Roxul Industrial Insulation Process User Manual

Industrial Insulation
Process Manual

Industrial & Mechanical Installation Guidelines

Overview: ROXUL® Industrial Insulation Solutions

1.2 Insulation of piping 23 1.6 Insulation of boilers 67

1.2.1 Insulation with pipe sections 29 1.6.1 Insulation of fire tube boilers 67

1.2.2 Insulation with pipe wraps (mats) 31

1.2.3 Insulation with wired mats 33

1.2.4 Insulation support 34

1.2.7 Insulation of valves and flanges 40

1.2.8 Insulation of pipe elbows and T pieces 42

1.2.9 Reducers 43

1.2.10 Expansion joints 44

1.2.5 Cladding 36

1.2.6 Pipe hangers and pipe support 39

1.2.11 Tracing 45

1.2.12 Foot traffic 46

1.3 Insulation of vessels 47

1.4 Insulation of columns 53

1.6.2 Supercritical steam generators 69

1.5 Insulation of storage tanks 59

1.7 Insulation of flue gas ducts 75

1.8 Cold boxes 82

Contents

1. System solutions 7

1.1 Planning and preparation 11

1.2 Insulation of piping 23

1.3 Insulation of vessels 47

1.4 Insulation of columns 53

1.5 Insulation of storage tanks 59

1.6 Insulation of boilers 67

1.7 Insulation of flue gas ducts 75

1.8 Cold boxes 82

2. Theory 85

2.1 Norms & Standards 88

2.2 Product properties & test methods 107

2.3 Bases for thermal calculations 120

3. Tables 127

3.1 Units, conversion factors and tables 130

3.2 Product properties insulation and cladding materials 146

3.3 Usage tables 149

4. Products 169

ProRox® PS 960NA 171

®

ProRox
ENERWRAP® MA 960
ProRox® SL 920
ProRox® SL 930
ProRox® SL 940
ProRox® SL 960
ProRox® SL 540
ProRox® SL 560
ProRox® SL 590
ProRox® SL 430
ProRox® SL 450
ProRox® SL 460
ProRox® SL 760
ProRox® FSL 920
ProRox® FSL 930
ProRox® FSL 940
ProRox® FSL 960
ProRox® MA 930
ProRox® MA 940

PS 980

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

ProRox® GR 903

®

ProRox
ProRox

LF 970

®

Rocktight

ROXUL® insulation provide superior thermal and
acoustical performance and are fire resistant, water
repellent, non-corrosive and resistant to mold.
Specialists often willingly turn to our products
and expertise in industrial and marine & offshore
insulation. We have now packaged that expertise into
a practical guide: the 'ProRox® insulation Process
Manual‘.

This manual offers a transparent overview of
our ProRox® product range, including thermal,
fire-resistant, compression, comfort/multi-purpose,
fabrication and acoustic insulation solutions for
technical installations in the process & power
generation industries.

The Process Manual is a convenient resource tool
with relevant information at your finger-tips. Fold-out
sections take you directly to the right page, whether
you are looking for straight forward piping insulation
or more complex applications for columns, tanks and
boilers. In addition to pictures and photographs, a
range of tables and diagrams are included.

The ROXUL Process Manual is a helpful tool for
the application of our ProRox® industrial insulation
solutions in a process environment. Should you need
any further information about a specific application,
procedure or practical problem, please consult

www.roxul.com or contact your local ROXUL

representative at 1 800 265 6878.

2

ROXUL

®

Industrial Insulation

ROXUL  an independent organization with the
ROCKWOOL Group - is a leading supplier of high
quality stone wool products in the industrial
insulation market. With the ProRox® & SeaRox®
lines for the industrial market and for the marine &
offshore industry, our experts provide a full range of
products and systems for the thermal, acoustic and
firesafe insulation of industrial installations. ROXUL
continuously monitors the market developments.
Our 75+ years of global experience is reflected
in a complete set of high-grade products and
expert advice. Today, we remain fully committed to
providing the very best service in the market and a
total range of cutting-edge insulation solutions.

3

The ROXUL® Industrial
Insulation Process Manual

Know-how for designers, engineers, site supervisors and managers of
industrial plants

Energy keeps the world in motion. Without it,
everything would come to a standstill. The global
economy is dependent upon a secure & efficient
supply of energy. Over eighty percent of the energy
currently being consumed is obtained from non­renewable resources. Those resources are becoming
increasingly scarce, while at the same time the
demand for energy is exploding. This means that
owners, designers and operators of large, industrial
plants are challenged with the task of reducing their
energy consumption as much as possible in order to
ensure the long term sustainability of their operations.

