The Snyder Industries 405 Gallon ASTM XLPE Double Wall Tank packs primary containment and an integral secondary wall into one footprint. It holds 405 gallons in black crosslinked linear polyethylene (XLPE), stands 73 inches tall on a 48 by 48 inch base, and carries a 1.9 specific gravity rating. If you have been searching for an XLPE double wall tank or a Snyder black tank rated for dense contents, this is the unit that answers it.
Does it work for your job?
Specific gravity is the headline spec. SG tells you the maximum density of liquid the tank wall is engineered to hold; at 1.9, this Snyder tank is built well beyond plain water. Filled with water (SG 1.0) the contents weigh roughly 3,378 pounds; at the full 1.9 rating the tank is engineered to carry up to about 6,418 pounds. Size your contents against that envelope before you commit. The double wall construction wraps secondary containment around the primary tank, so a primary breach is caught by the outer wall instead of reaching your pad or soil. For access, the drawing shows two distinct top fittings:
- Fill / vent: 18 inch PE threaded, vented fitting
- Inspection: manway with a 15 inch access opening
That 15 inch access port decides whether a pump, level sensor, or an arm fits inside, so check it against your plumbing and inspection plan using the technical drawing on this page. Working through usable volume versus rated capacity? The Tank Sizing Calculator and our Tank Sizing Guide help you match this tank to your draw and freeboard.
Why the 1.9 rating matters for a water tank
This tank is classified for water service but carries a 1.9 SG rating, which means it is over-built for plain water. If you only ever store water (SG 1.0, about 3,378 pounds), that headroom is capacity you are paying for. If there is any chance you move to denser contents down the road, that same headroom is exactly the reason to buy this double wall unit instead of a single-wall water tank now. Chemical suitability depends on the specific chemistry and is not covered by this listing's data, which addresses water and the density rating only, so confirm any non-water service with us before ordering.
The mistake to avoid
The 1.9 SG figure is a maximum density rating, not a license to ignore freeboard. The rated weight ceiling and the manufacturer's fill discipline still apply. Do not fill a double wall tank to the brim with a heavy liquid and assume the secondary wall covers a sizing error; the containment is there for a primary failure, not for an overfill. Before you order, also confirm doorway and ceiling clearance for the 73 inch height and a level 48 inch square pad, the most common cause of a tank that arrives but cannot be sited. The threaded fittings and manway cover seal on gaskets, so verify gasket material and that the cover hardware is included before you plumb it. For the engineering behind why fill discipline matters on Snyder double wall units, the Snyder double-wall freeboard sizing guide per ASTM D1998 walks through thermal expansion and the real volume you can actually use. If the outer wall will be buried, the cathodic disbondment testing reference covers the buried-boundary considerations.
Freight
This tank ships LTL freight from the Snyder plant in Chowchilla, California, and freight is quoted live to your ZIP code; it is not included in the list price. Get an exact number in seconds with the Freight Cost Estimator, or call us at 866-418-1777 and we will quote the lane and confirm fittings, gasket material, access, and lead time before you order.
