Sourcing gas turbine parts. Dealing with long lead times on gas turbine parts. Finding experts to install gas turbine parts.
These were the hot topics of conversation among power plant operators attending the 2024 AOG Users Group Conference in Savannah, Georgia. That’s why I was glad to be there with Chris Bailey, Plant Manager of InterGen’s Rocksavage Power Station, to present an update on the groundbreaking GT26 rebuild with used parts that we executed in 2022.
As Chris and I shared with AOG attendees, the GT is still going strong and the repair has exceeded expectations.
First, a little background: at 10:36 p.m. on May 21, 2022, Rocksavage’s Gas Turbine B (GTB) was nearing the end of its run cycle when high-temperature alarms began to go off. Twelve minutes from the initial alarm, the turbine was shut down. Borescope inspections revealed that the entire bottom half of the EV combustion section would have to be replaced. There was also significant damage across the turbine itself.
The OEM told Rocksavage it would take at least 46 to 48 weeks to provide the necessary new or refurbished parts. Neither plant leadership nor its insurers liked the idea of keeping GTB unavailable for nearly a year. They asked the OEM: Did they know of any other solutions? “The answer was: No, wait for the parts,” Bailey said.
That’s when the Rocksavage team and ST Power Services set out to devise a novel solution: gather used GT26 parts from Dock Sud in Argentina, repair them on-site, and rebuild GTB.
We had to go through a lot of due diligence and overcome many challenges to make it work. But to us, it wasn’t acceptable to leave the GTB essentially dead in the water for 46+ weeks.
Every step of the way through the rebuild, we kept asking the question: Are we doing the right thing? We were confident that we were, because of the expertise that we had. When we started making phone calls, we found people out there with expertise and knowledge that were far beyond the OEM’s capability. Every time that there was a problem, we stopped. We thought about it, we fixed it, and we kept going.
There are some risks with installing used parts, because these components have undergone thermal stresses during operation. But the assessment showed these components had enough service life left to reliably run for 18 months till scheduled C-inspection in CY2024.
Rocksavage has now run GTB, with its refurbished parts, for 16 months and 150 starts — 50% higher than what the OEM told us we could do. In that time, the plant saw a 96% starting reliability. None of the failed starts were due to GTB. “We were quite surprised with that,” Bailey said.
As part of a planned outage, we opened the machine up in April 2024. We were pleasantly surprised with the condition of the repaired Doc Sud parts installed in GTB EV Combustor.
The main obstacle to using used / repaired GT parts isn’t a technical challenge. Rather, it’s simply finding the right parts. Operators struggle to find not only large structural parts, but components as simple as thermo couples or valves — anything that would shut down the unit if the failed part(s) is not readily available.
Most gas turbine users have some level of inventory of spare parts, but plant A doesn’t know what plant B has. That’s why we’re working with thermal generation plants worldwide to establish a marketplace where users can help each other out with components. Stay tuned for more news on that front… and if you’re struggling with parts sourcing and long lead times, contact ST Power Services for innovative, pragmatic, and collaborative solutions.
Then connect with us to start the conversation.
