||H2O and trace elements
low chloride product
products with a lower level of chlorides are available by
They find application when temperature and humidity conditions
conducive to stress corrosion cracking of stainless steel are
likely to be encountered.
Continuous Use Temperature: 1000 deg C
Progressive devitrification eventually leading to
brittleness will occur above this temperature.
Short Term Use Temperature
Dalfratex products can be used up to the softening point if the
exposure is of limited duration. The actual duration of exposure
is a function of temperature and mode of use. Advice on the
suitability of a Dalfratex product for a given application may
be obtained from Ceramisis. Some examples of this type of use
are: Manufacture of flexible fire barriers and curtains. Fire
stopping of pipe penetrations through rigid fire walls.
Protection of personnel and plant from liquid metal splash.
Softening Point: approx 1600 deg C.
Thermal Shock Resistance : excellent
products have an initial high rate of shrinkage which is
irreversible, and occurs when they are first heated. The
following graph is given for guidance only, and is based on
measured values for broadcloth.
applications, shrinkage of Dalfratex in-situ during the first
heating may be undesirable. For these applications, most
Dalfratex products are available in a pre-shrunk form. Further
limited shrinkage may still occur in use, depending upon the
temperature and time conditions prevailing, but typically will
be less than 2% at 1000 deg C.
following values of thermal conductivity shown on the graph,
below, were determined using the water calorimeter procedure
described in BS 874: 1973, paragraph 4.2.5. Units are Wm/m2 °C.
The thermal conductivity values of ball in a slightly compressed
condition (density 96kg/rn3) are reported, being the most common
application form. In the fully relaxed, as supplied, condition
the thermal conductivity is 10% to 15% higher at elevated
250 C= 0.80
j/g deg C, 500 C= 0.88, 750 C= 0.96, 1000 C= 1.09
fibre is a good electrical insulator, with high electric
strength and low electrical conductivity.
For most design purposes it may be assumed that the electrical
breakdown strength of a region filled with Dalfratex, is
essentially that of atmospheric air.
The dielectric properties of Dalfratex at room temperature are
adversely affected by the presence of associated water. This can
substantially be removed by heating the material to 100 deg C to
200 deg C, when the losses are significantly reduced.
The electrical properties of Dalfratex have been measured by an
independent testing laboratory, and their report is available
upon request from Ceramisis Limited.
properties of Dalfratex are similar to those of vitreous silica
In general Dalfratex is compatible with mineral acids except
phosphoric and hydrofluoric and is also compatible with a wide
range of substances including air, chloride, carbon monoxide,
ammonia, sulphur dioxide.
Dalfratex products are compatible with silica refractories at
high temperatures. As there is no possibility of forming a
SiOz’Al203 eutectic, Dalfratex can safely be used in conjunction
refractories in coke ovens, glass melt tanks etc.
Dalfratex products are not recommended for use in contact with
bases such as sodium and calcium hydroxides or substances giving
the reaction of these, e.g. sodium silicate.
set out in this publication are for information purposes only
and their accuracy is not warranted or guaranteed. These
particulars do not constitute an offer or any part of an offer.