Secunda-based welding company Hydra Arc – ISO 3834 certified by the Southern African Institute of Welding Certification has grown into a leading South African specialised welder that provides services for Southern Africa’s petrochemicals, power, mining and minerals processing industries.

The company offers services in plant refinery maintenance and specialist turnaround contracts; the fabrication of heavy equipment, modular plant, pressure vessels and water tanks; and turnkey on-site construction services and repairs.

Owing to a lack of new investment in plant development in the heavy fabrication sector, Hydra Arc is undertaking a massive expansion of its Sky Hill facility to position the company as the ‘can-do’ destination for local and regional work that can only currently be accommodated overseas.

“From a machining perspective, we know of several cases where large components had to be sent to China for machining after being fabricated here,” says Hydra Arc engineering manager Ewan Huisamen.

He adds that the lack of large machining capacity also results in whole fabrication contracts being awarded overseas, despite the huge associated transportation costs.

The Sky Hill Heavy Engineering facility was opened in October 2009 to service the growing need for replacement and new plant components.

Completed projects include five 446 t, 59 m propylene bullets that were heat treated as a single piece in the company’s purpose-built 66 m furnace and the fabrication of 24 interconnectable plant modules for petrochemicals group Sasol’s Coal Tar Filtration East project, several of which have a mass of over 400 t.

“We have pioneered the local fabrication of a new approach to plant design and construction, an approach that strives to maximise the amount of factory-based fabrication and minimise on-site construction time,” explains Huisamen.

He says the company can complete the fabrication of all five bullets, under factory conditions over six months, but this is a project that could take up to several years to complete if undertaken on site.

“With a length of 500 m and a 23 m width, the near-complete Bay 4 of Sky Hill features a hook height raised to 19 m and a total lifting capacity of 1 500 t. Most notably, a state-of-the-art machine shop is currently being installed to complete the company’s factory-based manufacturing capability for heavy modules and plant equipment.”

He enthuses that the centrepiece of the new bay is a tandem horizontal boring mill from engineering company TOS Varnsdorf, the first machine of its kind globally.

Huisamen says the machine consists of two milling stations that travel along opposite ends of a 33 m common rail, allowing two independent machining operations to be completed on the same equipment simultaneously.

A floor-level bed 36 m long by 8.0 m wide sits in front of the rail and incorporates two rotary platforms that can handle 60 t and 40 t workpieces respectively.

“Setup times will be halved on very big fabrications as we have the capacity to machine both ends at the same time. Machining of 33 m in the x–, 5.0 m in the y– and 1.0 m in the z-direction can be accommodated on fabrications of up to 5.0 m high,” says Hydra Arc machine shop superintendent Gert Swanepoel.

He enthuses that with the new machine, along with the workflow and capacities of the supporting machines, the company aims to provide a cost-effective and time-saving service that is at or above international quality standards.

Swanepoel explains that what is critical to the modular plant approach is that, once on site, interconnectivity with other modules is seamless and precise.

Despite jigging and accurate clamping, machine tool tolerances are impossible to achieve through fabrication alone, he adds.

“This tandem TOS Varnsdorf boring mill allows us to machine heavy plant modules, pressure vessels, columns or heat exchangers to the precise tolerances required. It gives us a capability previously unavailable anywhere in Africa,” Swanepoel says.

In addition to the new Bay 4 and its machine shop, Bays 1 to 3 at Sky Hill are also being extended to the full 500 m length. “We have to move our heat-treatment furnace to accommodate the expansion and, in the process, we intend to upsize it to 15 × 15 × 80 m,” Huisamen reveals.

Skills Development

Hydra Arc prides itself on skills development and the use of local skills with its company’s Mshiniwami Training Academy, which has the capacity to train up to 1 000 artisans every year.

“This highly successful business, which feeds the needs of the Hydra Arc Group as well as the country’s fabrication industry, is a vital component for economic growth,” Huisamen suggests.

Mshiniwami offers practical skills development in boilermaking, pipefitting, welding and grinding, with the more competent trainees having the opportunity to complete their trade tests and to become fully fledged qualified artisans.

“While current work is mostly related to shutdowns or turnarounds at Sasol, crude oil refinery Sapref and international energy company Chevron, our current investments in Sky Hill clearly demonstrate our faith in the future of South Africa, its fabrication industry and the economy in general,” Huisamen concludes.