Patent ID: 8020664

Claim:
A turbomachine comprising an air compressor ( 3 ) and a lubrication-circuit with an oil tank ( 1 ) and an isolation valve ( 7 ) that allows to isolate the oil tank ( 1 ) from the rest of the lubrication circuit ( 4 , 4 A; 6 , 6 A), wherein the isolation valve is configured so as to: operate to close and open respectively as the engine ( 2 ) stops and starts; remain open when the engine ( 2 ) is running; and remain closed when the engine ( 2 ) is stopped; wherein said isolation valve ( 7 ) is pneumatically controlled; and wherein said isolation valve ( 7 ) is provided with a device ( 7 A) allowing to automatically select as an operation the more highly compressed source of compressed air from two different sources ( 9 , 10 ).