Regulation 33
Crude oil washing requirements
Every crude oil tanker of 20,000 tonnes deadweight and above delivered after 1
June 1982 shall be fitted with a cargo tank cleaning system using crude oil washing.
Regulation 35
Crude oil washing operations
Every oil tanker operating with crude oil washing systems shall be provided with an
Operations and Equipment Manual*
* Refer to the Standard Format of the Crude Oil Washing Operation and Equipment
Manual adopted by the Marine Environment Protection Committee of the
Organization by resolution MEPC.3(XII), as amended by resolution MEPC.81(43).
With respect to the ballasting of cargo tanks, sufficient cargo tanks shall be crude oil
washed prior to each ballast voyage in order that, taking into account the tanker's trading
pattern and expected weather conditions, ballast water is put only into cargo tanks which
have been crude oil washed.
Unless an oil tanker carries crude oil which is not suitable for crude oil washing, the oil
tanker shall operate the crude oil washing system in accordance with the Operations and
Equipment Manual.
Before departure on a ballast voyage:
• ballast water is put only into cargo tanks which have been crude oil washed.
Approximately one quarter of the cargo tanks shall be crude oil washed for sludge
control purposes on a rotational basis in accordance with the procedures specified
in the Operations and Equipment Manual. However, for these purposes, no tank
need be crude oil washed more than once in every four months;
(IMO Res. 446(XI) 6.1 and amendments A.496(XII) and A.897(21)
All external doors, ports and similar openings should be closed when the tanker,
or a ship at an adjacent berth, is conducting any of the following operations:
1. Handling volatile petroleum or non-volatile petroleum near to or above its
flashpoint.
2. Loading non-volatile petroleum into tanks containing hydrocarbon
vapour.
3. Crude oil washing.
4. Ballasting, purging, gas freeing or tank washing after discharge of volatile
petroleum.
All cargo operations should be carefully planned and documented well in
advance of their execution.
The plan should cover all stages of the transfer operations and as a minimum,
contain:
1. Quantity and grade of each parcel;
2. Density, temperature and other relevant properties;
3. A plan of the distribution, lines and pumps to be used;
4. Transfer rates and maximum allowable pressures;
5. Critical stages of the operation;
6. Notice of rate change;
7. Venting requirements;
8. Stability and stress information;
9. Drafts and trims;
10. Ballast operations;
11. Emergency stop procedures;
12. Emergency spill procedures and spill containment; and
13. Hazards of the particular cargoes.
14. Precautions against static generation;
15. Initial start-up rates;
16. Control of cargo heating systems;
17. Line clearing;
18. Crude oil washing procedures;
19. Under keel clearance limitations;
20. Bunkering; and
21. Special precautions required for the particular operation
22. Inert gas operations
Test of Cow system and check of COW equipment in good operational order
Before arriving in a port where it is intended to crude oil wash, the tank
washing system should be pressure tested to normal working pressure and
examined for leaks.
The system should be drained down after testing to avoid the risk of leaks
due to thermal expansion.
When tanks for crude oil washing are being changed over, the pressure in the
COW line should be reduced to a minimum before any valves on the system are
opened or closed, thereby minimizing the potential for damage due to surge
pressure.
(ISGOTT 11.5.5)
The oxygen content of each cargo tank to be crude oil washed shall be tested with
portable equipment prior to COW and the results recorded in the deck or cargo
log.
Cow tips, fresh oil, lighter oil to be used
Cow C/L
How many tanks to be washed simultaneously
When to start Cow
How to strip / Eductor requirement
Requirements before starting the cow operation
Cloud point definition
https://www.youtube.com/watch?v=_TyS5nHz6jc
https://www.youtube.com/watch?v=JZdvsQzOKuk
https://www.youtube.com/watch?v=UBXlPZWfvh8
