Selection of grease

Dear Edwin,

For this temperature and self aligning roller bearing you should consider PTFE+PFPE grease.
As a product i strongly recommend Klueber BARRIERTA L 55/2.
But you have to clean the bearings completely of the previous grease or even of the rust preventing agent if the bearings are new.
This is essential for the performance of the grease.
With the right selection of grease and a strict lubrication procedure, this temperature should not harm the selected self aligning roller bearing before its calculated rated life.
I wish you success with the application!

quote:

Originally posted by Edwin:
Dear all,

I am looking for grease which can lubricate the bearing even the temperature is at 250 Deg C.
So please suggest me some greases which can perform continuously at 250 Deg C.

Will this temperature harm the selected self aligning roller bearing before its calculated rated life?

Thank you all in advance

Edwin,

It's all about how high is the temperature ON the bearing. The bearing temperature should be lower then that unless it's inside an extremely hot place. If that is the case, first things first, choose your bearing very carefully. Then as Ciprian says, choose a PTFE PFPE grease, there are many in the market. But make sure you choose the right base oil viscosity before you buy the grease. I won't give you a brand, there are many out there that have this type of product. if you need anything else fill free to ask.

Pedro

Dear Edwin,

You pointed to a very important aspect: the exact temperature on the bearing.
This remindes me of a recent application I've ecountered in a bitumen membrane impregnating machine and maybe you, or someone else could help me.
I will post a new topic on this issue.
Thanks for reminding me!

Regards,

Ciprian

Dear all,

Thank you very much all of you for spending your valuable time to answer my question. After lots of discussion we came to the conclusion of using SKF Graphalloy bearing for this application as the temperature and misalignment requirement is high. Hope it should work for long time with out giving the Problem.

quote:

Originally posted by Edwin:
Dear all,

Thank you very much all of you for spending your valuable time to answer my question. After lots of discussion we came to the conclusion of using SKF Graphalloy bearing for this application as the temperature and misalignment requirement is high. Hope it should work for long time with out giving the Problem.

Hi Edwin,

Let`s say SKF bearing is the best bearing, and let`s say Kluber is the best grease for that application. Your next problem will be are in re lubrication, right volume of grease and right frequency. If you fail to get the right amount and frequency, breakdown will surely occur.

First i would ask what type of grease are you already using?

Dear Edwin,

The selection of grease depends on a number of factors, the critical being:
1. Operating temp 2. Operating conditions - in water 3. Base desired 4. Pumpability - NLGI number

1. Grease works best at temp between 30 to 40 Dec C below the drop point. However many Synthetic grease have a very high drop point or none.

2. If the operations are Marine or likely to have ingress to water ( Wheel bearings in flooded areas) the grease should have good resistance to water washout. In a Marine environment the grease should additionally be biodegradable and possibly meet HOCNF (Harmonised Offshore Chemical Notified Format).

3. For high temp operations, the base oils are invariably synthtetic & Group 3 or 4 type. Today a variety of EP additives are available. Graphite and Moly based greases or not in favour as before.

4. Pumpability is important in high temp operations and a NLGI 000,00, and 1 are best suited.

Hussam

You can try Nye uniflor 4622 R from nye lubricants usa .It is a PFPE base oil with PTFE as a thickener.website www. nyelubricants.com

Dear Edwin,
Alternatively (Kluber Barrierta L 55 series) you can use Klubertemp HM 83 402 it has a service temp range of +260 deg C

Here is a new high temperature grease with Dropping Point, °C, (°F) (ASTM D-2265)
345 (650) and water resistant Water Washout, % (ASTM D-1264)
=1

Not sure if it would be applicable in your application, but it is a new grease available mainly for offroad construction equipment that needs pound out resisitance.

More info at http://www.amsoil.com/storefro...por2.aspx?zo=1181889 .