The conditioning and maintenance of the lub oil varies with its application.
At my work, a large industrial gas turbine of about 230,000 hp, the lub oil system is very simple. There are two filters and thats it.
When on a shutdown, we move a portable centrifuge to the vicinity and run that.
We do take samples for analysis, and occasionally change the oil, maybe every 5 years or so, but that depends on degredation.
Of course, it has to be appreciated that lub oil in a diesel engine will pick up more contaminants than in a turbine due to the design and characteristics of the engine. Also, the mechanical loading of the oil in a reciprocating engine's bearings will be much greater than that of a purely rotational engine, resulting in shorter life.
Conversely, the bearing cooling requirements the oil is exposed to in a large turbine may be considerably higher than those of a large diesel. In the example given, the hot end bearing at full load is supporting a shaft running at 540 deg.c
Ian