DOUBLE-WALLED

Underground Storage Tanks

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Forgeweld’s double-walled steel tanks use secondary containment technology to protect the environment from contamination

The tanks consist of a primary steel tank enclosed within a secondary steel tank. After tank installation, the 25mm interstice between the inner and outer tank is filled with a mixture of water and glycol which not only provides insulation and temperature control and will activate an alarm to alert you to a drop in pressure or liquid level. A 2,5mm composite (Fiberglass-reinforced Polyester Resin or FRP) or 0,8mm polyurethane coating may be applied to the outer steel wall for corrosion protection.

Convenient access and fuel dispatch

Fitted with a 745mm underground manhole or optional forecourt manhole which incorporates pump suction apertures and fittings for filler, dip and breather. 25mm sockets on top of each end monitor the interstice. Fitted either with lifting lugs and flanged or dished ends.

Certified world class quality

Manufactured in South Africa, the 6mm carbon steel plate complies with Grade 335JR. Both the inner and outer tanks are submerged and arc welded for rugged strength. Our quality control measures are certified by the United States UL 58 standard as well as independent auditors.

Warranty policy

All storage tanks manufactured by Forgeweld Engineering (Pty) Ltd carries a warranty against defective materials and workmanship for a period of 24 months from the date of installation.

Tank dimensions and capacity

Standard sizes for Forgeweld’s double-walled steel tanks are shown below

VOLUME m3 IN. DIAMETER MM OUT. DIAMETER MM OVERALL LENGTH MM SHELL THICKNESS MM CALC. CAPACITY liters APPROX WIGHT kg
4.5 1810 1817 2050 6 4515 2090
9 1810 1817 3650 6 9024 3054
14 1810 1817 5350 6 13876 4017
23 2318 2330 5350 6 22442 5027
30 2318 2330 6100 6 29515 6265

Tanks can be produced to order. However, we recommend a maximum size of 40m2 due to mass considerations in transporting double-wall steel USTs as they are heavier than Permatank® Jacketed or Composite USTs of the same size.

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Click here to download our Double Walled brochure (PDF)