The gas turbine bubble of 2000 to 2004 saw between 600 and 700 GE installed across the U.S., with approximately 900 7EA units in operation worldwide. Two decades later, those units are converging on a common problem: rotor end-of-life. With the fleet facing a 144,000-hour, 5,000-start threshold set by the original equipment manufacturer (OEM), and with superalloy forging lead times stretching into years, the math presents a supply chain challenge that no single provider can solve alone.

MD&A, a Mitsubishi-owned company historically focused on steam turbines, recognized this convergence early. Beginning in the early 2010s under then-CEO John Vanderhoef, the company made a strategic pivot toward gas turbines, targeting the 7FA and 7EA frames specifically because of the sheer volume of installed units.

“When you want to get into a new industry, you focus on what investment to make based on what opportunities are out there,” said Dave Fernandes, MD&A’s Gas Turbine Program Manager. “The 7FA, and additionally the 7EA, were the two units of focus based on the sheer number of opportunities out there.”

Starting from Zero Hours

The foundation of MD&A’s reverse engineering effort was the acquisition of a 7FA.03 gas turbine & 7EA gas turbine, both of which had never been fired. Kevin Roy, MD&A’s Principal Engineer, Parts, who led much of the reverse engineering work, explained why zero-hour components were essential.

“You need something that is exactly as it was produced,” Roy said. “Those parts having not run, they’re exactly as they left the machine shop and left the factory. You don’t want to have to worry about how parts have worn over time or if they’ve deformed, trying to back into what it could have been.”

The reverse engineering process involved far more than dimensional scanning. Teams employed a combination of hand tools, coordinate measuring machines (CMM), and blue light scanning to capture geometry. But critical characteristics like coatings, shot peening, and surface finishes required hands-on expertise that no laser could provide.

“It takes a lot of expertise and experience to understand what a coated part looks like versus a shot-peened part, what surface finishes are—all things that you’re not going to get from a laser scan or from a CMM measurement,” Roy noted.

Material characterization came from separate used components that could be destructively tested, while the unfired parts provided pristine geometric references. MD&A’s parent company provided metallurgical support and testing capabilities that proved essential during the development phase.

Building a Global Supply Chain

Creating detailed production drawings was only the first step. MD&A then had to identify vendors worldwide capable of producing forgings and machining the high-temperature alloys used in turbine sections to the required tolerances and surface finishes.

“This is very niche capability within the world,” Roy said. “We had to search the globe for vendors that were capable.”

The company evaluated both internal resources and external suppliers, optimizing the supply chain for quality rather than convenience. MD&A continues to expand its vendor network to provide redundancy for critical components.

Quality control operates on multiple levels. First-article inspections received intense scrutiny, but that rigor extends to ongoing production. Jason Wheeler, MD&A’s Gas Turbine Rotor Repairs General Manager, described the verification process. “We lean on our vendors that we’ve gained this experience and relationship with, but then we also check the parts when they show up in the shop,” Wheeler said. “We’re probably providing more scrutiny than these vendors might be doing for other similar parts. We’re pushing quality as high as possible.”

The Seed Rotor Strategy

MD&A’s approach centers on minimizing customer downtime through a seed rotor exchange program, a model the company already operates successfully for 7FH2 generators. Rather than having customers wait while their rotor undergoes inspection and refurbishment, MD&A aims to maintain ready-to-install rotors that can be exchanged, limiting outages to the time required for removal and reinstallation.

“The downtime for customers that come our way for rotor life extensions only involves disassembly, putting the turbine on a half shell, removing the rotor, putting it on stands, taking the rotor that we’re providing, putting it into the unit, reassembly, and startup,” Fernandes explained.

The returned rotor then enters MD&A’s refurbishment cycle, eventually becoming available for the next customer. Recognizing that lead times can stretch for years, the company maintains strategic inventory of the components most frequently replaced during life extensions.

The Convergence Problem

The urgency for operators to plan ahead stems from a convergence of factors. Between 800 and 900 7FA units in MD&A’s target market are approaching or have reached their rotor life limits within roughly the same timeframe. The superalloy forgings needed for life extension carry multi-year lead times. And only a handful of facilities worldwide have the specialized equipment and capabilities to service these large gas turbines.

“The number of units, coupled with the long-lead-time parts, coupled with limited shop space in the world are the three prongs which should give customers some angst and make it a high priority to get out in front of their rotor life extension needs,” Fernandes said.

The situation is compounded by the data center boom driving increased utilization of existing gas turbine assets. Units that operators might have expected to run intermittently are now logging hours at higher rates, accelerating the timeline to end-of-life thresholds.

