The Snyder Industries 12,500 gallon double wall tank is built from crosslinked linear polyethylene (XLPE) to an ASTM specification, giving you full secondary containment in a single unit: a primary tank held inside an outer wall that catches any leak from the inner shell. It carries a 1.5 specific gravity rating, so it is rated to hold contents up to 1.5 times the weight of water. Filled with water, the inner tank holds roughly 104,250 lb; at its maximum rated 1.5 SG contents it carries about 156,375 lb. Plan the pad and foundation for that loaded weight before anything else.
Will it work for your site?
This is a large vertical double wall XLPE tank standing 274 inches tall on a 142 x 142 inch footprint - about 22.8 feet tall on an 11.8-foot square base. Confirm your slab is level, load-rated, and sized to the full footprint, and that you have the overhead clearance and delivery route for a tank nearly 23 feet tall. The fittings shown on the technical drawing on this page are a flange, an 18-inch PE threaded and vented opening, and a manway with 15-inch access for interior inspection of the primary tank. Before you set the tank, verify against the drawing that your fill and vent piping mates to the 18-inch threaded/vented top opening and that your inlet/outlet connections match the flange, and confirm gasket and seal requirements for your service from your own piping plan. To work out usable volume versus nameplate capacity, the Tank Sizing Calculator and Tank Sizing Guide walk through the numbers.
Freeboard and the volume you can actually use
With an XLPE crosslinked wall and a 1.5 SG rating, this tank is engineered for heavy storage duty, but the rated capacity is not the volume you should fill day to day. ASTM D1998 sizing discipline accounts for thermal expansion and the density of what you store, which is why usable volume falls below the 12,500 gallon nameplate. Our guide on Snyder Captor double-wall freeboard sizing per ASTM D1998 covers freeboard and the real volume you can count on, and the wall thickness at the vapor-saturated headspace writeup explains where premature failures tend to originate.
The mistake to avoid
The most common error on a natural white XLPE double wall tank this size is treating the 1.5 SG rating and the second wall as a license to skip site engineering. Size the foundation for the loaded weights above, not the empty tank, and use the interstitial space and the 15-inch manway access as designed for monitoring and inspection rather than sealing them up. For buried or partially buried outer-wall installs, review the cathodic disbondment testing methodology for double-wall interstitial spaces before finalizing the design. If this is part of a rural or remote fire-water reserve, our fire-water reservoir design guide covers NFPA 22 sizing and freeze protection.
This tank ships LTL freight from the Snyder plant in Lincoln, NE, quoted live to your ZIP. Get a freight number with the Freight Cost Estimator, or call 866-418-1777 and we will help you confirm fittings, access, and delivery logistics for a tank this size. Freight on a 12,500 gallon double wall tank is a serious line item, so get the quote before you commit.
