Signs of wear
Visible damage on the cutting edges and inner surfaces.
In the world of hydropower, age, wear, and the lack of original documentation often pose significant challenges when it comes to maintaining or restoring components of Pelton turbines. When damage occurs, replacing the entire runner can be costly, time-consuming, and, in many cases, not essential. This is where reverse engineering steps in as an intelligent, sustainable, and economically viable solution. At Global Hydro, we offer state-of-the-art reverse engineering processes that ensure cost savings, efficiency and quality as well as sustainability - repair instead of new production and thus waste of resources.
Reverse engineering is more than just a repair process – it's a high-tech approach to restoring components with unmatched accuracy. At Global Hydro, this process follows a structured path that ensures the highest quality outcome and time savings for our clients:
The runner is thoroughly examined for visible and hidden damages by our experts - either after its arrival at our facility or directly on-site as part of a site visit. This detailed inspection helps determine the full extent of wear and forms the basis for the next steps in the reverse engineering process.
Each bucket and its stencil are scanned in detail. The scans are overlaid to define the extent of wear and identify areas that require rebuilding.
Even without original blueprints, we are able to reconstruct the original geometry using bucket stencils, cutting curves, and advanced CAD methods. A differential volume is calculated for welding, and a perfect 3D model is created for precise CNC milling.
Our in-house welding robot enables continuous, high-quality welds with unmatched consistency. After programming one bucket, the robot applies identical procedures to all others – resulting in uniformity, superior quality and shorter production times.
After welding, the runner undergoes surface treatment using a 5-axis CNC milling machine. This enables highly accurate material removal, not only to recreate the original geometry but also to correct design-related weak points. Final grinding and polishing enhance the surface finish, ensuring improved flow characteristics and increased long-term durability.
The final step includes crack inspections and root integrity tests, and high-precision balancing – ensuring the highest quality standards and - again - reliable long-term performance.
One of our recent success stories comes from a hydropower plant located in Austria, generating renewable energy since 1910. With three Pelton turbines in operation, the plant is a key contributor to regional electricity supply – and a landmark of engineering tradition.
When signs of significant wear were discovered on one of the three Pelton runners, the operator turned to Global Hydro for support.
Our team began by examining the runner in detail. The wear was more advanced than expected, especially along the cutting edges. Using high-resolution 3D scanning, we were able to understand how the runner had changed over time. This allowed us to rebuild only the parts that truly needed it – preserving as much of the original material as possible while ensuring a strong and efficient hydraulic profile. In this case, the main and secondary cutting edges were rebuilt by robotic welding, while the interiors of the buckets were left untouched and later polished. This method reduced costs and processing time, while keeping performance at the highest level.
Reverse engineering offers a smart alternative to the production of new runners, combining at least 50% shorter delivery times with substantial cost savings and longer turbine lifespans. By restoring worn components based on actual wear data – and often improving on the original geometry – it ensures long-term efficiency and reliability.
In many cases, operators go one step further by investing in replacement runners – not as a luxury, but as insurance. Having a second runner on hand helps avoid unexpected downtime and allows for scheduled maintenance without pressure.
To support this, Global Hydro also offers mobile 3D scanning directly at the plant site – ideal for preparing a replacement runner even before the original is taken out of service.
Beyond restoring damaged components.
At Global Hydro, reverse engineering goes beyond simply restoring damaged components. Our dedicated specialist team – combining hydraulic design expertise, precision machining and digital modeling – ensures that each repaired runner not only matches its original performance but often improves on it. Even when original design plans are unavailable, our state-of-the-art 3D scanning technology ensures that each runner is reconstructed with exceptional accuracy, allowing for targeted repairs rather than costly full replacements.
By utilizing cutting-edge technologies such as robotic welding, Global Hydro delivers solutions that combine industry-leading precision with faster turnaround times. With our fully integrated production and development center in Austria, operators can trust that each project is handled with the utmost quality and care, ensuring reliability and performance for years to come.
Full replacements are often expensive, time-consuming, and not required. At the same time, damage such as worn cutting edges, deformed bucket interiors, or surface erosion can significantly reduce turbine efficiency and operational reliability. These challenges are further compounded by missing original documentation – a common issue in aging hydropower plants with decades-old Pelton runners.
Global Hydro offers a comprehensive reverse engineering process – from detailed damage analysis and high-resolution 3D scanning to digital modeling, robotic welding, and precision CNC milling. Even without original drawings, the geometry is recreated with outstanding accuracy. Only the damaged areas are rebuilt, while intact sections are preserved and polished to restore smooth flow surfaces. Final inspections by our experts ensure long-term durability and reliability.
With reverse engineering, operators benefit from at least 50% shorter delivery times and substantial cost savings compared to new production. At the same time, turbine efficiency and longevity are improved thanks to precision-driven, selective restoration.
This approach preserves resources and reduces downtime – making reverse engineering a smart and sustainable strategy for long-term hydropower success.
Reverse engineering is no longer just a reactive tool – it’s a smart, forward-thinking strategy for sustainable hydropower operations. With cutting-edge technology and skilled specialists, even heavily worn-out runners can be restored to peak performance – or beyond.
Contact Global Hydro to explore how reverse engineering can maximize efficiency, reduce downtime, and extend the lifetime of your hydropower plant.
Roland Fleischmann
Sales Manager Revitalization
+43 (7285) 514 0055
roland.fleischmann@global-hydro.eu İletişim