A hydropower utility customer had a severely cracked gate shift ring, which is a critical component that opens and closes the wicket gate for turbine speed control. If this hydro component fails, the entire unit could not be shut down safely. Timing was also crucial, so any repair option had to be completed within the return-to-service deadline.  After exploring various options, fabrication was determined as the best solution. A new part from OEM would cost more and take much longer to procure. Western Machine Works reverse-engineered the part, starting with making measurements of all critical dimensions. Unfortunately, the existing drawing was unreliable, with several  dimensions missing. The design and manufacturing print were then generated. Fabrication was completed within the required timeline, while saving capital dollars and providing a new gate shift ring with long-term reliability.

Project:

• Part: Gate Shift Ring
• Customer: Public Utility (hydroelectric power and thermal) 

Challenge:

• Gate shift ring was cracked in several locations and likely to fail, preventing the safe shutdown of the unit.
• OEM drawings were poor and not all dimensions were provided.
• Required reverse engineering of existing part to determine critical dimensions.
• Shift ring needed to be rolled to match critical circumferential dimensions to ensure expected fit and smooth operation.

Engineered Solutions:

• Measurement of existing gate ring to determine critical dimensions.
• Design and initiate new CAD drawing for fabrication.
• Roll new gate ring to the specific circumference to ensure proper fit.
• Weld and machine new gate ring yokes and fabricate new pins.
• Fabricate and attach new bronze bearings to shift ring.
• Add approved protective epoxy coating that is compatible with water.

Result:

• New gate shift ring fit the head cover unit.
• Customer saved significant capital dollars by not ordering the part from OEM.
• Fabrication was completed within client’s return-to-service deadline and outage schedule.

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