You could call this the “Year of the Shop Tour.” Most of the user groups dedicated to gas-turbine owners and operators are getting out of the classroom for a half day or so to see firsthand what’s going on in the manufacturing centers and repair shops serving the industry. Hundreds of millions have been invested in expanding and upgrading these facilities over the last several years to satisfy global demand and to transition, to the degree possible, from worker-intensive processes to automated machining centers, high-technology nondestructive examination (NDE), etc.
A visit to a modern manufacturing center dispels the notion that skills lost through worker retirement were going to cripple the industry. To the contrary, retirements may have facilitated the transition to hands-off manufacturing controlled by sophisticated software and machine tools. This is not to say skilled machinists are no longer needed; they most certainly are. However, today you need fewer of them today than in the past.
If you have been in the industry for three or four decades and haven’t visited a shop within the last decade or so, it’s almost unnerving to stand on the floor of a modern turbine/generator manufacturing center and watch product flow, with a minimum of human intervention, into special shipping containers to protect against damage. There are relatively few workers in view and the building is quiet, spotless, well lit, air conditioned, with no dust or odors in the air.
Manufacturers are flag-waving proud of their new facilities and the capabilities therein. They have invited user groups to hold their annual meetings nearby, thereby enabling tours. In most cases, the tours are conducted in groups of 10-15 users with headsets provided to assure that the finer points of a particular process are not missed by anyone.
Direct involvement of shop personnel on most visits is particularly valuable. Sanitized canned presentations by a tour guide are old school. Today you get to listen, for example, to the coating specialist at his or her workstation on what they do to assure quality of your hot-gas-path (HGP) parts; you have the opportunity to ask technical questions and get the answers you need to make better decisions for your plant and company. Worker pride is clearly in evidence at every tour stop. Not attending a user group meeting with a planned tour is a valuable opportunity lost.
A sampling of shop visits conducted, and scheduled, by users groups this year include the following:
• CTOTF Spring Turbine Forum: Alstom’s Midlothian turbine/generator shop, conducted.
• 7F Users Group: Pratt & Whitney Power Systems’ San Antonio manufacturing and repair facility, conducted.
• 501D5-D5A Users: Liburdi Turbine Services Inc’s repair facility, Pioneer Motor Bearing Co’s repair shop, Siemens Energy Inc’s facilities for manufacturing and repair of gas and steam turbines and generators, and components for those machines. All conducted; details below.
• Frame 6 Users Group’s upcoming visit to GE Energy’s turbine and generator manufacturing and repair shop in Greenville, SC.
• CTOTF Fall Turbine Forum’s upcoming visit to Solar Turbines’ San Diego manufacturing and repair center.
• 7EA Users Group’s upcoming visit to GE Energy’s turbine and generator manufacturing and repair shop in Greenville, SC.
• Although not a shop tour, the ACC Users Group will be visiting in-service air-cooled condensers during its late-September meeting in Gillette, Wyo. There are half a dozen ACCs operating in the Gillette area with O&M experience going back four decades.
501D5-D5A Users tour Liburdi’s Mooresville (NC) facility
The 501D5-D5A Users took full advantage of Siemens Energy’s invitation to visit its expanded Charlotte manufacturing and repair center, also scheduling tours of Liburdi’s Mooresville facility and Pioneer Motor Bearing’s Kings Mountain shop. The group’s steering committee—Chairman Gabe Fleck of Associated Electric Co-op Inc; Vice Chairman Barry Mayhew, Cardinal Power’s (Canada) maintenance manager; and Lonne Grote, lead O&M technician at Rocky Road Power—got high marks from the 40 attendees for the informative outings.
Liburdi operates two businesses from its Mooresville offices that support power producers: turbine services and welding equipment/services. Most of the users on the tour knew Liburdi because of its reputation for quality repairs of HGP parts for GE, Siemens, Alstom, and Nuovo Pignone gas turbines.
The company’s North Carolina shop specializes in the repair of fuel nozzles, combustion baskets/liners, transitions, nozzles/vanes, blade rings, and shrouds. The visitors reviewed Liburdi’s in-house capabilities—equipment, procedures, and qualified personnel—for removing coatings, providing state-of-the-art NDE (Fig 1) and metallographic techniques, etc. The company’s LPM® (Liburdi Powder Metallurgy) process was reviewed along with its machining (manual, CNC, and EDM), welding, heat treating, and atmospheric plasma spray capabilities.
Sister business, Liburdi Dimetrics, makes automated orbital welding equipment for sale or rent (Fig 2). The company offers a wide range of GMAW, GTAW, and hot-wire orbital weld heads and power supplies for precision joining of tubes, piping, and bellows. R, PP, and S stamps enable Liburdi to support training, certification, and welding activities in support of powerplant maintenance and new construction.
 1. Liburdi’s Rob Rowland explains the use of inspection arms for dimensional measurement (of a vane ring here) and model formation. Fit-up of transition pieces is verified in jig behind and to the right of Rowland |
 2. Dan Stankiewicz explains liner sectional replacement using automated welding methods |
501D5-D5A users visit Pioneer Motor Bearing
Pioneer Motor Bearing Co’s North Carolina plant opened in 1990, specially designed to facilitate the manufacture and repair of large babbitted journal and thrust-bearing assemblies. One cause of bearing damage that plant owner/operators are seeing more frequently today is arcing attributed to stray shaft currents. First step in dealing with such damage, as shown in Fig 3, is to the repair the bearing. Second step is to install a proper shaft grounding system.
