At 550 gallons in a knee-high, 44-inch profile, this is the workhorse Norwesco poly tank for nurse-trailer duty and tight chemical bays where headroom is scarce. The 1.5-specific-gravity wall handles fertilizers and ag chemicals up to 12.5 pounds per gallon, and at only 104 pounds empty it is light enough for two people to walk into place.

Specifications at a Glance

Every figure below is pulled straight from the live product record for this exact tank — the same data on the product page, so what you read here and what you buy never disagree.

Manufacturer	Norwesco
Manufacturer Part #	N-40023
Nominal Capacity	550 Gallons
Footprint (Diameter)	67"
Overall Height	44"
Empty Weight	104 lb
Material	Polyethylene (HDPE)
Color	White
Rated Specific Gravity	1.5
Certifications	IAPMO certified, CSA certified, FDA-compliant resin
Warranty	3-year limited (full replacement)
Shipping	Ships LTL motor freight

Standards & Materials

ASTM D1998 — Standard Specification for Polyethylene Upright Storage Tanks. Governs wall-thickness and hydrostatic design for vertical rotomolded poly tanks of this class.
FDA 21 CFR 177.1520 — Olefin polymers. The food-contact regulation the FDA-grade resin in this tank is compounded to meet.
Specific gravity rating 1.5 — the tank is engineered for liquids up to 1.5× the density of water (water is about 8.34 lb/gal). Confirm your fluid’s SG before storage.

Product Overview

The 550 Gallon Vertical Liquid Storage Tank is built for jobs where 550 gallons is the right pour and a low silhouette is the deciding factor. Standing just 44 inches tall on a 67-inch base, it slides under low eaves, rides on a flatbed without overhang concerns, and bolts to a nurse trailer without raising the center of gravity into trouble. Operators reach the 16-inch lid flat-footed — no step stool to check a level or drop in a fill hose.

That stout proportion is deliberate. A wide 67-inch base under a short body means the tank stays planted when half-empty and sloshing down a field road, and it puts the loaded weight across 24.5 square feet of ground rather than concentrating it. The natural-white walls let you eyeball the chemical line through the shell, and they bounce off enough sun to slow heat gain in the contents.

The shell weighs 104 pounds dry; brimming with a 1.5-SG liquid it climbs to roughly 6,984 pounds, so the surface beneath it has to carry about three and a half tons on that broad footprint. The factory fits a 2-inch outlet with a siphon tube down near the floor of the tank for near-complete draw, and the 16-inch lid serves as fill point and access hatch. No inlet bulkhead ships installed — fill through the lid or drill a port at the height your pump likes.

Like every tank in this line it is molded in one shot, with no seam or weld to open up later, and the UV stabilizer lives in the resin itself. Norwesco's 3-year defect warranty applies, and the tank is inspected at the plant and again before it leaves our dock.

Technical Drawing

Official Norwesco technical drawing — 550 Gallon Vertical Liquid Storage Tank

Key Features and Specifications

550-gallon capacity — sized for agricultural chemical and fertilizer storage
Constructed from virgin linear polyethylene (HDPE) with 1.5 specific gravity rating — handles liquids up to 12.5 lbs/gal
44" tall x 67" diameter — compact vertical footprint
104 lbs empty, approximately 6,984 lbs when full at rated specific gravity
2" fitting with 2" siphon NPT outlet fitting — factory installed and leak-tested
16" lid opening for fill, venting, and interior access
FDA approved for potable water and food-grade liquid contact
3 Year Warranty from Norwesco against manufacturing defects
Translucent white walls allow visual level monitoring without opening the tank and reflect sunlight to keep contents cooler
Rated for continuous service up to 120 F / 48 C
Seamless one-piece rotational molding — no seams, no welds, no leak points
Manufactured by Norwesco — a leading name in rotomolded polyethylene tanks
Place on a firm, level surface free of rocks or sharp objects that could damage the tank bottom. Ensure adequate ventilation if stored chemicals produce vapors
Ships via LTL freight — allow 2-3 weeks for delivery. Lift gate and residential delivery available at additional cost

Installation and Setup Guide

A 550-gallon tank is one of the easiest sizes to install well, precisely because it is so squat — but the low profile invites a common mistake, which is treating it casually and dropping it on whatever ground is handy. Even at this size, a full load is nearly 7,000 pounds, and poly punishes a careless base.

Site Preparation

Give it a firm, flat surface that fully covers the 67-inch diameter — a compacted gravel pad, a paver bed, or a slab all work. The surface needs to be level within a quarter inch across the width; on a tank this short, even a slight tilt sends the liquid to one side and loads a single edge. Sweep away gravel points and sharp debris before setting it down, because a flat-bottom tank presses its full weight onto whatever it lands on.

