4 Classification criteria
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1270 – Revised Guidelines for the Approval of Fixed Aerosol Fire-Extinguishing Systems Equivalent to Fixed Gas Fire-Extinguishing Systems, as Referred to in SOLAS 74, for Machinery Spaces – (4 June 2008) - Annex - Revised for the Approval of Fixed Aerosol Fire-Extinguishing Systems Equivalent to Fixed Gas Fire-Extinguishing Systems, as Referred to in SOLAS 74, for Machinery Spaces - Appendix 1 – Test Method for Fire Testing of Fixed Aerosol Fire-Extinguishing Systems - 4 Classification criteria

4 Classification criteria

  4.1 Class B fires should be extinguished within 30 s of the end of discharge. At the end of the hold period there should be no re-ignition upon opening the enclosure.

  4.2 The fuel spray should be shut off 15 s after extinguishments. At the end of the hold time, the fuel spray should be restarted for 15 s prior to reopening the door and there should be no re-ignition.

  4.3 The ends of the test fuel trays should contain sufficient fuel to cover the bottom of the tray.

  4.4 The wood crib weight loss should be no more than 30% during the 2 min pre-burn test, 50% during the 4 min pre-burn test and 60% during the 6 min pre-burn test.

  4.5 A re-ignition test should be conducted after the successful extinguishments of the tell-tale fires in test 1 (Fire A) within 30 s after completion of discharge. The test should involve the attempted ignition of two of the tell-tale fire containers. One container should be at the floor level and the other at the ceiling level at the diagonally opposite corner. At 10 min after extinguishment of the fires, a remotely operated electrical ignition source should be energized for at least 10 s at each container. The test should be repeated at 2 min intervals two more times, the last at 14 min after extinguishment. Sustained burning for 30 s or longer of any of these ignition attempts constitutes a re-ignition test failure.

  4.6 For the polymeric sheets, the laboratory extinguishing factor for each fuel is that which achieves satisfactory extinguishment of the fire over three successive tests (no flaming 60 s after end of discharge and no re-ignition after 10 min from end of discharge). The design factor is the highest of the laboratory extinguishing factors for the three fuels multiplied by 1.3.

Parent topic: Appendix 1 – Test Method for Fire Testing of Fixed Aerosol Fire-Extinguishing Systems
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