4.3 Definition of hazardous area zones
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4.3 Definition of hazardous area zones

Parent topic: Chapter 4 – Electrical Systems

4.3.1 Hazardous area zone 0

 This zone includes:

  • .1 the interiors of gas tanks, any pipework of pressure-relief or other venting systems for gas tanks, pipes and equipment containing gas.footnote

4.3.2 Hazardous area zone 1

 This zone includes:

  • .1 tank room;

  • .2 gas compressor room arranged with ventilation according to 2.10.4;

  • .3 areas on open deck, or semi-enclosed spaces on deck, within 3 m of any gas tank outlet, gas or vapour outletfootnote, bunker manifold valve, other gas valve, gas pipe flange, gas pump-room ventilation outlets and gas tank openings for pressure release provided to permit the flow of small volumes of gas or vapour mixtures caused by thermal variation;

  • .4 areas on open deck or semi-enclosed spaces on deck, within 1.5 m of gas compressor and pump room entrances, gas pump and compressor room ventilation inlets and other openings into zone 1 spaces;

  • .5 areas on the open deck within spillage coamings surrounding gas bunker manifold valves and 3m beyond these, up to a height of 2.4 m above the deck;

  • .6 enclosed or semi-enclosed spaces in which pipes containing gas are located, e.g., ducts around gas pipes, semi-enclosed bunkering stations; and

  • .7 the ESD-protected machinery space is considered as non-hazardous area during normal operation, but changes to zone 1 in the event of gas leakage.

4.3.3 Hazardous area zone 2

 This zone includes:

  • .1 areas within 1.5 m surrounding open or semi-enclosed spaces of zone 1footnote.

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