Roxul Industrial Insulation Process - Manual (Page 40)

Insulation of piping
The recommended sheet thickness deviates to a
certain level per standard/country. The thickness
recommended by CINI is shown in the table above
(values converted to inches). See page 148 in
Chapter 3.2.2 for the thickness according to DIN
4140 and BS 5970.
To reduce the risk of galvanic corrosion, it is
important to use the correct screws, straps etc.
See the table on page 21 for more information.
The basic guidelines are:
Fasten sheet cladding on lengthwise joints with
at least six sheet metal screws or blind rivets
every meter.
Place the screws or blind rivets equidistant.
If screws or rivets are fitted in two rows, do not
stagger the screws or rivets.
The cladding can also be held in place with
corrosion-resistant straps instead of screws
or rivets.
Do not use aluminum screws.
Influence of the cladding on the
surface temperature
In addition to the insulation thickness, the thermal
conductivity of the insulation and the ambient
conditions (for example temperature and wind),
the surface temperature of insulation is also
influenced by the emission ratio (emissivity) of the
cladding.
The following applies as a general rule for
thermal insulation: the shinier a surface is (lower
emissivity), the higher the surface temperature.
The following example shows the various surface
temperatures that depend on the cladding:
Diameter: 4 1/2" (114 mm)
Temperature of the medium: 930 °F (500 °C)
Place of installation: Interior [Wind speed 1.1
mph (0.5 m/s)]
Insulation: ENERWRAP ® MA 960 NA
pipe wrap (mat), thickness 4" (100 mm)
Various cladding materials
- Aluminum sheet
- Galvanized steel sheet, bright
- Stainless steel
- Paint-coated plastic cladding
Recommended sheet thickness and overlaps regarding cladding made from flat sheets (CINI)
External diameter of
the insulation (in)
Minimum thickness (inches) of metal cladding sheet (recomended by CINI)
Aluminum
(CINI 3.1.01)
Aluminized
steel sheet
(CINI 3.1.02)
Alu-Zinc coated
steel sheet
(CINI 3.1.03)
Zinc coated
steel sheet
(CINI 3.1.04)
Austenitic stainless
steel sheet
(CINI 3.1.05)
< 5.5" 0.024 0.022 0.020 0.020 0.020
5" to 12" 0.031 0.031 0.031 0.031 0.031
> 12" 0.039 0.031 0.031 0.031 0.031
Surface (cladding) temperature °F
Aluminum
cladding
100
105
110
115
120
125
130
Galvanized
steel
Stainless
steel
Paint-coated
Plastic
cladding
37