Placement and Connections

Aim the 2-inch siphon outlet toward your transfer pump and keep the plumbing tight and short. Use schedule-80 PVC or stainless on the threads, tighten by hand and finish with a strap wrench only, and put a flex section between the bulkhead and any hard pipe so vibration on a moving trailer does not work the fitting loose. A foot and a half of clearance around the tank is enough at this size for sampling and a visual once-over.

Venting

Because operators often pump out of a 550 quickly into a sprayer, vent capacity matters more than the small size suggests. A vent that cannot admit air as fast as the pump pulls liquid will let the upper wall suck inward. Size the lid vent to your fastest draw, and for any chemical that off-gasses use a pressure-vacuum relief vent matched to the product.

Maintenance and Long-Term Care

This tank asks for very little, and a five-minute look-over each quarter is the whole program. The reward is a tank that holds chemistry safely for the better part of two decades.

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Quarterly Inspection Checklist

Shell: Walk around it and look for any outward swell or a soft, flattened spot at the base — a sign the load is too heavy or the pad has shifted under one side.
Outlet: Feel the 2-inch fitting for dampness and snug it by hand; on a trailer-mounted tank, road vibration loosens fittings faster than a static install.
Base: Re-check that the pad is flat and that nothing has worked its way under the bottom edge.
Vent: Make sure the vent screen is open and free of chemical crust or nests so air moves freely both ways.

Cleaning

Empty the tank through the siphon outlet, then rinse the interior with a solution that neutralizes the prior product before you switch chemicals. The 16-inch lid is too small to climb through, so clean with a spray wand from above. Collect the rinse and dispose of it according to the chemical's safety data sheet rather than letting it soak into the yard.

UV and Weather Protection

The in-resin UV package carries this tank through years of outdoor service, but if it lives full-time on a south-facing trailer or pad, glance at the sun side once a year for chalkiness. Storing it under a lean-to or even a tarp between seasons noticeably extends the surface life in punishing sun.

Alternatives and Comparisons

The 550-gallon size is a crossroads. If you need the same volume but have the headroom and want a smaller ground footprint, a taller 550 stacks the gallons into a narrower base. If your real job is mobile spraying, this short, stable shape is the better trailer companion than any tall vertical. Should you require a clean, complete drain for batch work, a cone-bottom tank empties to the last drop where this flat bottom leaves a small heel. And if you are storing plain water rather than chemistry, a water-grade 550 is a more economical choice since it skips the heavier 1.5-SG construction this chemical tank is built with.

Frequently Asked Questions

How long will the 550 Gallon Vertical Liquid Storage Tank last?

Plan on fifteen to twenty years of dependable service if the tank lives within its 1.5 specific-gravity rating, sits on a flat base, and holds compatible chemistry. The one-piece molding has nothing to delaminate and the UV stabilizer is baked into the resin. The failures that cut that short are the avoidable ones — a liquid heavier than rated, a clogged vent that collapsed the wall, or a chemical attack on incompatible plastic.

What chemicals can I store in this tank?

Its 1.5-SG rating opens it to most liquid fertilizers, crop-protection chemicals, and a wide span of acids and bases up to 12.5 pounds per gallon. Polyethylene handles those well, but it is no match for strong oxidizers or many solvents, and flammable fuels like gasoline and diesel are never appropriate. Run your exact product past a poly compatibility chart and confirm its specific gravity before you fill.

What kind of foundation does a 550-gallon tank need?

Provide a flat, firm surface that covers the full 67-inch base and can carry the roughly 6,984 pounds of a full 1.5-SG load. Compacted gravel, pavers, or a concrete slab all qualify. Because the tank is so short and wide, the controlling factor is levelness — keep it flat within a quarter inch and clear of any rock that could dig into the bottom.

Does this tank come with a warranty?

Yes. Norwesco's three-year warranty covers material and workmanship defects — pinholes, molding flaws, and faulty factory fittings. It will not cover overloading past 1.5 SG, chemical attack from an incompatible product, a poor foundation, or impact damage. Hang on to your receipt and a couple of installation photos to keep any claim simple.

Can I install this tank underground?

No — this is strictly an above-ground tank. Its flat-walled body cannot resist the soil and water pressure of burial and would buckle, voiding the warranty in the process. If you need below-grade storage, choose an underground cistern, which is ribbed and reinforced for exactly that load.

Buying Considerations

Before ordering, weigh three things. First, the footprint: this tank wants 67 inches of width but only 44 inches of height, so it suits low-clearance bays and trailers far better than tall, tight corners. Second, the liquid — keep it at or below 1.5 specific gravity, and verify the weight of whatever you are storing. Third, the freight: a 550 ships on a pallet by LTL and unloads easily with a lift gate at residential sites. Call us if you want the delivery arranged to your door.