The Snyder Industries 4000 Gallon ASTM XLPE Double Wall Tank (SKU 5610000N42) is built from crosslinked linear polyethylene (XLPE) in natural white, with a 1.9 specific-gravity rating and a tank-within-a-tank design that wraps a secondary containment wall around the primary vessel. It stands 178 inches tall on a 102 x 102 inch footprint, so confirm your overhead clearance and pad dimensions before ordering. This is the configuration buyers look for as an XLPE double wall tank, where the integral outer wall delivers built-in secondary containment without a separate dike or basin.
Does it work for your application?
At 4000 gallons, a full load of water weighs 33,360 lb, while the tank is rated to carry contents weighing up to 63,384 lb. That higher figure comes straight from the 1.9 specific-gravity rating, which is what lets this vessel hold liquids substantially denser than water. Although it is configured here for water service, that 1.9 rating means the same tank is built for heavier-than-water liquids too, which gives you headroom if your service liquid is dense or if you anticipate a future change of service. Plan your foundation and structural support for the loaded weight, not the empty shell, and use the Tank Sizing Calculator and Tank Sizing Guide to match working volume to your draw and refill cycle.
Double-wall containment and fittings
The space between the primary and secondary walls is the interstitial monitoring zone, the defining feature of a double-wall tank; for the engineering behind interstitial-space integrity, see our guide on interstitial-space integrity for double-wall tanks. The technical drawing on this page details the factory fitting layout, which includes a flange, an 18-inch PE threaded and vented fitting, and a manway with a 15-inch access opening. The flange needs a matching companion flange and gasket (not included) sized to the drawing, and the 18-inch PE threaded/vented fitting accepts a mating PE threaded connection while letting the tank breathe as it fills and drains, so you avoid pulling a vacuum or pressurizing the headspace. The manway gives you a 15-inch top access opening for inspection, gauging, and tool or hose access. Confirm each thread size, bolt pattern, and gasket spec against the drawing before sourcing your plumbing, since fitting placement on a double-wall tank is set at the factory and the outer wall limits field modification.
Sizing the freeboard correctly
The most common mistake on a tank rated to this specific gravity is filling it to the brim without accounting for freeboard and thermal expansion. Our guide on Snyder Captor double-wall freeboard sizing per ASTM D1998 walks through how density and thermal expansion cut the real volume you can actually use. If this tank is headed into a fire-water or remote-site role, the fire-water reservoir design guide covers NFPA 22 sizing discipline and freeze protection, and for wall behavior at the vapor-saturated headspace, see the HDPE wall thickness guide.
This tank ships LTL freight, with Snyder producing from Lincoln, NE and West Virginia, so your origin and freight cost are quoted live to your ZIP. Get a number before you buy with our Freight Cost Estimator, or call 866-418-1777 and we will work the quote with you. Because of the 178-inch height and the loaded weight, confirm your delivery site can accept and offload a tank of this size before scheduling.
