A
one of our gas turbine MS-5001P tripped on hydraulic oil low pressure but the IGV'S didn't come to their close position.hydraulic oil pressure that operates the IGV'S and the fuel servo valves drops to zero then on actuation of 14HS trip relay solenoid valve 20TV should be energized to close the IGV'S. in what are the possible cause of IGV'S sticking. on sudden drop of pressure did IGV'S solenoid valve 20TV get time to drain the oil behind the piston that operate the IGV'S