Temperature at which water comes out of suspension STG ISO 32 Lube oil 1

[Tedops]

We just came out of a steam turbine overhaul and found the lube oil had been contaminated with water. I suspect the Lube oil has been too cool during operation and shutdown. Normal Tank oil temp during operation is nominal 120 Degrees F. There is no heater in the tank so when shutdowns occur tank temp can drop to around 80 degrees F. Water removal is handled by a centrifuge. At what temperature should I keep the turbine lube oil to ensure effective water removal by the centrifuge?

Thank for any help!

 

[byrdj]

The oil temperture to the bearings is critical and should not be varied outside the recomended operating. I'm familair with recomendatin 110F to 120F. the plant fine tunes oil temp most times to 115 to 120F for vibration. (Some OEMs do recomend hotter, but I'm familair)

Does this unit have coolers for the supply to the bearings (most common) or for the drain to the tank (I think I've heard of this design).

If system has coolers for the supply to the bearings, the tank temp will be the bearing drain temp proably 150 to 180F

If the system has coolers for the drain, then the tank cannot be any higher than recomended bearing supply.

If you have a steam seal gland exhuaster, is it working propery and shaft seals not puffing.

If the tank has vapor extrator, be sure it is pulling proper water column on tank (normally 1/2"h2o). If there is excessive water vapor, the vapor extracor may need to be temperarly increased due to the increased volume of vapor verse the normal air.

If the tank doesn't have vapor extractor, then....you might have a problem. (on the four units I know that doesn't, I made a temperory vent during SU)

 

[adamtom]

byrdj is right!
The gland steam seal could leak from rotor's gland to bearing housing for the space between them was pluggeg by insulation material. After overhaul it should be check the space is OK.