Snyder Industries 12500 Gallon Plastic Vertical Double Wall Liquid Chemical Storage Tank

Two tankers of dense chemical with the berm built in, certified

Put a regulated chemical in a single wall tank and the berm has to hold all of it, and at 12,500 gallons that berm is a room with a floor drain, a sump and a permit; the double wall tank carries its containment on the truck, and the Captor double wall SPCC compliance walkthrough shows how an inspector reads that under 40 CFR 112. A 1.9 wall is sized for a liquid nearly twice as dense as water, the certification against ASTM D1998 is what says both walls were sized that way, and 9,500 pounds is what two certified walls take on a shell nearly twenty-three feet tall, 1,000 pounds more than the cross-linked grade in the same mold. What follows is the chemistry the resin is rated to hold; check the liquid at its concentration in the chemical compatibility database, since a wall rated for the weight is not the same as a wall rated for the chemistry. The usable volume of a double wall tank is less than the nominal once thermal expansion and the interstice are accounted for; the freeboard sizing guide works out the real number, and for a dense chemical the expansion is large. The tank sizing calculator works the volume out from feed rate and delivery interval, and the tank sizing guide covers the reserve.

Grades on the 12,500 gallon double wall, and the sizes beside it

The N30 is the sulfuric acid resin in this same double wall at this tank's weight, molded for one chemical, and the N40 the cross-linked grade for oxidizers, 1,000 pounds lighter. The 1006600N30 is the sulfuric double wall at 10,000 gallons on this base 48 inches lower, and the 1006400N42 the cross-linked double wall at 8,700 gallons, 77 inches lower.

Want the certified one or the plain one? Call 866-418-1777 and say what the inspector asks for; or request a quote on the row you need.

Manway, outlet, alarms, interstice

• Access: 18 inch threaded, vented manway, 274 inches up; fill down a dip tube, run the vent outside on acid and caustic, and size it for the unload rate.
• Outlet: name the chemical when ordering so the bulkhead fitting matches it; on a double wall the outlet passes through both walls with a sealed transition, so it is set at the factory.
• Interstice: the space between the walls takes a leak sensor; fit one, wire it to an alarm, and test it with water at commissioning.
• Service limit: 120 F / 48 C.
• Listing: ASTM certification.

Choose the level sender for the chemical with the level gauge selection guide, read at ground level; on a tank this tall nobody climbs for a number. A double wall tank protects against a wall failure, not an overfill: a high-level alarm, an automatic cutoff on the fill line and a double block and bleed on the loadout are the layers the tank spillover redundancy guide lays out, and they are cheaper than the chemical they save. Full, the tank loads a 142 inch circle to 198,075 pounds at the rating, and the widest floor spans any hollow in a gravel base and cracks there when full, so the pad is an engineered slab in full contact under the whole outer wall, with the empty tank strapped against wind at two heights and the manway reached from a fixed platform with a rail. Keep the manway closed against vapor loss, and shade the tank where the chemical is light-sensitive.

The tanker unload

A tanker's pump moves liquid faster than a manway vent can pass air, so either the vent is sized to the unload rate or the fill comes in through its own top bulkhead with a separate vent line. The fill pipe runs to the floor so caustic or coagulant does not free-fall and foam; on a shell this tall that is a long drop. Never add water to the chemical; add the chemical to the water, because the dilution heat is real. The first delivery into a new tank is watched from start to finish, with the interstice sensor and the outlet transition checked as the level climbs, and every delivery after that goes in the log with a date and a strength.

Day-to-day duty

Ferric and other dense coagulants at a large plant that cannot build a berm and keeps certifications on file, acid feed for pH control at scale under a spill plan, heavy brine at plant scale, and any dense regulated chemical delivered two tankers at a time where the containment has to be on the drawing rather than in the floor. Never two chemicals in one tank, and one label that satisfies both inspectors.

Chemical service ratings

The resin is rated for the liquids below at the concentrations shown; the fitting and gasket called out are the ones to order with the tank. Verify the exact service on the linked page or in the chemical compatibility database before ordering.

• Acetic Acid 60% - PP/PVC fittings, EPDM gaskets
• Aluminum Sulfate 50% - PVC fittings, EPDM gaskets
• Calcium Chloride 40% - PVC fittings, EPDM gaskets
• DEF 32.5% - 316SS fittings, EPDM gaskets
• Ethylene Glycol 100% - PVC fittings, EPDM gaskets
• Ferric Chloride 50% - PVC fittings, EPDM gaskets
• Ferric Sulfate 60% - PVC fittings, EPDM gaskets
• Ferrous Sulfate 20% - PVC fittings, EPDM gaskets
• Hydrochloric Acid 37% - PVC fittings, Viton gaskets
• Hydrofluoric Acid 48% - PP/PVC fittings, Viton gaskets
• Hydrofluosilicic Acid 26% - PP/PVC fittings, Viton gaskets
• Hydrogen Peroxide 50% - PVC fittings, Viton gaskets
• Magnesium Chloride 30% - PVC fittings, EPDM gaskets
• Peracetic Acid 30% - 316SS fittings, Aflas gaskets
• Phosphoric Acid 85% - PVC fittings, Viton gaskets
• Polyaluminum Chloride - PVC fittings, EPDM gaskets
• Potassium Carbonate 50% - PVC fittings, EPDM gaskets
• Potassium Hydroxide saturated - PVC fittings, EPDM gaskets
• Propylene Glycol - PP/316SS fittings, EPDM gaskets
• Sodium Bisulfate - PVC/PP fittings, EPDM gaskets
• Sodium Bisulfite - PVC/PP fittings, EPDM gaskets
• Sodium Carbonate 30% - PVC fittings, EPDM gaskets
• Sodium Hypochlorite
• Sodium Thiosulfate 40% - PVC fittings, EPDM gaskets
• Sulfuric Acid 98% - CPVC fittings, Viton gaskets
• Urea Solution 50% - PP/PVC fittings, EPDM gaskets
• Zinc Orthophosphate - PP/316SS fittings, EPDM gaskets

From the plant to your site

At 142 inches across and 274 inches long on the deck the 1031100N45 is oversize freight on a flatbed at a lane rate, wider and longer than most loads on the road, so the estimator's lane matters; the freight cost estimator quotes the haul to your ZIP; what is listed is the price before freight. A crane sets 9,500 pounds upright on the slab; this is a rigging job with a plan. Water-fill the inner tank once to the manway, hold it, test the interstice sensor, then drain and dry before the chemical connection is made, and keep the certification paperwork with the project file. Keep one spare gasket for the outlet fitting on the shelf; it is the part that fails on a holiday.