2025 WTUI Recap: LM Engine Breakout Sessions

Contents

• 2026 Conference Overview: 35 Years of Powering Tomorrow
• WTUI Leadership: Foundation for Success
• 2025 WTUI Recap: LM Engine Breakout Sessions
• 2025 WTUI Recap: Special Technical Presentations
• Acronyms to remember for aeroderivative gas turbine equipment

Across WTUI 2025’s LM2500, LM6000, and LMS100 breakouts in Long Beach (March 30 to April 2, 2025), the technical conversation had converged on the same operating reality: outages and reliability outcomes had been driven as much by data quality, execution discipline, and supply chain constraints as by the underlying hardware.

Three common threads had surfaced repeatedly. First, contamination control and configuration control had remained the foundation for preventing repeat events, especially where bearings, variable geometry, and hot-section durability dominated the risk profile. Second, condition-based planning had continued to override “catalog intervals,” with borescope evidence and trending treated as the deciding inputs. Third, depot duration, parts lead times, and counter-history fidelity had increasingly shaped what owners could plan and defend, from spares strategy to life decisions and “as returned” accounting.

LM2500, GE Vernova

The LM2500 breakout sessions combined GE Vernova (GEV) fleet updates, an SPS ORAP® RAM review, user-only lessons learned, and third-party briefings on controls, depot services, fuel-system repairs, and insulation.

Discussions focused on unplanned engine removals, bearing contamination risk, compressor and hot-section life expectations, preservation for peaking or intermittent duty, and growing concern over repair turn times and parts support for package and controls hardware.

Session chair Josh Svejcar opened the first users-and-OEM block on Monday afternoon. GEV’s Nam Tran led the OEM segment with a safety moment, an agenda review, and introductions to product, field-service, fleet, and package engineering staff supporting the LM2500 and TM2500 fleets.

The session notes emphasized that the recap captured questions and discussion stimulated by presentations, and encouraged attendees to review posted slide decks for full technical detail.

Early questions focused on clarifying fleet definitions and product terminology.

GEV distinguished its electrical power generation fleet from Baker Hughes units supporting oil and gas applications, including power generation in that sector. Users asked about the “UPT,” which GEV described as a newer power turbine intended for power generation with G4 and G5 engines, with a larger diameter and higher output.

Package evolution came up quickly as well. Differences were discussed across generations, including older trailer-based layouts versus later configurations with top-mounted filtration and engine options.

Package experience and operating practices. GEV’s package team review covered common O&M themes and practical habits users said had improved condition awareness.

One site reported continuing operator rounds and manual gauge-reading documentation to build familiarity with the package, not just screen-based monitoring. Users discussed simple troubleshooting tools too, including handheld black lights used to trace oil leaks by fluorescence differences between fresh and aged oil.

For DLE fuel-gas characterization, GEV recommended using a chromatograph rather than a calorimeter when measuring gas composition for mapping.

For peaking-unit preservation, GEV suggested that a unit shut down for a month or more should have been started to full-speed, no-load, while shutdowns of less than 30 days did not require such a start. Users asked about preservation guidance for TM2500 packages, and GEV pointed to TP2200 as a practical guide for earlier generations, noting that later, generation-specific versions might follow. Heaters were described as a means to maintain temperatures above the dew point.

Unplanned engine removals. An extended discussion covered unplanned engine removals (UERs). Users described a range of recent UER experiences, including events attributed to bearings, power-turbine bearing failures, warped flanges, IGV bearing issues, a TMF collapse, and compressor blade or dovetail cracking findings.

GEV’s follow-on review of UER drivers stressed contamination control as the dominant bearing risk. In response to a question on event-type breakdowns, GEV said most bearing events had been tied to hard particle contamination, without offering a specific percentage. On early warning indicators, GEV said there had not been a reliable “telltale” sign ahead of failure.

Users asked about detection tools. GEV said it had not been aware of many MetalSCAN systems in power generation service and did not cite familiar examples of MetalSCAN-detected bearing failures in that segment, although a user noted experience with the system in oil and gas.

