Snyder Industries 750 Gallon Sodium Hypochlorite (UV) Double Wall Tank

The duty a double wall tank is bought to do

The buyer for this tank is an operation that has decided the contents must never reach the floor. That is the duty, and it is a decision usually made by someone who has already had the conversation about what a release would cost in cleanup, downtime, reporting and reputation. A double wall product answers it by building the second barrier into the tank itself: one vessel inside another, delivered as a single item, set on one pad, with one footprint to plan and nothing to pour. Against the alternative of a single wall tank standing inside a built bund, the trade is straightforward. A bund is site work with its own cost, its own drainage question and its own rainwater problem, and it takes floor space around the tank. A double wall arrives as one purchase and occupies 73 by 73 inches of floor at 67 inches tall, which is a shade over six feet square and a little under five feet eight to the top. That height is the quiet advantage of this shape. At 67 inches the manway is reachable from a modest platform, the tank fits under a low roof and in a bay with a door, and a delivery hose can be brought to a coupling at working level. Put the tank on a flat, continuous, level surface that carries the whole base, not on two rails and not shimmed at a corner. Above that base sits 6,255 pounds of water, and 11,884 pounds at the rating this sheet publishes, so the pad matters more than the tank does; the concrete pad sizing guide for above-ground polyethylene tanks sets out the framework and where its boundary lies. Two sizing points are specific to a double wall vessel and are worth getting right before you order rather than after. The first is that the usable volume and the headspace you actually have are not the same question as the nameplate, which is what the double wall freeboard sizing guide works through on thermal expansion, chemistry and density. The second is your delivery quantity: run it and your turnover through the tank sizing calculator, and take the freeboard discipline from the tank sizing guide, because a product that gasses or warms needs the space and a tank sized exactly to a delivery has none.

Five double wall tanks and three names on one 73 inch shell

Four of these six are 750 gallon tanks on the identical 73 by 73 by 67 inch shell at the identical 390 pounds, and what separates them is the name on the sheet and nothing the sheet explains. One is named for sodium hypochlorite with UV, one for sulfuric acid, and two are named as cross-linked to an ASTM standard with one of those listed black. We print the names as given and offer no interpretation of them, because guessing at what a name implies about a wall is exactly how the wrong tank gets bought. The chemistry you tell us is what decides which of the four is right, and that is a conversation to have before the order rather than a code to crack from a table. The two rows that are genuinely different sizes are worth reading closely, because the double wall geometry does not scale the way people expect. The 550 gallon 5040000N30 is listed at 76 inches square, wider than this 750 gallon tank, while standing two inches shorter at 65 inches and weighing 315 pounds; you get less volume on a bigger floor plan. The 1000 gallon 5990102N30 is 81 inches square and 69 inches tall at 500 pounds, which is a third more volume for eight more inches of width and two more of height. So if floor space is what you are short of, the step up to the 1000 is far better value in square feet than the step down to the 550 is in savings. Decide the volume on your delivery quantity and your turnover, then check the footprint against the bay you have.

Neighboring size a better fit? Every row links to its own page; freight to your ZIP is quoted on each, or call 866-418-1777.

The outlet field, the vented manway and the sixteen inch lid

• The discharge and the pump: the outlet field on this sheet reads 3/4 with no unit attached, so we print exactly that and claim no pipe size, no thread and no valve. Before the pump is specified, tell us the duty and the line size you need and we will confirm what this part number actually carries. On a small-bore discharge the pump selection and the suction arrangement matter more than usual, because a modest line will not forgive a pump that was sized for a bigger one.
• Draining and the low point: the sheet publishes no separate drain, no sump and no total drain fitting. Where a tank has to be emptied completely for a product change or an inspection, say so at order time, because that is a design decision and not an accessory.
• The manway: 18 inches, threaded and vented, at the top of a 67 inch tank. That is a reachable height from a modest platform, which is one of the real advantages of this squat shape over a tall one.
• The vent path: the manway is listed as vented and that vent is what keeps the wall out of trouble while a pump draws the tank down or a delivery fills it. Keep it clear, inspect it whenever the manway is opened, and never restrict it.
• The lid: the sheet also lists a 16 inch lid alongside the 18 inch manway.
• Limits: 120 F / 48 C, a specific gravity rating of 1.9, and a 3 Year Warranty. This is the only product in its batch that carries a warranty term and the only one with a numeric freight class.

Name the product and its strength when you order, because on this tank every fitting decision follows from it. Where the reason for buying a contained vessel is a regulatory one, the double wall compliance walkthrough goes through the requirements in order rather than asserting that a product satisfies them.

Where a contained 750 gallon tank gets set

Seven hundred and fifty gallons in a double wall is a common size at the point of use rather than the point of delivery: a disinfection room at a small municipal water or wastewater plant, a package treatment skid at a food, beverage or dairy facility, a cooling tower or boiler house holding treatment chemical beside its pumps, a pool and aquatics plant room, a laundry or wash operation, and industrial process lines that dose continuously and take a bulk delivery every few weeks. What those sites have in common is that the tank stands indoors or on a surface where a release would go somewhere expensive, and that the room is usually too small for a built bund. The squat 73 inch footprint under 67 inches of height is what lets it fit through a door and under a ceiling that would defeat a tall vertical of the same volume. One habit is worth building from day one on any contained tank: inspect the space between the walls on a schedule and write down that you did it, because the whole value of a second barrier is knowing it is still empty.

Chowchilla, class 300 and 390 pounds

This tank is moulded at Chowchilla, California, and the sheet lists California as the state it ships from, which makes the West Coast and the Southwest the short lanes. The freight class is given as 300 under NMFC 156600, and it shipments at 73 by 73 by 67 inches: a wide pallet rather than a tall one, so the constraint at your end is usually the door width and not the ceiling. Price the lane to your ZIP with the freight cost estimator; the listed price is before freight. At 390 pounds it comes off with a forklift under the base, never with a sling round the body and never by the manway. Measure the doorway and the turning room on the route to its final position before the truck is booked, because a six foot square object does not corner in a plant room corridor. Set it on the finished, level pad in its final position before anything is plumbed, then fill it with clean water and hold that 6,255 pound load while you read the manway seal, the outlet joint and the base all the way round. Drain it and let it dry before the working product arrives. Then open the interstitial space, look at it, and record the date on the tank; that first inspection is the baseline every later one is compared against. Once it is full and holding, leave it alone for a day before the plumbing goes on; a settled tank is a quiet one.