The first of three new units at the Tarbela Fourth Expansion in Pakistan has been officially inaugurated by the country’s Prime Minister Shahid Khaqan Abbas in a ceremony held on 10 March 2018.

Developed by the Water and Power Development Authority (WAPDA), the fourth expansion of the Tarbela hydropower plant raises the output of this plant, located in northern Pakistan, to a total of 4888MW, representing a capacity increase of around 40%.

For the expansion of the power plant – first inaugurated in 1974 – key partner Voith has supplied three generators, three Francis turbines with an output of 470MW each, automation systems, overhead 500kV transmission lines and the entire electromechanical power plant equipment. It is planned to have all three machine units providing power into the Pakistan energy grid by the end of May 2018.

As part of the approximately €200 million order, Voith also designed, produced, delivered, and installed three main inlet valves, which are installed between the pressure pipeline and the turbines in order to stop the flow of water in case of emergency and for maintenance work on the units. With a diameter of 7.5m and a total weight of around 750 tons each, they are regarded as the world’s largest main inlet butterfly valves of their kind with double seals. The experts at the research and development center of Voith Hydro in Germany and China jointly developed the valve based on their global references. The valves were completely produced at Voith Hydro Shanghai, China.

The Voith locations in Heidenheim, Germany and Shanghai, China have worked in close collaboration during the period of this complex and large- scale project. Voith Hydro Shanghai produced the Francis turbines, generators, main inlet valves, overhead 500kV transmission line and mechanical plant equipment, whilst Voith Hydro in Germany supplied the electrical equipment and the automation systems.

“Due to the size and complexity of this important project for Pakistan, there was a need for close cooperation and constant communication with all involved parties. This included the end customer WAPDA, the customer engineering consultant as well as other Chinese subcontractors at the site,” explains Uwe Wehnhardt, CEO of Voith Hydro and Member of the Corporate Board of Management. “Our global development and production foot-print and deep experience of working closely with Chinese EPC contractors definitely paid off for this.”

The integration of Voith’s OnCare AM in the Tarbela IV power plant is the world's first. The system, which was originally developed for paper machines, is used for planning all maintenance processes in the power plant. The system compares the key output figures, reads the stored data and reacts to any discrepancies. In this way, the customer is able to identify potential optimizations and plan preventive maintenance measures, thereby allowing the operator to greatly reduce unplanned downtimes and increase the availability of its plant.