The July technology evening featured a presentation by Katlego Setwaba of Pepperl+Fuchs. The main focus of her talk was Ex p (purging and pressurisation). However, she started off by reminding us of the damage done by explosions, demonstrating the catastrophic effects if these are not prevented.
Ann de Beer (left) thanks Katlego Setwaba for the presentation.
The three Gas Groups (IIA, IIB,and II C) and Dust Groups (III A, III B and III C) were tabled, A being the least sensitive to spark ignition, and C the most sensitive. She went on to cover zoning – Zone 0 being the most dangerous for gases, and Zone 2 has the least chance of the hazard being present. By contrast, dusts are correspondingly grouped into Zones 20, 21 and 22.
This was followed by the different explosion prevention techniques with a focus on flame proofing (Ex d, the containment of an explosion), intrinsic safety (Ex 1, limitation of temperatures and spark energy), followed by pressurisation and purging (Ex p, filling the equipment housing with clean air or inert gas).
Pressurisation is the maintenance of a positive pressure above atmosphere, after a preliminary purge. This can obviously not be done effectively in a dusty environment, so physical cleaning is required before pressurisation. In purging, the procedure is much the same, but instead of maintaining a static pressure, Katlego explained how there is a constant flow of clean air or inert gas through the enclosure. This of course requires a dedicated controller to carry out the pre-use purge, and to maintain the internal pressure.
It was an entertaining presentation, with plenty of questions, showing just how much expertise is required to prevent explosions. The branch thanks Pepperl+Fuchs for hosting the evening.
SAIMC Zambia SAIMC
SAIMC News
SAIMC Zambia marked its 21st anniversary with the annual SAIMC Banquet, held on 29 November 2025 at Mukwa Lodge in Kitwe, Zambia.
Read more...SAIMC: Durban branch SAIMC
SAIMC
The SAIMC Durban Branch closed off its 2025 technology meetings with an exceptionally well-attended session on selecting and applying signal transducers.
Read more...SAIMC: Durban year-end dinner SAIMC
SAIMC
The SAIMC Durban branch hosted its much-anticipated annual year-end dinner at the Mount Edgecombe Country Club on 22 November 2025. Durban’s summer weather provided the perfect backdrop for a warm, ...
Read more...Durban branch
SAIMC
At the Durban branch of the SAIMC held in October, Mitch Naidoo took the attendees on an interesting journey on Asset Health Management: Tracking The Pulse Of Your Plant.
Read more...SAIMC: Durban branch SAIMC
SAIMC
At the Durban branch of the SAIMC held in October, Mitch Naidoo took the attendees on an interesting journey on Asset Health Management: Tracking The Pulse Of Your Plant.
Read more...SAIMC: Johannesburg branch SAIMC
SAIMC
The SAIMC Johannesburg Branch technical evening was hosted by Proconics Advanced Solutions. The topic of the session was ‘Turning Big 3D Data into Actionable Engineering Insights – Challenges and Smart Solutions’.
Read more...SAIMC User Advisory Council Annual Summit 2025 SAIMC
SAIMC
October 2025 marked a pivotal moment for the South African automation and manufacturing community as the SAIMC User Advisory Council hosted its first annual summit under the SAIMC banner.
Read more...SAIMC: Johannesburg
SAIMC
The Johannesburg Branch of the SAIMC hosted a successful Technology Evening on 10 September. The event was well attended and generously sponsored by Phoenix Contact.
While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.
printer friendly version