FOLLOWING a rupture on the mainsteam piping system on one of the units at a major power station, Babcock’s Ntuthuko Engineering division, along with two other major boiler companies, was part of a competitive bidding process to develop a proposal in a very short period of time to repair the piping system as quickly as possible to the strictest of international standards.
Babcock was successful in its tender and was awarded the work to undertake the design, procurement and supply, fabrication, manufacture, and construction of the complete mainsteam and high-pressure bypass system for the power unit.
Keagan Naidoo, Piping Engineering Manager at Babcock Ntuthuko Engineering, explains that a complex project of this nature taking into account the engineering scope, manufacturing, logistics and the scope of construction involved, usually takes 18 to 24 months to execute. However, Babcock successfully completed the project in just seven months, working under pressure to restore the additional power capacity.
In order to assess the extent of the damage, Babcock used a combination of visual inspection and 3D scanning technology to scan the piping system and associated structures. Using specialised software, Babcock was able to digitise the real-world architecture by capturing existing plant conditions and complex geometry, resulting in a digital copy, which identified that large sections of pipework and structures had been displaced during the rupture.
Babcock was tasked to design the replacement system whilst establishing a safe working environment to enable the safe removal of the damaged sections of pipework; source and supply the replacement hardware on the piping system; and install it.
As part of removing the existing ‘as-damaged’ piping system, various techniques using load-bearing scaffolding and ratchet type restraints were employed to remove residual spring due to the event and prevent further displacement.
He says that the project was logistically demanding as specialty items such as forgings and piping had to be manufactured in Europe and delivered to South Africa within the strict project timelines, while complying with the best practices in accordance with the latest international design codes available, and benefiting from the design smarts to minimise calculated stresses.
“Quality control measures which formed key gate keepers leading to cold handover proved challenging as the majority of this was done over the festive season, meaning the availability of resources from sub-contractors was not as abundant as other periods,” says Naidoo.
“With great effort, dedication, teamwork from both Babcock and the client’s side, and many late nights and weekends, the unit was successfully and safely synchronised to the power grid on 16 February 2020,” he concludes.
