1.3 Definitions

Clasification Society 2024 - Version 9.40

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 - 1 Introduction - 1.3 Definitions

1.3 Definitions

For the purpose of these Standards, the following definitions are applicable.

1.3.1 “Flame arrester" is a device to prevent the passage of flame in accordance with a specified performance standard. Its flame-arresting element is based on the principle of quenching.

1.3.2 “Flame screen" is a device utilizing wire mesh to prevent the passage of unconfined flames, in accordance with a specified performance standard.

1.3.3 “Flame speed" is the speed at which a flame propagates along a pipe or other system.

1.3.4 “Flashback" is the transmission of a flame through a device.

1.3.5 “High velocity vent" is a device to prevent the passage of flame, consisting of a mechanical valve which adjusts the openings available for flow in accordance with the pressure at the inlet of the valve in such a way that the efflux velocity cannot be less than 30 m/s.

1.3.6 “Pressure/vacuum valve"^footnote is a device designed to maintain pressure and vacuum in a closed container within preset limits.

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