On monitoring strategy, GEV said it had no plans to add high-frequency vibration monitoring for bearing failures. The discussion highlighted practical limitations as well: sensor location and transfer functions reduced sensitivity to bearing distress, and earlier attempts to identify events via vibration had created false positives. Participants favored chip monitoring and analysis as a more reliable indicator.

Compressor and washing discussion. In compressor findings and preventive actions, GEV said hot-restart tip rub had been observed at the 4 o’clock and 8 o’clock positions, and noted that rub location depended on package cooling flow.

Users asked about “high time” engines after incorporation of VSV-related service bulletins. GEV said it did not know the high-time record but was not aware of issues after those bulletins were incorporated. A user recommended assigning a single competent person to approve FOD-zone cleanliness after maintenance.

Online water washing generated practical debate. GEV said a load limit had been used to prevent combustor blowout and recommended developing site-specific intervals based on borescope checks and experience, including trending ratios for baseload operation.

GEV said it had not seen an erosion risk from “too much” washing. Users countered that improved inlet filtration could reduce the need for washing, and some reported seeing limited efficiency benefit from online washes, preferring to trend efficiency in spreadsheets to guide cleaning decisions.

ORAP review and hot-section life expectations. SPS’s Bob Steele presented findings from the ORAP system, with the presentation available to participants on the WTUI user site.

GEV then continued the UER-driver review into combustion and hot-section events. Users raised controls-display needs, including the importance of showing fuel-to-water ratio for operators on certain package configurations.

Life and interval expectations triggered broader discussion. GEV described standard intervals of 25,000 hours for a hot section and 48,000 hours for an overhaul, with half intervals when operating on diesel oil, and cycle limits defined for critical parts only. GEV also explained that inspection intervals had been intended to indicate continued operability for the next interval after a successful borescope inspection, and that parts life depended on configuration and duty.

Users pushed back with mixed experience, ranging from hot-section parts falling well short of 25,000 hours at some sites to nearly 50,000 hours at others, with components such as VSV bushings driving decisions. Participants argued intervals should have been condition-based and said procurement and budgeting assumptions often treated 25,000 hours as a planning expectation, creating problems when life fell short. Users also raised concerns about cycle-limit notifications and depot “as returned” cycle accounting, and noted that k-factors for the cycle calculation had recently been included in the G4 O&M manual.

LM2500 users-only session

The users-only block focused on outage execution and verification practices. A user presentation on VSV bushing replacement and borescope inspection summarized practical lessons, including crane and rigging practices, taking advantage of engine-out access to replace the bellmouth seal, pre-ordering main engine mount bearings, and using alternative methods to suspend the engine and verify VSV settings when LVDTs were not available.

Discussion addressed HP recoup orifice practice as well. Users suggested keeping multiple orifice sizes on hand, increasing size cautiously one step at a time, and re-marking any orifice drilled to a new size. A third-party kit was mentioned as a workaround for measuring VSVs when LVDTs were not present.

Vendor qualification emerged as a theme after users described receiving an “OK to run” conclusion from a borescope performed with a nonconforming scope, followed by a later inspection that identified multiple holes in a combustor liner requiring changeout. Users discussed liner repair versus rotable replacement decisions and recommended inspecting rotables for cracks beyond the locations cited in the BSI manual.

Users also exchanged concerns about TM2500 Gen 8 package quality control and controls capability, citing overspeed events on startup and recommending verification of external overspeed settings. Several users described replacing certain control platforms with alternative systems. Additional package issues discussed included generator PMG weight liberation into the excitation system, ground-fault monitor reliability after heater-off conditions, and recurring transmitter failures that led some sites to switch transmitter brands.

Depot turn times, parts gaps. Depot turn times and communication quality drew sustained attention. Users cited cases where hot-section or engine work extended well beyond initial quotations, including assets remaining in depot for more than a year. One user said weekly status calls had improved progress visibility and sometimes helped move the process. Participants questioned whether service agreements had improved turn time and expressed concern over depot reporting cadence and content.

Hardware support gaps surfaced in separate user comments as well, including recurring air-oil separator hose failures on multiple G4 engines, reported oil loss rates, and limited OEM replacement parts availability, which prompted discussion of alternate sourcing options.

