Axial bearing for high temperature

[CptMaaB]

Hello valve engineers,
i have a question regarding metallic ball valves for temperatures up to +470°C.
What kind of axial bearing could i use (for the stem), that withstands such high temperatures, without increasing the actuation torque to much higher Levels.
Should i look for ceramic materials, or can i use maybe metallic materials with Tungsten carbide coating?
What material works the best?

Regards, Capt`n Maab.

 

[gerhardl]

Your temperature range is at a level where 'normal' high-temeprature bearings come to short. You will probably have to ask directly at a producer that have materials that covers your range and present your problem/design.

Graphalloy and others (google!) might help solve your problem and answer your question.

 

[CptMaaB]

Thanks gerhardl for your response.
I allready googled alot, but found nothing specific.
Graphalloy is new for me, so i would have a look on it, thank`s!