Chemical Tankers / Day 3 / Day 3 Topic 1 Cargo Planning & Stowage

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Certain chemicals require special care to ensure that they remain in the same condition as loaded. They may be intrinsically unstable or may react with air, heat, water, moisture or other materials.

These types of reaction change the composition of the mixture.

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Self-reactive cargoes must be protected by inhibitor or stabilizer. The ship must be provided with a “Certificate of Protection” (Inhibitor Certificate) from the manufacturer .

(Discussed on Day 1 topic 5)

This group of cargoes (e.g VAM, Styrene, Acrylonitrile) should never be stowed adjacent to heated cargo.

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Other group of chemicals react with oxygen even without any input of additional energy. Vegetable and animal oils are slowly oxidize

in contact with air. This process called putrefaction. This is dangerous as it generates foul vapors and oxygen deficiency in tank atmosphere. For such cargo a control of the temperature is very important.

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Certain Group of cargoes are very sensitive to moisture and water.Relatively small quantities of moisture or water are highly reactive with Acids.

Fatty Alcohols have a moisture limit 0.1% for shipment. Glycols, Isocyanates, Propylene Oxide are also very sensitive to moisture

and mostly requires a nitrogen blanket during the voyage for moisture protection. Absolutely dry tanks required for loading of such cargoes.

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Tank coating resistance list should always be consulted prior to proper cargo stowage to prevent coating damage due to reactivity of some cargoes.

The main source of such information is Manufacturer Compatibility Guide or Tank Coating Resistance Guide.

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Particular reactions with the coatings:

Possibility of increased acidity with certain slops, e.g. VAM;

Damage to Epoxy coatings due to adding water after Alcohols, Esters, Ketones, etc;

Alkaline and acid washings (Caustic & Phosphoric acid) in zinc coated tanks;

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Tank Coating Resistance

Guide with footnotes for

Zinc and epoxy coating.

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Footnotes explanation.

1.2 Stow Plan review

4. Compatibility (heat, reactivity, coating resistance)

Sigma epoxy coating

Resistance List.