MechChem Africa August 2019

⎪ Maintenance and asset management ⎪

the side of a busy road, at night, and in the rain. And in industrial failures of threaded fasteners, it will usually be at around two o’clock, usually on a Sunday morning. And it will be cold and probably raining, if notworse. After retrievingherwheel, we re-attached it with the two remaining studs and two nuts ‘borrowed’ fromotherwheels andadvisedher to go back the tyre fitment establishment. I don’t know whether she did or not. Knowing drivers on the East Rand, she’s probably still driving around like that. A failure looking for somewhere to happen. It’s impossible for an over-tightened threaded fastener to fail in fatigue, which is the most common cause of failure. When over-tightened, the tension in the fastener is far above the fatigue limit for the bolt, as- suming it’s made of steel whichmost are, and the resulting clamping forcewill bewell above that needed – also assuming it survives being over-tightenedwithout stripping the threads or breaking, which many do. Only an under- tightened fastener can be exposed to the cyclic loads in service that produce a fatigue failure, the most common cause of in-service failure in threaded fasteners. So, threaded fasteners, nuts and bolts are well known but, sadly, how they work is poorly understood. Their rules are, however, well understood. Learn them and obey them, and theywill serve youwell andwill hold your world, and your car, together. Ignore the rules and under- or over-tighten threaded fasten- ers at your own risk. Please note that the opinions expressed in this column are mine and mine alone. q

Leading provider of gas detectors and software offers direct-to-cloud connectivity

COMTEST, the local representative of Industrial Scientific, the global leader in gas detection, has announced the expan- sion of its connected safety portfolio to include cellular and wi-fi capability in the Ventis®Pro5 Personal Gas Monitor and a satellite communication gateway to con- nect mobile workers in real time. For area gas monitoring, the Radius ® BZ1 connects to the cloud via the RGX™ Gateway, which is certified for Class 1 Division 2 and ATEX Zone 2 hazardous zones around the globe. Personal and area monitors pass real-time data to iNet ® Now softwareallowing supervisors to seewhere workers are located and what hazards they are exposed to. The combination of real-time and historical data gives organ- isations the power to increase productiv-

ity, address risky behaviour and improve safety practices in a range of applications frommobileworkers to in-plantmonitoring and confined space entries. The connected devices also improve team and site safety due to their unique ability to share alarms between monitors. Local alarm sharing al- lows for faster, more informed responses fromnearbyworkers. Additionally, the local network feature enablesmonitoringwithin confined spaceswhere traditional wireless devices have limited connectivity. “Our connected safety offerings fo- cus on aligning people, devices, sensors and data to help businesses achieve key outcomes: saving lives, saving time, and using resources more efficiently,” says Justin McElhattan, president of Industrial Scientific. sales@comtest.co.za

Threaded fasteners, nuts and bolts are well known but, sadly, how they work is poorly understood.

Connected devices improve team and site safety due to their unique ability to share alarms between monitors.

August 2019 • MechChem Africa ¦ 11