Solar energy is just one of the possible alternatives.
Through, for example, solar power plants we
already succeed in converting concentrated sunlight
very efficiently into electricity. And this is just one
of the solutions that can help us drive down fuel
consumption and carbon emissions.

On top of that, insulation significantly reduces the
energy needed to manufacture a product or provide
a service. Also, new technologies for emission
controls at existing fossil burning facilities is greatly
enhanced by insulation. Nowadays there are a variety
of efficient insulation systems that enable scarce

energy reserves to be put to the best possible use.
The ROXUL Industrial Insulation Process Manual
illustrates these systems both theoretically and
practically. This process manual targets designers,
engineers, installers and managers of industrial
plants and provides an overview of the modern
insulation techniques for, by way of example, chemical
or petrochemical installations and power generation
facilities. Based on current standards and regulations
the manual provides accessible, practical guidelines
for the implementation of numerous insulation
applications.

Restriction of thermal losses to an absolute minimum,
including during transfer or storage, can considerably
reduce the energy consumption of industrial plants.
This also results in a reduction in carbon dioxide
(CO²) emissions, which are created each time fossil
fuels such as coal or gas are burnt and which, as a
greenhouse gas, is responsible for the global increase
in temperature.

From an environmental perspective, adequate
insulation of industrial plants is a significant means of
reducing (CO²) emissions.

4

In addition, the right insulation keeps temperatures,
for example in pipes and storage tanks, within
strict tolerances, thereby ensuring reliable process
efficiency. At the same time, adequate insulation
protects the plant itself. Modern insulating materials
can thoroughly protect plant components from
moisture and associated corrosion. Installation
and process maintenance costs can be reduced
considerably and the effective lifetime ofindustrial
plants can be successfully maximized.

Furthermore, industrial insulation also provides
a significant contribution to personnel protection.
Optimum insulation reduces process temperatures
and noise in the industrial environment to an
acceptable level, to the limits generally regarded
in the industry to be those required for a safe and
comfortable working environment.

With a complete range of techniques and insulation
systems, ROXUL® offers designers, engineers and
construction supervisors optimum tailored solutions
for the petrochemical, power generation, ship
building, offshore and processing industries.

In the 'Flow of Energy' diagram on the following
page, you will find an overview of all of the sectors
in which ROXUL is active. All of our ProRox® (and
SeaRox®) products, such as pipe sections and boards
(slabs) are designed to meet the highest quality and
safety standards and comply with the strictest, and
therefore safest, fire safety classes. Stone wool is
non flammable, non combustible and can withstand
temperatures up to 2150 °F (1177 °C) and therefore
provides a crucial contribution towards passive fire
protection.

As a supplement to this process manual, ROXUL
also regularly provides infor mation about technical
innovations, product solutions and recent and
relevant documents available online at our website

www.roxul.com. NOTE: The process manual is a

guideline and can only provide general advice for
specific instances in the field of plant and processes.
For these instances, the ROXUL Technical Services
Team is available to provide advice during the design,
engineering and implementation phases. Please find
our contact details on the back cover of this manual.

5

ROXUL® Industrial Insulation, Flow of Energy

Exploration, drilling and production

Sun

Waste

Coal

Gas

Oil

Flow of energy

Business Areas:

ProRox® insulation for industry:

Our ProRox® product line covers all our thermal, fire-resistant,
compression, comfort/multi-purpose, fabrication and acoustic
insulation solutions for industrial installations in the process
industry.

®

insulation for shipbuilding and offshore:

SeaRox

SeaRox® comprises the full marine and offshore product line.
This sharp focus enables us to combine our expertise and
extensive experience like never before to develop outstanding
insulation solutions for our customers.