LM2500, third-party briefings

Wednesday’s open sessions included third-party updates tied to near-term maintenance logistics:

• Baker Hughes reviewed digital services and said iCenter had already been available to customers.
• Score Energy discussed fuel system and accessories repair, including nozzle repair locations, typical 3–4 week turn times, limited spare-nozzle availability during repairs, and a recommendation to align nozzle repair with broader engine repair events.
• PROENERGY discussed LM2500 work scope from a Level IV depot perspective and said it had offered field services and rotables beyond hot sections.
• Woodward reviewed controls products, obsolescence, and upgrade paths, including limits on testing older valves and stated support expectations for specific platforms beyond 2027.
• GE Aerospace reviewed life-limited parts methodology and the impact of partial-power operation and partial cycles. Users emphasized that incomplete cycle tracking increased conservatism and could force premature replacement of parts with remaining life, and they argued depots, OEMs, and operators needed aligned processes because “history cannot be recreated.”
• Arnold Group discussed insulation solutions, citing a typical six-month path from scanning to installation and noting limited LM2500-specific data on efficiency gain at the time of the session.

Food for thought. Three themes cut across OEM, SPS, user-only, and third-party segments:

1. Contamination control remained central to reducing bearing-driven UER risk, and participants viewed chip monitoring as more dependable than vibration signatures for early detection.
2. Interval planning remained contentious. Users pushed for condition-based expectations and clearer communication of cycle limits and return-from-depot cycle accounting.
3. Execution discipline, including vendor qualification, FOD-zone verification, and careful preservation practices, offered practical ways to reduce avoidable downtime in peaking and intermittent duty.

LM6000 breakouts

The LM6000 break-out sessions covered GEV fleet updates, SPS ORAP® RAM benchmarking, a user-only discussion on recurring problem areas, and an independent forum featuring third-party service and monitoring perspectives.

Across the three days, recurring themes included combustor configuration tradeoffs, HPC stage 3–5 blade and bushing wear drivers, the need for disciplined borescope documentation and counter tracking, and practical steps that reduced forced-outage exposure through spares, inspections, and preservation.

How the break-out was structured. Session chair Dave Fink opened the Monday OEM session, reviewed the anti-trust statement, and noted he would step down as LM6000 chair after six years, with Luis Sanchez named as the incoming chair. Tom Christiansen of SPS served as session secretary.

The session notes were organized chronologically and did not reproduce the engineering depth contained in the posted slide decks. Approved end users can contact Wayne Feragen, wferagen@wtui.com, for access.

LM6000, GEV

GEV’s Nasser Chraibi opened with a safety moment and fleet overview. John Heaton then reviewed completed and active engine programs, using “legacy” to describe PA to PF models and “growth” for PF+, PF1, PF2, PG, and PH models. The discussion distinguished PF1 from PF2 primarily by combustor type and emissions capability.

RQM SAC combustor experience and tuning sensitivities. The OEM review included Rich Quench Mix (RQM) experience for SAC units, with discussion of reduced water demand for NOx compliance and questions around turndown capability, CO performance, and the role of fuel-nozzle gasket and shim selection. One user reported higher CO than expected with RQM compared to Jet-RAD and RAD-RAD at that site, while GEV said its broader experience had shown lower CO.

HPC stage 3–5 blades and the SB 310 discussion. For legacy engines, GEV attributed stage 3–5 blade failures primarily to VSV off-schedule operation and edge-of-contact conditions linked to starts, cycles, and load reversals. SB 310 was discussed as a response to the edge-of-contact issue, and GEV emphasized VSV system checks aligned with borescope intervals.

For PF+ engines, the discussion reviewed multiple dovetail-related field events and an ongoing fleet root-cause effort that included GE Aerospace participation as an independent reviewer. GEV said it had been stocking blades and reiterated that blade design mixing within a stage had not been acceptable. Users discussed the practical reality that there had been no OEM-authorized field service and that support and quality responsibilities differed across providers.

