Stem Packing for high pressure / temperature

[pingmi]

Hi,

I'm in process of designing a valve for a steam / condensate application 250 barg pressure and 525°C temperature. In order to select suitable stem packings, I need to explore different seal / packing options that provide reliable sealing (Class VI Leakproofness).

I know graphite (with SS reinforcement) packings work well for such applications but I do not have any design guidelines for the same. Can anyone help on this?

O rings provide reliable radial seals but at much lower working temeparatures (max upto 250/260°C or so).

Any other options possible?

Thank in advance.

 

[azigue]

You use packing graphite based "

http://www.garlock.co.uk"

if you don't have contact with oxygen(corrosion of graphite)
In some case you can use metallic seal. It depends on how the stem move