ProRox

Petroleum Rening Processing

®

Gas Processing

Petrochemicals

Solar Power Plant

Power Plant

End Products

Marine

Oshore

Processing industry

Industrial

Residential

Consumption

Non-residential

SeaRox

®

6

System solutions

Industrial insulation

System

solutions

1

1. System solutions

Table of contents

1.1 Planning and preparation 11

1.1.1 Decision criteria for the design of an insulation system 11
A. Functional requirements 12
B. Safety aspects 16
C. Economics 17
D. Environmental 18
E. Corrosion Prevention 18

1.1.2 Design & planning of the insulation work 19

1.1.3 Corrosion prevention 19

1.1.4 Storage of insulation materials 22

1.2 Insulation of piping 23

1.2.1 Insulation with pipe sections 29

1.2.2 Insulation with pipe wraps (mats) 31

1.2.3 Insulation with wired mats 33

1.2.4 Insulation support 34

1.2.5 Cladding 36

1.2.6 Pipe hangers and pipe supports 39

1.2.7 Insulation of valves and flanges 40

1.2.8 Insulation of pipe elbows and Tpieces 42

1.2.9 Reducers 43

1.2.10 Expansion joints 44

1.2.11 Tracing 45

1.2.12 Foot traffic 46

1.3 Insulation of vessels 47

1.4 Insulation of columns 53

1.5 Insulation of storage tanks 59

1.6 Insulation of boilers 67

1.6.1 Insulation of fire tube boilers 67

1.6.2 Supercritical steam generators 69

1.7 Insulation of flue gas ducts 75

1.7.1 Installation of the insulation systems for flue gas ducts 75

1.7.2 Cladding of flue gas ducts 78

1.7.3 Acoustic insulation of flue gas ducts 81

1.8 Cold boxes 82

9

Notes

10

1. System solutions

1.1 Planning and preparation

preparation

Planning and

The design of a suitable insulation system for
industrial installations is a major factor for its
economical operation, functionality, security,
durability and environmental impact. Additionally,
the installation-specific heat losses are specified
for the entire life cycleof the plant. Corrections at
a later stage, such as subsequently increasing the
thickness of the insulation, for example, may no
longer be possible due to lack of space. Correc­tions at a later stage may also entail a far greater
investment compared to the original planning.
Continually rising energy costs are also often
overlooked factors when dimensioning the
insulation. Insulation thicknesses that are
designed to last take energy price increases into
account. They form an important criterion for the
economical operation of the installation after just
a few years.

Properly dimensioned insulation systems
constitute an important contribution to
environmental protection, carbon dioxide (CO²)
reduction and to economic success. CO² reduction
is also an economical operation, as it lowers the
costs for CO² emission certificates.
Nowadays, conservational and economical
operations are no longer conflicting ideas, but are
two inseparable parameters.

1.1.1. Decision criteria for the design of
an insulation system

Selecting a suitable insulation system depends on
the following five parameters:

1. Functional requirements
a. Object dimensions
b. Operation of the installation
c. Operating temperatures
d. Permissible heat losses or temperature

changes ofthe medium
e. Frost protection
f. Ambient conditions
g. Maintenance and inspection

2. Safety aspects
a. Personal protection
b. Fire protection
c. Explosion prevention
d. Noise reduction within the plant

3. Economics

a. Economical insulation thickness

b. Pay-back time

4. Environment

5. Corrosion prevention

11

1.1 Planning and preparation

A. Functional requirements

a) Object dimensions

The space requirements of the insulation must be
taken into account when the installation is being
designed and planned. Therefore, the insulation
thicknesses should be determined in the early
planning stages and the distances between the
individual objects should be taken into account in
the piping isometrics. To guarantee systematic
installation of the insulation materials and the
cladding without increased expense, observe the
minimum distances between the objects
asspecified in the following illustrations.

Minimum distances between vessels and columns; dimensions in inches (mm)

31.5” (800)

40” (1000)

40” (1000)

40” (1000)

12

4” (100)

4” (100)

Minimum distances between insulated pipes; dimensions in inches (mm)

preparation

Planning and

4” (100) 4” (100) 4” (100)

Minimum distances within range of pipe flanges; dimensions in inches (mm)

4” (100)

4”
(100)

a = distance flange to normal insulation
a ≥ 2" (50 mm)
x = bolt length + 1.2" (30 mm)
s = insulation thickness

13

1.1 Planning and preparation

A. Functional requirements

b) Operation of the installation

To select a suitable insulation system, the
operating method of the installation must be
considered. A basic distinction is made between
continuous and interrupted operation. With
continuous operation, the operating temperatures
are constantly above or constantly below the
ambient temperatures. The interrupted operating
method, also referred to as intermittent or batch
operation, is characterized by the fact that the
installation is switched off between each
operating phase and during that time can assume
ambient temperatures. For special applications,
e.g. dualtemperature systems, the operating
temperature alternates above or below the
ambient temperature.