Other hardware items. The OEM segment also highlighted items users were encouraged to stock or monitor, including 11th-stage check valves, T48 thermocouples, and variable-geometry (VG) pumps, with discussion of failure consequences and replacement expectations.

Package programs and safety. Package program topics were presented by Jurgen De Ceuster and covered several safety and reliability issues:

• GEV described an interlock design on certain Universal Gen 1 and Gen 2 packages that could have forced unsafe access during engine handling, and emphasized that no one should have climbed on an engine while it was suspended.
• The session addressed the need to respect fire suppression saturation time before opening enclosure doors, and GEV indicated manuals and letters would be aligned to avoid conflicting guidance. Cameras were being evaluated as part of a potential kit.
• Cycling duty was associated with cracking in certain exhauster diffuser and clamshell designs. A redesigned diffuser approach was discussed with a target increase in cycle capability, along with changes in repair welding practices.
• A flashover event was tied to condensation risk, prompting a change in recommended cubicle thermostat settings from 70°F to 90°F, with planned documentation updates.
• WHRU heat exchanger distress and glycol leak issues were discussed, with the notes indicating an OEM update addressed an undersized glycol tank concern raised by a user.

Field services and more. Wayne Romeo continued the GEV segment with a One Field Services update that included best practices and lessons learned, and he made a recruiting request for mechanically inclined candidates.

Chraibi reviewed GEV bulletins and letters and provided a hydrogen roadmap update. In response to user questions, the notes indicated demonstration units operated on hydrogen only for a few hours based on fuel availability, and the discussion included expected NOx and CO ranges.

Heaton discussed positive clearance control migration to legacy units, including a revised boot design and a recommended heat-shield approach intended to improve durability near the LPT.

LM6000, ORAP

Tom Christiansen presented ORAP results for the LM6000 fleet and described SPS as an independent third party that collected and analyzed owner-operator data across prime movers and industries. For LM engines, participation was sponsored by GEV for its customers, with the primary user burden described as data reporting.

Key ORAP points included:

• Participation for LM6000 was cited at 310 units, representing about 29% of the installed base.
• The reported duty-cycle split among reporting units was 30% baseload, 14% cycling, and 56% peaking.
• SPS reviewed standard availability and reliability metrics, plus forced outage incidents and hours by major system, including top contributors.
• SPS indicated ORAP can import NERC GADS .txt files and could generate those files from ORAP inputs as part of participation.
• On gas fuel valve events, a user asked for detail on control valves versus shut-off valves, and the notes recorded a split heavily weighted toward control valves.
• SPS noted it had collected control system type but did not consistently capture control system age, and it referenced prior studies indicating control upgrades reduced trips.

LM6000, users-only session

The user-only session covered recurring issues and peer practices:

• Users compared combustor distress patterns, including cracking, ignitor ferrule issues, and TBC spallation experiences across configurations and duty profiles. Several comments linked cracking to post-overhaul outcomes, and users compared gasket and shim selections as part of tuning.
• Users discussed an updated PF1 and PF2 thrust orifice spreadsheet and noted that PF1 and PF2 thrust balance logic differed materially from legacy engines.
• One user described a best practice of collecting all borescope videos and photos before the inspector left the site, rather than relying solely on the final written report.
• Users discussed premature HPT stage 1 wear at low-load operation, the introduction of new Carboloy pads via service bulletin, and the value of carrying spare blade sets.
• Users described connector and wiring practices, including connector cleaning and wiring replacement tied to engine-change events, to reduce intermittent VSV and VBV feedback issues.
• Users compared hour-to-start ratios and replacement expectations for S2 nozzle assemblies, with multiple viewpoints on what constituted a realistic planning interval.
• Multiple users described operating without the PCC manifold, with one noting a performance impact and differentiating the value of PCC between legacy and growth engines for casing life.
• Users discussed SPRINT nozzle test methods, replacement criteria, and the economics of replacing large quantities annually, including reference to a site-built test rig described in prior years.
• Users discussed lubrication system biological growth and noted it could be difficult to eliminate once established, reinforcing proactive oil management practices.
• One user recommended third-party borescope inspection before accepting engines, even when represented as new, based on damage found post-test cell.
• The chair recommended post-run walkdowns to spot changes, while another peer described foil-wrapping suspected leak areas to localize the source after operation.
• Users compared camera approaches ranging from rated systems to low-cost “expendable” strategies and retrofits into existing rated housings.

