Large Bore Process Pipework
Where the pipe bore is too large for the pre-formed Crown Pipe
Insulation, Rocksilk Mattress provides a versatile
alternative.
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Rocksilk Mattress |
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Metal Band
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Products
Rocksilk Mattress is a
non-combustible rock mineral wool faced on one side with galvanised
or stainless steel wire mesh to form a firm but flexible general
purpose insulating mattress. It is available in two densities: SD1
is 100 kg/m3 and HD1 is 125 kg/m3.
The galvanised wire mesh is 0.82mm x 25mm (22 swg x 1”). Both
grades are also available in a water repellent grade and/or with a
stainless steel mesh, 0.9mm x 25mm, subject to enquiry.
Typical Construction
Rocksilk Mattress is
particularly Rocksilk Mattress suitable for the insulation of large
diameter and high temperature pipework. It is suitable for wrapping
any large curved surfaces or cutting to fit over irregular shaped
surfaces, such as valves.
Recommended minimum thicknesses of insulation
| Pipe
Size |
Operating
Temperature (°C) |
|
Bore |
o/d |
|
| (ins) |
(mm) |
(mm) |
100 |
200 |
300 |
400 |
500 |
600 |
700* |
| 3/8 |
10 |
17 |
50 |
75 |
75 |
75 |
100 |
125 |
125 |
| ½ |
15 |
21 |
50 |
75 |
75 |
100 |
100 |
125 |
125 |
| ¾ |
20 |
27 |
50 |
75 |
75 |
100 |
125 |
125 |
150 |
| 1 |
25 |
34 |
50 |
75 |
75 |
100 |
125 |
125 |
150 |
| 1¼ |
32 |
42 |
50 |
75 |
100 |
100 |
125 |
150 |
150 |
| 1½ |
40 |
48 |
50 |
75 |
100 |
100 |
125 |
150 |
150 |
| 2 |
50 |
60 |
50 |
75 |
100 |
125 |
150 |
150 |
175 |
| 2½ |
65 |
76 |
75 |
100 |
100 |
125 |
150 |
175 |
175 |
| 3 |
80 |
89 |
75 |
100 |
100 |
125 |
150 |
175 |
200 |
| 4 |
100 |
114 |
75 |
100 |
125 |
125 |
175 |
175 |
200 |
| 5 |
125 |
139 |
75 |
100 |
125 |
150 |
175 |
200 |
- |
| 6 |
150 |
168 |
75 |
100 |
125 |
150 |
175 |
200 |
- |
| 8 |
200 |
219 |
75 |
125 |
125 |
175 |
200 |
- |
- |
| 10 |
250 |
273 |
75 |
125 |
150 |
175 |
200 |
- |
- |
| 12 |
310 |
324 |
75 |
125 |
150 |
175 |
- |
- |
- |
| - |
- |
356 |
75 |
125 |
150 |
175 |
- |
- |
- |
| - |
- |
406 |
100 |
125 |
150 |
175 |
- |
- |
- |
| - |
- |
457 |
100 |
125 |
150 |
200 |
- |
- |
- |
| - |
- |
508 |
100 |
125 |
150 |
200 |
- |
- |
- |
| - |
- |
559 |
100 |
125 |
150 |
200 |
- |
- |
- |
Note:
This table is extracted from BS 5422:1990 and the thicknesses shown
are rounded to the nearest commercial thickness.
*For temperatures above 600ºC and up to 750ºC Rocksilk Mattress
Grade HD should be used
Installation
is a non-combustible
Rocksilk Mattress is wrapped round the pipe, with the wire mesh on
the outside surface. Pieces of closely butted mattress are joined
together by lacing the adjacent edges of the wire mesh together
with wire. The insulation is usually held in place by metal bands,
adhesive (except at high temperatures) or a combination of the
two.
Performance
Operating temperatures
Rocksilk Mattress can be
used up to continuous operating temperatures of:
- Up to 600ºC: SD Grade
- Up to 750ºC: HD Grade
Notes: Galvanised
wire mesh in contact with temperatures above 350ºC may suffer
embrittlement
Fire Performance
The rock mineral wool of Rocksilk
Mattress is non-combustible to
BS
476: Part 4: 1970 (1984).
Thermal Performance
The thermal conductivity of
Rocksilk Mattress varies with temperature as per the below:
| Mean
temperature |
Thermal
conductivity (W/mK) |
| (°C) |
SD
|
HD |
| 50 |
0.037 |
0.037 |
| 100 |
0.044 |
0.043 |
| 150 |
0.052 |
0.050 |
| 200 |
0.062 |
0.059 |
| 250 |
0.074 |
0.070 |
| 300 |
0.088 |
0.082 |
| 350 |
0.104 |
0.096 |
| 400 |
0.124 |
0.111 |
Note: Tested in
accordance with BS 874: 1973 (1980)
Insulation
thicknesses should be set by
the specification, but otherwise meet the Operating recommendations
given in
BS
5422:
1990/2001.
Acoustic
Performance
The use of Rocksilk Mattress
can significantly reduce the noise generated by liquid and granular
materials being transported at high velocity in pipework.
Other Advantages
- Corrosion free when used with austenitic stainless steel
- Reduced thermal bridging
- No deterioration of performance Acoustic over time
- Speed of installation
See Detailed Design Considerations for more
information.