1 Preface
1.1 The objective of these Guidelines is to establish an agreed method
for the sampling, from tanks, of liquid fuel oil intended to be used or carried for
use on board a ship and thereby promoting the effective control and enforcement of
the relevant provisions of MARPOL Annex
VI.
1.2 Fuel oil sampling should be performed in a manner that ensures the safety of
personnel and of the ship. Fuel oil sampling in accordance with these Guidelines
should be undertaken expeditiously and should not cause undue delay to the ship.
2 Sampling procedures
2.1 General
2.1.1 Tank sampling involves obtaining a sample of fuel oil from the tank in
question. The sample obtained is representative of the fuel oil at the location from
where it was drawn. Fuel oil in a tank may be sampled by use of the ship's fuel oil
transfer system or, in some instances, directly from the tank. Alternative sampling
approaches may be used provided they deliver a fuel oil sample which is
representative of the fuel oil at the location from where the sample was drawn.
2.1.2 The exact arrangements in each case should be agreed in advance with the ship's
representative.
2.1.3 In all instances, attention should be given to avoiding sample contamination by
extraneous or sedimented matter.
2.2 Sampling by use of the ship's fuel oil transfer system
2.2.1 When sampling by use of the ship's fuel oil transfer system it should
preferably be set up to recirculate to the tank from which it is drawing. In
instances where that is not possible, close attention should be given to not
over-filling the receiving tank or mixing fuel oils from different consignments. It
should be noted that for a viscous fuel oil to be in a pumpable condition it will
typically need to be at a temperature corresponding to a viscosity of around 800 –
1,000 cSt.
2.2.2 Sampling should be undertaken downstream of the pump using a suitable sampling
connection drawing from the flowing fuel oil. That sampling connection should fulfil
all the following conditions:
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.1 it should be easily and safely accessible;
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.2 the sampling connection point should be in a position shielded from heated
surfaces or electrical equipment, and any necessary shielding device or
construction should be sturdy enough to ensure that any leaks, splashes or
spray, under transfer pump discharge pressure, do not impinge onto such
surfaces or equipment; and
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.3 the sampling connection should be provided with suitable spill collection
arrangements or drainage to the drain tank or other safe location.
2.2.3 Having established that the fuel oil transfer system is handling the fuel oil
to be sampled, the sampling connection should be thoroughly flushed through and
thereafter the required sample should be obtained.
2.3 Direct sampling from a tank
2.3.1 System tanks, such as settling or service tanks, should preferably be sampled
using the 2019 Guidelines for on board sampling for the verification of the
sulphur content of the fuel oil used on board ships. To be noted that
viscous fuel oils in such tanks will be at elevated temperatures and hence due
caution would be necessary. Such tanks may be sampled directly only by means of
tapping points mounted on the tank which should meet the requirements given above in
2.2.2.1 to 2.2.2.3. Sampling from a system tank should not be undertaken by means of
removing an access plate or from the test drain connection.
2.3.2 Loaded cargo or other ship operational factors may preclude direct sampling
from a tank.
2.3.3 Where direct tank sampling is to be undertaken, via – for example – a suitable
access plate or tank hatch, it should be understood that the ship itself may not
carry the necessary sampling equipment. In order to take a fuel oil sample direct
from a tank, consideration should be given to the use of a specialist service
provider having the appropriate sampling equipment, such as that given in ISO
3170:2004, and the expertise necessary to obtain the required sample in a safe and
competent manner.
2.3.4 Since a sample obtained is representative of the fuel oil at the level or point
from where it was drawn, it will therefore not always be necessary to take samples
from more than one level or point in a tank.
2.3.5 Sampling may alternatively be undertaken from the sounding pipe of a tank by
means of a suitable sampling arrangement.footnote When sampling from a sounding pipe, the design of that
sounding pipe and the recent filling history of that tank should be considered to
assess the relationship of the fuel oil in the sounding pipe to that in the
associated tank.