Holistic approach for the Ex sector
Take for instance an electric motor for use in an Ex environment. It is designed and manufactured to meet minimum safety standards and may be covered by IECEx Certification, but until recently, the mechanical items driven by the electrical motor, e.g. pumps, gearboxes, and so forth, were ignored and left to the many differing local or regional requirements. This has now changed with the inclusion of non-electrical equipment in the set of International Standards developed by IEC Technical Committee (TC) 31: Equipment for explosive atmospheres, via its Subcommittee (SC) 31M: Non-electrical equipment and protective systems for explosive atmospheres, and the integration of these Standards into the IECEx operations. IECEx is the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres.
The early days
The necessity to develop specific techniques to reduce or eliminate the risk of explosion for electrical equipment used in hazardous areas involving gases, vapours and mists, led the IEC to establish Technical Committee (TC) 31: Equipment for explosive atmospheres. That was in July 1948.
For close to 70 years, the TC and its SCs have published International Standards dealing with explosive (Ex) atmospheres – the IEC 60079 series – covering the life-cycle of electrical equipment from design and manufacture to installation, maintenance and repair. Area classification and inspection are also addressed in TC 31 publications.
Extending the scope to include non-electrical equipment
To meet growing industry needs, standardization work addressing non-electrical equipment used in explosive atmospheres was initiated in 2007. A joint decision made by the IEC and the International Organization for Standardization (ISO), through the IEC Standardization Management Board (SMB) and the ISO Technical Management Board (TMB), led to the establishment of SC 31M.
In its scope, SC 31M defines non-electrical equipment as "equipment which can achieve its intended function mechanically", and protective system as “devices other than components of the equipment which are intended to halt incipient explosions immediately and/or to limit the effective range of an explosion".
SC 31M is authorized to produce both dual-logo ISO/IEC and single-logo IEC or ISO International Standards within IEC and IEC TC 31. The development process occurs according to IEC procedures but voting on Committee Draft for Vote (CDV) and Final Draft International Standard (FDIS) documents is conducted in parallel, with each organization following its own rules for voting.
The ISO/IEC 80079 series
While all International Standards developed by IEC TC 31 and its SCs follow the IEC numbering, i.e. IEC 60079-x, SC 31M publications are in the ISO/IEC 80079-x series. The first Standard issued by SC 31M was ISO/IEC 80079-34, Explosive atmospheres – Part 34: Application of quality systems for equipment manufacture, in 2011.
Since then SC 31M has published four other International Standards:
- ISO/IEC 80079-20:2016, Explosive atmospheres - Part 20-2: Material characteristics - Combustible dusts test methods
- ISO/IEC 80079-38:2016, Explosive atmospheres - Part 38: Equipment and components in explosive atmospheres in underground mines
- ISO 80079-36:2016, Explosive atmospheres - Part 36: Non-electrical equipment for explosive atmospheres - Basic method and requirements
- ISO 80079-37:2016, Explosive atmospheres - Part 37: Non-electrical equipment for explosive atmospheres - Non electrical type of protection constructional safety "c", control of ignition source "b", liquid immersion "k"
IECEx issues the first certificates for non-electrical equipment
Both ISO 80079-36 and ISO 80079-37 were published in February 2016 and in June, the first Certificate for non-electrical equipment used in Ex areas – dosing pumps – was issued by INERIS, the French National Institute for Industrial Safety and Environmental Protection.
In addition to the three examples above, non-electrical equipment may include couplings, pumps, gearboxes, brakes, hydraulic and pneumatic motors and any combination of devices that are part of machinery, fans, engines, compressors, assemblies and so forth.
Higher level of trust
With the testing and certification of both electrical and non-electrical equipment, IECEx truly becomes THE one-stop shop for all players in the Ex sector. Confidence in IECEx has been at a high level for many years, and the holistic approach will undoubtedly bring increased trust in the System.
For more information: www.iecex.com