Gas Turbine Major and Generator Test & Balance

Mechanical Dynamics and Analysis (MD&A) was contracted after a forced outage to perform a major overhaul on a cogeneration unit’s MS5001PA gas turbine to remove, test and inspect the generator field. Because the unit dispatches as baseload and the turbine is a critical asset, MD&A was asked to complete the repair work as quickly as possible. MD&A was able to meet the customer’s expedited schedule, limiting the time the machine was offline.

Because the nature of the forced outage was not fully known when the job was awarded, the defined initial scope of work was incomplete. Despite the uncertainties, MD&A’s experienced technical team quickly evaluated the damage and developed a comprehensive scope of work.

As part of its work, MD&A’s gas turbine maintenance team opened, inspected, repaired and reassembled the gas turbine. The turbine rotor was removed and shipped it off-site for refurbishment and high-speed balance at our St. Louis repair facility.

As well, MD&A removed the generator field and sent it to our St. Louis facility for a complete test & inspection and high-speed balance before being returned to site.

The scope of work included:

Site Work Services

• GT Major Inspection & Rotor Removal
• Generator Major Inspection and test & inspection – the insulation was repaired, flux probes installed and completely re-painted inside
• Stage 9 Stator Hook Fit Mod- removal of Upper & Lower Compressor Casings
• Installed New Electronic Gas Valves – removal of old Hydraulic Gas Valves
• Remove Existing Liquid Fuel System, and associated support systems, such as Atomizing Air and Water Injection – A Controls Software Upgrade to eliminate these control sections
• Accessory and Load Gear Refurbishments
• Exhaust Frame Repairs

Shop Work Repairs

• Gas Turbine Rotor Inspection
• Remove and Inspect 1st stage buckets – Apply coating for excessive rock and repair Aft Angel Wings
• Replaced 2nd stage buckets
• Compressor Blade Blending
• Refurbish HGP Components & Combustion Hardware
• Generator Field Rings Off Inspection, test & inspection, and high-speed balance
• Gas Turbine Rotor High-speed balance

New Parts

• 2nd Stage Buckets
• 2nd Stage Shroud Blocks
• Consumables & Hardware
• Auxiliaries
• Exhaust Plenum

MD&A also performed major repairs on the turbines accessory system, including refurbishment of Accessory & Load Gears, replacement of turbine compartment vent fans, rebuilding of Exhaust Ducting, replacement of Exhaust Expansion Joints, as well as removal of hydraulic overspeed bolt and replacement with redundant electronic overspeed protection.

MD&A’s specialized services range from Combustion, Hot Gas Path and Major Inspections, as well as, Compressor & Turbine Rotor Repairs to Plant Performance Testing and Analysis. We also provide turbine internal alignment for your gas turbine, along with vibration analysis and balance (low-speed & high-speed.)

Call MD&A at +1 (518) 399-3616 today.

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