We have different servos, Make:MOOG for the IGV,SRV and GCV of Frame-VI & Frame-IX Gas turbine, Make:GE.

I would like to know that can we interchange the servo between IGV & GCV or GCV & SRV?

What are the characteristic/performance data to be check, while selecting/procuring the Servo.

For preventive Maintenance, Which parameters to be checked?

 

You have not provided enough information for anyone to say conclusively that this or that servo can be interchanged. Servos changed over the years depending on the type and pressure of the hydraulic systems, the actuators, etc. We would have to know a lot more about the units at your site, the actuators, the hydraulic systems (pumps, pressures, etc.).

How difficult is this?

Have you made a list of the Moog part numbers for the various servo-valves that you have for the two frame sizes at your site? You could use a spreadsheet (since nobody uses paper and pencil any more) with two columns: one for the Frame 6 and one for the Frame 9. You would then have a row each for IGV servos, GCV servos, and SRV servos.

You could then compare the part numbers to see if there are any servos used on the Frame 6 that have the same part number as those used on the Frame 9, or vice versa.

If you find the same part numbers for any of these servos, then you have an answer.

If you don't find many or any similarities or if you want more possible information, you have a choice of sending the information to the packager of the units (BHEL, GE, etc.) or whomever you buy your spares from to ask them if they have any servos that can be used interchangeably. Or, you can send the list to Moog or a Moog vendor representative and ask them the same question: Are there any servos which can be used interchangeably on the two units? (If you contact GE or a GE packager, you should probably add the GE Part Number information to the spreadsheet.) These two sources could more or less quickly analyze the characteristics by part number to see if there are any possible substitutions or compatibilities.

Most vendors are more than willing to provide this kind of information and assistance if there's a chance they can sell you something. If you search control.com, you will find a couple of companies advertising they sell or refurbish servo valves in addition to Moog or a GE packager (most GE packagers and GE don't refurbish equipment, but some might).

 

For one shaft GT the servos are all interchangeable. So in your case like the FR6 moog servos are interchangeable with each other. GE part number for your servo will start with 312A6077P005 (model G771K200, 5GPM 3k PSI). Some other GE BA's or ex- BA's might use different part numbers such as RVOXXXXX, XXXX-XXXX-XXXX etc. For GE manufactured Moog servo valves you can find the part number information from the dark red label pasted on the side of the servo (so called CUST PN).
Note: In case of having part number 312A6077P003 (model G772K240), this usually used for two shaft GT's S2N (second stage nozzle control).

Good Luck....TEMPUS FUGIT...