The Snyder Industries 4000 Gallon HDLPE Vertical Double Wall Liquid Chemical Storage Tank is built for full-strength chemical service, carrying a 1.9 specific gravity rating in a one-tank-inside-another double wall configuration that delivers integral secondary containment without a separate basin. Both shells are molded in high density linear polyethylene (HDLPE), the inner tank holds 4000 gallons, and the unit stands 178 inches tall on a 102 x 102 inch footprint. If you have been searching for a vertical storage tank or a double wall tank that handles aggressive liquids, this is the configuration to evaluate.
Will it work for your application?
The engineering numbers matter more than the nameplate gallons here. A full load of plain water weighs 33,360 lb, while the structure carries a maximum rated contents weight of 63,384 lb. That spread is what lets you store dense chemicals up to 1.9 SG, but it also means you cannot assume a full 4000 gallons of every liquid stays under the ceiling: contents weight scales with specific gravity, so a heavier chemical reaches the structural limit before the tank is geometrically full. Plan your working volume and freeboard against that, not against nameplate capacity. Use the Tank Sizing Calculator and Tank Sizing Guide to size the fill, and read our walkthrough on freeboard sizing per ASTM D1998 for the volume you can actually use. On foundation: 63,384 lb of rated contents sits over roughly an 8.5 x 8.5 ft footprint at 178 inches tall, so plan a level concrete pad and confirm anchoring for your wind and seismic zone.
As-molded fittings and building your wetted kit
The technical drawing on this page shows the as-molded configuration: a flange, an 18-inch PE threaded and vented fitting, and a manway with 15-inch access for entry and cleanout. See that drawing for placement and elevations. From there, build your wetted fitting and gasket kit to match the chemical, not the other way around. The compatibility data below carries those material calls for you, and the escalations are where most failures start: a 316SS threaded outlet for DEF and peracetic acid, CPVC for 98% sulfuric acid, Viton gaskets for the oxidizers and strong acids, and Aflas for peracetic acid. Do not reuse a generic PVC bulkhead across every service.
Chemical compatibility
This is an HDLPE shell rated to 1.9 SG, which is what makes it a true chemical-duty vessel rather than a water tank pressed into service. Compatibility depends on the resin, the wetted fitting material, and the gasket, so always confirm against the manufacturer's chemical-resistance chart at your specific concentration and temperature. Drawing from that chart, the following chemicals are compatible with this HDLPE tank at the listed conditions:
- Acetic Acid 60% with PP/PVC fittings and EPDM gaskets
- Aluminum Sulfate 50% with PVC fittings and EPDM gaskets
- Calcium Chloride 40% with PVC fittings and EPDM gaskets
- DEF 32.5% with 316SS fittings and EPDM gaskets
- Ethylene Glycol 100% with PVC fittings and EPDM gaskets
- Ferric Chloride 50% with PVC fittings and EPDM gaskets
- Ferric Sulfate 60% with PVC fittings and EPDM gaskets
- Ferrous Sulfate 20% with PVC fittings and EPDM gaskets
- Hydrochloric Acid 37% with PVC fittings and Viton gaskets
- Hydrofluoric Acid 48% with PP/PVC fittings and Viton gaskets
- Hydrofluosilicic Acid 26% with PP/PVC fittings and Viton gaskets
- Hydrogen Peroxide 50% with PVC fittings and Viton gaskets
- Magnesium Chloride 30% with PVC fittings and EPDM gaskets
- Peracetic Acid 30% with 316SS fittings and Aflas gaskets
- Phosphoric Acid 85% with PVC fittings and Viton gaskets
- Polyaluminum Chloride with PVC fittings and EPDM gaskets (confirm rated concentration against the chart)
- Potassium Carbonate 50% with PVC fittings and EPDM gaskets
- Potassium Hydroxide saturated with PVC fittings and EPDM gaskets
- Propylene Glycol with PP/316SS fittings and EPDM gaskets (confirm rated concentration against the chart)
- Sodium Bisulfate with PVC/PP fittings and EPDM gaskets (confirm rated concentration against the chart)
- Sodium Bisulfite with PVC/PP fittings and EPDM gaskets (confirm rated concentration against the chart)
- Sodium Carbonate 30% with PVC fittings and EPDM gaskets
- Sodium Hypochlorite at less than 16.5% with PVC fittings and Viton gaskets
- Sodium Thiosulfate 40% with PVC fittings and EPDM gaskets
- Sulfuric Acid 98% with CPVC fittings and Viton gaskets
- Urea Solution 50% with PP/PVC fittings and EPDM gaskets
- Zinc Orthophosphate with PP/316SS fittings and EPDM gaskets (confirm rated concentration against the chart)
- Ozonated Water up to 10 PPM with PVC fittings and EPDM gaskets (database entry pending)
Notice how the gasket choice shifts to Viton for the oxidizers and strong acids and to Aflas for peracetic acid, while the threaded outlet on DEF and peracetic acid moves to 316SS. Matching the fitting and gasket to the chemical is the difference between a tank that lasts and one that leaks, so build from these conditions and the full Chemical Compatibility Database.
The mistake to avoid
The most common error on a double wall chemical tank is treating the 1.9 SG rating as a clearance for any liquid. It is a structural ceiling, not chemical approval. A chemical can sit well below 1.9 SG and still attack the wrong gasket, and a hot concentrated acid can exceed the chart's tested temperature even when its density is fine. Verify SG, concentration, and temperature together, and never assume sodium hypochlorite at the 16.5% threshold behaves like a dilute solution. For containment design and alarm logic, read our walkthroughs on Snyder Captor double-wall tanks for SPCC 40 CFR 112 compliance, level gauge selection for chemical service, and spillover redundancy and high-level alarm architecture.
This tank ships LTL freight from the nearest stocking Snyder plant, with freight quoted live to your ZIP code. Get an exact number with the Freight Cost Estimator or call 866-418-1777 to confirm the molding plant, fittings, lead time, and delivery requirements for your site before you order.
