The Chem-Tainer TC3166JP is a 150-gallon closed-top cone bottom tank paired with a matched poly stand, molded in natural white polyethylene with a 1.9 specific gravity rating - the top density tier for this line, and exactly what you want when you are storing dense chemistry rather than water. The tank stands 66 inches tall on a 31-inch diameter footprint, weighs 100 pounds empty, and comes with an 8-inch threaded vented lid up top and a 1.5-inch outlet at the cone apex so the tank drains itself by gravity. The full-drain cone geometry is why buyers choose this style for batching, settling solids, and clean-out between chemicals. It carries an FDA-approved resin rating.
Will it work for your application
Size the tank by the weight of what it will actually hold, not by gallons. Filled with water this tank carries about 1,251 pounds; at its full 1.9 SG rating the contents can reach roughly 2,377 pounds, and the poly stand plus the cone outlet fittings have to be rated for that loaded weight. Run your fluid through the Tank Sizing Calculator and the Tank Sizing Guide to confirm the stand and outlet suit your medium. Note the proportions: 66 inches of height over a 31-inch base is roughly a 2:1 ratio, so a full tank sits top-heavy on its stand - anchor and secure the poly stand to the floor, particularly in seismic zones, since this tank ships from California. The 1.5-inch cone outlet is the other constraint worth sizing early: it sets your gravity drain speed and dictates the bulkhead fitting and valve you need to source. Because this is a cone bottom on a stand, fitting and vent placement on the 8-inch lid matters - our guide on tank-top fitting placement walks through keeping fill, vent, and level lines from fighting each other. If you are weighing this poly stand against a steel frame, or matching a cone tank to the right stand across brands, see our stand selection decision tree and the stand compatibility matrix. For drainage behavior specific to Chem-Tainer cones, the 30° vs 45° comparison covers residual heel and solids handling.
Chemical compatibility
This tank is polyethylene with a 1.9 SG rating. The resin is recorded as HDLPE with a question mark, so before you commit it to chemical service, confirm whether your intended tank is HDLPE or XLPE (cross-linked) - the two behave differently against certain chemistries. Compatibility below is drawn from the Snyder Industries OEM chemical-resistance chart and is concentration- and temperature-specific; always confirm your exact chemical, concentration, temperature, and the fitting and gasket materials before ordering.
At its 1.9 SG rating this tank suits heavier chemistries including Ethylene Glycol (100%, PVC fittings, EPDM gaskets), Ferric Chloride (50%, PVC/EPDM), Ferric Sulfate (60%, PVC/EPDM), Hydrochloric Acid (37%, PVC fittings, Viton gaskets), Hydrofluoric Acid (48%, PP/PVC, Viton), Hydrofluosilicic Acid (26%, PP/PVC, Viton), Hydrogen Peroxide (50%, PVC, Viton), Phosphoric Acid (85%, PVC, Viton), Polyaluminum Chloride (PVC/EPDM), Potassium Carbonate (50%, PVC/EPDM), Potassium Hydroxide (saturated, PVC/EPDM), Sodium Bisulfate and Sodium Bisulfite (PVC/PP, EPDM), Sodium Thiosulfate (40%, PVC/EPDM), and Sulfuric Acid (98%, CPVC fittings, Viton gaskets). Lighter-density chemistries that only need a 1.35-1.5 SG tank are also within range here, including Acetic Acid (60%), Aluminum Sulfate (50%), Calcium Chloride (40%), Ferrous Sulfate (20%), Magnesium Chloride (30%), and Sodium Carbonate (30%).
A handful of chemistries here break the usual PVC pattern and require stainless steel fittings - do not put PVC on these: DEF (32.5%, 316SS, EPDM), Urea Solution (50%, PP/PVC, EPDM), Peracetic Acid (30%, 316SS, Aflas gaskets), Propylene Glycol (PP/316SS, EPDM), and Zinc Orthophosphate (PP/316SS, EPDM). Two more carry hard upper limits rather than a working concentration: Sodium Hypochlorite is capped at a maximum of 16.5% (PVC, Viton) and Ozonated Water at a maximum of 10 PPM (PVC, EPDM) - treat those as ceilings, not targets. Cross-check every candidate against our Chemical Compatibility Database at your real concentration and temperature.
The mistake to avoid
The specific-gravity trap catches people. This tank is rated to 1.9 SG - Chem-Tainer's top density rating for this line, so there is no heavier version to upsize to. If your fluid exceeds 1.9 SG, you need a different construction, not a bigger number. And that 1.9 rating protects the tank wall - it does not automatically cover your fittings or gaskets. Note how the chart pairs Viton gaskets with the oxidizers and strong acids (sulfuric, hydrochloric, hypochlorite, peroxide) and EPDM with the salts and glycols; putting EPDM where Viton is called for is how a tank that is "compatible" still leaks at the bulkhead. Match the outlet fitting and gasket material to your chemical, and confirm the HDLPE-vs-XLPE resin question before you fill it.
This tank ships LTL freight from the Chem-Tainer plant in Hanford, CA, quoted live to your ZIP through our Freight Cost Estimator - the listed price is before freight. See the technical drawing on this page for exact fitting locations and cone geometry. Questions on sizing, chemical fit, or the poly stand, call 866-418-1777.
