The procedure of sampling of fuel oil during bunkering

Taking bunker fuel oil sample is utmost an important process during any bunkering as equal to calculation of transfer quantity. The Bunker fuel sampling includes the method of taking the sample, the location of sampling and witnessing it. Marine fuel deliveries are usually measured by volume but paid for by weight, so bunker sample testing allows ships owners to measure density & thus to calculate the weight of fuel oil delivered and to ensure the parameters were meeting with requested or suitable for engines. Bunker fuel oil samples are also to be maintained on board for Port State Inspection under MARPOL 73/78 annex VI.

Location of Sampling

According to IMO Guidelines & MARPOL Annex VI, the bunker sampling to be collected at the receiving ship’s inlet bunker manifold if there is no prior instruction from the concerned.

If the vessel’s manifold is not fitted with a proper line sampler and the bunker tanker is unable to provide a proper custody transfer sampler, the sample should be taken at the bunker tanker manifold, provided the bunker tanker manifold is fitted with accepted type of sampling device.

If both the vessel and bunker tanker do not have any proper sampling device at the manifold, use of sampling valve on the bunker line or tank sampling may be considered with agreement from all parties concerned. If there is no sample flow at vessel’s manifold sampling device (eg. due to vacuum effect), representative sample shall be taken at the best possible alternative location.

Sampling Device

Commonly used sampling devices during fuel oil bunker transfer through pipeline are one of the followings

Manual drip sampler
Flow proportional automatic sampler
Time proportional automatic sampler

During Bunkering

Vessel representative shall ensure that the sampling device and receptacle for sample collection. The receptacle used shall be a clean and transparent container, which is to be fixed and sealed securely to the sampling device. Sample collection shall be started immediately upon the commencement of bunkering. During the process of sampling, should be monitored the sampling at regular intervals. The continuous sampling shall be stopped only upon completion of bunkering. If it vital that the tanks allocated on board are clean, free of sludge or previous bunker residues.

Vessel’s Chief Engineer to be ensured that the sample collected is properly mixed before pouring into the sample bottles. The sample bottles shall be sealed & labelled immediately after pouring and taken ashore to a reputed lab for testing & report to send to the vessel promptly. Typical time taken is 4 days. Until such time Chief Engineer is not expected to star using the bunker received in the main or auxiliary engines.