We have Boiler F.D. Fan with spherical roller bearing (skf 22224E)with self lubrication. The fan is centre hung with 1786 RPM.

We have a concern regarding which oil type to use for this. Plant maintenance says they use ISO VG 460 cst. Equipment datasheet/manual or not available.
As per me, oil type should be VG 46 or 68.

Could any body help me for selecting the right oil type and criteria in case of no supporting documents available
best regards,

Srinu,
The fan bearings of this size and speed require ISO VG 46 or 68 grade lube. You are right, you could use VG 46 grade lube. We at our FD Fan for boiler used VG 46.

For criteria for the lube selection, i would send you something by tomorrow.

Regards
Mohammad

I agree with you 46 or 68... I would go with 68. 460 is ridiculous and will cause the bearing to run much hotter than it needs to.

Here is SKF's method
http://www.skf.com/portal/skf/...g=en&newlink=1_0_119

Slide 2 shows bearing dimensions from which we determine mean diameter Dm = 167.5mm

Slide 3 shows SKF's figure 5. We enter with horizontal axis Dm=167.5mm. Find intersection with curve Speed = 1800rpm curve. Read accross to vertical axis showing Min viscosity ~ 7.5 cSt

Slide 4 shows SKF's figure 6. Enter with 100C max temperature on Horizontal axis (conservatively high), 7.5 min vis at temp on vertical axis, read the intersection at the curve corresponding to VG46.

Also you can choose "calculations" from left side of above link, then "viscosity" to pull up a screen similar to slide 5, which also shows min viscosity VG46.

My preference is to go to the next higher grade to provide a small margin for error, so I would use VG68.

Attachment: 800k was too big?!? I had to put it here:
http://home.comcast.net/~elect...kf_LubeFor22224E.ppt

This message has been edited. Last edited by: electricpete,