LM6000, third-party briefings

The Wednesday open forum included outside organizations and case-study style discussions:

• SISO Engineering discussed analytics capability, data handling, and the feasibility of adding “first out” capability to older control systems depending on platform constraints.
• GE Aerospace reviewed life-limited parts methodology and the impact of partial-power operation and partial cycles. Users emphasized that incomplete cycle tracking increased conservatism and could have forced premature replacement of parts with remaining life, and they argued depots, OEMs, and operators needed aligned processes because “history could not be recreated.”
• Wattbridge discussed monitoring insights and alarm strategy considerations using examples from field issues.
• Premium Plant Services described cleaning approaches and tooling intended to protect coatings and seals during cleaning processes, with discussion of exposure time and impacts.
• SCORE Energy discussed fuel nozzles and accessories, including typical rebuild turn times for VG pumps and HCUs and practical variability driven by part variants.
• Entrust discussed root cause analysis approaches and case studies relevant to LM equipment.

Points to Consider going forward.

1. Combustor performance and durability outcomes varied by configuration and site conditions, and the discussion reinforced that tuning details, including gasket and shim selections, influenced emissions and operability outcomes.
2. HPC stage 3–5 distress remained a fleet priority, with VSV health and edge-of-contact exposure repeatedly tied to blade outcomes and inspection practices.
3. ORAP participation continued to provide a benchmarking path for availability, reliability, and forced-outage drivers, but the value of the dataset depended on consistent reporting inputs, especially around controls-related event categorization and cycle history.
4. Users emphasized verification practices, including comprehensive borescope media capture, practical leak-finding methods, and disciplined spares strategies for recurring failure items.

LMS100 breakouts

The LMS100 break-out session an ORAP reliability review, GEV updates, and open user discussion aimed at turning fleet experience into practical maintenance and outage-planning decisions.

Session chair Jason King framed the break-out around user questions and peer exchange, with the goal of surfacing issues that affected real-world operation and maintenance planning.

LMS100, ORAP

SPS’s Sal DellaVilla used the ORAP dataset to review current and historical RAM experience for LMS100 units whose owners reported to ORAP. SPS and GEV reviewed findings ahead of WTUI to align key parameters.

Several clarifications affected how attendees interpreted the KPI plots:

• Scope of RAM metrics. The RAM parameters discussed applied to the simple-cycle plant, including the GEV package and associated station equipment or balance of plant.
• Aggregation across duty cycles. The metrics pooled all reported duty cycles, which reduced the influence of high duty-cycle units with longer mission time. SPS indicated it was considering KPI views by duty cycle for a future WTUI meeting.
• Trend line discussion. The ORAP pages shown during the session indicated RAM performance had trended downward since 2021.
• Downtime contributors. Major contributors to downtime were summarized on an incidents basis and a downtime-hours basis. SPS said it planned to revise these views to make component sources of downtime more actionable.
• Data process improvement. SPS noted interest in a future ORAP-focused session on data reporting and collection, including the value of the Equipment Breakdown Structure (EBS) and how ORAP differed from other reporting systems.

LMS100, GEV

Supply chain and parts strategy. GEV’s Tim Schneck described organizational changes among GEV, Baker Hughes, the Aero JV, and GE Aerospace that were intended to broaden access to parts inventory while keeping GEV Aero Services as the primary supply channel.

In the parts update, Greg Dickey outlined a strategy aimed at keeping assets running, including a push toward a more “unconstrained” global supply chain approach. GEV also described steps to expand inventory availability and said it planned to add overhauled parts in 2025 as an additional path to increase coverage.

Users raised specific pain points that shaped the discussion:

• Turbine parts lead times varied widely, with some items extending into multi-year horizons.
• Users cited gaps for specific components, including NOx water pumps, and characterized certain items as single-source with long lead times.
• Users also questioned Service Bulletin execution material availability and consistency.