Wheeler emphasized that customers who wait for a forced outage to address rotor issues face the worst outcomes. Added Roy, “If you know you need a rotor in three to five years, it starts getting built today. These are not parts that get built in a week. These are parts that take multiple years to be produced.”

Proving the Concept

MD&A has completed several 7FA & 7EA rotor end-of-life inspections and refurbishments, but the 7FA.03 rotor currently in the St. Louis shop represents a milestone. It’s the first 7FA.03 rotor purchased specifically for the company’s seed rotor program to go through the full production cycle with newly manufactured MD&A components integrated alongside serviceable original parts.

“There’s a fear that what you’ve done over the past 10 years is not going to line up, not going to be correct, not going to mate up to old-run mating components,” Wheeler acknowledged. “On the rotor that’s stacked right now, there are a couple of new wheels intermixed in the middle of a compressor with a bunch of old wheels. They mated up to the old wheels perfectly—as expected and designed.”

MD&A has delivered a life-extended 7FA.03 rotor to a leading power producer in 2026. In a highly risk-averse power generation market, a major owner’s decision to partner with MD&A and move forward with this deployment underscores strong confidence in both the 7FA Rotor Life Extension program and MD&A’s ability to execute it end-to-end.

The successful integration validates MD&A’s decade-long investment and positions the company to offer utilities an alternative path for extending the life of their 7FA & 7EA fleet, one that doesn’t depend solely on OEM capacity and timelines. For operators running 7FA & 7EA gas turbines beyond their original design life, the message from MD&A is clear: the time to plan is now, because the forgings needed three years from now need to enter production today.

The post MD&A Positions Itself as Alternative Source for 7FA & 7EA Gas Turbine Rotors appeared first on MDA Turbines.

In the power generation industry, reliability and efficiency are paramount. Gas turbines, such as the 7FA series, are critical assets for utilities, and their performance directly impacts grid stability and profitability. Periodic major inspections are essential to ensure these machines operate within OEM specifications and maintain compliance with environmental and safety standards.

For this combined project, MD&A provided all tooling, supervision and labor to perform the outage work scope.

• 7FA Gas Turbine Overhaul: Complete disassembly of the compressor, combustion, and turbine sections for inspection and refurbishment.
• 7FH2 Generator Inspection: Disassembly and electrical testing of the 7FH2 generator, including stator and field assessments.
• Technical Information Letters (TILs): All TILs were completed.

As part of the outage, the inlet filter house and ducting were visually inspected internally down to the inlet plenum and confirmed to be in sound operating condition.

A customer-supplied, refurbished gas turbine rotor would be installed after MD&A inspection.

Arrival

Once onsite, tooling preparation and disassembly began, working two shifts. All as-found clearances were measured, and initial alignment checks were completed.

Turbine compartment scaffolding and field stands were installed, and preparations were made for removal of both the gas turbine rotor and the generator field.

Throughout disassembly, all reusable materials were identified, stored, and prepared for reuse.

7FA Gas Turbine

Following turbine casing and bearing removal, compressor component inspection and repairs began. Inlet guide vanes (IGVs) were inspected and would be returned to service. IGV inner bushings and spring/thrust washers were replaced. Bearings were replaced as needed.

Oil deflectors and seals were prepared for shipping to MD&A Bearings, Seals and Hydraulics Division in Ohio for inspection and repair. New seals would be required.

Stator compressor blades S1-4 and S5-8 were worn and replaced. Several rows exhibited foreign object damage (FOD) and casing pinch marks, requiring precision blending and vane replacement.

For the combustion section, chamber components revealed wear and coating damage. MD&A experts replaced the following with either new or refurbished parts: liners, flow sleeves, crossfire tubes and retainers, liner caps, FWD cans, TP bull horns and transition pieces. Check valves were also replaced. Fuel nozzles were swapped and flow-tested to ensure proper atomization.

For the hot gas path, First-, second-, and third-stage buckets and nozzles were installed with concentricity and clearance checks verified against OEM tolerances. For the exhaust, flex seals were replaced with new pins installed, and the diffuser was weld-repaired.

A new Bearing T1 was replaced. T3 and T4 bearings were also transported to MD&A Bearings, Seals and Hydraulics division in Ohio, refurbished, returned, and reinstalled. The T1 thrust journal was also replaced.

Degraded gaskets were replaced in the discharge casing, and the casing received blend repairs.

7FH2 Generator

At project start, generator shaft jacking devices and eyebrows were installed. Our team constructed our generator field support platform to allow for easy removal of the field when performing this 7FH2 Generator Major Inspection.

This system addresses the unique challenges associated with the 7FA/7FH2 configuration:

1. The shaft centerline height is 13 feet above machine baseline (grade)
2. The gas turbine inlet ducting and filter house limit crane access.