c) Operating temperature

The appropriate insulation material should be
resistant to the intended operating/peak
temperatures. Thisproduct property is assessed
by the maximum service temperature (also see
Chapter 2.2 “Product properties & test methods”).

d) Permissible heat losses or temperature

changes ofthemedium

With many technical processes, it is essential that
media in vessels, columns or tanks do not fall
below a specific lower temperature limit,
otherwise chemical processes will not proceed as
intended or the media will set and can no longer
be pumped or extracted. Over-cooling can lead to
the precipitation of, for example, sulphuric acid in
exhaust and flue gas streams, which promotes
corrosion in the pipes or channels.
With flowing media, it is essential to ensure that
the temperature of the medium is still at the
desired level at the end of the pipe. The thermal
insulation is designed according to these
requirements. Under extreme conditions (e.g.
lengthy periods of storage, longtransport routes
or extreme temperatures), installing tracing may
be necessary, to ensure that the media is kept
within the required temperature limits.

Thermo-technical engineering calculation
programs like NAIMA's 3E Plus® or ROXUL's
"ROCKASSIST" (coming soon) can aid in ensuring
the optimum engineering and design of
these insulation systems. More information can be
found on our website www.roxul.com. For special
situations please contact the ROXUL® Technical
Services Team for further guidance.

Inside buildings, uninsulated or poorly insulated
parts of installations unnecessarily increase room
temperatures, which can have a negative effect on
the working environment - both for the people
who work long hours under these conditions and
for the electronic components. In addition to the
increased heat loss, the need for climate
controlled rooms requires further energy
consumption. The design of the insulation and the
related reductions in terms of heat loss from
parts of installations should be relevant to the
entire infrastructure and use of the building.

14

e) Frost protection

Installations that are situated outside are at risk
from frost in the winter. In addition to the
malfunctioning of installations, installations also
risk damage caused by the expansion of frozen
water. Adequate measures against frost protection
are critical to protect the installation from
freezing. Insulation can reduce heat loss and aid
in frost protection. Insulation alone cannot
indefinitely prevent the installation from freezing.
Installing additional tracing may be necessary
between the object and the insulation. To prevent
freezing, the insulation must be designed so the
heat flow rate of the insulated object is less than
the heat provided by the tracing.

f) Ambient conditions

Select an insulation system that offers long-lasting
resistance to the surrounding environme nt.

Atmospheric influences: wind, rain
Mechanical loads such as vibrations or

foottraffic

Corrosive environment (proximity to sea,

chemicals,…)

an air space of at least 2/3” (15 mm) between the
insulation and the cladding, and create 0.4”
(10 mm) diameter ventilation and drain holes in
the covering at intervals at a maximum of 12"
(300 mm). If necessary, the insulation and
cladding must resist chemical influences that
develop within the environment.
Installations operating below ambient
temperatures have a high risk of moisture
condensing from the ambient air inside the
cladding. Use a continuous vapor retarder on
piping operating below ambient temperatures and
seal all joints, surfaces, seams and fittings to
prevent condensation (use of staples is not
recommended).

g) Maintenance and inspection

To avoid complicating routine maintenance and
inspection work unnecessarily, maintenance­intensive areas must be taken into account,
especially when designing the insulation work.
Removable insulation systems, such as removable
coverings and hoods, could be fitted in such areas,
for example. Easily removable covering systems
are also recommended for flanges and pipe
fittings. These coverings are generally fastened
with quick-release clamps, which can be opened
without special tools.
The insulation of fixtures such as flanges or pipe
fittings must be interrupted at a sufficient
distance to allow installation or dismounting to be
carried out. In this case, take the bolt length at
flange connections into consideration. Any fixtures
in the range of the insulation, including the
interruption in the installation, should be
insulated with removable coverings overlapping
the insulation and maintaining continuity across
the fixture.

preparation

Planning and

Moisture accumulation in insulation increases
thermal conductivity and the risk of corrosion of
the insulated installation components. Cladding
must be installed to prevent the ingress of
moisture into the system. If the ingress of
moisture into the insulation is unavoidable, retain

15

1.1 Planning and preparation1.1 Planning and preparation

B. Safety aspects

a) Personal protection

Surface temperatures in excess of 140 °F (60°C)
can lead to skin burns, if the surface is touched.
Therefore, all accessible installation components
should be designed to protect personnel and
prevent injuries. The insulation applied to such
plant components must ensure that surface
temperatures in excess of 140 °F (60°C) do not
occur during operation. Consult our Technical
Services Team to determine the required
insulation thickness to aid in personnel
protection. All of the operational parameters must
be known to achieve a reliable design, including,
for example, the temperature of the object, the
ambient temperature, air movement, surface
materials, distance from other objects, etc.

