1 General
1.1 These test and performance specifications for type
approval relate to add-on equipment for oil filtering equipment type approved in
accordance with resolution MEPC.60(33) (hereinafter referred to as "oil filtering
equipment"). In addition, the electrical and electronic systems of the add-on equipment
should be tested in accordance with the specifications for environmental testing
contained in part 3 of resolution MEPC.107(49).
1.2 The test of add-on equipment should be carried out in
combination with oil filtering equipment to which add-on equipment being tested is
intended to be added on.
2 Test specifications
2.1 These specifications relate to add-on equipment for oil
filtering equipment. A set of oil filtering equipment and add-on equipment should be
capable of producing an effluent for discharge to the sea containing not more than 15
ppm of oil, when 3,000 ppm oil in water emulsions are fed.
.2.2 The test rig must be so constructed as to include not
only oil filtering equipment and add-on equipment, but also the pumps, valves, pipes and
fittings as shown in figure 1:
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.1 for the testing of oil filtering equipment having
no integral pump, the centrifugal pump "A" (figure 1) is used to feed oil
filtering equipment with valves 2 and 4 open, and valve 3 closed. The rate of flow
from the centrifugal pump "A" is matched to the design throughput of oil filtering
equipment by adjustment of the centrifugal pump's discharge valve;
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.2 a centrifugal pump "B" should be fitted to
re-circulate the test fluid "C" in the tank to ensure that the test fluid "C" is
maintained in a stable condition throughout the testing;
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.3 to ensure a good mix of the test fluid and the
water, a conditioning pipe as specified in paragraph 2.4 should be fitted
immediately before oil filtering equipment;
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.4 other valves, flow meters and sample points should
be fitted to the test rig as shown in figure 1; and
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5 the pipe work should be designed for a maximum
liquid velocity of 3 metres/second.
Figure 1 Test rig
2.3 Tests should be performed using test fluid "C" as
defined in resolution MEPC.107(49).
2.4 If oil filtering equipment includes an integrated feed
pump, oil filtering equipment and add-on equipment should be tested with that pump
supplying the required quantity of test fluid and water to oil filtering equipment at
its rated capacity. If oil filtering equipment is to be fed by the ship's pumps, then
the unit will be tested by supplying the required quantity of test fluid and water
mixture to the inlet of a centrifugal pump operating at not less than 1,000 rpm (see
dotted line in figure 1). This pump should have a delivery capacity of not less than 1.1
times the rated capacity of oil filtering equipment at the delivery pressure required
for the test. If a centrifugal pump is used, the excess pump capacity should be
controlled by a throttle valve on the discharge side of the pump. In all cases, to
ensure uniform conditions, the piping arrangements immediately prior to oil filtering
equipment should be such that the influent to oil filtering equipment should have a
Reynolds number of not less than 10,000 as calculated in fresh water, a liquid velocity
of not less than 1 metre per second and the length of the supply pipe from the point of
test fluid injection to oil filtering equipment should have a length not less than 20
times its diameter. A mixture inlet sampling point and a thermometer pocket should be
provided near oil filtering equipment inlet and an outlet sampling point and observation
window should be provided on the discharge pipe.
Figure 2 Diagram of sampling arrangements
- A Distance A, not greater than 400 mm
- B Distance B, sufficient to insert sampling bottle
- C Dimension C, straight length should not be less than 60 mm
- D Dimension D, pipe thickness should not be greater than 2 mm
- E Detail E, chisel-edged chamfer (30°)
2.5 In order to approach isokinetic sampling – i.e. the
sample enters the sampling pipe at stream velocity – the sampling arrangement should be
as shown in figure 2 and, if a cock is fitted, free flow should be effected for at least
one minute before any sample is taken. The sampling points should be in pipes running
vertically.
2.6 In the case of oil filtering equipment and add-on
equipment depending essentially on gravity, the feed to the system of the test water and
test fluid mixture should be maintained at a temperature not greater than 40ºC, and
heating and cooling coils should be provided where necessary. The water shall have a
density of not more than 1.015 at 20ºC. In other forms of separation where the
dependence of separation efficiency on temperature is not established, tests should be
carried out over a range of influent temperatures representing the normal shipboard
operating range of 10ºC to 40ºC or should be taken at a temperature in this range where
the separation efficiency is known to be worst.
2.7 In those cases where, for oil filtering equipment and
add-on equipment, it is necessary to heat water up to a given temperature and to supply
heat to maintain that temperature, the tests should be carried out at the given
temperature.
2.8 The tests with test fluid "C" should be carried out as
follows:
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.1 prior to the test with test fluid "C", oil
filtering equipment and add-on equipment should be filled up with water (density
of not more than 1.015 at 20ºC);
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.2 oil filtering equipment and add-on equipment
should be fed with a mixture composed of 6% test fluid "C" and 94% water to have
emulsified oil content of 3,000 ppm in the test water until steady conditions have
been established. Steady conditions are assumed to be the conditions established
after pumping through oil filtering equipment and add-on equipment a quantity of
test fluid "C"/water mixture not less than twice the volume of oil filtering and
add-on equipment; and
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.3 the test should then proceed for 2.5 h. Samples
should be taken at the effluent outlet at 50 minutes and 100 minutes after
conditioning. At the end of this test, an air cock should be opened on the suction
side of the pump and, if necessary, the test fluid "C" and water valves should be
slowly closed together, and a sample taken at the effluent discharge as the flow
ceases (this point can be checked from the observation window).
2.9 Sampling should be carried out as shown in figure
2 so that the sample taken will suitably represent the fluid issuing from the
effluent outlet of add-on equipment.
2.10 Samples should be taken in accordance with ISO
9377–2:2000. The sample is to be extracted on the same day of collection, and be
sealed and labelled in the presence of a representative of the national authority
and arrangements should be made for analysis as soon as possible and in any case
within seven days, provided the samples are being kept between 2ºC and 6ºC at
laboratories approved by the Administration.
2.11 The oil content of the samples should be
determined in accordance with part 4 of the annex to resolution MEPC.107(49).
2.12 When accurate and reliable oil content meters
are fitted at inlet and outlet of add-on equipment, one sample at inlet and outlet
taken during each test will be considered sufficient if they verify, to within
±10%, the meter readings noted at the same instant.