20000 Gallon Vertical Liquid Storage Tank: Complete Buyer's Guide
20,000-gallon white liquid storage tank built for agricultural chemical and fertilizer storage. Manufactured by Norwesco from virgin linear polyethylene (HDPE) rated to handle liquids up to 12.5 pounds per gallon. FDA approved for contact with potable water, ensuring safe storage for drinking water and food-grade liquids.
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.
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 20,000 Gallon Vertical Liquid Storage Tank is the largest single-piece rotomolded vessel in the catalog and one of the largest poly tanks made. At 242 inches — over twenty feet — it towers, holding twenty thousand gallons of chemical for the biggest fertilizer terminals, regional treatment facilities, and industrial operations that buy and store product at maximum scale. This is a permanent landmark of an installation, sited and engineered once for the long term.
Norwesco rotationally molds the body in one seamless piece of virgin linear polyethylene rated to 1.5 specific gravity, handling agricultural and industrial liquids to 12.5 pounds per gallon — twenty thousand gallons with not a single weld in the shell. The translucent natural-white wall lets operators read inventory from a distance and reflects sunlight to keep contents cooler, with compounded UV inhibitors and a 120 F / 48 C ceiling.
It weighs 5,016 pounds empty and reaches roughly 255,216 pounds full at 1.5 SG — over a hundred and twenty-seven tons that requires a major engineered foundation. The 3-inch stainless-steel bolted fitting with a 3-inch by 5.5-inch siphon handles the full column load and complete draw-down, and the 22-inch lid permits interior access twenty feet up. Norwesco warrants the tank for 3 years against manufacturing defects.
Technical Drawing
Official Norwesco technical drawing — 20000 Gallon Vertical Liquid Storage Tank
Key Features and Specifications
- 20,000-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
- 242" tall x 165" diameter — compact vertical footprint
- 5016 lbs empty, approximately 255,216 lbs when full at rated specific gravity
- 3" Stainless Steel Bolted Fitting -with 3" x 5-1/2" siphon NPT outlet fitting — factory installed and leak-tested
- 22" 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
- Large tanks require professional installation. Ensure the pad is level within 1 inch across the full diameter and that all piping connections allow for thermal expansion
- Ships via dedicated freight carrier due to oversized dimensions — contact us for delivery timeline and site access requirements
Installation and Setup Guide
Over a hundred and twenty-seven tons of chemical standing twenty feet tall makes this the most demanding installation in the lineup by every measure — foundation, crane work, plumbing, and the simple logistics of a twenty-foot shell.
Major Engineered Foundation
A structural engineer must design a substantial reinforced concrete slab for roughly 255,216 pounds over the 165-inch base, flat within one inch across the full diameter and built as major secondary containment. At this weight and height the foundation, soil-bearing analysis, and reinforcement are a serious engineering exercise; do not proceed without a stamped design. Cure fully and grade the entire site for comprehensive spill capture.
Logistics and the Bolted Fitting
A twenty-foot, two-and-a-half-ton empty shell is a major oversized load requiring route planning, permits, and a large crane to stand it upright on the cured slab. The 3-inch stainless-steel bolted fitting must be installed with even torque and chemistry-compatible gaskets, because it carries the immense hydrostatic load of a twenty-thousand-gallon column. Plumb from it in schedule 80 PVC or stainless with the siphon for full draw-down.
Venting at Maximum Scale
The air exchange when filling or emptying twenty thousand gallons is enormous. Fit a large pressure/vacuum relief vent in the 22-inch lid, rated for your chemical and sized to your maximum transfer rates; an undersized vent on a tank this large is a serious collapse hazard. Plan safe elevated access for inspecting and servicing the lid and vent twenty feet up.
Maintenance and Long-Term Care
A 20,000-gallon tank is operated as critical infrastructure, with foundation surveillance under one hundred twenty-seven tons, strict chemical-compatibility control, and a safe-access plan for working at twenty-foot height.
