Roxul Industrial Insulation Process - Manual (Page 117)

2.2 Product properties & test methods
2.2.3 Maximum service temperature
Application of maximum service
temperature
The practical application of the test methods
varies by country and plant owner. In case of
special conditions, where the insulation is
permanently exposed to high dynamic loads and
temperatures (e.g. Power Plants), a considered
insulation selection is required as it cannot be
included within the measurements. This can be
done based on expert judgement or by using the
reduction factors (fa) as defined in the German
Standard AGI Q101 “Insulation works on power
plant components”. The calculated service
temperature is generally below the maximum
service temperature.
When selecting a suitable insulation material in
terms of the maximum service temperature, the
external influences affecting the insulation system
must be considered, for example:
Static loads (e.g. cladding)
Dynamic loads (e.g. oscillations)
Type of construction (with or without a spacer).
The table shown on the following page, showing
general reduction ratios f
a
for determining the
working temperature, is taken from AGI Q101.
In this respect, the maximum service temperature
should be multiplied by f
a
.
Reduction ration (f
a
)
Maximum service
temperature
With spacer and support
construction
Without spacer and support
construction
With spacer and support
construction + air space
(°F) (°C)
Pipes ≤ NPS 20
(DN 500)
752 400 1.0 0.9 0.9
1076 580 0.9 0.9 0.9
1310 710 0.9 0.8 0.8
Pipes ≥ NPS 20
(DN 500)
752 400 0.9 0.8 0.9
1076 580 0.9 0.8 0.9
1310 710 0.9 0.8 0.9
Flue gas ducts, hot air ducts,
steel chimneys, vessels,
gas turbine ducts
752 400 0.9 0.8 0.9
1076 580 0.9 0.8 0.9
1310 710 0.9 0.8 0.8
Boiler walls 0.8
Within range of boiler roof 0.9
Dead spaces 0.8
Reduction ratio (f
a
) for determining the working temperature
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