MD&A’s team removed the turning gear and disassembled the journal bearings, and shipped them to MD&A Bearings, Seals and Hydraulics division in Ohio for refurbishment. Oil deflectors and hydrogen seals were also prepared for shipment.

After end shield and fan blade removal, MD&A experts removed the generator field for covered storage on the turbine deck. The field was inspected, and field windings were found to be clean.

The generator end shields and gas shields were inspected, cleaned, and returned to service.

MD&A performed high-resolution borescope visual inspection of normally inaccessible areas on the generator, outside of the bore region. These areas include under the collector and turbine end retaining rings and the stator end windings, field coil end turns, auxiliary components and stator terminal connections.

The generator stator received visual inspection, insulation resistance testing, winding resistance measurements, DC leakage and RTD tests, and wedge inspection. The field received visual inspection, insulation resistance testing, winding resistance and impedance tests, and turn-to-turn pole balance.

T3 and T4 H2 casings were removed, visually inspected and sent to MD&A Bearings, Seals and Hydraulics division for further inspection and repair. New seals would be installed with refurbished casings.

New T3 and T4 lift oil lines were installed.

Stator testing revealed that more than one-third of the wedges were loose and/or hollow. MD&A experts therefore performed a complete rewedge on the generator stator. A full stator wedge tightness survey map followed.

The new turning gear was installed and aligned, followed by the hydrogen leak check. The gas turbine/generator load coupling was aligned to OEM specifications.

Rewedge on the Generator Stator

Completed Stator: New Rewedge, Painted

Startup

Precision alignment was critical to minimize vibration and extend component life. Rim/face checks were performed and coupling bolts were replaced.

The unit was started on schedule and tuned with no issues.

Long-term recommendations to increase owner/operator confidence in continued operation included monitoring of the T3 area, ongoing inspections of variable inlet guide vanes, filter house visual and mechanical checks (with specific details), water washing frequency, and monitoring CDC (compressor discharge casing) slip issues.

MD&A’s multi-divisional team of experienced technicians and product experts successfully completed the GE 7FA gas turbine major inspection and 7FH2 generator major inspection on schedule. The project demonstrated MD&A’s ability to coordinate cross-divisional resources and execute complex inspection and repair scopes. Detailed recommendations were also provided to support long-term reliability, giving the customer assurance of a well-executed outage and confidence in future full-service operations.

For service of any generator regardless of original design, contact the premier non-OEM service provider to the global turbine-generator market. Call us at (518) 399-3616 today or use our contact form.

The post 7FA Gas Turbine and 7FH2 Generator Major Inspections appeared first on MDA Turbines.

MD&A has an inventory of new or refurbished generator fields in our field exchange fleet, featuring the latest in rewind technologies. Additionally, we have stator rewind kits with stator bars available in stock, ready to support planned or forced outages.

Disassembly and Component Inspection

MD&A’s experts disassembled the generator and inspected critical components in the process.

Our team conducted visual and non-destructive examinations (NDE) on the load coupling Riverhawk bolting. No indications were found – all components successfully passed VT and UT requirements before being returned to service. The unit’s generator bearings were also inspected dimensionally and visually by our technicians before being sent to MD&A’s Bearing, Sealing and Hydraulics Division for refurbishment and sizing to ensure proper fit for the new field journals.

Rotor fan blades were removed, hand-cleaned, and subjected to NDE and visual inspection before being returned to service with new locktabs during the final installation. Hydrogen seal components were also examined, with MD&A providing new seals properly sized to the refurbished rotor configuration and lapped to the refurbished gland specifications.

Our technicians sent the H2 gland seals to MD&A’s Bearing, Sealing and Hydraulics Division for segment replacement and housing refurbishment. Oil deflectors were  modified for insertable teeth design before being reinstalled and aligned to shaft specifications. In addition, our experts removed and replaced the old seal carrier.

Stator Rewind

During this planned outage, MD&A’s team performed a full stator rewind. Our onsite experts performed baseline and post-disassembly ELCID testing to assess stator core iron integrity, with all results indicating acceptable lamination condition. The existing opposing wedge system was then removed by the team.

Our personnel removed series loop connections, circuit ring connections, and top and bottom bars. Core compression flange nuts underwent breakaway torque verification. Several nuts were found to be well below OEM specifications. Our team cleaned the mating surfaces and retorqued all nuts.  Following core tightening, the belly bands were tightened with new shim packs installed.

New 7FH2 bars were installed with proper alignment verification. Our technicians completed electrical testing, which included hi-pot tests at specified voltages, with all phases achieving resistance results within target ranges.

Impressively, this all was completed within 21 days. MD&A has a consistent track record of handling rewinds of this complexity, including core and belly band tightening, within the same timeframe.

