The Snyder Industries 1100 Gallon Double Wall Storage Tank is a tank-within-a-tank built for liquids that demand secondary containment without a separate dike or berm. The inner vessel is rated to 1.9 specific gravity, so it holds dense liquids that thinner-walled storage tanks cannot. It stands 104 inches tall on a 76 x 76 inch footprint, and at the full 1.9 SG rating the inner tank carries up to 17,431 lb of contents. Design your pad, slab loading, and tie-downs to that number, not the 9,174 lb a water fill would weigh.
Will it work for your job
This is a double wall tank in Natural White High Density Linear Polyethylene, with the inner vessel rated to 1.9 specific gravity. The 1.9 SG rating is the headline reason to choose this unit over a thinner-walled storage tank: confirm your liquid's specific gravity at operating temperature falls at or below 1.9. If your fluid sits near 1.9, you have no margin left, so treat that rating as a hard ceiling rather than a target. The footprint is 76.0 x 76.0 inches and overall height is 104 inches, so verify door, ceiling, and access clearances before delivery. If you are still choosing a capacity, run your fill volume through the Tank Sizing Calculator and the Tank Sizing Guide.
Fittings and access
Per the technical drawing on this page, this tank carries a flange fitting, an 18" PE threaded and vented fitting, and a manway with 15" access. Because this is a tank-within-a-tank, those fittings penetrate to the inner vessel that holds your contained liquid, while the integral outer shell stays sealed as the containment barrier. The 15" manway accesses the inner tank for inspection, cleaning, and gauging. Reference the technical drawing on this page for exact fitting placement and elevations before you set the tank and plumb your lines, since the vent and threaded connection need to stay accessible once the tank is in position. Confirm the gasket and seal material on the bolt-on flange and manway against your specific liquid before plumbing, since seal compatibility is separate from the tank's resin rating.
Double wall containment and sizing the freeboard
Because this is a double wall tank, the integral outer shell captures a leak from the inner vessel, which is what makes it a fit for SPCC-regulated and fire-water storage. Two of our engineering write-ups go deeper here: the Snyder Captor double-wall freeboard sizing guide per ASTM D1998 walks through thermal expansion and the real usable volume, and the Snyder Captor double-wall SPCC 40 CFR 112 walkthrough covers the compliance side. For private fire-protection reservoirs, see the rural fire-water reservoir design guide. If you are weighing this against a single-wall option, the 1100 gallon vertical storage tank buyer's guide covers the same capacity in a single-wall configuration.
The mistake to avoid
The common error on a double wall storage tank is engineering the foundation and anchoring for the water weight. At 1.9 SG this inner tank can hold up to 17,431 lb, nearly double the 9,174 lb of a water fill. Build for the rated 1.9 SG load and your actual liquid's density, and do not assume the inner rating tells you anything about your gasket and fitting compatibility, which you must confirm separately.
This 1100 gallon XLPE-class double wall tank ships LTL freight from our Philippi, West Virginia plant, quoted live to your ZIP. Because it stands 104 inches tall on a 76 x 76 footprint and carries serious rated weight, a liftgate truck cannot handle this load: confirm your site has forklift or crane access to offload before you order. Get your freight number from the Freight Cost Estimator or call 866-418-1777.
