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High Temperature Seat Seals for Ball Valves 1

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bogiedreamer

Mechanical
Apr 14, 2005
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For ball valves, we usually use Spring Energized Teflon seals for the seat position for temperature range under 300C. But now we have an application where the fluid temperature can be 400C to 450C where Teflon will not work, what kind of seal should we use?

thanks,
 
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At 400 degree C you need a metal seat (not elastomer) eliminate most conventional ball valves. Several threads exist that list some of the suitable manufacturers. Examples that may be suitable and may not exactly be a ball valve include Orbit, Mogas, Argus, Adams, perhaps Worchester or Velan.
 

JLSeagull is correct in my opinion.

At this temperature you should have a serious look at your valve selction, and include in the selection process type of fluid, pressure before and after the valve, necessary pressure class (pressure and temperature determined!), performance required (thigtness,tests,special considerations as anti-static,firesafe, pressure loss etc) and also lifetime expectancy of the different valve types including sealing.

It is always better to optimize from process requirements and engineering and equipment economy than starting with a certain type of valve in mind.


 
At 400-450 C you are into metal seats. You are well beyond PEEK. And the valve you get will be VERY different than the resilient seated valve you're accustomed to.

Take a good hard look at whether or not a ball valve is the right selection for your service. Other valve designs exist for a reason...

If you still need a ball valve, there are still plenty of manufacturers to choose from who know how to do metal seats properly. They're not cheap, though.
 
i have had mogas valves, with metal to metal seats on plant for a number of years causing little problems, this is on a superheated steam system. Assuming that water/steam is the medium i think metal is a cost affective and low maintenance way.
 
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