Field Spare Rewind

Our team also conducted a field rewind on the 7FH2 generator field. Our technicians disassembled the unit, which included removal of the bore copper and collector rings. The field forging underwent media blasting and comprehensive non-destructive examination (NDE), including magnetic particle testing on the field body and penetrant testing on wedges and retaining rings. All NDE results were satisfactory.

During reassembly, our generator experts installed newly insulated bore copper, main lead studs, and coil components in a controlled, clean room environment. Each coil underwent individual electrical testing before installation and clamping. The field completed a successful bake cycle during which the coils were compressed to their specified diameter via bake clamps.

Throughout the rewind process, MD&A’s engineers performed thorough electrical testing. These tests included: insulation resistance, polarization index, AC impedance, winding resistance, as well as repetitive surge oscillation (RSO), turn-to-turn testing, pole balance, and AC hi-pot. Once fully wound, the field was then high-speed balanced, which included a heat run before the unit was staked, painted, and wrapped for storage.

Reassembly and Alignment

The arrival of the refurbished generator field marked a pivotal moment in the outage. Our team constructed our generator field support platform to allow for easy install of the field. This system addresses the unique challenges associated with the 7FA/7FH2 configuration: 1) the shaft centerline height is 13 feet above machine baseline (grade), and 2) the gas turbine inlet ducting and filter house limit crane access.

During reassembly, MD&A’s technicians performed a 16-point turbine-to-generator alignment. The stator was repositioned to meet OEM specifications. The newly rewound replacement field was then carefully set into place, followed by the installation of lower half bearings with precise tilt and twist measurements recorded.

All of the generator’s systems were returned to service with proper clearances and operational parameters verified.

Conclusion

This multi-faceted scope, including a 7FH2 generator field replacement and full stator rewind, demonstrates the technical complexity and precision required for successful power generation equipment maintenance.

The project required specialized expertise across multiple disciplines. Our ability to coordinate these complex activities with our expert knowledge of OEM specifications and decades of field-proven success exemplifies why power generation customers worldwide rely on MD&A to keep their assets operating reliably.

Call us at +1 (314) 880-3000 today or use our contact form.

The post 7FH2 Generator Field Replacement with Stator Rewind appeared first on MDA Turbines.

MD&A specializes in servicing E- and F-class gas turbine rotors.

To provide the best solutions for your gas turbine rotor, MD&A will evaluate your specific needs in addition to assessing rotor inspections.

Learn more from Dave Fernandes, MD&A’s Gas Turbine Program Manager, & Spencer Hamilton, MD&A’s Gas Turbine Services Sales Director in the following Q&A:

1. 1. In the early 2000s the US gas turbine market saw a significant boom, often referred to as a «bubble.” – what is the bubble?
      

      The «bubble» refers to the surge in new gas turbine–based power plant expansion in the United States. It was driven primarily by shrinking power reserve margins, relatively low natural gas prices, and power market deregulation.

   2. What did that mean for GE® sales & installs at the time?
      

      GE’s production of gas turbines rose dramatically—from a capacity of about 80 machines per year in 1998, to 180 in 1999, and 240 in 2000. The majority of these sales were the GE 7FA gas turbine.

   3. Fast forward, what does that mean for these gas turbines for their remaining life? Why is it important to look at?
      

      A large percentage of the 7FA installed base came from the 1998–2001 bubble. Many of these units are now approaching their rotor end-of-life, as outlined by the OEM: 144,000 fired factored hours (FFH) or 5,000 fired factored starts (FFS).

      Operating profiles vary, but some combined cycle units can accumulate more than 7,000 fired factored hours in a single year.

      As a result, many bubble-era units—especially base-loaded combined cycle plants—are nearing their end-of-life limits.

   4. What role do these aging assets currently play in our overall energy mix, and how critical are they to grid reliability?
      

      Thanks to their favorable heat rate (efficiency) and lower emissions compared with many other fossil fuel plants, 7FA combined cycle units form one of the backbones of the U.S. power grid. In addition, simple-cycle 7FA and 7EA units play an essential role in supporting peak load demand and grid stability.

   5. Are all 7FA rotors the same?
      

      No. The early 7F models, known as 7F.01 and 7FA.02, have significant design differences compared with later models (7FA.03 and beyond). Most of the turbines installed during the bubble were the 7FA.03, which remains widespread today, along with the 7FA.04. There are no major differences between the 7FA.03 and 7FA.04 rotors. The difference between a 7FA.03 and 7FA.04 gas turbine is associated with the combustion and hot gas path parts.

   6. With the high demand for new manufacturing impacting the industry & other items, Why should customers be thinking now about their rotor for next 3-5 years? Why the urgency? 
      

