Roxul Industrial Insulation Process - Manual (Page 110)

2. Theory
2.2 Product properties & test methods
The requirements for industrial insulation are high
and varied. Piping, boilers, storage tanks require
insulation materials with particular properties.
Although the application and type of products may
vary, the basic definition of all product properties is
the same.
2.2.1 Fire behavior
2.2.2 Thermal conductivity
2.2.3 Maximum service temperature
2.2.4 Water leachable chloride content
2.2.5 Water repellency
2.2.6 Water vapor transmission
2.2.7 Longitudinal air flow resistance
2.2.8 Compression resistance
2.2.9 Density
The relevant standards, guidelines and project
specifications are explained in 2.1. The following
text outlines the most important product
properties of stone wool (mineral wool) insulation
products for insulation of technical installations.
2.2.1 Fire behavior
a) Introduction
The fire load in a building or industrial installation
is increased considerably by flammable/
combustible insulation materials. Non-combusti-
ble insulation materials such as mineral wool,
with a melting point higher than 1800 °F
(1000 °C), on the other hand, not only have a
positive impact on the fire load, but also constitute
a certain form of fire protection for the insulation
installations.
Often one confuses fire resistance with reaction to
fire.
Fire resistance indicates how well a building
component, for instance, can hold back the fire
and prevent it from spreading from one room to
another – for a stated period of time. Does it
function as a fire shield or not? Fire resistance is
an extremely important characteristic. For
example, a vessel containing flammable liquids.
Serious accidents/explosions can occur if a vessel
is not protected against fire from the outside.
Reaction to fire indicates the smoke development
and combustibility / flammability if the insulation
is exposed to fire.
b) CEN standards
A distinction is generally made between non-com-
bustible and combustible building materials. The
insulation materials are exposed to fire. The
flammability and smoke development and droplets
of melted insulation are observed and rated.
The classification of insulation materials depends
on the relevant fire standards. In the second half of
the 20
th century, almost every country in Europe
developed their own national system for fire testing
and classification of building materials in particu-
lar. The European Community has developed a new
set of CEN standards. The “Reaction to fire”
classes test three properties: spread of fire, smoke
intensity and burning droplets.
Spread of Fire
The building components are classified in class
A1, A2, B, C, D, E and F. Additional classifications
provide information on products tending to
produce smoke and burning droplets or particles.
Class A1 products are non combustible. They
will not cause any sustained flaming in the non
combustibility test.
Class A2 product must not show any sustained
flaming for more than 20 seconds in the non
combustibility test. The A2 products have to be
tested for fire contribution, smoke intensity and
burning droplets.
Class B product flaming must not spread more
than 6" (150 mm) in 60 seconds, when
evaluated by a small flame test. Class B
products have to be tested for fire contribution,
smoke intensity and burning droplets
Class C product contributes to flashover after
10 min.
Class D product contributes to flashover after 2
min.
Class E product for less than two minutes.
Class F is not tested.
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