Page 5 - Design Criteria.qxd

® Welcome to the Next Generation of Sealing Technology
6
Soft Cut Gaskets
Compressed Asbestos Fiber
(CAF) gaskets served indus-
try’s needs for many years.
With the shift to non-
asbestos gaskets, gasket
manufacturers have devel-
oped a myriad of replace-
ment products. Some of the
initial materials developed
proved inferior to their
asbestos based predecessors
in regard to temperature,
chemical resistance, creep
resistance and sealing char-
acteristics.
More recently Flexi-
tallic has developed non-
asbestos gasket sheet prod-
ucts approaching, and in
some instances surpassing the capabilities of asbestos sheet gaskets. Some of these products have
been fiber reinforced grades, manufactured by the traditional calendering or sheeter process. Other
product ranges are fiber-free and some of these materials have exceptionally good properties which
exceed the capabilities of CAF.
Flexitallic Thermiculite is a high temperature gasket material based upon the mineral vermic-
ulite. The product is reinforced with a metal core and is designed for use at temperatures which
exceed the capability of graphite based sheets. The temperature capability of CAF is also exceeded
by Thermiculite.
The Flexitallic Sigma range of biaxially orientated PTFE products has superb chemical resist-
ance, far exceeding that of CAF. These materials can be used at temperatures from cryogenic to
260°C (500°F). Being intrinsically clean they are especially suitable for use in the food, pharmaceu-
tical and electronics industries.
Flexicarb is the name given to Flexitallic’s range of graphite based products. The range
includes graphite foil as well as graphite laminates which contain reinforcing metal cores to overcome
the fragility of the non-reinforced foil. Graphite products have excellent stress retention properties
and are resistant to most chemical media with the exception of strong oxidizing agents. Reinforced
Flexicarb sheets are the standard sealing product for many arduous applications in the petrochemical
and refining industries.
The Flexitallic SF and AF product ranges are rubber bound, fiber reinforced sheets made by
the traditional calendering or sheeter process. A wide range of fiber types are used, often in combi-
nation, ranging from cellulose, rockwool and glass to aramid and carbon.
Soft cut gasket sheets are typically used in Class 150 or Class 300 flanges; some of the metal
reinforced products can also be used in higher classes. The temperture capability of the fiber/rubber
products is highly thickness dependent, with thin gaskets having a wider service envelope than thick-
er ones.