The Snyder Industries 120 Gallon ASTM XLPE Black Double Wall Tank (SKU 5700102N48) is a self-contained double-wall vessel built from crosslinked linear polyethylene (XLPE), rated to a 1.9 specific gravity, and stands 51 inches tall on a compact 34 x 34 inch square footprint. The double-wall construction puts a secondary containment shell around the primary tank in a single unit, so you get interstitial containment without installing a separate basin. The 1.9 SG rating is the top of the density class for poly tanks, which means this black double wall tank carries contents heavier than plain water where a standard 1.0 to 1.5 water-grade tank cannot. Buy the rating once instead of re-buying when your fluid changes.
Will this tank work for your application?
The primary tank holds 120 gallons. Filled with plain water (specific gravity 1.0), the contents weigh roughly 1,001 lb; filled to the tank's maximum 1.9 SG rating, the contents reach about 1,902 lb. That spread is the whole point of buying to the rating instead of to water weight — size your pad, anchoring, and any support structure to the 1,902 lb figure, not the 1,001 lb water number, if you intend to run anything denser than water. The 34 x 34 inch footprint and 51 inch height let it fit through standard doorways and into tight equipment rooms where a wider tank will not go. Plumbing comes off a 14-inch PE threaded and vented top fitting — the vent prevents vacuum or pressure buildup on fill and draw, and the PE thread accepts standard threaded-bulkhead plumbing. A manway with 11-3/8 inch access lets you reach in for inspection, cleaning, and gasket replacement over the tank's life. Confirm both positions against the technical drawing on this page before you set the tank and trench your lines. If you are sizing for a specific duty, run the numbers through our Tank Sizing Calculator and read the Tank Sizing Guide first.
The mistake to avoid: size to the rating, not to water
This is a crosslinked polyethylene (XLPE) tank rated to a 1.9 specific gravity, so the resin and rating — not price alone — should drive your decision when you intend to store contents denser than water. The second common error on any double-wall tank is sizing fill volume without accounting for freeboard: the 120 gallons is the nominal primary rating, but usable working volume sits below that once you allow headspace for thermal expansion per ASTM D1998. Use the Tank Sizing Calculator above to set your real working gallons rather than assuming a flat 120. A third detail buyers miss is the seal: when you add or swap a bulkhead at the 14-inch port, match the gasket to the PE thread and re-torque per the drawing, and treat the manway gasket as the seal you will service most. Our deep-dives on Captor double-wall freeboard sizing per ASTM D1998 and wall thickness at the vapor-saturated headspace walk through exactly where that math bites operators, and the cathodic disbondment testing piece covers the interstitial-space considerations for double-wall service.
Freight and ordering
This double wall tank ships LTL freight from the Snyder plant in Marked Tree, Arkansas, quoted live to your ZIP — so Central and South-region buyers typically see shorter LTL lanes. There is no flat shipping number on a tank this size, so get a real quote before you buy: drop your ZIP into the Freight Cost Estimator, or call 866-418-1777 and we will quote freight, confirm the 14-inch fitting and 11-3/8 inch manway access against your plumbing and gaskets, and give you lead time. Listed price is the tank only, before freight.