Scheduled Inspection
- Foundation and containment: Inspect the major slab, curbing, and grade for cracking, settlement, and containment breaches on a strict cycle. At this weight, any foundation movement is a critical finding.
- Stainless bolted fitting: Verify even bolt torque and gasket integrity at the outlet, which bears the full load of a twenty-foot column — the single most safety-critical fitting on the tank.
- Wall: Using safe elevated access, read the wall top to bottom for bulging or stress whitening, with particular focus on the lower wall under peak pressure and any swelling that flags a compatibility problem.
Product Changes
Take the tank offline, drain through the siphon, and clean the interior via the 22-inch lid under full confined-space procedures with elevated-access safety in place. Decontaminate per the incoming chemical's specification, verify the new product on a polyethylene compatibility chart, and confirm the bolted-fitting gaskets suit the new chemistry. This vessel has no potable role; cleaning is compatibility and carryover control.
UV and Heat
The compounded UV package protects the vast wall through years of sun; inspect the accessible portions annually in high-UV regions. The reflective white finish moderates internal temperature and vapor pressure across an exceptionally large sun-exposed surface.
Alternatives and Comparisons
At 20,000 gallons you are at the practical ceiling for a single rotomolded poly tank, which frames the entire comparison.
Maximum single tank vs. multiple large tanks: This 20,000-gallon tank concentrates the most capacity into one foundation and one set of plumbing at the lowest cost per gallon, but it is a single point of failure, a twenty-foot crane-and-permit logistics challenge, and a tank that must be fully offline to service. Two 10,000-gallon tanks cost more and need more containment, yet they halve the height, ease the logistics, allow product variety, and let you run one while servicing the other. For sheer single-product volume the big tank leads; for manageability and redundancy, two large tanks often make more operational sense.
Frequently Asked Questions
How long will the 20000 Gallon Vertical Liquid Storage Tank last?
On a major engineered containment foundation and within its 1.5 SG and 120 F ratings, this tank readily serves 15 to 20 years even at maximum scale. The compounded UV package and seamless shell are built for it, and the stainless bolted fitting endures when its torque and gaskets are maintained. The foundation and chemical compatibility govern the rest.
What chemicals can I store in this tank?
Rated at 1.5 specific gravity, it covers most liquid fertilizers, crop-protection chemicals, and industrial solutions up to 12.5 pounds per gallon. Confirm each product on a polyethylene compatibility chart and verify the bolted-fitting gaskets, since the resin resists many acids and bases but not certain solvents and oxidizers. No fuels or flammables. It is a chemical tank, never a potable-water vessel.
What kind of foundation does a 20000-gallon tank need?
A full 20,000-gallon tank weighs about 255,216 pounds at 1.5 SG — over one hundred twenty-seven tons. That requires a major engineered reinforced concrete slab with soil-bearing analysis, stamped by a structural professional and built as substantial secondary containment. The foundation is a serious engineering project and the most important part of the installation.
Does this tank come with a warranty?
Yes. Norwesco's 3-year warranty covers manufacturing defects in materials and workmanship under normal use, excluding damage from incompatible chemicals, exceeding the rated density, an inadequate foundation, or impact. Retain complete documentation and photographs of the engineered foundation and the crane installation.
Can I install this tank underground?
No. A twenty-foot vertical tank is engineered strictly for above-ground service and cannot resist soil pressure; burial would collapse it and void the warranty. Storage of this magnitude below grade requires purpose-engineered reinforced structures, not a poly tank.
Buying Considerations
Three major commitments come with a 20,000-gallon tank. First, the major engineered containment foundation: a substantial reinforced slab sized for one hundred twenty-seven tons, stamped by a structural professional, curbed for containment, and cured before delivery. Second, oversized-load logistics — route planning, permits, and a large crane to stand a twenty-foot shell. Third, your chemistry, verified against a polyethylene compatibility chart including the bolted-fitting gaskets. We coordinate the dedicated-carrier delivery and crane access to your ZIP. Listed at $36,633.56 before freight.
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