Page 470 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

Lube, Seal and Control Oil System Best Practices Best Practice 7 .32

Fig 7.32.5 Steam turbine shut-off valves. Left: Trip and throttle (Courtesy of Gimple Corp.). Right: Trip (Courtesy of Siemens)

Trip valve is only as reliable as valve to move
Should periodically (minimum one per month) exercise valve to Most domestic vendors rely only on trip valve to shut off steam
ensure movement supply. (Throttle valves remain open.)
Exercisers will not trip turbine European vendors close both trip and automatic throttle valve
If valve does not move, must be remedied immediately
on trip signal.

Fig 7.32.6 On-line manual exercise of trip valve Fig 7.32.7 Protection system philosophies

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