Westinghouse Steam Turbine Major Inspection

Power Services Group, Inc. (PSG) was contracted to perform a major inspection on an industrial Westinghouse steam turbine generator at a paper mill in the Midwest United States. PSG arrived and began mobilization activities. The office and tool containers were off-loaded and the turbine deck set up for the outage. The set-up personnel were safety orientated for the customer’s specific safety policy before work commenced.  During the project, a Safety Meeting was held prior to the start of any work. The Safety Meeting topics were based on work activities to be performed during the upcoming shift. In addition, hazardous observations which could impact the safety of the team were discussed and resolved.  Prior to performing work, a Job Safety Analysis (JSA) form was completed by the work team. This project had zero accidents and zero first aid incidents. 

The unit was taken offline and allowed to cool down over the weekend. The outage began after Lockout / tag out (LOTO) was accomplished. The instrumentation was removed by plant E&I personnel.  The V-1 and V-2 control valves were removed from the turbine casing and put on stands. The valves were disassembled and inspected and NDE was performed on the poppets and valve stems.  The casing bolts and dowels were removed from the HP and LP turbine casing.  An “as found” swing check was performed. The coupling TIR was recorded. The coupling bolts were removed, and the coupling separated. A 4-point face reading was recorded during disassembly.  The casing was rigged and jacked up, using jack bolts, about two inches and leveled before total removal. The casing was removed and flipped to access the upper half diaphragms for removal. The thrust bearing clearance was checked before disassembly. A set of wheels and packing clearances were taken with the rotor in running position. The thrust bearing was disassembled, and the total float and strike points were recorded. A set of oil bore measurements were taken before removal of the turbine rotor.

The rotor was removed and prepped for blast cleaning and staged on the turbine deck. The upper half and lower half diaphragms were removed and staged on pallets for blast cleaning. The rotor and diaphragms were blast cleaned and NDE inspected.  The axial and side slips were recorded and found to be in tolerance. 

The generator field was removed from the generator stator for inspection. The electrical inspection of the generator was performed by a plant subcontractor.  Some minor cleaning was performed on the stator and rotor.   The generator coolers were disassembled, cleaned and vacuum tested; with no leaks found. The coolers were reassembled with new gaskets and tested before startup. 

The turbine and generator bearings were cleaned and dimensionally inspected. The bearings were UT’d to check for bonding issues with the base metal. The #2 journal bearing failed NDE. A new bearing was supplied by the customer and was installed.  The turbine and generator oil seals were cleaned and dimensionally inspected. The #3 inboard oil seal had excessive clearance. The oil seal was sent out for repair and final machining. 

The control valves were disassembled, cleaned and inspected. The valves were blue checked upon reassembly. The trip throttle valve was disassembled, cleaned and inspected. It was blue checked during reassembly to verify proper contact.  The spray chamber was disassembled, cleaned, and inspected.  The lube oil pumps were removed from the lube oil reservoir for inspection. The pumps were disassembled, cleaned, and inspected. PSG rebuilt the steam driven lube oil pump. The lube oil tank was cleaned by a plant subcontractor. The lube oil coolers were disassembled, cleaned and vacuum tested with no leaks noted. The lube oil system was flushed for 24 hrs. using the existing pumps. 

The unit was brought up and over speed tests were performed.  The mechanical tripped at 3970 rpms. The electrical tripped at 3792 rpms. The unit was put online and brought up to partial load.  PSG was released from the customer’s site.

Murray Steam Turbine Inspection & Repairs

We recently completed another Murray Steam Turbine overhaul at our Steam Path Repair facility in Pevely, Missouri.  We completely disassembled the unit, replaced damaged blades, performed minor diaphragm repairs, performed minor case repairs, balanced the rotor, and reassembled the unit for shipment.  If you have an industrial steam turbine that will need inspection and repair in the future please contact us for a free estimate.  Our qualified repair technicians perform excellent work, and you can rest easy knowing your turbine will run smoothly and efficiently throughout the next run cycle.

