Hazardous Area Zones 0, 1, 2, 20, 21, 22 - Definitions

Hazardous Area Zones 0, 1, 2, 20, 21, 22 - Definitions

Hazardous Area Classification Zones 

The Probability of an Explosive Atmosphere Occuring.

 

 

 

Hazardous Area Electrical Equipment

T&D Supply Oil, Gas & Petrochem Projects With Hazardous Area Equipment

 

  • Zone 0 defines an area in which an explosive atmosphere caused by a mixture of air and gases, vapours and mists is present continuously for long periods or very frequently.

 

  • Zone 1 defines areas in which an explosive atmosphere caused by a mixture air and gases, vapours and mists is expected to occur occasionally.

 

  • Zone 2 defines areas in which an explosive atmosphere caused by a mixture of air and gases, vapours and mists is unlikely and if it should occur it will be for a short time and then only rarely.

 

  • Zone 20 defines an area in which an explosive atmosphere caused by a cloud of combustible dust and air is present continuously for long periods or very frequently.

 

  • Zone 21 defines areas in which an explosive atmosphere caused by a cloud of combustible dust and air is expected to occur occasionally.

 

  • Zone 22 defines areas in which an explosive atmosphere caused by a cloud of combustible dust and air is unlikely and if it should occur it will be for a short time and then only rarely. 

 
Hazardous Area Classification for Flammable Gases and Vapours - HSEHazardous Areas

Hazardous area classification may be carried out by direct analogy with typical installations described in established codes, or by more quantitative methods that require a more detailed knowledge of the plant. The starting point is to identify sources of release of flammable gas or vapour. Flammable gas or vapours may arise from constant activities; from time to time in normal operation; or as the result of some unplanned event. In addition, inside process equipment may be a hazardous area, if both gas/vapour and air are present, though there is no actual release.

Catastrophic failures, such as vessel or line rupture are not considered by a hazardous area classification study. A hazard identification process such as a Preliminary Hazard Analysis (PHA) or a Hazard and Operability Study (HAZOP) should consider these abnormal events.

The most commonly used standard in the UK for determining area extent and classification is BS EN 60079 part 101, which has broad applicability. The current version makes clear the direct link between the amounts of flammable vapour that may be released, the ventilation at that location, and the zone number. It contains a simplistic calculation relating the size of zone to a rate of release of gas or vapour, but it is not helpful for liquid releases, where the rate of vaporisation controls the size of the hazardous area.

Other sources of advice, which describe more sophisticated approaches, are the Institute of Petroleum Model Code of Practice (Area Classification Code for Petroleum Installations, 2002), and the Institution of Gas Engineers Safety Recommendations SR25, (2001). The IP code is for use by refinery and petrochemical type operations. The IGE code addresses specifically transmission, distribution and storage facilities for natural gas, rather than gas utilisation plant, but some of the information will be relevant to larger scale users.

T&D - Worldwide Suppliers Of Hazardous Area Electrical Equipment

  • Junction Boxes (Electrical Enclosures)
  • Local Control Stations
  • Control Panels
  • Power Switching
  • Lighting
  • Torches
  • Digital Cameras
  • Electrical Safety Equipment
  • Emergency Shutdown, Call Points, Breakglass
  • Sounders & Beacons
  • Trace Heating Systems
  • Duct Seals
  • Plugs and Sockets
  • Cable Containment (Tray, Ladder, Basket)
  • Cable Joints
  • Cable Glands
  • Cable Cleats
  • Cable Ties
Hazardous Area Electrical Products & Equipment
Thorne and Derrick Hazardous Area Manufacturers

 

T&D Hazardous Area Product Overview

Adobe

Safe Working with Flammable Substances in Hazardous Areas - HSE

UK Time - GMT: