Snyder Industries 500 Gallon Plastic Vertical Double Wall Liquid Chemical Storage Tank in White with Sulfuric Acid Resin

Acid, contained

Concentrated sulfuric acid weighs nearly twice what water does and attacks the wall of an ordinary linear polyethylene tank from the inside, at the surface and in the vapor space above the liquid. Snyder's N30 resin is compounded for that service, so a tank in it is sized for the acid's weight and its chemistry together. A leak of acid is a burn hazard and a fume hazard before it is a cleanup, and the interstitial space holds it; the SPCC 40 CFR 112 compliance walkthrough covers where a double wall tank satisfies a spill plan on its own. The chemistry list below is what the resin is rated for; check the liquid at its concentration in the chemical compatibility database. The tank sizing calculator sizes the tank to feed rate and delivery interval, and the tank sizing guide covers the reserve; acid expands more than water with temperature, so the reserve includes freeboard.

Grades on the 53 x 81 inch double wall, and the sizes beside it

The N45 is the general linear grade for caustic, coagulant and brine, the N42 is cross-linked polyethylene for hypochlorite and the other oxidizers, and the N51 is another linear grade, all at the same weight in the same shell. The 5990702N30 is the sulfuric-grade 405, 8 inches shorter on a base 5 inches narrower, and the 5040000N30 is the sulfuric-grade 550 laid down to 65 inches on a 76 inch base.

Neighboring size a better fit? Every row links to its own page; freight to your ZIP is quoted on each, or call 866-418-1777.

Manway, outlet and the space between the walls

• Access: 18 inch threaded, vented manway on the primary, 81 inches up; fill through a dip tube, and vent to a scrubber or outdoors, never into the room.
• Outlet: through both walls together, with the transition supported off the floor; specify an acid-rated fitting and gasket when ordering.
• Service limit: 120 F / 48 C.

Two levels to watch: the primary, with a sender rated for concentrated acid per the level gauge selection guide, and the interstitial space, which is the leak alarm and gets a float switch, a look into the port each shift, and a logged check each week. If the space is ever wet, the primary is leaking and the tank comes out of service the same day. Strap it to a wall; a 53 inch base under 81 inches of a liquid this dense has a high center of gravity. Acid draws water from the air and heats when it does, so the manway stays closed and the vent carries a drying trap. Never add water to the tank; dilution is done elsewhere, water first.

What it holds in practice

Sulfuric acid feed for pH control at water and wastewater plants, regeneration acid at a demineralizer, pickling and plating acid make-up, and any 500 gallon vessel of concentrated acid inside an occupied building. Acid only, labeled, with the eyewash within reach of the manway.

Chemicals this resin is rated for, with the fitting and gasket to order

These are the chemicals listed for this tank at the concentrations shown. Each links to the full compatibility page; confirm your exact concentration and temperature there or in the chemical compatibility database before ordering.

• Sulfuric Acid at 98% (CPVC fittings, Viton gaskets)
• Hydrochloric Acid at 37% (PVC, Viton)
• Phosphoric Acid at 85% (PVC, Viton)
• Hydrofluoric Acid at 48% (PP/PVC, Viton)
• Hydrofluosilicic Acid at 26% (PP/PVC, Viton)
• Acetic Acid at 60% (PP/PVC, EPDM)
• Peracetic Acid at 30% (316SS, Aflas)
• Hydrogen Peroxide at 50% (PVC, Viton)
• Sodium Hypochlorite below 16.5% (PVC, Viton)
• Ferric Chloride at 50% (PVC, EPDM)
• Ferric Sulfate at 60%
• Ferrous Sulfate at 20%
• Aluminum Sulfate at 50%
• Calcium Chloride at 40%
• Magnesium Chloride at 30% (all PVC, EPDM)
• Sodium Carbonate at 30%
• Potassium Carbonate at 50%
• Potassium Hydroxide saturated
• Sodium Thiosulfate at 40%
• Sodium Bisulfate
• Sodium Bisulfite (both PVC/PP, EPDM)
• Polyaluminum Chloride (PVC, EPDM)
• Zinc Orthophosphate (PP/316SS, EPDM)
• Ethylene Glycol at 100%
• Propylene Glycol (PP/316SS, EPDM)
• Urea Solution at 50%
• DEF at 32.5% (316SS fittings, EPDM gaskets), and ozonated water up to 10 PPM (PVC, EPDM).For full concentration and temperature data, see our

Getting it to the pad

The 5780102N30 ships palletized as LTL freight (NMFC 156600-03) at a class rate; the freight cost estimator turns your ZIP into a freight number; the price on this page is before freight. A pallet jack moves 290 pounds. Water-test the primary, confirm the interstice stays dry through the hold, then drain and dry completely before the first acid delivery; water left in an acid tank is the first mistake. Once it is full and holding, leave it alone for a day before the plumbing goes on; a settled tank is a quiet one.