Valves in High Temp Seawater Service 1

[FIF99]

Hi,

At this moment I'm reviewing some high alloy valves within High Temperature (above 400 degr.C) FlueGas/Seawater application. Graphite gaskets and Stem Seals are no option due to expected Galvanic Corrosion.
Could somebody share some experiences with me regarding sealing materials for such an application.

For this moment I am not awaire of any alternatives for graphite for which suitability is shown.

Thanks in advance!

Regards,
FKE

 

[moltenmetal]

Seems to me that you either have "seawater" or you have 400 C- not both. If you do have both (at different times perhaps, or one in the form of exterior spray and the other internal), work on design to separate them.

Expanded graphite is the seal material of choice (or last resort) for these sorts of temperatures, though the galvanic issue is there in aqueous services. You lost your nearest option (PEEK) at ~315 C. Other options like ceramic fibre, "Thermiculite" etc. are less suitable alternative options that work reasonably well as fillers in spiral wound gaskets etc. but perform less well as a stem packing.

 

[FIF99]

Hi,
Thanks for your info!

Is "Thermiculite" as stem packing less suitable due to the sealing properties (external leakage)?

This material is indeed known as gasket material, but I don't have experienced this material as stempacking, although fabricators explained it can be fabricated hereof.

Do you or anybody else have any experience in Graphite Stem packings with Corrosion Inhibitors.

Again, thanks in advance.

Regards,
FKE