The Enduraplas 500 Gallon Black Horizontal Sump Bottom Leg Tank ships as a complete unit with its integral steel frame, built for mobile and stationary transfer where a low, stable profile matters more than vertical footprint. The tank holds 500 gallons in a polyethylene body measuring 49 inches high, 57 inches wide, and 80 inches long, riding in a frame that sets the footprint at 57.0 x 80.0 inches. The sump bottom drains the contents toward a low point so you can pull the tank down to the last usable gallons instead of leaving heel behind, which means you should plumb the outlet at that sump low point so the fitting you select lands where the tank actually drains. With water (specific gravity 1.0) the body carries roughly 4,170 pounds of liquid when full; that is liquid weight only, so add the steel frame and tank shell on top of it for axle and trailer math. The tank carries a 1.9 specific gravity rating, which puts the maximum rated contents weight at 7,923 pounds for dense fluids. Color is black throughout. Resin is not confirmed in our records, so verify the exact polyethylene grade with the manufacturer before chemical service. See the technical drawing on this page for the frame layout and fitting locations before you plumb it.
Will it work for your job
This is a horizontal leg tank, the format farmers and applicators reach for when a load needs to sit low on a trailer or skid and stay put under transport. The 1.9 specific gravity rating is the number that does the real work here: it tells you the tank wall is built to hold liquids up to 1.9 times the density of water, so the 500-gallon volume translates to as much as 7,923 pounds of dense fertilizer or chemical without overstressing the shell. Common dense ag fluids in the fertilizer and chemical service this format targets approach that ceiling, but anything above specific gravity 1.9 is out of spec for this shell. Size the load against your axle and trailer rating using the liquid-only full-water figure of 4,170 pounds as your light end and the 7,923-pound rating as your ceiling, then add frame and shell weight. The Tank Sizing Calculator and the Tank Sizing Guide will help you match volume and weight to your equipment before you commit. If this tank rides on a trailer for road use, read our notes on applicator and leg tanks for fertilizer and DOT non-roadable trailer scope and the 49 CFR agricultural exemption and DOT classification for farm fleet use.
Chemical compatibility
The tank is polyethylene with a 1.9 specific gravity rating, which is what makes this body a candidate for dense chemical service rather than plain water hauling. The resin record is not confirmed, so confirm HDLPE versus XLPE and the exact resin grade with the manufacturer before you put any chemical in it, because different resins behave differently against aggressive media. The chemicals below are compatible at the listed concentrations per the OEM chemical-resistance chart, which is concentration- and temperature-specific, so match your actual service conditions to the chart before ordering fittings or gaskets. Note that fitting and gasket materials are not all the same across these chemicals.
- Acetic Acid at 60% — PP/PVC fittings, EPDM gaskets
- Aluminum Sulfate at 50% — PVC fittings, EPDM gaskets
- Calcium Chloride at 40% — PVC fittings, EPDM gaskets
- DEF at 32.5% — 316SS fittings, EPDM gaskets
- Ethylene Glycol at 100% — PVC fittings, EPDM gaskets
- Ferric Chloride at 50% — PVC fittings, EPDM gaskets
- Ferric Sulfate at 60% — PVC fittings, EPDM gaskets
- Ferrous Sulfate at 20% — PVC fittings, EPDM gaskets
- Hydrochloric Acid at 37% — PVC fittings, Viton gaskets
- Hydrofluoric Acid at 48% — PP/PVC fittings, Viton gaskets
- Hydrofluosilicic Acid at 26% — PP/PVC fittings, Viton gaskets
- Hydrogen Peroxide at 50% — PVC fittings, Viton gaskets
- Magnesium Chloride at 30% — PVC fittings, EPDM gaskets
- Peracetic Acid at 30% — 316SS fittings, Aflas gaskets
- Phosphoric Acid at 85% — PVC fittings, Viton gaskets
- Polyaluminum Chloride — PVC fittings, EPDM gaskets
- Potassium Carbonate at 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 at 30% — PVC fittings, EPDM gaskets
- Sodium Hypochlorite at <16.5% — PVC fittings, Viton gaskets
- Sodium Thiosulfate at 40% — PVC fittings, EPDM gaskets
- Sulfuric Acid at 98% — CPVC fittings, Viton gaskets
- Urea Solution at 50% — PP/PVC fittings, EPDM gaskets
- Zinc Orthophosphate — PP/316SS fittings, EPDM gaskets
- Ozonated Water up to 10 PPM — PVC fittings, EPDM gaskets (no dedicated reference page yet)
The most common mistake on a tank like this is matching the gasket to the tank instead of to the chemical: notice that the acids above call for Viton or Aflas rather than EPDM, and DEF and peracetic acid call for 316 stainless steel fittings, not PVC. Plumb those fittings at the sump low point and get the elastomer and fitting material right for your specific media and concentration. For the full picture, work from our chemical compatibility reference alongside the OEM chart.
Freight
This tank ships LTL freight from the Enduraplas plant in Neche, North Dakota, quoted live to your ZIP code. Because freight on a framed horizontal tank depends on distance, accessorials, and your delivery situation, get an exact number with our Freight Cost Estimator or call us at 866-418-1777 and we will quote it for you. The listed price is before freight.
