African Fusion visits eNtsa, the internationally recognised research and innovation hub and engagement institute within Nelson Mandela University, and talks to its director, Danie Hattingh.
Nelson Mandela University’s eNtsa, a registered Engagement Institute within the university, started operations as the Automotive Components Technology Station (ACTS) in May 2002 at the then Port Elizabeth Technikon, which was merged into Nelson Mandela University (then NMMU) in January of 2005. The name ‘eNtsa’, derived from the word, ’eNtsha’ meaning new in one of the local isiXhosa African languages native to the Eastern Cape, was adopted in 2011 with a view to strengthening the industrial focus of its work and commercialising patented technologies.
The current director, Professor Danie Hattingh, was one of the group’s original founding members. An active consultant who continually develops networking links with industry, Hattingh employed two Masters students during those early years.
In the mid 2000s, Hattingh and his team were involved with research and development work in aid of high value large-scale engineering projects, most notably with Eskom to develop alter- native materials’ sampling and weld repair techniques for its ageing steam boiler fleet. From the Eskom side, this work was pioneered by the late Philip Doubell, Eskom’s Chief Welding Engineer, who with the eNtsa team won multiple awards for the work in developing techniques for determining the fitness- for-purpose and safe extended life for operating power plant components.
At the heart of this development was the now patented WeldCore® sample ex- traction and repair technique, which has now been widely adopted by Sasol and Eskom in South Africa as well as international plant operators for assessing the condition of turbine and thick-walled steam piping subject to high pressures and temperatures.
Describing the technique, Hattingh says that WeldCore® is a novel sample and repair technique that involves in- situ material sampling, of high-pressure steam lines, for example, followed by an immediate hydro pillar weld repair to replace the extracted core. This allows a sample to be quickly extracted from a steam line for materials evaluation without compromising the integrity of the piping.
A representative cylindrical metallurgical core sample is removed from the pipe wall while leaving a blind-hole, with the inner wall intact. The hole is then repaired using Tapered Friction Hydro Pillar Processing (TFHPP), a purpose-developed solid-state friction welding technique. Both the sample cutting and the TFHPP repair equipment are mounted onto the same machining frame – developed by Hattingh’s team in conjunction with Philip Doubell – enabling sampling and repair to proceed as sequential processes.
“Initially the process was applied outside of the existing welding codes but since achieving incorporation of the repair procedure into ASME IX (2015), the application numbers increased drastically to about 35 sampling tests per a year.
“The total investment in the development phase of WeldCore was R32-million with the main support coming from Eskom and the TIA. The initial research in solid state welding at the Nelson Mandela University started in 2000 and can be seen as the knowledge foundation on which the WeldCore technology was built. Our involvement with the process and the first prototype application dating back to as far as 2006 gives us high levels of confidence in the process,” Hattingh tells African Fusion.