The Snyder Industries 3500 Gallon Vertical Double Wall Liquid Chemical Storage Tank is a self-contained primary-plus-secondary containment unit molded from High Density Linear Polyethylene (HDLPE) in white, rated to a 1.9 specific gravity. The double-wall design builds the containment basin around the primary tank, so a single 102 x 102 inch footprint carries 3,500 gallons of process chemical with integral spill protection. At 158 inches tall on that 102-inch footprint, this is a tall vertical storage tank built for fixed installation, not relocation once filled.
Will it work for your chemical?
The 1.9 specific gravity rating is the number that matters here. Full of plain water this tank loads to roughly 29,190 lb, but the wall section was engineered for liquids up to 1.9 SG, which is why the maximum rated contents weight reaches 55,461 lb. That headroom is what lets it hold dense chemistry like concentrated sulfuric or phosphoric acid where a 1.0 or 1.5 SG tank would be undersized at the wall. At 1.9 SG this tank already sits at the top of the standard density band, so there is no higher-SG alternative needed here — if your chemical exceeds 1.9 SG, call to confirm before ordering. Verify your chemical's specific gravity against the 1.9 rating first, then use the Tank Sizing Calculator with the Tank Sizing Guide to set freeboard for thermal expansion. The Captor double-wall freeboard sizing walkthrough shows how density and temperature cut into the volume you can actually use.
Fittings, venting, and access
Per the technical drawing on this page, this unit carries a flange, an 18-inch PE threaded and vented fitting, and a manway with 15-inch access. The 18-inch vented fitting is the tank's atmospheric vent — size your fill rate so the vent can keep up, and pair it with the high-level alarm architecture covered in the spillover redundancy guide. The 15-inch manway access supports interior inspection and cleanout between chemical changes, which matters if you cycle this tank across the chemistries below. Note that the drawing fittings are the molded tank penetrations; bulkhead fittings, gaskets, and valves are selected separately to the materials in the compatibility table below (for example, a PVC body with a Viton gasket for sulfuric service). For dosing and transfer setups, the level gauge selection guide covers the instrumentation that keeps a double-wall tank from overfilling, and if your site falls under federal spill-prevention rules, review the SPCC 40 CFR 112 compliance walkthrough.
Chemical compatibility
This is an HDLPE tank rated to 1.9 specific gravity. The chemicals below are drawn from the chemical-resistance data for this resin, which is concentration- and temperature-specific, so verify your exact conditions against it before service. Confirmed compatible with this resin and SG rating: Acetic Acid (60%, PP/PVC fittings, EPDM gaskets, details); Aluminum Sulfate (50%, PVC, EPDM, details); Calcium Chloride (40%, PVC, EPDM, details); DEF (32.5%, 316SS fittings, EPDM, details); Ethylene Glycol (100%, PVC, EPDM, details); Ferric Chloride (50%, PVC, EPDM, details); Ferric Sulfate (60%, PVC, EPDM, details); Ferrous Sulfate (20%, PVC, EPDM, details); Hydrochloric Acid (37%, PVC, Viton, details); Hydrofluoric Acid (48%, PP/PVC, Viton, details); Hydrofluosilicic Acid (26%, PP/PVC, Viton, details); Hydrogen Peroxide (50%, PVC, Viton, details); Magnesium Chloride (30%, PVC, EPDM, details); Peracetic Acid (30%, 316SS, Aflas, details); Phosphoric Acid (85%, PVC, Viton, details); Polyaluminum Chloride (PVC, EPDM, details); Potassium Carbonate (50%, PVC, EPDM, details); Potassium Hydroxide (saturated, PVC, EPDM, details); Propylene Glycol (PP/316SS, EPDM, details); Sodium Bisulfate (PVC/PP, EPDM, details); Sodium Bisulfite (PVC/PP, EPDM, details); Sodium Carbonate (30%, PVC, EPDM, details); Sodium Hypochlorite (under 16.5%, PVC, Viton, details); Sodium Thiosulfate (40%, PVC, EPDM, details); Sulfuric Acid (98%, CPVC, Viton, details); Urea Solution (50%, PP/PVC, EPDM, details); Zinc Orthophosphate (PP/316SS, EPDM, details); and Ozonated Water (up to 10 PPM, PVC, EPDM). Two cautions worth flagging: the gasket changes by chemical — oxidizers and strong acids such as hydrogen peroxide, sodium hypochlorite, and sulfuric acid call for Viton rather than EPDM, and peracetic acid moves to Aflas — so the most common mistake on this tank is reusing one gasket material across a multi-chemical site. And if you are storing diesel exhaust fluid, use the DEF line (32.5%, 316SS fittings), not the 50% Urea Solution line, since the fitting materials differ. Cross-check every chemical against the full Chemical Compatibility Database.
This double wall tank ships LTL from Lincoln, NE, with freight quoted live to your ZIP. Filled, it carries up to 55,461 lb across a 102 x 102 inch footprint, so plan delivery for a site with crane or forklift access and a level, fully supporting pad. Get a freight estimate now with the Freight Cost Estimator, or call our team at 866-418-1777 to confirm fittings, gasket selection, and lead time before you order.
