The Snyder Industries 3500 Gallon Captor double wall tank gives you secondary containment without a separate dike: a sealed inner tank nested inside an outer shell, both molded in crosslinked linear polyethylene (XLPE) and rated to 1.5 specific gravity. It holds 3,500 gallons in a 102-inch square footprint and stands 158 inches tall in black, so it answers the three questions every buyer asks before a containment install: will it hold what I'm storing, what does it cost to get here, and where do people get it wrong.
Will it work for your storage
The XLPE wall and 1.5 specific gravity rating mean this tank handles dense liquids up to 1.5 times the weight of water without a heavier-tank upgrade, which makes it a fit for fire-water reservoirs, SPCC containment, and other demanding black double wall storage roles. Full of water, the contents weigh 29,190 lb; at the full 1.5 SG rating the contents can reach 43,785 lb, so plan the pad and foundation for that loaded figure, not the empty shell. The 102 x 102-inch footprint and 158-inch height should be checked against your door, gate, and overhead clearance before delivery. Per the technical drawing on this page, the tank carries a flange, an 18-inch PE threaded and vented fitting, and a manway with 15-inch access for entry and inspection. The vented 18-inch PE fitting is the atmospheric path that keeps the sealed shell from pulling a vacuum on drawdown or building pressure on fill, so do not cap it off. Confirm those fitting locations and the manway clearance match your plumbing and service plan; the drawing on this page is the authority for placement.
Sizing it correctly
A double wall containment tank is not all usable volume once you account for freeboard and thermal expansion. Our Tank Sizing Calculator and Tank Sizing Guide help you work backward from the volume you actually need to draw, and the Captor freeboard sizing guide per ASTM D1998 walks through how density and thermal expansion eat into the rated 3,500 gallons. If this tank is going into a regulated containment role, the SPCC 40 CFR 112 compliance walkthrough covers how the integral double wall fits the secondary-containment requirement, and for emergency or rural fire-protection storage the NFPA 22 fire-water reservoir guide covers the sizing discipline.
The mistake to avoid
The most common error on a black XLPE Captor double wall tank is undersizing the foundation for the rated load instead of the water load: spec the pad for 43,785 lb, not 29,190 lb. The second is treating the inner shell's rated 3,500 gallons as your working volume with no freeboard allowance. Third, the XLPE wall's resistance to your stored chemistry does not guarantee the seals will hold up, so confirm the gasket and fitting elastomer compatibility against what you are storing before service. And because this is a crosslinked (XLPE), not standard linear, polyethylene tank, confirm its material matches what your specification calls for before substituting. The vapor-headspace wall-thickness guide explains why inspection should include the upper shell, not just the wetted wall.
This Snyder double wall tank ships LTL from the Lincoln, NE plant; freight is quoted live to your ZIP rather than included in the list price. On a tank that loads to nearly 44,000 lb, origin and lane drive the freight number more than anything else, so get a real figure with our Freight Cost Estimator or call 866-418-1777 and we will quote it to your delivery address.
