The Snyder Industries 5500 Gallon ASTM XLPE Double Wall Tank (SKU 5660000N42) is a containment-grade vessel built in crosslinked linear polyethylene (XLPE) and rated to a 1.9 specific gravity. The inner tank nests inside a secondary outer wall, and the interstitial space between the two walls is what lets you catch a leak visually before anything reaches the ground - the entire reason to choose this over a flat-priced single-wall water tank. At 5,500 gallons in a Natural White finish, it stands 172 inches tall on a 120 x 120 inch footprint, so size your pad and overhead clearance around those numbers before the truck arrives.
Will it work for my application?
This is a double wall tank engineered for storage where secondary containment is required, and the 1.9 specific gravity rating is the premium feature here: water fills at roughly 45,870 lb, while the tank is rated to carry contents up to about 87,153 lb. That is nearly 1.9x of headroom over a standard 1.0-SG water tank, so if there is any chance you will later store a denser fluid, buying the SG headroom now is the honest call. The XLPE wall plus the 1.9 SG rating are why buyers searching for an XLPE double wall tank land here rather than on a standard single-wall water tank. To confirm 5,500 gallons fits your draw-down and refill cycle, run the numbers through our Tank Sizing Calculator and review the Tank Sizing Guide.
Fittings and site planning
The drawing for this tank shows three fittings an installer needs to confirm before plumbing the job:
- Flange - structural/connection point
- 18" PE threaded / vented - the fill and vent connection
- Manway with 15" access - entry for inspection and interior service
See the technical drawing on this page for exact fitting positions and elevations, then plan for 172 inches of overhead and a pad rated for the full-water dead load (~45,870 lb) up to maximum rated contents (~87,153 lb). Confirm your fill line lands on the 18" PE threaded/vented fitting and that your crew can clear the 15" manway access before delivery.
The mistake to avoid
The most common error on a double wall tank is treating freeboard as wasted space. ASTM D1998 sizing accounts for thermal expansion and the density of what you actually store, so usable volume is not simply the nameplate gallons. Walk through the math in Snyder Captor double-wall freeboard sizing per ASTM D1998 before you commit to a capacity. Two more references for this class of tank: where premature wall failures originate at the vapor-saturated headspace, and if this is going into private fire protection, the fire-water reservoir design guide covering NFPA 22 sizing and freeze protection.
Freight and ordering
This tank ships LTL from Snyder's single plant in Lincoln, NE, and freight is quoted live to your ZIP rather than included in the list price. Because it loads at 172 inches tall on a 120 x 120 inch footprint, it moves as an oversized LTL load and freight cost is driven hard by distance from Nebraska - a buyer on either coast should price it before budgeting. Get your real number through the Freight Cost Estimator. For pad prep, fitting placement, or help confirming this is the right double wall tank for your site, call 866-418-1777 and we will walk it through with you.
