Roxul Industrial Insulation Process - Manual (Page 115)

2.2 Product properties & test methods
2.2.3 Maximum service temperature
The temperature at which an insulation material
is used should be within the temperature range
specified for the material, in order to provide
satisfactory long-term service under conditions
of use.
This temperature is defined as maximum service
temperature. The following factors should be
considered when selecting insulation materials to
be used at elevated operating temperatures.
Ability to withstand loads and vibrations
Loss of compression strength after heating
Linear shrinkage after heating
Change in thickness after heating and loading
Internal self-heating (exothermic reaction or
punking) phenomena
Type of finishing of the insulation
Support structures for the insulation
Support structures for the cladding
IMPORTANT NOTE
The maximum service temperature of
insulation materials can be tested in
accordance with the test methods: EN 14706
and -7 (replaces AGI Q 132), ASTM C411 or
BS2972. Each test standard has a different
test method and its own criteria. ASTM C411
and BS2972 can be used to determine the
maximum operating temperature at which an
insulation material can be used, without its
insulating capacity deteriorating. EN 14706
and -7 are used to classify insulation
materials according to their behavior at high
temperatures based upon time-load
exposure. Due to the effect of load during
testing, the measure maximum service
temperature in accordance with EN 14706
and -7 is lower than the other standards and
therefore tends to reflect a more practical
temperature limit for design performance.
ASTM C411
ASTM C411 is the standard test method for
hot-surface performance of high-temperature
thermal insulation.
This standard covers the determination of the
performance of wraps (mats), boards (slabs) and
pipe sections when exposed to simulated
hot-surface application conditions.
Wraps (mats) and boards (slabs) are tested with
the heating plate or pipe apparatus. The heating
plate or pipe is uniformly heated to the declared
maximum service temperature. Products are
exposed to one sided heating.
ASTM C411 places no specific demands on the
product performance after heating. Only the
following results must be reported.
Extent of cracking, other visible changes
Any evidence of flaming, glowing, smouldering,
smoking, etc.
Decrease in thickness, warpage, delamination
Sagging pipe (pipe insulation)
BS 2972
This standard specifies test methods for the
various properties of inorganic thermal insulation
materials. Section six “heat stability of this
standard” is designed to determine the
performance of insulation materials when
exposed to heating for 24 hours in an oven or
furnace at the designed temperature.
BS 2972 places no specific demands on the
product performance after heating. Only the
following results must be reported:
Average percentage change of length, width,
thickness and volume of specimens;
Percentage change of mass of the specimens
before and after the test
Change in compression strength of the
specimens before and after the test.
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