AS NZS 60079.13 pdf download

AS NZS 60079.13 pdf download.Explosive atmospheres
1 Scope
This part of IEC 60079 gives requirements for the design， construction， assessment, verification and marking of rooms used to protect internal equipment: – located in a Zone 1 or Zone 2 or Zone 21 or Zone 22 explosive atmosphere (an area normally requiring an equipment protection level (EPL) Gb，Gc, Db or Dc) without an internal source of gas/vapour release and protected by pressurization; located in a Zone 2 explosive atmosphere (an area normally requiring EPL Gc) with or without an internal source of gas/vapour release and protected by artificial ventilation; – located in a non-hazardous area, containing an internal source of gas/vapour release and protected by artificial ventilation; – located in a Zone 1 or Zone 2 or Zone 21 or Zone 22 explosive atmosphere (an area normally requiring EPL Gb, Gc，Db or Dc), containing an internal source of gas/vapour release and protected by both pressurization and artificial ventilation. The term “room” used in this document includes single rooms, multiple rooms, a complete building or a room contained within a building. A room is intended to facilitate the entry of personnel and includes inlet and outlet ducts. An acoustic hood and other like enclosures designed to permit the entry of personnel can be considered as a room. This document also includes requirements related safety devices and controls necessary to ensure that artificial ventilation, purging and pressurization is established and maintained. A room assembled or constructed on site， can be either on land or off-shore. The room is primarily intended for installation by an end-user but could be constructed and assessed at a manufacturer’ s facility, where the final construction such as ducting can be completed on site. Rooms can be located in an explosive gas atmosphere requiring EPL Gb or Gc，or a combustible dust atmosphere requiring EPL Db, or Dc. This document does not specify the methods that may be required to ensure adequate air quality for personnel with regard to toxicity and temperature within the room. National or other regulations and requirements may exist to ensure the safety of personnel in this regard. Protection of rooms by using an inert gas or a flammable gas is outside of the scope of this , document. It is recognized that such applications are special cases, which in part may be addressed using the principles from IEC 60079-2, but in all probability will also be the subject of additional， stringent engineering standards，procedures and practices. Pressurized enclosures for equipment that are not intended to facilitate the entry of personnel are addressed in IEC 60079-2, and are not in the scope of this document. NOTE Maintenance recommendations are contained in Annex A until they can be included in IEC 60079-17. This document supplements and modifies the general requirements of IEC 60079-0, except exclusions as indicated in Table 1. Where a requirement of this document conflicts with a requirement of IEC 60079-0, the requirement of this document takes precedence.
3 Terms and definitions
For the purposes of this document， the terms and definitions given in IEC 60050-426, IEC 60079-0 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: ●IEC Electropedia: available at http://www.electropedia.org/ ●ISO Online browsing platform: available at http://www.iso.org/obp NOTE Unless otherwise specified, the terms “voltage” and “current” mean the RMS values of an alternating, direct or composite voltage or current. 3.1 airlock means of egress, consisting of two interdependent doors designed to maintain the internal pressure of the room in order to prevent or significantly reduce the entry of a surrounding explosive atmosphere 3.2 alarm piece of apparatus that generates a visual or audible signal that is intended to attract attention [SOURCE: IEC 60050-426:2008, 426-09-05] 3.3 clean air air that is essentially free of combustible dust, and contains no more than trace amounts of flammable vapour or gas 3.4 dilution mixing of flammable vapour or gas with air which, over time, will reduce the flammable concentration