NOTE

As the surface temperature depends on a set
of physical parameters, which cannot always
be calculated or estimated with any degree
of certainty, the surface temperature is not
a guaranteed measurement. If the required
protection (temperature) cannot be achieved
by insulation, apply additional protective
devices, such as safety guards or enclosement
of theobject.

companies and the operator.

As a basic principle, consider the fact that the fire
load in a building or industrial installation can be
considerably increased by flammable insulation
materials. On the other hand, non-flammable
insulation materials such as mineral wool (stone
wool), which has a melting point of >2150 °F
(>1,177 °C), not only have a positive impact on the
fire load, but in the event of a fire, also constitute
a certain fire protection for the installation
component.

b) Fire protection

The general fire protection requirements imposed
on structural installations are usually defined
within the local Building Codes or the
specifications of plant owner. Structural
installations must be designed, built, modified and
maintained to prevent the outbreak of a fire and
the spread of fire and smoke. In the event of a fire,
the rescuing of people and animals and effectively
extinguishing the fire must be made possible.
During the design of the installation, it is vital to
determine the nature and scope of the fire
prevention measures together with the building
supervisory board, the fire department, insurance

16

Installation components with tracing, in particular,
which use thermal oil as a heat transfer medium,
have an increased risk of catching fire in the event
of a leak. In this case, ensure that the thermal oil
cannot penetrate into the insulation material.

c) Explosion prevention

If there is a risk of fire and explosion, the surface
temperature of the object and the cladding must
be considerably lower than the ignition
temperature of the flammable substance and/or
gas mixtures. This requirement also applies to
thermal bridges, such as pipe mounting supports,
supporting structures and spacers etc.
With regard to insulation systems, explosion

preparation

Costs

Planning and

protection can only be achieved with a doubleskin
covering. A doubleskin covering is a factory made
cladding that has been welded or soldered to
make it air proof and diffusion-resistant. In
addition special (local) explosion regulations must
be observed.

In explosive areas electrostatically charged
substances like unearthed cladding or non­conductive plastics must be grounded (earthed).
For further guidance please consult your local
safety guidelines relating to static electricity.

d) Noise protection

The guidelines for noise in the ordinance and
workplace are stated in the local regulations and
standards. Generally, the level of the guideline values
depends on the nature of the activity.

C. Economics

In the industry there are two grades of insulation.
The first grade focuses on reducing heat losses
and the prevention of injuries to people operating
or working nearby the installations. The second
grade of insulation, the so called “economical
insulation thickness” focuses on significant heat
loss reduction and as a result achieving a better
return on investment.

a) Economical insulation thickness

Insulation reduces the heat losses from the
object. Thethicker the insulation, the greater
theheat reduction and consequently, the more
energy is saved. However, the investment and
expenditure, e.g. for depreciation, interest rates
and higher maintenance costs also rise ifthe
insulation thickness is increased. At a certain
insulation thickness, the sum of the two cost flows
reaches a minimum. This value is known as the
economical insulation thickness. Aqualitative
curve of a similar costs function is shown below.

Economical

insulation

thickness

Total costs

The sound propagation of installation components
can be reduced using insulation systems. The
nature and effect of the sound insulation depend
onthe frequency and the sound pressure level.

Insulation costs

Heat loss costs

Insulation thickness

The energy costs cannot be based solely on the
current price. Developments over recent years
indicate energy costs will continue to rise.

17

1.1 Planning and preparation1.1 Planning and preparation

C. Economics

Increasing energy prices are tending to bring
about a shift in economic insulation thicknesses
towards larger thicknesses.

b) Pay-back time

In addition to the economical insulation thickness,
another frequently used economical parameter is
the return on investment period (ROI), also
referred to as the payback period. This is defined
as the period within which the cost of the
insulation is recuperated through savings on heat
loss costs.