Westinghouse Utility Steam Turbine Major Inspection

We recently completed a Major Inspection on a Westinghouse Steam Turbine and Hydrogen-cooled Generator for a Utility in the Southeast U.S.  The project consisted of inspecting the HP/IP Turbine, LP Turbine, and Valves.  The steam path components were blast cleaned and inspected, with minor blade repairs performed on-site.  The turbine rotors had boresonic inspections performed, confirming the good condition of the components.  Bearings T1 – T4 were inspected and found to be in good condition.  The oil deflectors were re-toothed and machined at our qualified repair facility.  The Governor Valves were sent to our valve facility in Gainesville, Georgia where a flexitallic gasket modification was performed.  We performed on-site machining of the steam chest to accept the newly modified gaskets.  The Throttle, Reheat Stop, and Intercept Valves were all inspected at site.  A laser alignment was performed to align steam path components.  Final reassembly was completed, and the unit was turned over to the customer for startup.   This was another excellent project where we finished on-schedule, on-budget, and most importantly – zero safety incidents.  Great work by the PSG team!

Shaft Welding & Machining

We were recently contracted by a major utility in the Midwest U.S. to repair a damaged shaft at one of their power generating facilities.  The remediation process included machining the existing shaft to remove the damaged area and hard spots, weld build up of the shaft, and final machining to achieve desired diameters and tolerances.  This repair was performed by our trained technicians, utilizing specialty equipment designed for this application.  The end result was a repaired shaft, and a happy customer.

If you have any shafts in need of repair at your facility please contact us to discuss.  To learn more about our shaft repair services please CLICK HERE for the latest brochure.


Westinghouse 251B Gas Turbine Inspection

We were recently contracted to perform a modified Combustion Inspection on a Westinghouse 251B Gas Turbine by a customer in the United States.  Below is a summary of the activities we completed during this inspection.  All activities were completed with an attention to safety, and our quality processes, to ensure a successful outage completion.

Upon arrival for setup of tools the unit was shut down and locked out to perform the inspection. The necessary roof sections were removed for crane access to disassemble the components. All combustion parts were removed and replaced with new/refurbished during the inspection – pilot nozzles, support housings, baskets and transition pieces.

During this outage, the upper half compressor case was removed for the inspection of the R1 – R7 in the compressor section.

During this inspection, due to the condition of the compressor it was decided to remove two bottom R-1 vanes (#21 & #22) for a visual inspection and then reinstall.

The inlet access door was removed for inspection of the inlet scroll and the Inlet Guide Vanes. The Inlet Guide Vane angles were checked and verified. The row #1 compressor blade tip clearances were also checked. The Inlet Guide Vanes were greased after inspection. The inlet was cleaned and visually inspected by the plant personnel and our Technical Field Advisor prior to closing.

The exhaust was opened, and the bullet cone inspection cover was removed for inspection of the exhaust bearing pedestal. The exhaust struts were inspected, and cracks were repaired as needed by the site welding contractor.

The end result was another successful turbine inspection – zero safety incidents, quality work, and an on-time and on-budget outage completion.

Valve & Bearing Inspection

Turbine Generator Maintenance (TGM) was contracted by an industrial customer in the United States to perform a valve and bearing inspection on their General Electric (GE) condensing steam turbine and hydrogen-cooled generator. The turbine and generator set is of a four bearing design.

During the project, a Safety Meeting was held prior to the start of any work. The Safety Meeting topics were based on work activities to be performed during the shift. In addition, hazardous observations which could impact the safety of the team were discussed and resolved. Prior to performing work, a Job Safety Analysis (JSA) form was completed by the work team. This project had no accidents and no first aide incidents.

The generator rotor remained in the stator and both of these components, the generator rotor and generator stator, received visual inspections and electrical testing.  The journal bearings were removed and visually and dimensionally inspected. The pedestal oil deflectors were removed and visually and dimensionally inspected. The #3 outboard (OB) and #3 and #4 inboard (IB) oil deflectors showed to have excessive clearance. These deflectors were conveyed to a local machine shop for repairs. The remainder of the deflectors were cleaned and returned to service.

The inlet control valves (CV) were removed, cleaned and inspected. The valve seats and poppets were found in acceptable condition, CV’s 3, 4, 5 and 6 received new stems sourced from customer spares. The valve bushings showed to be worn and were recommended for be replacement at the next planned outage. The main stop valve (MSV) and operator were disassembled, cleaned and inspected. All components were approved for reassembly and were returned to service.

