Roxul Industrial Insulation Process - Manual (Page 74)

Insulation of boil
er
s
temperature ranges, as are often encountered in
dead spaces. Outer layers can be constructed with
different types of ProRox
® insulation to optimize
the overall performance, depending on the
temperature of the adjacent layer. AGI guideline
Q101 suggests, galvanized wire netting and
galvanized stitching wire in wired mats can only be
heated up to a temperature of 750 °F (400 °C).
With tempera tures above 750 °F (400 °C),
austenitic stainless steel wire netting and
stitching wire must be used. To reduce the
convection in the insulation of vertical
constructions such as boilers, only use insulations
that exhibit an air flow resistance of ≥ 50 kPa s/m².
Before starting the insulation works, ensure that
all preparatory work on the object has been
completed. Refer to Chapter 1.1 for details.
ProRox ® insulation is minimum 5 pins per board
(or 6 pins per m 2 ), and a minimum of 8 pins per
board (or 10 pins per m 2 ) on the underneath. The
pins are either welded directly onto the surface of
the object or are screwed into nuts. With finned
walls (tube-fin walls), the pins cannot be fixed to
the pipes, but must be welded onto the bars
between the pipes. Observe the following when
pinning the insulation:
With insulation thicknesses ≤ 5" (120 mm), use
8GA (6AWG) pins with a minimum diameter of
0.162" (4 mm).
With insulation thicknesses ranging from 5 1/2"
to 10" (130 to 240 mm), use 6GA (4AWG) pins
with a minimum diameter of 0.2043" (5 mm).
With insulation thicknesses ≥ 10" (240 mm) use
4GA (3AWG) pins with a minimum diameter of
1/4" (6 mm).
If the cladding rests directly on the insulation
without a gap between the two, the pins must
be 3/8" (10 mm) shorter than the insulation
thickness.
Fasten each insulation layer with clips.
With wired mats, all the lengthwise and crosswise
joints must be sewn or wired together, or joined
with six mat hooks per meter. If the insulation is
assembled in multiple layers, the joints of the
individual insulation layers must be staggered.
The following illustrations show a number of
typical methods of insulating vessels.
1. Tubed wall - 2. Insulation: ProRox ® Wired Mats -
3. Fastening pins with spring plates - 4. Cladding
Diagram of a boiler insulation system with
wired mats
Diagram of a boiler insulation system with a gap
between the insulation and sheet cladding
1. Finned pipe - 2. ProRox ® insulation - 3. Fastening pins
with spring plates - 4. Aluminum foil if necessary -
5. Metal cladding (e.g. profiled sheet)
71