What is the difference between Gas Turbine 9E & 7FA Machine?

its difficult question in that sense both are gas turbine and principle of gas turbine is same for all

Hello My friend

9E is the Turbines that are manufactured in Europe (France) by GE factory, the output power is ranging from 125 MW up to 145 MW in the new models or generations. it is a 17 stage compressor and 3 stage Turbine machine, & 1 stage IGV. 

as for 7FA is US manufactured GE Turbine, the output power is ranging from 241 MW up to 260 MW in new models. it is a 14 stage compressor and 3 stage Turbine machine, but with 4 stage IGVs in the beginning of compressor. 

GE gas turbines were basically divided into 2 different classes.1. E - class Ex: 6B, 9E2. F - class Ex: 6FA, 7FA, 7FB, 9FA, 9FB,9FA+eF class machines are newer machines and has higher power generation capacity.9FA means : "9" indicates Frame size and "F" indicates F - class machine. FA and FB are two categories of F - class machines.9E means : "9" indicates Frame size and "E" indicates E - class machine.9FA+e means : "9" indicates Frame size, "F" indicates F - class machine and "+e" indicates extended version of 9FA.For ex: 9FA+e 'inspection interval' is more compared to 9FA.

7FA POUR LES PAYS DISPOSANT UNE ALIMENTATION DE 50HZ PAR CONTRE LAUTRE DE UNE ALIMENTATION DE 60HZ

7FA frame GTs are designed for countries have 50 Hz power supply whereas 9E frame GTs are designed for Countries having 60 Hz power supplly.

7FA GTs are configured as Generator - Compressor - Turbine

9E GTs are configured as Compressor - Turbine - Generator

7FA GTs have DLN 2.6/DLN 2.6+ combustion system where as 9E GTs have DLN 1/1+ combustion system. Both GTs have 14 Combustion Cans.

Series 9 machines are designed for generating @ 50 hertz whilst 7FA generates @ 60 HZ