The lube oil system main, AC and steam driven oil pumps were disassembled and received inspections. The main oil pump (MOP), which is driven by the turbine rotor, was returned to service with no repairs being necessary. The steam driven auxiliary oil pump (AOP), was found to have acceptable clearances and was reassembled and returned to service.  One row of carbon steam packing was found to be damaged and was replaced. The AC driven oil pump was found to have acceptable clearances and was reassembled and returned to service. The lube oil reservoir was opened and cleaned.

The generator coolers and air ejector condensers were opened on the water side for inspections. The tubes were rodded out, flushed and vacuum tested. All were OK and the components were reassembled. The lube oil coolers were opened and cleaned.  The system trip devices were cleaned and received visual inspections; all linkages were checked for wear and proper freedom of movement. The devices were latched and checked for tripping operation. The governor speed control trip latch oil pressure trip cylinder piston rings were found to be seized. New rings were manufactured and installed.

Upon startup, the unit operation was accepted and the unit placed online.  Our personnel demobilized the job site and were released to travel the following morning.

Another successful project and satisfied customer.

Running Condition Assessment

We performed a running condition assessment (RCA) inspection on an industrial GE Steam Turbine, in which we performed a variety of inspection processes to determine the overall running condition of the steam turbine generator and its auxiliary equipment at a facility located on the East Coast, USA. This RCA was completed as an annual inspection to determine the condition of the turbine and generator and to better prepare and schedule the next major inspection for this unit.

We met with the customer and discussed the goals of the Running Condition Assessment, how the unit was operating, and the plan to inspect and evaluate the unit to help determine a time frame for the next major inspection of this unit.

A walk down of the turbine and the visual survey portion of the RCA was completed. The detailed findings were included in a comprehensive 400 page final report. A vibration survey, thermal imaging survey and ultrasonic survey of the unit was performed while on site. The underside of the turbine was surveyed for the condition of the thermal insulation and other visual defects. The auxiliary equipment which included the generator and coolers, lube oil tank, pumps, gland exhaust system, steam traps, and pipe hangers was also surveyed.  Running readings were obtained from local instrumentation as well as from the units control system.

The end result provided the customer with an assessment of how their turbine generator set was currently operating, as well as the trending data from previous years’ assessments.  This data was analyzed and discussed at the customer meeting, allowing the customer to budget and tentatively schedule their next Major Inspection based on the year over year trends and recent assessment findings.  The goal of the RCA program is to help customers extend the duration between Major Inspections, while assessing and correcting minor issues on an annual basis.




Shaft Machining

Our Field Machining Division was dispatched to repair an inboard fan shaft for a Utility customer in the Midwest.  We mobilized a total of 4 specialty field machining personnel, and began the process of machining the inboard fan shaft which had severe shaft damage and hard spots.  We cleaned up 100% of the shaft, had hardness checks performed, and then proceeded to final hone and polish.

The total duration of the project was 3 days from start to finish, and the end result was another satisfied customer.  The photos below will give you an idea of the severity of the original shaft damage, as well as the final condition upon completion.  Another great project by our Field Machining Division!


As Found:


Upon Completion:

Steam Turbine Major Inspection

We’re lifting the LP upper half casing on a Westinghouse Steam Turbine.   Great attention to detail and planning is required to perform a safe, quality lift of this nature.  Nice job team!

D-11 Turbine Inspections

We are seeing many inspections scheduled on the D-11 fleet of steam turbines all across the United States.  This fleet has very specific needs when it comes to maintaining and repairing them, and we have solutions for many of the common repairs needed.  From the diaphragms to the packing boxes, and every other component on this machine, we offer repair solutions that will provide you with an efficient and reliable turbine for the foreseeable future.  We will execute a turnkey field service inspection at your site with our qualified Technical Field Advisors and turbine execution teams, perform any of the steam path repairs (rotor, diaphragms, etc.) at our Midwest Steam Path Repair Facility, as well as inspect, repair, and manufacture new components for the associated steam valves at our Southeast Valve Repair Facility.  If you have any inspections scheduled on your D-11 steam turbines please contact us today to learn more about what we can offer.