The Norwesco 335 Gallon Plastic Chemical Injection Tank (SKU N-63890) is a white, high density linear polyethylene (HDLPE) specialty tank rated to a 1.5 specific gravity. At 49 inches tall on a 44 x 56 inch footprint, it holds 335 gallons in a compact stance well suited to injection skids, day-tank duty, and metering setups where floor space is tight. Built by Norwesco, it belongs to the family of chemical tanks and Norwesco tanks that handle a defined range of treatment fluids rather than open-ended storage. The 32.5% DEF and 50% urea solution entries below make it a workable DEF or urea day-tank as well, with the fitting caveats noted in the compatibility list.
Will this tank work for your application?
Start with weight, because that is what governs your pad, your skid, and your handling plan. Filled with plain water this tank carries roughly 2,794 lb. At its full 1.5 SG rating the contents can reach about 4,191 lb, so size the slab or stand for the loaded number, not the empty shell. Your actual loaded weight is 335 gal x 8.34 lb/gal x your fluid's specific gravity, anywhere up to that 4,191 lb ceiling, so a mid-density fluid lands between the water figure and the rated maximum. The 1.5 SG rating is the deciding spec for chemical service: it tells you which fluids the wall thickness supports at the densities listed below. To pin the right capacity and stand for your draw rate, run the figures through the Tank Sizing Calculator and the Tank Sizing Guide.
Chemical compatibility
This is an HDLPE tank rated to 1.5 specific gravity. Match every fitting and gasket material to the fluid, and verify against the OEM chemical-resistance chart at your specific concentration and operating temperature before committing to chemical service. EPDM gaskets cover most fluids on this list; DEF is the one anomaly, requiring 316SS fittings rather than PVC. The following chemicals are compatible with this 1.5 SG tank at the concentrations shown:
- 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
- Ferrous Sulfate (20%) - PVC fittings, EPDM gaskets
- Magnesium Chloride (30%) - PVC fittings, EPDM gaskets
- Sodium Carbonate (30%) - PVC fittings, EPDM gaskets
- Urea Solution (50%) - PP/PVC fittings, EPDM gaskets
- Ozonated Water (up to 10 PPM) - PVC fittings, EPDM gaskets (verify ozone concentration and contact time against the OEM chart)
The full set lives in our Chemical Compatibility Database, concentration and temperature specific.
The mistake to avoid: don't run a heavier chemical in a 1.5 SG tank
The most common error on a chemical injection tank is pushing a denser fluid into a wall that was not built for it. This tank is rated to 1.5 SG. Several common treatment chemicals require a higher 1.9 SG tank instead, including Ferric Chloride, Sodium Hypochlorite, Sulfuric Acid, Hydrochloric Acid, Phosphoric Acid, Hydrogen Peroxide, Peracetic Acid, Ethylene Glycol, Propylene Glycol, Polyaluminum Chloride, and Potassium Hydroxide, among other higher-SG chemistries. Note too that some of those require Viton or Aflas gaskets rather than EPDM. If your fluid is on the higher-SG list, it needs a 1.9 SG-rated tank rather than this one. Use the Chemical Compatibility Database to match the right 1.9 SG tank to your fluid, or call 866-418-1777 and we will confirm it. One more detail that bites people: lay out your top fittings deliberately so vent, fill, level, and drain do not conflict in service. See our guide on tank top fitting placement strategy and, for instrumentation, level gauge selection for chemical service.
Compliance and sampling for bulk chemical service
Once the tank is filled and labeled, two operational practices protect you. Label it correctly for the chemistry it holds, and pull samples on a defined cadence so what is in the tank stays what you think is in it. Our references on tank label and signage compliance and the chemical sampling protocol walk through both. Refer to the technical drawing on this page for fitting locations and overall dimensions.
This tank ships LTL freight from the nearest Norwesco plant to you, either Marked Tree, AR or Shawnee, OK, with the rate quoted live to your ZIP. Get your number in seconds with the Freight Cost Estimator, or call us at 866-418-1777 and we will confirm the right SG rating, fitting package, and freight before you order.
