Pressure vessels and piping fabrication specialist and construction fabrication consortium Hydra Arc Group is one of the subcontractors assisting with the construction of an air separation unit for energy and chemicals company Sasol.

The project’s main contractor, multinational gas and services supplier Air Liquide, will build, own and operate the 5 000 t/d air separation train that will supply oxygen and nitrogen to Sasol’s proprietary synthetic fuels and chemicals manufacturing process. This is the seventeenth train to be built at Sasol’s Secunda complex.

Hydra Arc COO Sheldon Nel says the company has been contracted by construction entities Group 5 (G5) and Stefanutti Stocks’ oil and gas divisions. G5 contracted the company for the fabrication of pipe spools for a cooling water line for the (seventeenth) oxygen train, while Stefanutti required work on piping and ducting for the new train.

He comments that Hydra Arc was contacted by G5 in January and Stefanutti in February. The train projects are still under way, with G5 and Stefanutti expected to conclude their projects this month and by February 2017 respectively. Hydra Arc and Sky Hill have supplied the bulk of the pipe spools for the G5 project.

Nel states that the projects required about 3 300 diameter inches to be manufactured for G5, in addition to the estimated 16 000 diameter inches for Stefanutti. The products are being manufactured at Hydra Arc’s Sky Hill Heavy Engineering facility, located in Secunda, in Mpumalanga.

The Hydra Arc group is also a fabricator of novel plant modules for the petrochemicals industry. Hydra Arc engineering manager Ewan Huisamen comments that the workshop is developing outside battery limit modules for Sasol’s Coal Tar Filtration East (CTFE) project.

The CTFE project is an extension of the Secunda plant that is expected to reach beneficial operation in the first half of 2017.

He states that the project involves a novel approach to plant design and construction. Also, it comprises an intricate network of piping and cable racks, divided into subsequent modules that form a part of the CTFE plant. “The whole plant will comprise interconnected modules, which maximises the amount of factory-based fabrication and minimises on-site construction time. The idea is that each module is fabricated to include all its equipment, vessels, piping, instrumentation and supporting structures.”

He explains that, once the site foundations have been prepared, the modules are delivered to site and coupled to form a functional plant, but adds that these modules are not skid-based systems. This means that site works and modular fabrication can be run simultaneously, reducing time and cost.

One completed module has a mass of more than 400 t and includes two pressure vessels and all the interconnecting piping, flanges and support structures. The CTFE plant currently being built consists of 24 individual modules.

The modules were built in Bay 3 and 4 of the Sky-Hill facility, which is exclusively reserved for new fabrication projects of small to very large-scale components in any material type, whether pressure vessels (drums, columns, wall vessels); heat exchangers (fixed/floating tube sheets, channel/bonnet types); larger bore piping prefabrication; and supported flat-bottom-type storage tanks.

Huisamen comments that these modules are becoming increasingly popular worldwide, especially in harsh environments and complex building environments such as Canada and Russia.

Hydra Arc has also fabricated and installed 37 stainless steel water tanks for municipalities in Mpumalanga. The company is also trying to attain a CE Marking, which indicates that its products meet all the legal requirements and standards stipulated by the European Commission, and can therefore be sold in all European Union countries. Once it has received the marking, the group expects that its exports will increase by about 30% after the first five years.