Snyder Industries 405 Gallon HDLPE Vertical Double Wall Storage Tank with Sulfuric Acid Resin

What the sulfuric grade is for

Concentrated sulfuric acid weighs nearly twice what water does and attacks the wall of an ordinary linear polyethylene tank from the inside, at the surface and in the vapor space above the liquid. Snyder's N30 resin is compounded for that service, so a tank in it is sized for the acid's weight and its chemistry together. The double wall matters more for acid than for anything else: a leak is a burn hazard and a fume hazard, and the interstitial space holds it until the tank is drained. The SPCC 40 CFR 112 compliance walkthrough covers where a double wall tank satisfies a spill plan on its own, and the Captor double wall freeboard sizing guide works out the usable volume once thermal expansion, which is large for acid, and the interstice are accounted for. Full, it puts 6,418 pounds on a 48 inch circle at the rating; the concrete pad sizing guide covers the slab. The tank sizing calculator sizes the tank to feed rate and delivery interval, and the tank sizing guide covers the reserve.

Grades on the 48 x 73 inch double wall, and the sizes beside it

The N45 is the general linear grade with ASTM certification, the N42 is cross-linked polyethylene for hypochlorite and the other oxidizers, and the N48 is another linear grade, all at the same weight in the same shell. The 5760102N30 is the squat sulfuric-grade 360, 10 inches shorter on a 53 inch base, and the 5780102N42 is the cross-linked 500 gallon double wall, 8 inches taller.

Not sure which one? Tell us the liquid, the site and the ceiling height at 866-418-1777, or request a written quote with freight to your ZIP.

Where the pipe goes, and the leak alarm

• Access: 18 inch threaded, vented manway on the primary, 73 inches up; fill through a dip tube, and vent to a scrubber or outdoors, never into the room.
• Outlet: both walls together at one penetration, the transition braced off the floor; specify an acid-rated fitting and gasket when ordering.
• Service limit: 120 F / 48 C.

There are two levels to watch: the primary, with a sender rated for concentrated acid, and the interstitial space, which is the leak alarm and gets a float switch, a look into the port each shift, and a logged check each week. Anything found in the space is a primary leak, and the tank comes out of service that day. Strap it to a wall; a 48 inch base under 73 inches of a liquid this dense has a high center of gravity. Acid draws water from the air and heats when it does, so the manway stays closed and the vent carries a drying trap. Never add water to the tank; dilution is done elsewhere, water first.

Applications

Sulfuric acid feed for pH control at water and wastewater plants, regeneration acid at a demineralizer, pickling and plating acid make-up, and any 405 gallon vessel of concentrated acid inside an occupied building. Acid only, labeled, with the eyewash within reach of the manway. With water in it, the shell is also a well buffer or a cell of the small fire reserve the fire-water reservoir design guide describes, but a tank bought in this resin is bought for acid.

On the truck

The 5990702N30 ships palletized as LTL freight (NMFC 156600-03) at a class rate; the freight cost estimator quotes it to your ZIP, and what is listed here is the price before freight. A pallet jack moves 250 pounds. Water-test the primary, confirm the interstice stays dry through the hold, then drain and dry completely before the first acid delivery; water left in an acid tank is the first mistake. Mark the vent and the outlet on the outside of the shell so nobody caps the wrong one in the dark.