High-temperature and pressure static equipment solutions provider Steinmüller Africa has received two orders to upgrade State-owned utility Eskom’s Tutuka and Duhva power stations, in Mpumalanga, with a total of 14 new high-pressure heaters.

As specified by Eskom’s requirements, these header-type heaters will range from 12 m to 14 m long and will be 2 m in diameter.

Using Steinmüller Africa’s customised designs, the heaters will achieve various pressures, ranging from 1.5 MPa to 30 MPa and handle very high temperatures of between 230 °C to 300 °C.

The project requires six new designs, three process and three mechanical, which have been developed swiftly, despite the challenges posed by Covid-19.

To meet the tight design and planning deadlines, while also adhering to Covid-19 protocols, the Steinmüller Africa team worked 12-hour shifts, some remotely and others in the office. This was all achieved using three-dimensional modelling software Inventor.

Now well-into material procurement phase, the company has begun initial fabrication on Tutuka’s high-pressure heaters and Duhva’s are due to follow in the next few months. Steinmüller Africa expects to complete all high-pressure heaters by 2024, as both power stations’ equipment is reaching mid-life status and requires replacement.

Steinmüller Africa says it completed extensive preparation and testing procedures to ensure Eskom’s exact specifications are met. The engineering team completed various iterations, modifying procedures and production of the header to nipple welding.

By redeveloping their processes of drilling, re-aligning, fit-up, welding, nondestructive testing (NDT) and ultrasonic testing (UT), the company created a new process and set of protocols based on existing European methodologies.

The company also extensively tested the best-suited machinery to meet requirements when bending snake or serpentine tubes. Automated, semi-automated and manual machines were all tried-and-tested for best-fit.

Moreover, the tube bending process also required specific heat treatment, which is currently being tested and proven in its efficiency.

These heaters come with both a manufacturing and engineering guarantee, which are confirmed by an external reviewer on fabrication and design completions, respectively.

Steinmüller Africa’s high-pressure heaters are expected to perform for over 30 years, which can be extended with the help of their repairs and maintenance services.