The Snyder Industries 500 Gallon ASTM Black Double Wall Tank (SKU 5780102N51) is a contained double wall vessel: a primary tank molded inside a secondary shell, giving you built-in spill containment without pouring a separate berm. It holds 500 gallons, stands 81 inches tall on a 53 x 53 inch square footprint, and is molded from high density linear polyethylene rated to a 1.9 specific gravity. This is a black double wall tank built to the ASTM standard for above-ground poly storage.
Will it work for your site
Filled with water this tank carries about 4,170 lb, so the pad or slab under it has to support that fully loaded weight. The 1.9 SG rating is a structural ceiling, not a water feature: the wall is rated for liquids up to 1.9 times water density, roughly 7,923 lb of maximum rated contents. For plain water at 4,170 lb you sit well under that limit, so the extra headroom only matters if you later run a denser fluid. Plan for a level 53-inch-square pad and 81 inches of overhead clearance for the manway lift. At 81 inches tall it will not pass through a standard doorway, so plan on outdoor placement or roll-up access. Use the Tank Sizing Calculator and Tank Sizing Guide to confirm both volume and clearance before delivery.
Fittings and containment
The tank comes with an 18-inch PE threaded and vented port plus a manway with 15-inch access for filling, inspection, and cleanout. The 18-inch is a poly-threaded lid, not an NPT connection, so any inlet or vent line adapts through a bulkhead fitting with an EPDM gasket for water service. No separate outlet or bulkhead port is listed, so confirm outlet locations from the technical drawing on this page before you order hardware. The double wall design puts an interstitial space between the primary and secondary shells: if the inner wall is ever compromised, the outer shell catches the release instead of letting it reach the ground. For the volume math behind that shell, read Snyder Captor double-wall freeboard sizing per ASTM D1998, and for wall behavior at the vapor headspace where failures often start, see the HDPE wall thickness guide.
The mistake to avoid
Buyers size to the nameplate 500 gallons and forget freeboard. Per ASTM D1998 sizing, usable working volume is less than the full 500 gallons once freeboard is deducted, so plan your fill target below nominal and check the freeboard guide linked above. The second miss is the foundation: spec it for the full 4,170 lb of loaded water, more if your contents are denser, and do not shrink the pad because the outer shell looks the same size.
This double wall tank ships LTL freight from the Snyder plant in Marked Tree, Arkansas, quoted live to your ZIP. Get your rate with the Freight Cost Estimator or call 866-418-1777 to lock in delivery on your 500 gallon double wall tank.
