MechChem Africa visits ACTOM Turbo Machines in Sasolburg, a division of ACTOM (Pty) Ltd, and talks to Mark Gulbis, project engineer, about his division’s expertise in the maintenance repair and reverse engineering of high-speed rotating machines.
ACTOM Turbo Machines is a turbo-machinery specialist division that maintains and repairs steam and gas turbines; radial and centrifugal integrally geared compressors; reciprocating, screw and lobe compressors; ID and FD fans and blowers; single- and multi-stage high-pressure pumps; and all other high speed rotating equipment along with the associated turbo train auxiliaries.
“We can deal with units of up to 200 MW in the power generation sector, but we mostly service the industrial sectors – petrochemical, oil & gas, steel, mining, sugar and paper and pulp – that generally use units of below 100 MW,” Gulbis tells MechChem Africa.
“We are one of the 39 operating units within the ACTOM Group, which is the largest manufacturer, solution provider, repairer, maintainer and distributor of electro-mechanical equipment in Africa,” he says.
ACTOM Turbo Machines operates within ACTOM Marthinusen & Coutts, the leading repairer of electrical rotating machines in Africa and, together, they offer a full electro-mechanical solution to the market.
“We also partner with specialist companies to take responsibility for the intermediate and high-speed gearboxes that are often connected to these drive trains. The gear teeth on these are ground to a precise profile that straightens under torque to maximise contact and minimise transmission stresses on the teeth. It is not a trivial matter to remanufacture and grind these gears,” he notes.
The division’s offering is divided into two areas, namely site services and workshop services. “We offer a complete field and technical services team led by a senior turbine technician available for either permanent or temporary deployment to a customer site. We are very lucky to have a large cohort of 22 turbine fitters, ably assisted by 20 mechanical fitters. This enables us to do planned and general maintenance and fault finding along with emergency site repairs and recommissioning,” Gulbis says, adding that “a truly 24/7” service response culture is integral to the offering.
In addition, at the division’s Sasolburg premises in Naledi Industrial Park, experienced workshop engineers and technicians working according to rigorous quality control procedures and specifications carry out workshop-based inspections, refurbishments and repairs. “Here we have the capacity to reverse engineer and remanufacture components before reassembling the equipment and restoring it to full health so that it can be safely and quickly put back into productive service,” Gulbis assures.
“Together with Marthinusen & Coutts, we have vast experience and an extensive network in Africa with workshops in various southern African countries.”
Reverse engineering for a faster response at lower costs
Gulbis believes that reverse engineering became part of the maintenance culture of South Africa back in the days of sanctions and embargoes. “Our large state-owned entities in the petrochemical and steel industries, for example, had no choice but to create their own drawings, because the overseas OEMs were not allowed to support the installed base,” he says.
“Today, though, reverse engineering is very much market- and end-user-driven. End-users always need alternatives to OEMs, as they cannot rely on any single-source supplier to act in their best interests. Plant operators can never allow themselves to be monopolised, which almost always leads to higher prices and falling response times.
“Reverse engineering also helps end-users mitigate against escalating costs, maximise response times, minimise downtime and it allows them to establish far better local service support structures,” Gulbis says. “So this is where division’s such as ACTOM Turbo Machines find their niche; supplying end-users with responsive maintenance services and cost-effective reverse engineered parts that are not readily available on the aftermarket,” he adds.
All maintenance service providers do reverse engineering to some extent, repairing parts when spares are scarce, for example, or when the repair can be done more quickly and/or at a lower cost than purchasing a replacement from the OEM.
“We at ACTOM sell ourselves on our repair capabilities. For us, this entails being very knowledgeable about the form and the function of the turbo machines we deal with: understanding the operating principles; how each component is manufactured, the materials used; how the machines are assembled; how they start up; how they operate; and how they are shut down.
“We need to know that every new part we put back into a machine is fit-for-purpose and does not negatively influence the operation of any other part in any way. We make an effort to understand each of the hundreds of components that make up a machine, because the ones we reverse engineer might have a significant or catastrophic effect on some of the others,” Gulbis tells MechChem Africa.
He says that simple reverse engineering involves taking a new part, measuring it, identifying the materials of construction and then manufacturing an identical copy. “The complex reverse engineering that we tend to offer, however, involves manufacturing processes and materials that are not that straight forward or easy to work with,” he notes.
Emphasising the engineering aspect of reverse engineering, he says that experience of the machines, its components and the technologies involved is critical. “On a turbo machine drive train, you cannot simply disassemble and remanufacture the broken parts,” he warns, before beginning to describe a successful recent project: the refurbishment, reverse engineering and life extension of a fleet of multi-stage high-pressure descaler pumps for the steel industry.
“These are very high-pressure (160 bar) water pumps that spray water through nozzles to peel off the scale on milled plate coming out of a hot steel mill,” he explains, adding that 160 bar is a “massive pressure” for an incompressible fluid such as water. In addition, “the environment is harsh, the water quality is not great and these seven-stage pumps weren’t lasting longer than six months”.
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