Flare stacks require regular inspection and maintenance. Flare stacks are similar to smokestacks or silos, and range from 50 m to 80 m in height. Their function is to burn off surplus or dangerous excess gases that cannot be utilised or stored.

Traditionally, sizeable cranage needs to be mobilised to lift the necessary equipment and personnel to the top in order to be able to carry out the work required. This has major implications for both productivity and safety.

Recently rope-access specialist Skyriders was called upon to assist a major petrochemical producer in Mpumalanga during a shutdown of a major flare stack to carry out ultrasonic (UT) wall-thickness testing, Marketing Manager Mike Zinn reports.

Prior to this, the five-person team was required to remove all damaged lagging and cladding, and afterwards replace it with new material. The lagging is an insulating material that is covered with a protective layer of thin steel sheeting.

“Our challenge was to ensure that our methodology was planned correctly, and that everyone in the team knew exactly what they were required to do,” Zinn explains. The fact that Skyriders was only called upon in the final days of the shutdown added an element of time pressure to the fast-track project.

“Our success here could definitely lead to additional work in this niche sector. It is a prime example of the safety and cost-savings that can result from applying rope access,” Zinn stresses. UT wall thickness measurement is a specialist inspection service offered by Skyriders, which has technicians trained specifically in this regard.

UT measurement comprises the non-destructive testing of the local thickness of a solid element such as a wall, based on the time taken by the ultrasound waves to return to the surface. This measurement is determined by an ultrasonic thickness gauge.