ROI period =

In the case of industrial insulation systems, the
return on investment period is generally very
short, often being much less than one year.
Considering only the return on investment period,
however, can be deceptive, as this approach
disregards the service life of the installation.
With long-life installations, it is advisable to select
higher insulation thicknesses, even if this means
accepting a longer return on investment period.
Throughout the entire service life of the
installation however, the increased insulation
thickness results in a significantly higher return
on the investment in insulation and achieves a
much more economic operation of the installation.

Costs of the insulation

annual saving

[a]

D. Environmental

The burning of fossil fuels, such as coal, oil or
gas, not only depletes the available primary
energy sources, but also, due to the emission of
carbon dioxide (CO²) into the atmosphere, places
aburden on the environment.

The increasing CO² concentration in the Earth’s
atmosphere plays a significant part in the global
increase in temperature, also referred to as the
“greenhouse effect”. CO² absorbs the thermal
radiation emanating from the earth’s surface
andin doing so reduces the dissipation of heat
into space. This is leading to a change in the
world’s climate with as yet inestimable
consequences. Reducing CO² emission can only
beachieved through more efficient management
of fossil fuels. Increasing the insulation
thicknesses is essential for the reduction of CO²
emissions.

Reducing CO² emissions also has a positive
financial benefit for businesses within the context
of an emissions trading scheme. The benefits of
increased insulation thicknesses in industrial
installations are twofold, as the costs for both
energy consumption and CO² emissions are
decreased.

E. Corrosion Prevention

See Chapter 1.1.3

18

preparation

Planning and

1.1.2 Design & planning of the
insulation work

Requirements for insulation work must be
included in the design and construction phase of
industrial plants. It is advisable to involve all
project managers at an early stage to avoid
unnecessary issues or delays.

All preparatory works must be completed
according to the relevant insulation standards.
The following preconditions must be fulfilled:

If necessary, work has been carried out on the

object to protect against corrosion

Tracing and technical measurement equipment

have been installed

The minimum distance between the objects

hasbeen observed (see illustrations on pages

12and 13)
Surfaces have no coarse impurities
Mounting supports have been installed on the

object to accommodate the support structure
Collars and sealing discs have been fitted to

theobject
Taps on the object are long enough to ensure

that flanges lie outside the insulation and can

be screwed on without hindrance
Supports are designed so that insulation,

watervapor retarders and cladding can be

professionally installed
The insulation can be applied without any

obstacles (e.g. scaffolding)
Welding and bonding work has been carried out

on the object
The foundations have been completed

1.1.3 Corrosion prevention

Industrial facility disruptions are due to the lack
of, or inadequate forms of, protection against
corrosion. This considerably reduces the service
life of industrial plants, and more frequently,
essential shutdown or overhaul work impairs the
efficiency of the installation.
It is commonly, but wrongly, assumed that the
insulation system also protects an installation
against corrosion. For each installation it must be
determined whether protection against corrosion
is required and, if so, which are the appropriate
measures.

Generally, the design of the insulation system &
corrosion protection will depend on the following
parameters.

Operation of the installation

- Continuous operation

- Interrupted/intermittent operation

- Operation involving varying temperatures

- Type of plant (e.g. Petrochemical,
pharmaceutical, etc)

Operating and Ambient temperatures of the

installation

Metals and Materials Used

- Non-alloy or low-alloy steel

- Austenitic stainless steel

- Copper
External influences upon the installation

- Environment of the installation (chemically

aggressive?)

- Location

The best practices may vary per country and/or
standard. The design of corrosion protection is
often carried out on the basis of a small selection
of standards, such as ASTM C795, that do not
adequately take into account all the specific
features of protecting against corrosion in
insulation systems. For further details on
corrosion protection we recommend referring
NACE SP0198 and the ROXUL® Corrosion Under

Insulation (CUI) brochure.

19

1.1 Planning and preparation1.1 Planning and preparation

1.1.3 Corrosion prevention

In the case of cold insulation, if the object is

made of non-alloy or low alloy steel, it must be
protected against corrosion.

In the case of objects made, for example, of

austenitic stainless steel or copper, the
installation must be tested in each individual
case by the planner to determine whether
protection against corrosion is necessary.

