Roxul Industrial Insulation Process - Manual (Page 36)

Insulation of piping
1.2.3 Insulation with wired mats
Pipe insulation with wired mats has been a
time-tested universal solution for many decades
now. Due to their flexibility and high temperature
resistance, wired mats can be easily cut and
mounted onto the piping. These wired mats are
ideal for application on large pipe diameters and
shaped pieces as elbows or T-joints.
Wired mats have a relatively low resistance to
pressure and from a practical point of view should
only be mounted in combination with spacers.
Because of the resulting thermal bridges, better
insulation performances are often achieved in the
lower and middle temperature range [up to 550 °F
(300 °C)] with pipe sections or load bearing wraps
(mats) rather than with wired mats.
Installation
Before starting the insulation works, ensure that
all preparatory work on the object has been
completed. Refer to Chapter 1.1 for details.
Cut the wrap (mat) to a length so that it can be
fitted to the pipe with slight pre stressing. Wire
the closing joints (lengthwise and circular) of the
wraps (mats) together using steel wire or secure
with wrap (mat) hooks. Stainless steel pipes and
pipes with an operating temperature > 750 °F
(400 °C) can only be insulated with wired mats
with stainless steel stitching wire and wire netting
to prevent galvanic corrosion cracking.
With an insulation thickness of more than 5 inches
(120 mm) [or temperatures > 550 °F (300 °C)],
apply multiple layer insulation. If the insulation is
assembled in multiple layers, the lengthwise and
crosswise joints of the individual insulation layers
must be staggered. If mechanical loads are
anticipated, use steel straps to secure the wired
mats.
Support structures and spacers
As wired mats do not offer sufficient resistance
to pressure to bear the weight of the cladding,
spacer or support structures should be applied.
More information can be found in 1.2.4.
With pipes that have been installed vertically,
with a height in excess of 14 feet (4 m), fit support
structures to transfer the dead load of the
insulation system onto the pipe. Attach the first
support ring to the lowest point of the vertical
pipe. The distance between the support rings
should not exceed approximately 14 feet (4 m).
1. Pipe - 2. Insulation: ProRox ® Wired Mats - 3. Stitching
of the joint edge with binding wire - 4. Sheet cladding -
5. Sheet-metal screw or riveted bolt - 6. Spacer ring
1. Pipe - 2. Insulation: ProRox ® Wired Mat- 3. Joint
edge closed with mat hooks - 4. Sheet-metal cladding -
5. Sheet-metal screw or riveted bolt - 6. Spacer ring
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