Controls and counting cycles. Counter tracking emerged as both a technical and commercial concern because it affected rotable life decisions, shop planning, and risk. GEV said a controls change intended to help with counter tracking was expected to be available in 2025.

Users also pressed for better counter history fidelity for rotables and clearer alignment between actual rotable condition, applied duty, and tracked counters.

Repairs and life-extension work With limited availability of some new replacement parts, GEV described assessing industrialization of selected repairs and evaluating the potential to open operational and life limits where technically justified.

Examples discussed included frame and tube hardware, compressor blade sets planned for 2025 availability, and an IPT cooling manifold. The expected results were described on a 2026 to 2027 timeline for some items.

GEV also described service-support needs under consideration, including outage forecasting customization, repair capability expansion, and efforts to reduce turnaround time.

Pricing concerns and planning signals. Users raised concerns about escalations in new-part pricing, including examples of large increases. GEV said scarcity was not driving pricing and committed to reviewing cases where users saw significant escalation. Users also emphasized planning practices such as risk-buy analyses and using ORAP data to support spares and outage planning decisions.

Reliability and enhancements. GEV’s Karen Kornuta presented RAM KPI results as median values, meaning half the fleet was at or above the reported value and half was at or below it.

The reliability enhancement discussion included hot-section durability topics, with an emphasis on following recommended maintenance and replacement intervals for affected components. On the IPT, the discussion referenced field-change hardware, a planned improved fix to increase cooling air to S2N, and interest in user evaluation sets, with new hardware availability discussed on a longer-term timeline.

LMS100, end-user session

In the user-only session, consultant Dave Brownell summarized themes from long experience with the LMS100 platform and emphasized a “trust, but verify” approach to maintenance execution.

User-facing practices that were reinforced included:

• Reference control. Users described verifying that manuals and GEKs were current through the OEM portal.
• Borescope (BS) plug inspections and spares. Users discussed increasing instances of stuck or difficult-to-remove BS plugs and the risk of losing future borescope access. The discussion emphasized correct plug selection and installation details, plus documenting plug condition with photos in borescope reports.
• FOD and DOD awareness. Users discussed installation details and housekeeping steps intended to reduce the risk of loose hardware becoming foreign object debris.
• Flow-path health and cleanliness. Users emphasized recurring borescope inspection discipline and water washing ahead of BSI to support effective maintenance.
• External inspections and small-parts readiness. Users highlighted field inspection focus areas and the value of keeping certain spares available on site.
• Counter discipline. Users reinforced tracking cycles for life-limited parts and reporting counter values at the unit, module, and rotable level to improve planning and data fidelity across the fleet.

Operational considerations for LMS100 users. Several near-term actions appeared to have broad support across users and the OEM:

1. Counter tracking should be treated as a reliability input, not an administrative task. When counter data was incomplete, rotable risk increased and life decisions became harder to defend.
2. Outage scope and spares planning need to account for long lead times and obsolescence risk. Users described parts that fell into long lead-time categories and raised concerns about obsolescence for some controls and electrical items.
3. Fleet RAM trends should be translated into component-level work lists. Users signaled that KPI views were most valuable when they directly informed outage scope and spares strategy.
4. Inspection discipline protected future maintenance options. The BS plug discussion reinforced how small installation details could remove diagnostic capability and increase forced-outage risk.

Reflection points to consider for WTUI 2026

1. Contamination and configuration control remained the simplest high-leverage reliability actions. Bearing outcomes, variable geometry health, and combustor and compressor durability had repeatedly traced back to what entered the machine and how it was set up and operated.
2. Condition evidence carries more weight than interval language. Borescope findings, trending, and documented history had driven planning scope, especially where “standard intervals” did not match site results.
3. Counters and event categorization has become planning infrastructure. Incomplete history and inconsistent categorization had increased conservatism, created disagreement, and could have forced premature replacement decisions.
4. Depot and supply chain constraints shape outage strategy. Lead times, depot duration variability, and communication quality had influenced risk buys, spares coverage, and how early owners had to commit to scope.