Guidance notes for the harmonized implementation of the revised guidelines and specifications for pollution prevention equipment for machinery space bilges of ships (resolution mepc.107(49)) during the type approval process
The requirements set out in paragraphs 4.1.5, 1.2.9.6 (Part 1), 3.2.2.3 (Part 3) and test result diagrams (Appendix to Appendix 1) of the Revised Guidelines are open to different interpretations. In order to ensure the uniform application of these requirements, the following Guidance notes for harmonized implementation, set out in italics, should be followed:
Paragraph 4.1.5
Paragraph 4.1.5 of the revised Guidelines states that the system should require the minimum of attention to bring it into operation. In the case of equipment used for engine-room bilges, there should be no need for any adjustment to valves and other equipment to bring the system into operation. The equipment should be capable of operating for at least 24 h of normal duty without attention.
Present situation during type approval
The timetable for the complete type approval with the test fluids A, B, and C is approximately 9 h. Although the system should be capable to operate 24 h of normal duty without attention, it is not required to verify this operation in detail.
Possible problem
There is no definition of the term normal duty. Furthermore the equipment manufacturer may carry
out individual tests with each test fluid or may use test results from previous type approvals.
Guidance note
Paragraph 4.1.5 of resolution MEPC.107(49) should be interpreted as follows: It should be understood that the complete type approval with the test fluids A, B and C should be performed in series, without interruption to attend, clean or maintain the bilge water separator. This test would be regarded as a simulation of the 24 hours of unattended operation not requiring any crew attention.
Paragraph 1.2.9.6 of part 1
According to paragraph 1.2.9.6 of Part 1 of the Annex to the revised Guidelines a test lasting a minimum of 2 h should be carried out to check that the 15 ppm bilge separator will operate continuously and automatically.
Present situation during type approval
Some separation processes may require one or more interruptions, e.g., for back flushing, filter
cleaning or batch operation within the 2 hour test run with test fluid A and also for the test with the
remaining test fluids B and C.
Possible problem
If the required time for the continuous operation incorporates also the previous mentioned interruptions, the total throughput of the separator may be reduced significantly compared to a separator with a continuous separation process. In that case the performance standards are not comparable.
Guidance note
Paragraph 1.2.9.6 (Part 1 of the Annex) of resolution MEPC.107(49) should be interpreted as
follows:
It should be understood that the 15 ppm bilge separator should operate continuously and
automatically without any interruptions.
It should be assured that back flushing if performed during the certification test does not
cause:
Dilution of the test fluids A, B, or C, or
Dilution of the test sample sent to the laboratory for analysis.
If input flow of the test fluid is interrupted during the performance of the test it should be
assured that the total quantities of the test fluids A, B, and C processed automatically are not
less than the nominal flow of the separator multiplied by the specified test duration for
each fluid.
While all the time, the bilge separator operates continuously and automatically without
human intervention.
Paragraph 3.2.2.3 of part 3
According to paragraph 3.2.2.3 of Part 3 of the Annex to the revised Guidelines (humidity test), the
equipment should be left switched off for a period of 2 h at a temperature of 55ºC in an atmosphere
with a relative humidity of 90%. At the end of this period the equipment should be switched on and should operate satisfactorily for 1 h.
Present situation during type approval
The electronic part of the equipment may only be tested under ambient workshop conditions
(15 to 25°C and 54 to 66% relative humidity).
Possible problem
The equipment is not tested sufficiently and malfunctions may happen later on board, e.g., under
tropical conditions.
Guidance note
Paragraph 3.2.2.3 (Part 3 of the Annex) of resolution MEPC.107(49) should be interpreted as
follows:
First the temperature test of the electronic part should be operated under the test condition mentioned under 3.2.2.2 (part 3 of Annex) of the guidelines, followed by the humidity test.
Appendix to appendix 1
The test result diagrams of the Appendix to Appendix 1 (Certificate of Type Approval) in the revised Guidelines show a continuous operation of the 15 ppm separator during the performance test with test fluid A, B and C.
Present situation during type approval
Some separation processes may require one or more interruptions, e.g., for back flushing, filter
cleaning or batch operation.
Possible problem
If the required time for the continuous operation incorporates also the previous mentioned interruptions the total throughput of the separator may be reduced significantly compared to a separator with a continuous separation process.
Guidance note
The test result diagrams (Appendix to Appendix 1) should be interpreted as follows:
The continuous and automatic operation should apply to the performance tests with the test fluids A, B and C according to the test result diagrams in the Appendix to Appendix 1.
However if due to the separation process any interruption in feeding the test fluid with nominal flow rate, e.g., for back flushing, is deemed necessary, the time for these interruptions should be added to the required time of the test step which was interrupted during the performance test. While all the time, the bilge separator operates continuously and automatically without human intervention.