UL 60079-13-2020 pdf download

UL 60079-13-2020 pdf download.Explosive Atmospheres – Part 13: Equipment Protection by Pressurized Room “p” and Artificially Ventilated Room “v”.
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
3.13 pressurized room room volume protected by pressurization and of sufficient size to permit the entry of a person who may occupy the room 3.14 artificially ventilated room room volume protected by artificial ventilation and of sufficient size to permit the entry of a person who may occupy the room Note 1 to entry: The room volume can be an entire room (general) or part of a room (local ventilation). 3.15 purging operation of passing a quantity of clean air through the room and ducts in a pressurized or artificially ventilated room, so that the concentration of the explosive gas atmosphere is brought to a safe level 3.16 room volume <of the pressurized or artificially ventilated room> volume of the empty room and including any associated ducting without internal equipment 3.17 pressurization “pb” pressurized room that provides an equipment protection level Gb or Db 3.18 pressurization “pc” pressurized room that provides an equipment protection level Gc or Dc 3.19 artificial ventilation “vc” artificial ventilation of a room with or without an internal source of release, such that the room provides an equipment protection level Gc 3.20 artificial ventilation technique of guarding against an explosive atmosphere by the use of mechanical means to provide for the movement of air 3.21 ventilation system complete installation required to produce artificial ventilation.
4.2 Type and level of protection 4.2.1 Pressurization “p” Rooms with pressurization “p” and located in a hazardous area shall be one of the following: a) Level of protection “pb” (EPL Gb or Db). The pressurized room maintains an internal overpressure reducing the risk of ingress of an explosive atmosphere and is suitable for use in an area requiring EPL Gb or Db, permitting unprotected equipment to be installed within the pressurized room except for pressurization safety devices (see 6.3.1). b) Level of protection “pc” (EPL Gc or Dc). The pressurized room maintains an internal overpressure reducing the risk of the ingress of an explosive atmosphere and is suitable for use in an area requiring EPL Gc or Dc, permitting unprotected equipment to be installed within the pressurized room except for pressurization safety devices (see 6.3.1). 4.2.2 Artificial ventilation “v” The artificial ventilated room maintains artificial ventilation to dilute a release of flammable substance to reduce a hazardous area inside such that the required EPL is reduced from either Gb or Gc to non- hazardous or from Gb to Gc. Rooms with artificial ventilation “v” and located in a hazardous area shall be: • level of protection “vc” (EPL Gc). The ventilated room maintains artificial ventilation to dilute a release of flammable substance to reduce a hazardous area such that unprotected equipment can be installed within the artificially ventilated room, and is suitable for use in an area requiring EPL Gc. NOTE This permits equipment with a lower EPL to be installed within the artificially ventilated room except for ventilation safety devices (see 7.3.1).UL 60079-13-2020 pdf download.