TG531 – (GE) Combined Cycle Steam Turbine Maintenance

TG531 – (GE) Combined Cycle Steam Turbine Maintenance

4.5 days - 32 PDH Credits Awarded



Planning, scheduling, and implementing a steam turbine-generator outage can be one of the most demanding tasks you perform.  Especially, when problems are found that were not anticipated (and there are always these kinds of problems).  In the class we will learn to better plan the work (from a technical perspective).  Once the work is planned, as we know, the next task is to work the plan.  Here is where the surprises can occur.  Some components will not disassemble according to procedure – what are your options?  Some components do not meet OEM specifications – what are your options?  Some components won’t go back together according to procedure – again, what are your options?  These options usually involve repair / replace / reuse decision making.  Effective decision making is a function of your knowledge of the importance of this component, your understanding of recommended tolerances, and your understanding of how different options can impact the schedule and/or cost of this outage.  Complicating this issue is a strong need to make outages shorter in length, AND longer in frequencies between outage.  It’s simple:  You need to do more with less time and money available.  This course is intended to help you (or your staff) make better steam turbine-generator maintenance decisions.                Topical Outline includes: Planning, Scheduling and Decision Making; Maintenance of Shells, Casings & Rotors; Journal and Thrust Bearings; Couplings, Steam Valves; Steam Path Alignment; and Job Wrap Up. HPC Technical Services course on the (GE) Combined Cycle Steam Turbine Maintenance is the newest steam turbine maintenance course we offer.  The course targets those individuals who have a need to better understand the maintenance process on largely the A-10 and D-11 Steam Turbines.  This includes engineers (who have not yet received formal training on this topic), experienced-mechanics, mechanical maintenance foremen, planners and management.


Upon completion of this course the participant will be able to:
  1. List steam turbine-generator operational and safety issues that typically cause the scheduling of a maintenance outage.
  2. List the considerations that must be included when developing an outage plan or schedule.
  3. Describe the major considerations when making a replace/reuse/repair decision.
  4. Describe the procedures necessary for the safe and effective disassembly and reassembly of steam turbine components.
  5. Describe the purpose and operation of the major steam valves.
  6. Describe the disassembly and reassembly of the major steam valves.
  7. List the five (5) most common causes of steam path damage and their possible affects upon future operation.
  8. Describe three (3) common causes steam path defects and their impact upon turbine efficiency and reliability.
  9. Describe the type and purpose of clearance and alignment measurements commonly taken during the disassembly and reassembly of a steam turbine generator.
  10. Describe the measuring instruments used to determine steam turbine component clearances.
  11. List and describe the various non-destructive examinations performed during disassembly of the steam turbine.
  12. Describe the common procedures for cleaning and inspecting steam turbine components.
  13. Describe the criteria used to evaluate steam turbine defects.
  14. Describe the common repair methods for repair of steam turbine components.
  15. Describe the purpose of conducting a steam path audit, and how that audit would be accomplished.
  16. Describe the common types and operation of journal and thrust bearings.
  17. Describe the common causes of bearing damage.
  18. Describe the measurements required to determine oil clearances.
  19. Describe common bearing inspection and repair procedures.
  20. Describe the considerations to be taken into account when evaluating alignment of steam turbine components.
  21. Describe the methods used to properly align steam turbine components.
  22. Demonstrate the ability to perform the necessary calculations to align steam turbine components

Course Synopsis


  • Planning, Scheduling and Decision Making: This presentation is intended to provide participants with an understanding of those major items that must be considered PRIOR to commencing a scheduled turbine outage. Discussion will also include those items we need to consider when making repair/replace/reuse decisions.
  • Turbine Shells, Casings & Rotors: Two hours into the course and we're into the meat! This lecture is intended to prepare the participant to safely and efficiently disassemble/reassemble major turbine components, as well as improve inspection/repair techniques, communications on equipment, and make better replace/repair/reuse decisions. Presentations include specific discussions on the different types of distress typically found on these components including the problems associated with the N-2 packing on D-11 turbines.


  • Turbine Shells, Casings & Rotors continues for ½ day.
  • Journal & Thrust Bearings: Learn the different types of bearings and their applications, disassembly/reassembly procedures, inspection techniques, and typical types of distress as well as causes.


  • Couplings: Learn what types of couplings are used on A-10 and D-11 T-G sets, how torque is transferred, how to properly disassemble/reassemble, how to inspect, what measurements to take, and what they mean.
  • Steam Valve Maintenance: Learn the purpose of the various steam turbine valves, how to properly disassemble/reassemble, how to inspect, what are the typical types of distress, what measurements to take, and what they mean. The A-10 and D-11 steam turbines have a number of valves that are different from those on other GE fossil units. These include the Combined Main Stop & Control Valves (CSV) and LP Stop & Control Valves.  Then there are also the LP Admission Valves.


  • Alignment: Learn how to properly take clearance/alignment and how to evaluate. Discussions include how to calculate and make moves for stationary equipment such as diaphragms. Discussions also include how to take coupling rim/face readings, how to calculate moves to correct for coupling misalignment, and how to calculate and make moves to bearings to accomplish alignment objectives.


  • Job Wrap-Up: Learn what kind of data should be recorded following the outage, and what checks to make as we prepare to return the equipment toservice.
  • Steam Turbine Field Engineer / Mechanic Certification Examination

Course Dates / Location / Fee

See for detail on the course dates / locations / and registration fees. HPC’s 3-4-2 policy applies:  Sign up 3 for the same course/date and pay for only 2! HPC Technical Services reserves the right to cancel any course/seminar within 10-working days of the scheduled date.  Fees are 100% refunded or credited to another Seminar (clients' choice) if HPC should cancel any Seminar.  HPC is not responsible for non-refundable airline tickets or other travel expenses under any circumstance.

What you will receive

  1. 1 copy of HPC Technical Services' textbook, (GE) Combined Cycle Steam Turbine Maintenance, drafted by Ray Militello (with significant support by others)
  2. A Certificate of Completion with 31 PDH awarded.

Steam Turbine Maintenance Certification

There are two levels of certification and this course can be substituted for TG531:
  1. Engineer
  2. Mechanical Technician
Those who attend this course are automatically qualified to take HPC Technical Services' Certification Examination. This examination is offered at no additional expense to the participant. An 80% passing grade is required. The examination length will not exceed 2-hours. Those who complete this examination will receive a revised "certificate of completion" that recognizes this accomplishment along with two-copies of a "To Whom It May Concern" letter that states their accomplishment. (Two copies are provided, one for the participants' employer and one for the participants' personal file.)  Consult HPC's website,, for detail on this certification program.

Frequently Asked Questions

  • Will HPC Technical Services bring this course to our location for our personnel only? YES, call or email Stephen Parker, for a price quotation.
  • Will HPC Technical Services customize the presentation at our site to suit our particular needs?
  • Is HPC Technical Services' textbook available for purchase as a reference document? No, not at this time.
  • What is the cost for HPC Technical Service to deliver this course at our location? Well, of course that can vary and it needs to priced on an individual need basis.  You gain from the customization and price.
  • Is HPC Technical Services' consultants available for "technical advise" during our upcoming outage?   Call Stephen Parker, for a rate sheet.