Snyder Industries 4000 Gallon ASTM XLPE Double Wall Tank

Why the 1.9 sheet and not the lighter one beside it

This part number shares its 102 by 102 by 178 inch shell with 5610000N40, and on paper the two look identical until you read the two figures that actually separate them. This one is listed at 3,200 pounds empty and rated at a specific gravity of 1.9. The N40 is listed at 2,400 pounds and its own sheet carries the lower of the two ratings in this shell. That is the whole published difference, and it is the right way round: the heavier listing is the one with the higher rating, and 5610000N30 is listed at the same 3,200 pounds as this tank. Read the consequence rather than the arithmetic. At 1.9 this sheet carries 63,384 pounds of maximum contents against 33,360 pounds of plain water, which means it is listed for liquids appreciably denser than water at the full 4,000 gallons. If what you are storing is water, rinse water or a solution close to water, the lighter listing does the same job and is easier to set. If the product on your site is heavy, this is the row to order and there is no sensible substitution for it. Do not read the difference off the part number suffix; read it off the rating line, because the suffix explains nothing and the sheet offers no interpretation of it. The rest of the decision is the site. At 178 inches this is close to fifteen feet of tank standing on an eight and a half foot square plan, and that proportion is what the pad, the route and the roof have to answer. The surface underneath wants to be flat, continuous and level across the whole footprint, with no rails and no packing at one corner, because above it sit 33,360 pounds of water. The framework for that surface, and the point at which a general recommendation has to give way to an engineer's drawing, is set out in the concrete pad sizing guide for above-ground polyethylene tanks. Two sizing questions belong before the order rather than after it: the volume you can actually use is not the nameplate figure, which the Captor double wall freeboard sizing guide works through on thermal expansion, chemistry and density, and your delivery quantity and turnover want checking in the tank sizing calculator against the freeboard discipline in the tank sizing guide. Two pieces of engineering are worth reading alongside them. A polyethylene wall's hardest service is at the vapour line and not under the liquid, which the wall thickness at the vapour saturated headspace guide explains, and where somebody asks how the space between two walls is tested, the cathodic disbondment testing guide for double wall interstitial spaces sets out the methodology and where the polyethylene boundary lies.

The 102 inch shell from 3500 to 4500 gallons

Four of these six are the same 178 inch shell and the sheet splits them into two listed weights: this tank and 5610000N30 at 3,200 pounds, 5610000N40 and 5610000N46 at 2,400 pounds. The sheet gives both figures without explaining either, and this page prints what it says rather than inventing a reason. What it does not do is tell you which to buy from the table, because that decision belongs to the chemistry and the density of what you are storing, and that is a conversation with us rather than a code to be read out of a suffix. The two rows that are genuinely different sizes matter more to most buyers. 5600000N30 holds 3,500 gallons on the identical 102 inch square plan at 158 inches and 2,500 pounds, so stepping down from this tank costs you five hundred gallons and buys back twenty inches of height with no change to the floor at all. 5620000N30 goes the other way: 4,500 gallons at 197 inches and 3,800 pounds, again on the same plan. That is the useful thing about this whole family. Every one of these shells stands on the same eight and a half foot square, so capacity is bought and sold purely in height, and the constraint that decides your row is almost always the roof steel, the door lintel or the fill point rather than the floor. Measure the clear height at the final position, subtract what a platform and a fill arrangement need above the manway, and the row picks itself. Where you are choosing between this tank and one of its lighter shellmates instead, the deciding figure is the rating line on each sheet and nothing else.

Two rows look the same? The difference is the wall; call 866-418-1777 with the liquid and we will say which, or ask for a quote on both.

The vent in the 18 inch threaded manway

• The vent: the manway on top is listed as a threaded vented manway, and that vent path is the wall's protection every time a delivery pushes air out and every time a pump draws the level down. On a vessel holding 33,360 pounds of water the volumes moving through it are large, so keep it clear, look at it whenever the manway is opened, and never restrict or blank it to hold back an odour.
• The opening: 18 inches is the only opening this sheet publishes, which makes it the fill route, the inspection route and the cleaning route at the same time. It is generous enough to get a proper look inside and to work a lance, but everything you want on top has to share it, so plan the fill arrangement before the tank is set.
• Reaching it: the top is at 178 inches, well above any step, so a fixed platform, a ladder and a fall protection arrangement are part of the installation rather than an afterthought. Bringing the delivery coupling down to working level is usually the better answer than sending a driver up.
• The outlet: the outlet field reads "1 Manway / Lid", an opening and not a pipe size, and the inlet field is empty, so no outlet dimension, thread, flange or valve is claimed here. Tell us the duty, the product and the line size and we will confirm what this part number carries before pipe is bought.
• The space between the walls: the sheet publishes no monitoring port, no gauge and no alarm. How that space is watched and recorded is specified separately, and it is worth specifying, because the value of a second barrier is the evidence that it is still empty.
• Limits: 140 F / 60 C, a specific gravity rating of 1.9, and a 3 Year Warranty. That is the whole of what this sheet publishes about service.

Name the product and its temperature at order time; on a contained vessel the wetted parts are the only route a release can take, and a fitting chosen from a catalogue default is the part that undoes the rest of the design.

Where a tall contained vessel earns its floor

Four thousand gallons at the 1.9 rating is bought where the product is heavy, the delivery is bulk and the floor underneath is somewhere a release would be expensive: municipal water and wastewater treatment, food, beverage and dairy processing, power station and large boiler house chemical storage, pulp, paper and metals plants, mine site water treatment, and industrial process lines that dose continuously between deliveries. The reason it is contained rather than plain is almost always the surface it stands on. Where the alternative was a built bund, this tank is the bund, and it arrives as one item on one footprint. Set up the receiving procedure at the same time as the tank: agree where the driver connects, who watches the fill, what the stop level is and what happens if the vent is obstructed, because deliveries into a vessel that is fuller than anyone thought are where nearly all the bad days on a tank this size begin. Where your site is instead planning private fire water storage, that is a different duty on a different scale and the fire water reservoir design guide for rural and remote sites is where that starts; nothing on this page is a claim about that use.

Thirty-two hundred pounds out of Lincoln

The sheet gives Lincoln, Nebraska as the plant and lists two ship-from states, Nebraska and West Virginia; both fields are printed as given and nothing is reconciled. Freight is LTL at class 250 with no NMFC number, and the load is 102 by 102 by 178 inches at 3,200 pounds. Price the lane to your ZIP with the freight cost estimator; the listed price is before freight. The height is what plans this delivery: close to fifteen feet of tank means overhead lines, gate frames, low bridges and roller shutters on the route all want measuring before the truck is booked, and it means the offloading equipment needs reach as well as rating. Take it under the base with forks or a rated sling arrangement and never lift it by the manway. Set it on the finished, cured, level surface in its final position before a single pipe is connected, and check it is plumb in two directions while it is still empty. Then fill it with clean water, hold that 33,360 pound load, and read the manway seal, the base all the way round and the surface under it in that order. Drain it, let it dry, open the space between the walls and look at it in good light, then write the date on the shell in paint marker. A tall tank that is a degree out of plumb is obvious from the doorway and invisible from beside it, so take that last look from across the bay before you sign the job off. Mark the vent and the outlet on the outside of the shell so nobody caps the wrong one in the dark.