When discussing high temperature seals, the first thing that needs to be defined is just what we mean by a high temerature seal. Some customers consider a high temperature seals as one that will handle 500 F. Others feel 1000 F is high temp. So lets first break down what we mean.
If your looking for an elastomer that is high Temperature your probably looking for FKM / Viton, Aflas, Amerirez or Kalrez. When we go beyond elastomers the highest of which is Kalrez at approx. 600 F, then we get into what we consider high temperature seals.
In non-elastomer products, when looking for high temperature seals we offer several options. To know which of these materials is best suited for your application key factors must be considered.
The first thing to be considered is what is the maximum temperature your application has.
The primary non-metallic, non-asbestos, materials used in "high temperature seals" include the following materials or a composition containing the following materials: flexible graphite, mica, vermeculite, fiberglass, and silica. There Temperature ratings do vary and in the case of flexible graphite it varies with the presence of oxygen.
To determine which of these materials is right for you several things have to be evaluated.
You must consider the PH value the seals will see. Are there chemicals present ? If so are they present continuously or just during a cleanout.
Are we sealing a liquid or a gas ?
Is the seal dynamic or static ? If it's dynamic what is the speed and direction.
What is the pressure ? Is the pressure continuous or are there spikes ?
Once we know the details of your application we can help you with your high Temperature application.
Because Grafoil® is so conformable it takes on the shape of any opposing
flange which is why it seals so very well. With it's 0-14 ph capability
it's compatible with most chemicals. From a temperature standpoint Grafoil©
is also very flexible. Compatible with Cold (-400 F) to very hot (5400
F in Non-oxydizing atmosphere).850 F in oxydizing atmosphere. Grafoil®
is also available in Oxidation resistant grades offering 975 F rateing.