      Planning ahead is critical due to supply chain constraints. Forging houses that produce gas turbine components also serve the aerospace and defense industries, all of which are experiencing simultaneous surges in demand. This results in longer and less predictable lead times.

      Shop capacity is also strained, with limited space and workforce available to handle the growing number of gas turbines nearing rotor end-of-life. Securing both parts and shop availability early is essential to keeping these valuable assets running.

   7. Is there increasing difficulty or expense in sourcing parts and technical expertise for these aging turbine models? 
      

      Yes. Supply chain challenges have driven costs higher, while shifting tariff policies add further unpredictability to the price of key components.

      In addition, OEM technical expertise often shifts toward supporting newer product lines—particularly as the latest “bubble” of gas turbine development has emerged, with the H-class leading new unit sales.

      In contrast, MD&A remains committed to legacy assets, continuing to prioritize support for the 7FA, 7EA, and 7B fleets for years to come.

With changes in the industry, growth and the bubble, you should be thinking now for next 3-5 years!

A Rotor Life Assessment & Extension service can help decide if component repair, replacement, or use is the best option for your gas turbine rotor to meet operational and maintenance forecasts.

Want to learn more? Watch our Video!

Or Secure a spot to our Rotor Life Extension webinar

The post The Clock Is Ticking On 7FA And 7EA Gas Turbine Rotors: Is Your Fleet Prepared? appeared first on MDA Turbines.

MD&A provided all project management, inspection and analysis, supervision, labor and tooling for the owner’s dual-unit work scope.

During disassembly of the first unit, MD&A Gas Turbine Services personnel first removed roof sections, recorded thrust and lift checks, removed all relevant casings, and labeled/removed relevant piping/hoses. Half shell readings were taken on the turbine and compressor by recording all rotor and stator tip clearances.

The service run 7FA.04 hot gas path components were inspected and analyzed onsite by specialists from MD&A’s San Antonio Service Center to determine the potential for future component repairs. Our team has extensive knowledge on a range of gas turbine component repairs, including weld repair, blending, dimensional restoration, and machining. They can extend the service life of gas turbine components whose OEM service limit has passed or whose configuration is no longer suitable to operate. These experts provided feedback on the component repairability.

For these outages, the turbines’ first, second, and third stage buckets were removed and replaced with Customer provided components.

Additionally, nozzles and shrouds were removed and exchanged. For the compressor, stage 14 through EGV’s stator vanes were removed; new vanes were drilled and pinned upon installation.

MD&A inspected T1 and T2 bearings and determined replacements were required, in addition to new thrust bearings.

All combustion components were removed and inspected. Transition pieces, liners, flow sleeves, outer bellows, inner crossfire tubes and fuel nozzles were exchanged during reassembly.

The GE® 7FH2 generator was disassembled, including coolers, oil deflectors, gas shields and bearings. Hydrogen casings and seals were removed and sent to MD&A’s Bearings, Seals and Hydraulics Division in Euclid, Ohio for refurbishment.

The generator field was then removed and transported to our Turbine-Generator Repair Facility in St. Louis, MO for a complete field rewind utilizing the existing copper. The rewind process was expedited to allow for the rewound field to be installed in the sister unit. A spare generator field from the Customer’s inventory was installed on the first unit, to support the expedited outage schedule.

MD&A experts inspected the generator stator and found areas of greasing indicated a loose wedge structure and necessitating a full stator rewedge. Core and bellyband tightening was also required.

Stator electrical testing was completed, and electromagnetic core imperfection detections (ELCID) tests were conducted before and after wedge replacement.

MD&A’s Generator Experts replaced the wedges, then completed bellyband and core tightening. With the stator repairs complete, the generator field from owner/operator’s inventory was able to be installed.

During component reassembly, new hydrogen seals and springs provided by MD&A’s Bearings, Seals and Hydraulics facility were utilized.

Following reassembly of the gas turbines and generators, coupling alignments were performed by MD&A technical experts in full collaboration with the Owner/Operator.

MD&A’s Turbine and Generator Controls Division performed a complete inspection of the exciter and inverter equipment, ensuring no issues on return to service. Startup was completed with no operational concerns and full compliance with emissions standards.

Following execution of the first outage, MD&A personnel shifted focus to the sister unit, to complete a nearly identical work scope.

For this unit, turbine first, second, and third stage buckets were replaced as were nozzles and shrouds.

A spare Customer provided Gas Turbine rotor was installed after conducting green rotor inspections and repairs. At startup the green rotor run-in was completed in compliance with industry standards.

As with other unit, all Technical Information Letters were listed as completed, as were all Extra Work Authorizations.

For this unit, the service run generator field was removed for transport to our Turbine-Generator Repair Facility for a complete field rewind utilizing the existing copper. This field would be rewound and returned to Customer after the outage to be held as inventory.

