A、reduce wear on the valve stem
B、permit the use of alloy valve seat materials
C、reduce heat transfer from the valve seat
D、facilitate valve removal for servicing
更多“Valve cages are used on some large diesel engines to （）”相关的问题
A、the direct acting relief valve is used for controlling lower flows and pressure B、the pilot operated relief valve is used for controlling higher flows and pressure C、the pilot operated relief valve is used for controlling lower flows and pressure D、the controlling accuracy of direct acting relief valve is worse than that of the pilot operated relief valve
A、one valve seats upwards, while the other seats downwards B、the reed valves used on the discharge are made substantially thicker and heavier than the suction valves C、the suction valve springs exert a greater tension than the discharge valve springs D、the discharge valve springs exert a greater tension than the suction valve springs
A、the inlet valve is open B、the exhaust valve is open C、both valves are close D、both valves are open
A、the inlet valve is open B、the exhaust valve is open C、both valves are closed D、both valves are open
A、the stem and heads are made of different material B、low-alloy steel is used throughout C、a replaceable valve disk is welded to the head D、the self-centering action comes from motion of the valve stem in the guide
A、low relative humidity is maintained B、triple banded squirrel cage fans are used C、air circulation is a maximum D、high relative humidity is maintained
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