5.3.1 Sampling points should be so located that
relevant samples can be obtained from those outlets that are used
for operational discharges in accordance with paragraph 5.1.1. The sampling probes
located in the overboard discharge lines and the piping system connecting
the sampling probes to the oil content meter should meet the requirements
of this section.
5.3.2 The piping and probes should be of a material
resistant to fire, corrosion and oil and be of adequate strength,
properly jointed and supported.
5.3.3 The system should have a stop valve fitted
adjacent to each probe, except that, where the probe is mounted in
a cargo line, two stop valves shall be fitted, in series, in the sample
line; one of these may be the remote controlled sample selector valve.
5.3.4 Sampling probes should be arranged for easy
withdrawal and should as far as practicable be mounted at an accessible
location in a vertical section of the discharge line. Should it be
necessary to fit sampling probes in a horizontal section of the discharge
line it should be ascertained, during the installation survey, that
the pipe runs full of liquid at all times during the discharge of
the effluent. Sampling probes should normally penetrate inside the
discharge pipe to a distance of one quarter the diameter of that pipe.
5.3.5 Means should be provided for cleaning the
probes and piping system by the provision of permanent clean water
flushing arrangements or an equivalent method. The design of the probes
and piping should be such as to minimize their clogging by oil, oily
residue and other matter.
5.3.6 The velocity of the fluid in the piping
should be such that, taking into consideration the length of the piping,
the overall response time should be as short as possible between an
alteration in the mixture being pumped and the alteration in the meter
reading and in any case not more than 40 seconds, including the response
time of the meter.
5.3.7 The location of sampling probes in relation
to any point of flow diversion to a slop tank should be selected with
regard to the need for sampling the oily water in the recirculation
mode.
5.3.8 The arrangements for driving the sampling
pump or any other pumps used in the system should have regard to the
safety requirements of the space in which the pump is located. Any
bulkhead penetration between a hazardous and a non-hazardous area
should be of a design approved by the Administration.
5.3.9 The flushing arrangement should be such
that where necessary it can be utilized for test-running and stabilizing
the oil content meter and correcting for zero setting.
5.3.10 Sample water returning to the slop tank
should not be allowed to free-fall into the tank. In tankers equipped
with an inert gas system a U-seal of adequate height should be arranged
in the piping leading to a slop tank.
5.3.11 A valve should be provided for the manual
collection of samples from the inlet piping to the meter at a point
downstream of any sampling pump or at an equivalent location satisfactory
to the Administration.