Work in progress when the users visited included babbitt being poured. The gas-turbine O&M specialists in attendance knew that the dynamic behavior of rotating machines can change over time but some may not have realized that bearings sometimes can be modified to provide a smooth-running machine, reducing requirements for special maintenance and restricted operations. Pioneer’s message: The company has the field experience, design skills, and manufacturing capabilities to deal effectively with bearing issues.
 3. Stray shaft currents caused by arcing that damaged this thrust bearing shoe |
A good complement to the shop tour is the presentation Technical Services Manager Fred C Wiesinger Jr made to attendees of the CTOTF’s Combined Cycle Roundtable at the group’s recent Spring Turbine Forum in Williamsburg, Va. There was no classroom-style presentation on the care and feeding of fluid-film bearings at the 501D5-D5A Users meeting. Wiesinger’s presentation, available for viewing by any user registered with the CTOTF Presentations Library (it’s easy to register), covered bearing casting processes, NDE to verify proper bonding of metals, importance of proper lubrication, inspection, damage identification, analysis, and investigation, and several case studies. It is worthwhile reading whether or not you were on the tour.
Siemens hosts 501D5-D5A Users at its mega-shop
Experienced powerplant personnel are not easily impressed. After two decades or more of deck-plates O&M experience, user group meetings, and shop tours they’re confident they’ve pretty much “seen and heard it all.” Then they get the opportunity to visit the new Siemens facility in Charlotte, and minds must be recalibrated regarding the capabilities of American manufacturing for the global electric power industry both in terms of quality and quantity. You don’t have to be impressed with the more than one million square feet of shop space under roof, the 100-ft-high manufacturing bays, and the latest automated machine tools and inspection techniques, but if you’re not “show me better,” as the saying goes.
 4. Gas turbine assembly area at the Siemens Charlotte manufacturing facility can accommodate seven engines |
 5. First 501FD4 rotor made in Charlotte was delivered to a customer in Mexico |
The 501D5-D5A visitors were told to keep a sharp eye for ongoing construction in the facility, which will employ more than 1800 upon completion. But there was so much manufacturing in progress it was difficult to believe the mega-shop was not finished. Charlotte has three basic products: gas turbines, steam turbines, and generators (Figs 4-8). Capacities offered extend from 150 to more than 1600 MW depending on the machine and its application. The shop also is a center of excellence for mods, upgrades, and major repairs and does some critical parts manufacturing as well (such as gas-turbine transition pieces).
 6. Two-flow steam-turbine element is readied for shipment |
 7. Charlotte is Siemens’ lead manufacturing plant for generators. Here a stator is inspected |
Part of the overall facility is more than 40 years old—Westinghouse Electric Corp built the first 550,000-ft2 shop space in 1969 to build LP turbines for nuclear powerplants—but that has been upgraded and spruced-up. Siemens acquired Westinghouse in 1999 and announced plans to add more than 400,000 ft2 to the Charlotte manufacturing complex in March 2010. The integrated facility hums round the clock every day of the year. You can get more history at www.siemens.com/energy/charlotte.
 8. The end of the manufacturing line: Generator rotor balance area |
Here are a few of things recalled by the editors following the tour:
• Rotor and compressor component manufacturing incorporates the latest lean-flow principles. There is no reverse flow on the shop floor, distance between work stations is minimal, zero-gravity lifts are used to the extent possible.
• Rotor manufacturing is conducted in an aisle about 200 yards long and adjacent to the rotor service center, which includes incoming inspection. Everything need to assure success in rotor manufacture and repair is located on the shop floor—including offices, machining, heat treatment, all tooling, NDE, etc.
• At the component level, one skilled employee typically handles the operation of two or more machining centers.
• The generator section of the shop gave the impression of a wartime mobilization unit with perhaps more than two dozen rotors in various stages of manufacture (or repair). There were rotors for 50- and 60-Hz machines with far-off destinations, in some cases, according to workflow paperwork. The tour leader guessed that only about one-third of the generator rotors produced might be for domestic service. Process flow through the generator rotor manufacturing area was continuous and straight ahead like the GT rotor line.
• With such high bays throughout the shop, storage facilities for machine parts, tools, etc, are vertical.
• The GT assembly area was particularly impressive, having the capability to build seven 200-MW-class units simultaneously and ship upwards of one gas turbine a week if necessary. Only 501FD4s were being assembled during the user tour. These engines are distinguished by their relatively short rotors compared to earlier versions of the 501F. Thirteen-stage compressors are the reason. Recall that earlier versions of the 501F compressor had 16 stages. The new machines also have inlet guide vanes on four stages instead of the traditional one.
• Siemens went the extra step to accommodate the D5 and D5A users by putting out on the shop floor various pieces of combustion equipment for “show and tell,” including some cutaways to get a first-hand feel for the hardware that would be discussed in the classroom the following day.
