optional Bottom Thru-Containment Outlet available
  • We recommend double wall tanks be supplied with a top suction line to avoid any holes below the water line.