Snyder Industries 12500 Gallon HDLPE Vertical Double Wall Liquid Chemical Storage Tank in White

What a double wall buys at this scale

A single wall tank of regulated chemical needs a berm sized to its volume, and at 12,500 gallons that is a concrete basin the size of a garage, with a sump, a drain valve that must stay closed, and a rain problem every storm. A double wall tank carries its containment inside the outer shell, so the 142 inch footprint is the whole footprint and the tank can stand where a berm would not fit or would not be permitted. The interstitial space between the walls is the leak alarm: a float or conductivity switch, a look into the port each shift, a logged check each week, and anything found there is a primary leak that takes the tank out of service that day. Nothing leans on the outer shell, nothing penetrates it, and the interstice is never a storage space. The whole double wall tank line is on one page for comparison across sizes and grades.

Twenty-three feet tall: the foundation and the wind

At its rating this tank loads a 142 inch circle to 156,375 pounds plus 8,500 pounds of shell; with water alone the contents are 104,250. Either number is a reinforced slab designed for the site's soil, with the ring load and the bearing checked by an engineer, and flat enough that a 274 inch shell stands plumb. Empty, 8,500 pounds standing nearly twenty-three feet tall is a sail, so the tank is anchored against wind before the first fill, and delivery is a crane job with a lift plan. Instrumentation at this height is a hydrostatic sender at the outlet or radar on the manway, never a routine climb, and the vent on the primary is sized for a tanker's unload rate or the fill goes through a dedicated top bulkhead with its own vent line. The tank sizing calculator sizes the volume to feed rate and delivery interval, and the tank sizing guide covers the reserve to carry between tankers.

Grades on the 142 x 274 inch double wall

Four grades share this shell. The N43 is the 1.5 rated linear-resin tank for brine, fertilizer and dilute chemicals. The N45 carries 1,000 more pounds of resin with ASTM certification and a heavier primary for concentrated chemicals; the N40 is the cross-linked polyethylene version at this tank's weight, for oxidizers and warm liquids, also certified; and the N30 is the sulfuric acid grade at 9,500 pounds. The 1006600N30 is the 10,000 gallon sulfuric double wall, 48 inches shorter on the same base. The list below is the resin's rated chemistry; check the liquid at its concentration in the chemical compatibility database; the weight rating and the chemical rating are two different questions.

Still deciding between these? Freight to your ZIP often settles it; the wider tanks ship differently. Or call 866-418-1777 and we will walk the table with you.

Openings, instruments, sampling

• Access: 18 inch threaded, vented manway on the primary, 274 inches up; vent outside on caustic and acid service, fill through a dip tube to the floor.
• Outlet: both walls together at one flanged penetration, expansion joint after it, valve supported from the slab; specify the fitting for the chemical when ordering, and re-check it after the first full fill.
• Service limit: 120 F / 48 C.

Choose the primary's level sender for the chemical, and put a switch in the interstice. A twenty-three foot column of coagulant or brine stratifies, so samples come from the body of the liquid and not the top. Label the tank for the fire inspector and the workplace inspector at once, with the hazard diamond and pictograms placed where they read from the road, and keep the tanker's approach clear.

Fill day

The driver's pump can deliver faster than a manway vent can breathe, so the vent is sized for the unload rate or the fill has its own line. A fill pipe to the floor keeps the liquid from free-falling and foaming. Dense liquids heat up when diluted, so a tank topped off with water for a batch is filled water first, chemical second, never the other way. Watch the first delivery from the first gallon to the last, with eyes on the slab edge, the outlet fitting and the interstitial port as the tank fills; after that, a dated log of each delivery is what turns a guess about turnover into a schedule.

Put to use

Bulk brine, liquid fertilizer, coagulant and dilute caustic at plants and co-ops that take full tanker loads and cannot build a berm; chemical storage inside a building where a spill must never reach a floor drain; and any regulated liquid at a site an inspector visits. One chemical per tank, labeled, manway closed against vapor loss, and the tank turned over on a schedule the chemistry tolerates.

How it ships

At 142 inches across and 274 inches long on the deck the 1031100N43 is oversize freight (NMFC 156600) on a flatbed at a lane rate, with permits on most routes; the freight cost estimator prices the lane to your ZIP, and the listed price is before freight. Book a crane for 8,500 pounds with a lift plan, have the slab cured and surveyed, and plan a staged water fill of the primary with a hold at each stage, confirming the interstice stays dry, before any chemical is ordered. A strap that is checked once a season is a strap that holds; put it on the same calendar as the gutters.

What this tank is listed to hold

Each line is a liquid the resin is rated for, at the concentration shown, with the fitting and gasket to order. Follow the link for the full rating, or search the chemical compatibility database before ordering.

• Sodium hydroxide
• Sodium hypochlorite
• Ferric chloride
• Phosphoric acid
• Hydrochloric acid
• Calcium chloride
• Acetic acid