SAIMC


SAIMC: Johannesburg branch

September 2019 SAIMC

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.
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.



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

MESA Africa Summit has been expanded and rebranded
SAIMC Supplier Advisory Council SAIMC
We are writing to share some exciting developments regarding the evolution of the MESA Africa Summit, which has been a cornerstone event in industrial automation and manufacturing excellence.

Read more...
How to claim CPD points
SAIMC Supplier Advisory Council SAIMC
SAIMC makes it possible for you to claim CPD points for attending courses and technical meetings, or completing an online quiz on a SA Instrumentation & Control magazine.

Read more...
SAIMC: From the office of the CEO:Slaughtering AI holy cows
SAIMC SAIMC
A couple of sessions at various dealers, a wrong delivery, a failed holiday plan, a two-week unplanned vacation and 32 kg of steel on the back seat awaited us as we left South Africa on a dream holiday. But let me start at the beginning.

Read more...
SAIMC: Secunda branch
SAIMC SAIMC
At the most recent SAIMC Secunda technical evening, Jenine Jansen van Vuuren, sales account manager from Comtest Technologies, gave a presentation on the calibration of process instruments.

Read more...
SAIMC: Durban branch
SAIMC SAIMC
The Durban branch of the SAIMC held its October technology meeting, not on the first Wednesday of the month as usual, but on the second Wednesday to accommodate the very interesting presenter, Nico Erasmus from Abacus Automation.

Read more...
SAIMC: Johannesburg branch
SAIMC SAIMC
The October Technology Evening was hosted by Pepperl+Fuchs. Patience Moila, the enterprise mobility expert for sub-Saharan Africa, presented on ‘Lone Worker Protection for the Mobile worker 4.0’.

Read more...
SAIMC Johannesburg golf day
SAIMC SAIMC
The Johannesburg branch of the SAIMC recently held its annual Golf Day at Jackal Creek.

Read more...
SAIMC: It’s not black and white
SAIMC Editor's Choice SAIMC
Grey imports are a problem worldwide, not least in the automation industry in South Africa. The Supplier Advisory Council (SAC) operates under the umbrella of SAIMC, and is tackling this problem head-on.

Read more...
How to claim CPD points
SAIMC Supplier Advisory Council SAIMC
SAIMC makes it possible for you to claim CPD points for attending courses and technical meetings, or completing an online quiz on a SA Instrumentation & Control magazine.

Read more...
SAIMC: From the office of the CEO: The real damage of fake news
SAIMC SAIMC
People depend on accurate information and their own reasoning and belief systems to draw conclusions or make decisions. However, when they are inundated with fake news, the reliability of the information they receive is compromised.

Read more...