Objects made from austenitic stainless steel do

not require protection against corrosion if the
temperature never – even for a short period –
exceeds 120 °F (50 °C)

NOTE

Protection against corrosion should be applied
in the case of all installations made from
non-alloy or low-alloy steel where the
operating temperatures are below
250 °F (120 °C). Protection against corrosion
may be omitted in the case of:

Installations operating continuously under

extremely cold conditions [below -50 °F
(-50 °C)] such storage tanks.

Insulated surfaces of power plant

components, such as boiler pressure
components, flue gas and hot air ducts and
steam pipe systems with operating
temperatures that are constantly above

250 °F (120 °C).

If austenitic stainless steel is insulated with any
type of insulation - For temperatures of up to
930 °F (500 °C), aluminum foil of not less than
.06 mm thick to be applied to the steel surface,
arranged to shed water with overlaps of not less
than 2" (50 mm) at the joints.

CINI Manual “Insulation for industries”

CINI recommends applying corrosion protection
prior to the insulation work at any time.

In all phases, pay attention to CUI (corrosion

under insulation) prevention: design,
construction, paint & coating work, application
of the insulation system, inspection and
maintenance. Equipment and piping sections
like nozzles, supports etc. should be designed
and maintained to prevent ingress of water into
the insulation system.

The “paint” specifications are split up into:

-

Construction material
(carbon steel, stainless steel)

- Temperature ranges from -22 °F (-30 °C) to
1000 °F (540 °C) with special attention to the
temperature range between 0 °F (-20 °C) and
300 °F (150 °C).

The corrosion protection can be achieved using

aluminum foil wrapping, thermal sprayed
aluminum (TSA) or paint.

Protection against corrosion may be omitted in the
case of installations operating continuously under
extremely cold conditions [< -22 °F (-30 °C)]

Application

Before applying corrosion protection coating, the
surface must be free from grease, dust and acid
and, for better adhesion, the priming coat should
be roughened. Blasting is recommended as a
surface preparation method (with austenitic
stainless steel, use a ferrite free blasting
abrasive).
Observe the corresponding processing guidelines
of the coating manufacturer. If metals with
different electrochemical potentials, such as
aluminum and copper, come into contact with one
another, there is a risk of electrochemical
corrosion. If necessary, this can be avoided using
insulating, intermediate layers such as non­metallic straps. The presence of moisture will
increase the development of electrochemical
corrosion.

20

preparation

Planning and

The table further on this page, which has been
derived from the standard DIN 4140, indicates the
initial risks of electrochemical corrosion in cases
where various combinations of metals are used.

Electrochemical Corrosion Potential

Material Combination material

Metal

Zinc

Aluminum

Ferritic steel

Lead

Austenitic stainless
steel

Copper

Surface ratio in proportionto

combinationmaterial

Small - M M H H H

Large - L L L L L

Small L - L H H H

Large L - L M L H

Small L L - H H L

Large L L - L L L

Small L L L - H H

Large L L L - M M

Small L L L L - M

Large L L L L - L

Small L L L L L -

Large L L L L L -

Zinc Aluminum

NOTE

The table does not take into account forms
ofcorrosion with other root causes, such as
stress corrosion. For further information, see
Chapter 2.2 “Product properties & test
methods” – AS-Quality on page 115.

Ferritic

steel

Lead

Austenitic

stainless

steel

Copper

L - Light or little corrosion to material
M - Moderate corrosion to material, for example, in very humid atmospheres
H - Heavy electrochemical corrosion to material

Observation: The table shows the corrosion of the “material”, and not that of the “combination material”.
“Light” means: “small-scale in proportion to the combination material”, “heavy” means: “large-scale in
proportion to the combination material”.

Example 1: Material is a zinc galvanized screw in combination material, a cladding made from austenitic
stainless steel: Row “zinc small”: “H” – heavy corrosion of the screw.

Example 2: Material , a cladding made from austenitic stainless steel screwed on with a screw galvanized
with combination material zinc: Row “austenitic stainless steel large”. “L” – the corrosive attack upon the
austenitic steel is light.

21

1.1 Planning and preparation

1.1.4 Storage of insulation materials

Incorrect storage of insulation materials outdoors
can cause insulation to deteriorate. Insulation
should be protected when stored, during
installation and when fitted to minimize moisture
exposure, physical damage and contamination. If
storage indoors is not possible, protect the
insulation material from weather influences by
covering it with waterproof material. Insulation
should also be stored a minimum of four inches
above ground and kept on a solid surface away
from ponding water and ground moisture.

