When a critical aerator gear unit failed, Orange County (Florida) Utilities faced a 24-week OEM lead time, no dimensional drawings, and an increasing risk to treatment reliability and regulatory compliance. Because aeration is essential to continuous biological treatment, the replacement strategy had to restore operation quickly while avoiding the added cost, installation complexity, and downtime associated with structural rework.
The challenge
The issue went beyond lead time. Without dimensional drawings for the original gearbox or coupling, a conventional replacement would likely not have matched the existing footprint and interface geometry. This mismatch would have increased the need for structural rework to the foundation, mounting arrangement, and coupling components. For the plant operators and engineers responsible for keeping the system online, the replacement had to be engineered with the existing installation rather than forcing structural rework to accommodate the new unit.
Developing a solution
To develop a replacement that would match the existing aeration drive installation, SEW-EURODRIVE engineers performed an on-site 3D scan and precision measurement of the original system. Using that data, the team reverse-engineered a complete solution, including a custom baseplate matched to the existing foundation and a custom low-speed coupling half designed for the installed interface geometry. This engineering approach made it possible to deliver a replacement package that fits the application without requiring structural changes in the field.
Installed solution and results
Assembled at SEW-EURODRIVE’s U.S. Heavy Industry Gearing Assembly Center in Wellford, South Carolina, the reverse-engineered replacement reduced lead time from 24 weeks to 14 weeks. For plant personnel, that meant a faster change-out, fewer installation variables, and a more predictable startup. After delivery, the entire system was returned to operation in less than one day.
The installed solution was a SEW-EURODRIVE parallel-shaft mixer gearbox (model X3FS200/HU/B) rated for more than 448 hp, with a 32.13 ratio and 37 rpm output speed.
For wastewater treatment facilities managing aging assets or limited legacy drawings, this project highlights the value of a replacement strategy built around application-specific engineering and installation readiness. In this case, Orange County Utilities received a solution 10 weeks faster than the OEM timeline, with zero structural modifications required.
Beyond restoring operation quickly, the solution delivered:
- Improved efficiency
- Reduced total cost of ownership
- Full engineering support from design through commissioning
For operators, maintenance teams, and engineers evaluating replacement options for critical process equipment, this project demonstrates how reverse engineering and U.S.-based assembly can help reduce replacement risk, simplify installation, and accelerate return to service.
