Tank Filling Calculator

Tank Capacity Actual Volumes.  

Caution:  Actual tank volume may be 20-80 litres less or more than the tank decals indicate. Check the tank build certificate, or tanks CSC Data Plate for actual tank volume.

Specific Gravity (SG) and Density 

Specific Gravity (SG) is the weight of the product compared to water @4c. Water = 1 (1KG) at 4c

Density is property of matter defined as the ratio of mass to a unit volume. It’s typically expressed in units of grams per cubic centimetre or kilograms per cubic meter.

IMDG Code, Chapter 4.2.1.9.6 (20/80 Filling Rule)

Dangerous Goods shall not have a degree of filling more than 20% or less than 80% unless using baffle tanks or subject to viscosity conditions ~

Maximum Degree of Filling for Dangerous Goods

For Maximum Degree of Filling for dangerous goods, apply the formulas found under the IMDG Code, Degree of Filling, Chapter 4.2.1.9

STOP! – TAKE NOTE!

TP1 97 does NOT mean 97% maximum degree of filling!

TP2 95 does NOT mean 95% maximum degree of filling!

Actual calculated filling can be 2%-5% less than 95% and 97% (see example below)

Always use the formulas from the IMDG Code Chapter 4.2.1.9 to determine correct degree of filling

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Degree of Filling Formulas IMDG Code Chapter 4.2.1.9

IMDG Code, TP1 Chapter 4.2.1.9.2,

Degree Of Filling = 97/1+ Alpha x (tr-tf)

IMDG Code, TP2 Chapter 4.2.1.9.3, 

Degree Of Filling = 95/1+ Alpha x (tr-tf)

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Practical Example for calculating degree of filling – Methanol.

UN1230, Proper Shipping Name, Methanol, Class 3 Flammable Liquids, Subsidiary Risk 6.1 Toxic, Packing Group II

  Methanol Density at 20c = 0.7918

  Methanol Density at 15c = 0.79567

  Methanol Density at 50c = 0.76259

  Density variance of Methanol from 15c to 50c = 0.03308

  Density of Methanol at tr = 15°C = 0.76259 and at tf = 50°C = 0.79567

1. Calculate α:  α = (0.79567 – 0.76259) / (35 x 0.76259) = 0.001239385
2. Calculate tr – tf: 50 – 15 = 35
3. Multiply α by the difference: 0.001239385 x 35 = 0.043378475
4. Add 1 to the product: 1 + 0.043378475 = 1.043378475
5. Divide 95 by this sum: 95 / 1.043378475 = 91.05037364317872
6. Rounded Result: ceil(91.05037364317872 x 100) / 100 = 91.1

    Final rounded results = 91.1% Maximum Degree of Filling using TP2 formula for Methanol.

Using TP2 formula in this example outcome is 3.9%, less than 95%

Overfilling tanks is unsafe, poses high risk of incidents, is non-compliant under many transport regulations, and may be illegal resulting in heavy penalties and/or incarceration.

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Max Gross Weight Calculations

Always Check Tanks CSC Data Plates for Accurate Container Volume & Weights.

For Maximum Gross Weight transport regulation compliance, calculate the tank weight and product weight together.

Tank container tare weights and maximum design gross weight allowance can be found on the tanks build certificate, or on the tanks CSC Data Plate.

Product weight is the specific gravity multiplied by actual fill volume in litres intended. e.g. SG0.85x 21000 Litres = 17850 Kgs (17.85 Metric Ton)

Example Gross Weight Calculation

Empty Container Weight = 3400kgs

Product Weight = 17850kgs

Gross Wight = 21250Kgs (21.25 Metric Ton)

For safety and compliance, never exceed the tanks maximum design gross weight allowance.