2.3 Performance Standards
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC/Circular.677 – Revised Standards for the Design, Testing and Locating of Devices to Prevent the Passage of Flame into Cargo Tanks in Tankers – (Adopted on 30 December 1994)1 Amended by MSC/Circ.1009 - Annex - Revised Standards for the Design, Testing and Locating of Devices to Prevent the Passage of Flame into Cargo Tanks in Tankers - 2 Standards - 2.3 Performance Standards

2.3 Performance Standards

  2.3.1 Devices should be tested in accordance with 3.5 and thereafter shown to meet the test requirements of 3.2 to 3.4, as appropriate.

  2.3.2 Performance characteristics, such as the flow rates under both positive and negative pressure, operating sensitivity, flow resistance and velocity should be demonstrated by appropriate tests.

  2.3.3 Devices should be designed and constructed to minimize the effect of fouling under normal operating conditions. Instructions on how to determine when cleaning is required and the method of cleaning should be provided for each device in the manufacturers' instruction manual.

  2.3.4 Devices should be capable of operating in freezing conditions (such as may cause blockage by freezing cargo vapours or by icing in bad weather) and if any device is provided with heating arrangements so that its surface temperature exceeds 85°C, then it should be tested at the highest operating temperature.

  2.3.5 Devices based upon maintaining a minimum velocity should be capable of opening in such a way that a velocity a 30 m/s is immediately initiated, maintaining an efflux velocity of at least 30 m/s at all flow rates and, when the gas flow is interrupted, be capable of closing in such a way that this minimum velocity is maintained until the valve is fully closed.

  2.3.6 In the case of high velocity vents, the possibility of inadvertent detrimental hammeringfootnote leading to damage and/or failure should be considered, with a view to eliminating it.

Parent topic: 2 Standards
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