Product
Rocksilk Universal Slabs
are semi-rigid to rigid rock mineral wool slabs, bonded with a high
performance binder.
They are available unfaced or faced with aluminium foil or white
tissue and in a range of densities from 33 to 200
kg/m3.
Typical Construction
Rocksilk Universal Slabs
are used for the thermal and acoustic insulation of buildings,
building services and industrial applications, but mostly for
thermal insulation of process vessels.
Note: Vessels can include large and small
rectangular, cylindrical and irregular pieces of equipment, high
towers for chemical process plants, large storage tanks and spheres
as well as boilers and steam turbines.
In selecting the most suitable product, the following criteria must
be considered:
- Maximum service temperature
- Degree of insulation efficiency required
- Robustness of insulation necessary to support the applied
finish and withstand the environment.
Generally, the higher the
temperature, the higher the density required.
However, it may be prudent to
select a density of slab higher than that necessary for the
temperature where a more robust insulant is required to support the
covering and other loads which may at times be imposed, such as
foot traffic on top of large tanks.
Installation
For weatherproofing,
PIB
sheeting may also be applied. For
additional mechanical strength, metal sheeting should be
used.
Cylindrical vessels
 |
Rocksilk Universal Slabs |
For cylindrical vessels up
to 1120mm outside diameter, Knauf Insulation recommend that they
should be insulated as pipes where preformed pipe insulation is
available or with Rocksilk Universal Slabs having a density of not
more than 33 kg/m3.
For cylindrical vessels between 1120mm and 3500mm in diameter,
Knauf Insulation recommend Rocksilk Universal Slabs with a density
of 45 kg/m3. These slabs are sufficiently flexible for
this curvature.
For cylindrical vessels over 3500mm in diameter, Knauf Insulation
recommend Rocksilk Universal Slabs of any density. The metal bands
should not be over tensioned so as to significantly reduce the
thickness of the insulation. On vertical surfaces, circumferential
support rings shall be fitted and spaced apart at distances which
will provide adequate support according to the weight of the
insulation. The support rings shall protrude from the vessel to a
maximum distance of 10mm less than the thickness of the insulation.
All joints must be well butted together and vertical joints
staggered on adjacent courses. In multi-layer applications, all
joints should be staggered.
The insulation may be fixed to domed ends by impaling over pins and
secured with spring washers or forked pins welded to the vessel. In
either case, the outer ends of the pins should be depressed below
the surface of the insulation to prevent heat being transmitted
direct to the covering.
Rectangular vessels
|
Rocksil Universal Slabs |
 |
Pins fixed to the surface of the vessel |
Rocksilk Universal Slabs shall be
secured to the surface with suitable adhesive. The adhesive to be
applied should cover the entire surface (it is important to follow
the manufacturer’s instructions).
Alternatively, the insulation may be impaled over pins fixed to the
surface of the vessel at the following pitches:
- Vertical surfaces at an approximate square pitch of 450mm
- Upward facing surfaces 600mm
- Overhanging or downward facing surfaces 300mm.
Location of pins should be arranged
so that there is a pin not more than 50mm from each corner of the
slab.
All joints should be closely butted together. Vertical joints (and
in multi-layer applications, all joints) must be staggered and at
corners, adjacent slabs must be overlapped to the thickness of the
insulation.
When using pins with spring clip washers, the length of the pin to
be 10mm shorter than the thickness of the insulation to avoid hot
spots on the cladding. This is normally achieved by compressing the
mineral wool insulation with the spring washer by 10mm and cropping
the pin back to the washer.
Note: Vessels operating at sub-ambient
temperatures must have an adequate continuous vapour seal applied
over the insulation and fixings.
Performance
Fire performance
Rocksilk Universal Slabs are
classified as non- combustible to
BS
476: Part 4: 1970 (1984), Class 1
surface spread of flame to
BS
476: Part 7:1997 and Class ‘O’ to the Building Regulations.
Moisture resistance
Rocksilk Universal Slabs are
non-wicking when tested to
BS
2972: 1989: Section 12. When exposed to 90% relative humidity and
20°C, Rocksilk Universal Slabs absorb less than 0.004% of
moisture.
Thermal performance
The thermal conductivity of
Rocksilk Universal Slabs vary with thickness and temperature.
|
Thermal Conductivity (W/mK) |
| Mean
Temperature °C |
| TYPE |
10 |
25 |
50 |
100 |
150 |
200 |
250 |
300 |
350 |
400 |
| RS33 |
0.035 |
0.037 |
0.040 |
0.052 |
0.069 |
- |
- |
- |
- |
- |
| RS45 |
0.033 |
0.035 |
0.038 |
0.049 |
0.061 |
0.079 |
- |
- |
- |
- |
| RS60 |
0.033 |
0.034 |
0.037 |
0.046 |
0.057 |
0.071 |
0.089 |
- |
- |
- |
| RS80 |
0.033 |
0.034 |
0.037 |
0.044 |
0.054 |
0.066 |
0.080 |
0.097 |
- |
- |
| RS100 |
0.033 |
0.034 |
0.037 |
0.044 |
0.052 |
0.062 |
0.074 |
0.088 |
0.104 |
- |
| RS128 |
0.033 |
0.034 |
0.037 |
0.043 |
0.050 |
0.059 |
0.070 |
0.082 |
0.096 |
0.111 |
| RS140 |
0.033 |
0.034 |
0.037 |
0.043 |
0.050 |
0.059 |
0.069 |
0.081 |
0.094 |
0.109 |
| RS200 |
0.034 |
0.035 |
0.037 |
0.042 |
0.049 |
0.057 |
0.066 |
0.077 |
0.089 |
0.102 |
Acoustic performance
Rocksilk Universal Slabs will provide effective control of noise,
however the actual performance varies with insulation thickness and
surface finish.