Conclusion

Throughout these major overhauls on two 7F.04 Gas Turbines and 7FH2 Generators, detailed daily written and visual (photographic) job reports and updates documented all current and planned activities, alerts, needs, schedules, recommendations, and resolutions.

For every repair job, large or small, the speed and effectiveness of our response team is matched only by the depth and breadth of our engineering expertise.

Successful completion of these back-to-back projects clearly exemplifies the multi-divisional breadth, versatility, and corporate commitment of MD&A as a premier non-OEM service provider to the global gas and steam turbine-generator market. Call us at (518) 399-3616 today or use our contact form.

The post Back-to-Back Major Overhauls on Two 7F.04 Gas Turbines and 7FH2 Generators appeared first on MDA Turbines.

The planned scope of work included replacement of combustion and hot gas path (HGP) hardware and components, IGV gears, ring gear, and bushings. Additional replacements included the torque converter, flow divider, and liquid fuel stop valve. The fuel gas stop valve was also to be removed and replaced. Once completed, the team conducted generator testing. Recommendations for future repairs and considerations were provided as part of the inspections.

Compressor

MD&A’s experts inspected several compressor components. These include the bellmouth casing and inlet guide vanes which were cleaned, inspected and returned to service. The IGV inner and outer bushings as well as the spring/thrust washers were found to have light wear and replaced with new parts. The team mapped and buffed the compressor casing. They also mapped and blended the compressor’s rotor blades. The stator vanes were also removed, cleaned and inspected, demonstrating heavy rubbing with rolled material on the tips. MD&A’s experts blended, performed NDE and reinstalled the vanes.

Combustion Section

Several components in the combustion chambers were found to have various degrees of wear, and other deficiencies. The fuel nozzle tip assembly demonstrated heavy wear. MD&A’s experts replaced the fuel nozzles, combustion liners and caps, crossfire tubes/retainers, combustion cans and transition pieces. The piping components, igniters and flame scanners were found to be in acceptable condition and were cleaned and reused.

Compressor Discharge Casing (CDC)

The team found the first stage wheelspace thermocouple guide tubes and clips to be worn/broken. All were replaced. Additional CDC components were inspected including the inner barrel, clearance plugs, bolting and S1N support ring. All were found to be in acceptable condition and therefore cleaned and reused.

Turbine Section

MD&A’s team performed major repairs and replacement within the turbine’s hot gas path. Buckets for the 1^st, 2^nd and 3^rd stage were all removed and inspected. The 1^st stage buckets showed discoloration and TBC loss. MD&A replaced the buckets, pins, and D-keys. The 2^nd stage buckets also some discoloration and normal wear. The 2^nd stage buckets and pins were replaced.  The 3^rd stage buckets showed normal wear and missing material. They were replaced along with the pins.

The shroud blocks for each of these stages were also removed and inspected. The 1^st stage blocks were discolored along with TBC loss. Normal wear was noted on the other two as well. MD&A’s experts replaced the shroud blocks, pins and seals for all three stages.

The 2nd stage buckets were removed and inspected. Slight discoloration and normal wear were noticed during this visual inspection. New 2nd stage buckets and pins were provided by and installed by MD&A.

The 3rd stage buckets were removed and inspected. Normal wear as well as missing material was noted during this inspection. New buckets and pins were supplied by and installed by MD&A.

The nozzle assemblies were also inspected on all three stages. Slight discoloration and deterioration were noted on all three, while the 2nd and 3^rd stage nozzle segments also had small cracks. MD&A’s experts replaced nozzle segments and hardware for all three assemblies.

Other turbine section repairs in included tapping the casing’s plug threads and cleaning the bolting and replacing the discourager seal.

Exhaust Section

MD&A’s team inspected the exhaust section. The frame was found to be in good condition, while several seals were replaced. The diffuser, frame bolting, cowl and exhaust duct were cleaned and reused.

Bearings

The T1, T2 and T3 bearings were all removed, cleaned and inspected. Each showed heavy wear, were sent out for refurbishment, then inspected and installed. Other related components such as the thrusts, shims, thermocouples and wires were found to be in fair condition. MD&A’s experts cleaned and inspected the thrust runner, as well as the T1, T2 and T3 journals. 

MD&A Bearings, Seals & Hydraulics Division also offers Rapid-Spares bearing exchange program. We maintain a new, identical turbine bearing in our inventory for our customers, eliminating uncertainty and excess costs. This program removes uncertainty from the bearing refurbishment process during critical outage intervals by giving customers the assurance that their bearings are ready to ship, in many instances, even before an outage begins.

