Page 2 - Design Criteria.qxd

Flexitallic’s new Thermiculite™* sheet gasket
will not oxidize, even at temperatures up to
1600°F.
This graph illustrates that, unlike graphite, the load loss at
operational temperatures does not increase with time.
G R A P H 1
Thermiculite Relaxation vs. Temperature in
Comparison with Data from Graph 3
(All data generated by TTRL)
FLEXITALLIC’S new high-temperature, sheet-sealing material is
comprised of chemically exfoliated and thermally exfoliated vermi-
culite on a tanged, 316 stainless steel core.
This revolutionary new product simulates the structure of
exfoliated graphite but with one notable exception . . . Thermiculite
Gaskets by Flexitallic maintain their integrity, even at extreme
temperatures.
Thermiculite is thermally stable, ensuring against thermal
oxidation (see Graph 2).
Independent testing at TTRL, Montreal (see Graph 4) shows
that Thermiculite has excellent sealing properties.
* Patented and patents pending
Oxidized graphite sheet gaskets like this
one have been a common sight since the
reduction in the use of asbestos. Flexitallic
rose to the challenge of creating an alter-
native to graphite soon after a
Westinghouse paper was presented at the
1990 Boston, MA ASME/IEEE Power
Generation Conference (“Evaluation of
Asbestos Free Gasket Materials” by
W.F.Jones and B.B.Seth, Westinghouse,
Power Generation Technology and Strategic
Operations Division). This paper limited
graphite sheet material to 650°F in five
years of service. This conclusion was
corroborated by the outcome of a PVRC
project at the TTRL (see Graph 3).
Vermiculite’s thin, flexible, soft plates can
be exfoliated like graphite. They retain the
sealability and low porosity of graphite, but
Flexitallic’s new Thermiculite sheet gaskets
will not oxidize at high temperatures.
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