Tank Weighing Load Cells: Sizing, Mounting and Kits for Tanks and Hoppers
Reviewed by MNM Scales technicians · Updated November 3, 2026 · Prices checked November 3, 2026
Short answer: tank weighing load cells sit under each leg of a tank or hopper and add up to its total weight. Size them from the empty tank weight plus the heaviest full load, divided by the number of legs, with headroom on top. Our four-cell kits run from the 20,000 x 0.5 lb kit at $2,499 to the 400,000 x 10 lb tank scale at $4,299, all in stock. Send us your tank size and contents, or call (832) 290-3120.
Shop the 200,000 lb tank scale Call (832) 290-3120 Get a quote
This guide is for plant engineers, maintenance teams and equipment builders who want to weigh tanks, hoppers, bins and silos on legs. MNM Scales has sold, calibrated and repaired scales for over 30 years from our shop in Cypress, Texas, and we are one of the largest scale distributors.
How to size tank weighing load cells
- Find the empty weight of the tank or hopper with its agitator, motor, platforms and anything else bolted to it.
- Add the heaviest full load. For liquids, multiply gallons by 8.34 lb per gallon for water, then by the specific gravity of your product.
- Divide by the number of legs to get the load on each cell.
- Add headroom for uneven filling, an off-center agitator, wind on outdoor tanks and shock from dumping material, then choose the next cell size up.
- Pick the readability you need for batching or inventory, and match it with the indicator.
Example: a 3,000 gallon water tank holds about 25,020 lb of water. With a 5,000 lb empty tank, the total is about 30,020 lb, or about 7,505 lb on each of four legs. Four 10,000 lb cells, as in our 40,000 x 1 lb kit, leave headroom on each leg. If the load can shift toward fewer legs, step up to the 100,000 x 10 lb kit with 25,000 lb cells.
Three legs or four
- Three legs: a three-leg tank shares its weight across all three cells without shimming, which makes vertical round tanks simple to install.
- Four legs: square hoppers, rectangular bins and tall tanks often sit on four legs for stability. Shim each mount so all four cells carry load before calibration.
- Our kits use four cells. For a three-leg tank, or more than four legs, call us and we will quote the cells, mounts and junction box.
Mounts, footings and the summing box
- Compression mounts: each cell sits in a mount that carries the leg, lets the tank grow and shrink with temperature, and keeps the tank from walking or lifting. Weld or bolt the top plate to the leg and the base plate to a level footing.
- Footings: pour or shim the footings level and stiff enough that they do not flex under a full tank; a soft floor reads as error.
- Summing junction box: the four cells wire into one junction box that combines their signals for the indicator and lets the technician trim each corner. See our load cell summing junction box guide.
- Indicator: choose a display with the outputs your plant needs, such as setpoints for filling. See our scale indicator buying guide.
- Hazardous areas: for tanks of flammable liquids, dusts or solvents, see our explosion-proof scale guide before you buy.
For a tank that hangs from a beam on rods, use tension cells in place of leg-mounted compression cells; see our tension load cell guide.
Wind, piping and heat
- Wind: wind on a tall outdoor tank adds load on the downwind legs and lifts the upwind legs. Size cells with that in mind, and add restraint rods that keep the tank in place without carrying its weight.
- Piping: rigid pipes bolted to the tank carry part of its weight and change the reading as the tank fills. Use flexible connections, run pipes horizontally away from the tank and support them off the tank structure.
- Heat: hot product, steam jackets and sun on one side make the tank and legs expand. Mounts that allow sideways movement keep that growth from pushing on the cells.
- Vibration: agitators, mixers and vibrators on the tank add noise to the reading; use the indicator’s filter settings and read weight with them stopped where you can.
Tank scale kits in stock
| Kit | Capacity x readability | What it includes | Price |
|---|---|---|---|
| MNM Scales 20,000 lb tank scale kit | 20,000 x 0.5 lb | 4 x 5,000 lb compression load cells, stainless steel indicator and junction box | $2,499 |
| MNM Scales 40,000 lb tank scale kit | 40,000 x 1 lb | 4 x 10,000 lb compression load cells, stainless steel indicator and junction box | $2,699 |
| MNM Scales 100,000 lb tank scale kit | 100,000 x 10 lb | 4 x 25,000 lb compression load cells, stainless steel indicator and junction box | $2,299 |
| MNM Scales 200,000 lb tank scale | 200,000 x 5 lb | 4 x LPD-50K (50,000 lb) compression load cells | $3,498 |
| MNM Scales Tank Scale 400K | 400,000 x 10 lb | 4 x IDS-672-100K (100,000 lb) compression load cells, center thread | $4,299 |
Rules: NTEP and Texas for tank scales
A tank or hopper scale used to buy, sell or charge by weight is a commercial scale: it has to be legal for trade, with NTEP-certified load cells and indicator, installed and tested to NIST Handbook 44, and in Texas placed in service. Our TDA-registered technicians can do that. See our NTEP guide and, for choosing cells in general, our load cell buying guide.
Texas note: TDA does not require an NTEP certificate for every device, but the scale must meet NIST Handbook 44 and suit its use; some scales do need one, so we recommend NTEP models and can check yours. See TDA’s scales used in trade guidance (PDF) and our TDA scale certification guide, or call us or TDA to confirm your use.
Calibration and rental
- Tank and hopper systems over 150 kg: in-house calibration with a certificate or NIST calibration with a NIST-traceable certificate; call us for the price on your system. See NIST vs in-house certificates.
- On-site service: $295 + $2 per mile per visit across the Houston area, with calibration charged per scale; see our industrial scale calibration service, scale calibration in Houston and on-site calibration.
- How it is done: test weights, a known amount of water or material substitution, depending on the tank. See our load cell calibration guide.
- Repairs and rentals: have us repair the brands we sell, ship smaller scales for mail-in calibration, and rent all types of scales while yours is out of service.
Weighing a tank or hopper? Send us the tank size, empty weight, product and density, number of legs, indoor or outdoor, and the readability you need, and we will size the cells and quote a kit, mounts and calibration. Shop: 21249 FM 529 Rd, Cypress, TX 77433, visits by appointment.
Get a quote Call (832) 290-3120 Shop the 200,000 lb tank scale
Frequently asked questions
How do I size load cells for a tank?
Add the empty tank weight to the heaviest full load, divide by the number of legs, then add headroom for uneven loading, wind and shock and choose the next cell size up.
How many load cells does a tank need?
One per leg. Three legs share weight without shimming; four legs suit square hoppers and tall tanks and are shimmed so every cell carries load.
What does a summing junction box do on a tank scale?
It combines the signals from every cell into one for the indicator and lets the technician trim each corner so the tank reads the same wherever the load sits.
Why does my tank reading change when pipes are connected?
Rigid pipes carry part of the tank’s weight. Flexible connections and pipe supports off the tank keep the cells reading the full weight.
Do I need NTEP load cells for a tank scale?
A tank scale used to buy, sell or charge by weight has to be legal for trade, with NTEP-certified cells and indicator. We recommend NTEP models and can check your use; call (832) 290-3120.
Can you calibrate a tank scale on site?
Yes. On-site service is $295 + $2 per mile per visit across the Houston area, with calibration charged per scale. Call (832) 290-3120 for a quote.