Generator Inspection

MD&A’s experts also conducted a minor inspection of the generator field and stator. The scope of the inspection included visual inspection, borescope inspection and electrical testing. The field was found to be in good condition overall, except for some minor contamination which was removed. Other observations were noted, such as additional contamination and insulation migration, but not actionable at the time of inspection.

Electrical testing was conducted on the generator field including 500VDC IR with PI, DLRO and AC impedance testing. All results were satisfactory.

MD&A’s experts also performed a visual and mechanical inspection of the TG1 stator. The axial support hardware was found to be loose and was tightened and secured with epoxy. Other observations were made including oil contamination throughout the machine, minor greasing in end winding areas and partial discharge at phase breaks on the stator end arms. The team also completed visual inspection of the neutral enclosure, which revealed typical oil and dust contamination.

Stator electrical testing was performed as well. This included RTD element resistance and 500VDC IR test, DLRO, 5kVDC IR with PI and CD leakage testing. All results were satisfactory.

Alignments

MD&A’s experts realigned several coupling sections to OEM specifications as needed. These included cranking motor to torque convertor, torque convertor to accessory gearbox, accessory skit to turbine, and generator to turbine. They also aligned the bearing houses as required.

In addition to turbine major inspection and the generator minor inspection, MD&A’s team addressed:

• Dovetail Material Abrasion
• Upgrades to Fuel Controls
• Spacer Seal Replacements
• Replacement of Compressor Blades
• Maintenance And Inspection Requirements for Gas Turbine Air Inlet System
• Shim Inspections
• Inspection Procedures for Variable Guide Vanes
• Handling and Maintenance of Flexible Metal Hoses
• Turbine Shell Inspections
• Rub Prevention

Startup/Testing

Upon completion of the work, MD&A’s experts were onsite for startup assistance. Some minor issues were noted and immediately addressed, leaving the system up and running later that day.

Conclusion

The scope of this 7EA Turbine Major was vast and demonstrates our depth of experience and capabilities, with the ability to conduct inspection and repairs across the entire power plant system. It’s another testament to MD&A being the reliable and dependable one-stop partner of choice for turbine-generator repair worldwide. Call us at (518) 399-3616 today or use our contact form.

The post 7EA Turbine Major & 7A6 Generator Minor Inspection appeared first on MDA Turbines.

As a result, over 40 years later, MD&A has evolved from a small firm to a large service provider with over 600 employees reaching more than 100 customers each week during outage season.  The reputation for outstanding service in the US has enabled MD&A to spread globally with parts, repairs, and services on large turbine-generator sets.

Watch our company video!

The post MD&A Company Video appeared first on MDA Turbines.

MD&A was contracted to manage and apply their hands-on skills to disassemble, inspect, re-stake, and reassemble a 9FA gas turbine with DLN 2.6 Gas Only configuration in the United Kingdom, ultimately saving both time and project cost for the owner/operator.

Throughout each stage of the project, comprehensive inspections were performed, assessed and verified by MD&A experts, drawing on our world-class experience and knowledge.

MD&A arrived and immediately set up the foreign material exclusion zone inside the turbine compartment, removed all piping and ducting, then addressed the forward can assemblies. We worked closely with the customer to help procure specialized ITH equipment specific for their gas turbine.

The upper half combustion system transition pieces were soon removed allowing compressor blade inspection. The rotor was pushed downstream to take as-found turbine clearance measurements.

Visual inspection of the Stage 17 rotor blades showed migration downstream. At this point in the project, flowpath staking work was performed and NDE-verified on all R-17 compressor blades.

With the gas turbine compressor rotor blade re-staking complete, reinstallations and close-out inspections began.

While reinstalling the transition pieces, MD&A detected misalignments from a previous major outage. An inner floating seal had not been properly engaged. A new seal was installed by MD&A and work continued.

Setback readings were then taken and reviewed by MD&A experts. Consensus was reached to continue buildout of the combustion system.

Next, the majority of the turbine and combustion piping was installed and a close-out inspection of the combustion system was performed with the owner/operator. The upper half turbine shell manway cover was installed and work began on the turbine compartment roof sections.

Ducting work soon followed, leading to pressure testing of the turbine compartment. Positive and negative ventilation were tested and passed.

The turbine compartment was then cleaned and the site team demobilized. On-site work was completed in 26 days.

Throughout the project, sequenced and unobstructed photographs were taken of all inspection findings and details. Communication & follow-through was key to this & all projects success.

Specific recommendations were prepared for the owner/operator that included well-defined borescope examination locations and intervals, monitoring locations, and precise rationale for each task.

Every MD&A project concludes with a comprehensive report featuring specific recommendations in addition to spare parts review.

