IMO: Guidelines for onboard sampling for verification of sulphur content

IMO has issued guidance addressing the location of onboard fuel sampling points and the handling of samples for the testing of sulphur content for MARPOL Annex VI compliance. IMO recommends the use of designated sampling points, as agreed with the vessel’s Flag State. If there are no designated sampling points, advice is given on selecting suitable sampling locations.

IMO ‘s Circular  entitled “Guidelines for Onboard Sampling for the Verification of the Sulphur Content of the Fuel Oil Used On Board Ships”  recognizes the need to establish an agreed method for sampling to enable effective control and enforcement of liquid fuel oil being used on board ships under the provisions of MARPOL Annex VI, approved the Guidelines for on-board sampling for the verification of the sulphur content of the fuel oil used on board ships.

Sampling location

The on-board representative sample or samples should be obtained from a designated
sampling point or points as agreed by the Administration. In the absence of the sampling point or points, the fuel sampling point to be used should fulfil all of the following conditions:

1. be easily and safely accessible;
2. take into account different fuel oil grades being used for the fuel oil combustion machinery item;
3. be downstream of the in-use fuel oil service tank;
4. be as close to the fuel oil combustion machinery as safely feasible taking into account the type of fuel oil, flow-rate, temperature, and pressure behind the selected sampling point;
5. the sampling point should be located in a position shielded from any heated surface or electrical equipment and the shielding device or construction should be sturdy enough to endure leaks, splashes or spray under design pressure of the fuel oil supply line so as to preclude impingement of fuel oil onto such surface or equipment;
6. be proposed by the ship’s representative and accepted by the inspector; and
7. the sampling arrangement should be provided with suitable drainage to the drain tank or other safe location.

Fuel oil samples may be taken at more than one location in the fuel oil service system to determine whether there is a possible fuel cross-contamination in the absence of fully segregated fuel service systems, or in case of multiple service tank arrangements.

Sample handling

The fuel oil sample should be taken when a steady flow is established in the fuel oil circulating
system. The sampling connection – the valve and associated pipework designated for sample collection which is connected to the fuel oil service system – should be thoroughly flushed through with the fuel oil in use
prior to drawing the sample. The sample or samples should be collected in a sampling container or containers and should be representative of the fuel oil being used. The sample bottles should be sealed by the inspector with a unique means of identification installed in the presence of the ship’s representative. The ship should be given the option of retaining a sample.

The label should include the following information:

1. sampling point location where the sample was drawn;
2. date and port of sampling;
3. name and IMO number of the ship;
4. details of seal identification; and
5. signatures and names of the inspector and the ship’s representative.

Please click herebelow to view IMO MEPC.1/Circ.864