In a 300 MW unit turbine

the temperature of No.1 and No.2 high pressure regulating valves' servo-motor was higher than that of the No.3 and No.4 high pressure regulating valves' servo-motor

resulting in oil leakage problem.Analysis showed that

the over short distance from the regulating valve's servo-motor to the support

and the inside EH oil was unable to flow and carry out the heat were considered as the major reasons.Therefore

the water cooling device was installed at top cylinder liner of the regulating valve servo-motor

and the contact area between the support of regulating valve actuator and the control valve stand was shortened.Besides

the insulating layer was added between the regulating valve actuator support and the control valve stand

and the seal components between the piston rod and the cylinder liner were changed regularly.After all the above measures were taken

the temperature of the high pressure regulating valve's servo-motor returned to normal.