Bringing such expertise onsite not only assures success, but also offers a learning process for all participants. During the critical lift meeting, MD&A professionals added an experience-based recommendation going forward, suggesting a jacking system upgrade that would further improve efficiency for the customer on future projects.

This project exemplified many of the knowledge-based benefits brought to a project by MD&A, including:

• Forward-looking analysis and communication with all project participants.
• Globally recognized attention to detail.
• Project management skills and coordination.
• Clear understanding of the owner/operator’s schedule and cost.
• A strong commitment to all rotating equipment as part of a complete gas turbine/steam turbine/generator portfolio.
• Specific commitment to long-term operation of large-frame gas turbines.

MD&A’s technical directors and service technicians bring decades of experience to each project regardless of OEM, a process now proven in more than 20 countries worldwide.

We invite you to discuss any global gas turbine issue with us today. Call us at (518) 399-3616 or use our Contact Form.

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Here are the significant initiatives we have in place to ensure continuous growth and development within our organization.

Mentoring Program and Succession Planning

Kristin Esterby, our Human Resources Director, addressed the critical need for effective succession planning, particularly as many of our seasoned professionals approach retirement. «We’re facing a unique challenge with our workforce,» Kristin noted. «Not only are we navigating the aftermath of the COVID-19 pandemic, but we also have an aging workforce.» This demographic shift necessitates proactive measures to maintain our high standards of service and expertise.

To address these challenges, MD&A has implemented several strategic initiatives:

• Succession and Talent Planning: Our approach focuses on evaluating individual performance, setting clear goals, and creating tailored development plans. This ensures that our employees are prepared to step into critical roles as they become available.
• Mentoring Programs: We are in the process of developing both formal and informal mentoring programs. These initiatives aim to facilitate knowledge transfer between experienced leaders and newer employees, fostering an environment of continuous learning and growth. Technical-specific mentorships are also being established to address the unique challenges of our industry.

Kristin emphasized the importance of these programs in bridging the knowledge gap and ensuring a smooth transition of expertise. «Mentorship is not just about transferring knowledge; it’s about building relationships and creating a culture of support and mutual growth,» she explained.

Learning and Training (LEAP)

One of our most impactful initiatives is the Leading Effectively at Power (LEAP) program. This week-long training event brings together 20-25 leaders from various divisions to enhance their leadership skills. The curriculum covers crucial topics such as finance, legal considerations, and change management. Participants engage in interactive sessions that promote cross-functional learning and collaboration.

Kristin highlighted the dual benefits of the LEAP program: «Participants not only gain insights from our expert instructors but also learn from each other, which is invaluable for their development as leaders.» This collaborative learning environment helps build a cohesive leadership team equipped to handle the complexities of our industry.

In addition to LEAP, we are launching a pilot series called Leadership and HR 101. This program aims to equip our leaders with foundational knowledge in key areas such as human resources and basic management principles. By providing this training, we ensure that our leaders are well-prepared to manage their teams effectively and foster a positive workplace culture.

Engineers in Training (EIT) Program

Charles Monestere, our General Manager of Technical Services, provided insights into the Engineers in Training (EIT) program. Initially, MD&A focused on hiring experienced engineers. However, in 2009, we shifted our strategy to recruit recent graduates, recognizing the value of fresh perspectives and new talent. This structured program combines intensive classroom training with hands-on, on-the-job experience under the mentorship of our seasoned engineers.

Charles outlined the program’s objectives: «We aim to hire about ten new engineers each year. Our goal is to provide them with a comprehensive understanding of our operations and prepare them for long-term careers with MD&A.» The EIT program has grown significantly since its inception, reflecting its success in developing well-rounded engineers who are ready to contribute to our mission.

Personal Experience: Colin Baker

To provide a personal perspective on the EIT program, Colin Baker, a Field Engineer and recent EIT program graduate, shared his journey. «I joined MD&A straight out of college with minimal turbine experience,» Colin recounted. «The EIT program allowed me to learn from experienced engineers and apply that knowledge in the field.» He emphasized the importance of networking and continuous learning, which are integral components of the program.

Colin’s story is a testament to the program’s effectiveness. He highlighted how the EIT program not only provided technical training but also fostered a supportive environment where he could grow both professionally and personally. «The mentorship and hands-on experience I received were invaluable. It helped me build confidence and develop the skills necessary to excel in my role.»

Looking Ahead

At MD&A, we believe that investing in our people is crucial to our long-term success. Through our comprehensive mentoring and training programs, we are preparing our workforce to meet future challenges head-on while fostering a culture of continuous learning and development. These initiatives ensure that we remain at the forefront of the power industry, delivering excellence and innovation.

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The post Building A Powerful Future: Insights from Our Mentoring and Training Programs appeared first on MDA Turbines.