Almost every parts enquiry that stalls does so for the same reason. The frame was never established, so nobody can confirm what will fit.
General Electric
GE uses two systems that describe the same machines. The short form is a frame number: Frame 5, Frame 6, Frame 7, Frame 9. The long form is an MS designation carrying more detail, so MS7001FA is a Frame 7 in the FA configuration.
The letter suffix matters more than the number. A Frame 7B and a Frame 7FA are separated by decades of development and very little crosses between them. When an enquiry says only “a Frame 7”, the next question is always which one.
Westinghouse
Westinghouse machines run on a W prefix: W251 and W501. The suffix again carries the detail, so W501-D5 and W501-D5A are not interchangeable in every position even though they read almost the same.
Siemens
Older Siemens units use a V designation, V84 and V94 being the common ones. Newer machines use the SGT range, numbered by output class from SGT-100 upward, with the SGT-A series covering the aeroderivative units.
Why it decides the whole enquiry
Hot gas path parts are frame specific. Combustion liners, transition pieces, nozzles and buckets are cut for one machine at one stage, and a part that is close is a part that does not fit.
Compressor blading is a little more forgiving across a family but still tied to the stage. Balance of plant items such as filters, fasteners, seals and instrumentation cross frames more freely, which is why they are usually the quickest lines to quote.
What to send
- The frame and its suffix, in full.
- The stage, where the part is staged.
- The OEM part number if the nameplate or the old part carries one.
- A photograph, if the number has worn off. It is often enough.
Our parts catalogue is searchable by number, description and frame, so the frame alone is usually enough to narrow it.