Moisture causes many types of corrosion that
virtually never develop in a dry system. The major
types of corrosion in relation to insulation
technology are oxygen, electrochemical and stress
corrosion. Insulation materials that are
manufactured with properties (such as low
chloride content or added inhibitors) can
irrevocably lose these properties when exposed to
contamination or additives are leached out.

The thermal conductivity of water is approximately
25 times greater than that of air. An increase in
moisture therefore results in an increase in the
thermal conductivity of the insulation and,
correspondingly, a decrease in the insulation
efficiency. Higher moisture can also mean a
significantly higher weight, which, as a rule, is not
taken into account in the static design of an
insulation system. It is therefore important to
protect the insulation from moisture after
installation, as well as ensure insulation is
thoroughly dry when installed (especially in sealed
application at low temperatures or where the
temperature cycles).

22

1. System solutions

1.2 Insulation of piping

Piping plays a central role in many industrial
processes in chemical or petrochemical
installations such as power plants, as it connects
core components such as appliances, columns,
vessels, boilers, turbines etc. withone another
and facilitates the flow of materials andenergy.
Toguarantee a correct process cycle, the
condition of the media within the pipes must
remain within the set limitations (e.g.
temperature, viscosity, pressure, etc.). In addition
to the correct isometric construction and
fastening of the piping, the piping insulation also
has an important function. It must ensure that
heat loss are effectively reduced and that the
installation continues to operate economically and
functionally on a permanent basis. This is the only
way to guarantee the maximum efficiency of the
process cycle throughout the design service life
without losses as a result of faults.

Requirements for industrial piping

The basic efficiency and productivity factors of
piping for the processing industry include: energy
efficiency, dependability and reliability under
different conditions, functionality of the process
control, appropriate support structure suitable for
the operating environment, as well as mechanical
durability. The thermal insulation of piping plays a
significant role in fulfilling these requirements.

Thermal insulation

The functions of proper thermal insulation for
piping include:

Reduction of heat losses (cost savings)
Reduction of CO² emissions
Frost protection
Process control: ensuring the stability of

theprocess temperature
Noise reduction
Condensation prevention
Personnel protection against high temperatures

ProRox® products for pipe insulation

ROXUL Inc offers a wide range of high-quality stone
wool insulation products for the insulation of
industrial plants. These products are part of our
extensive ProRox® range for industrial insulation.
With this specific field of application in mind we
developed our pre-formed pipe sections and pipe
wrap (mat) products for pipe insulation. All these
products are easy to install and contribute to a high
level of efficiency, functionality and reduced heat
losses. Continuous internal and external inspection
and high levels of quality assurance ensure the
consistently high quality ofall ROXUL® products.

The examples of use below cannot fully take into
account the particular circumstances of the
construction-related factors. Determine whether
the products are suitable for the corresponding
application in each individual case. If in doubt,
consult the ROXUL Technical Services Team.

The applicable standards and regulations must
also be observed. A few examples follow:

NACE SP0198 (Control of corrosion under
thermal insulation and fireproofing materials - a
systems approach)

MICA (National Commercial & Industrial
Insulation Standards)

DIN 4140 (Insulation works on technical

industrial plants and in technical facility
equipment)

AGI Q101 (Insulation works on power plant

components)
CINI-Manual “Insulation for industries”
BS 5970 (Code of practice for the thermal

insulation of pipework, ductwork, associated
equipment and other industrial

installations)

of piping

Insulation

23

1.2 Insulation of piping

Hot insulation systems

Principally, a thermal insulation structure for
piping consists of an appropriate insulating
material, usually covered by sheet metal cladding.
This protects the object and the insulation from
external influences such as the weather and
mechanical loads. Spacers are also essential with
insulation such as wired mats, which do not offer
sufficient resistance to pressure to hold the
weight of thecladding and other external loads.
These spacers transfer the cladding loads directly
onto the object. In thecase of vertical piping,
support structures are fitted totake on the loads
of the insulation and the cladding. Ingeneral,
support structures and spacers form thermal
bridges.

Selecting a suitable insulation system depends on
numerous parameters. These are described in
greater detail in Chapter 1.1. Regarding the
different forms of pipe insulation, a fundamental
distinction can be drawn between the following
insulation systems.

Insulation with pipe sections

Generally, the best insulation is achieved using
ProRox® Pipe Sections and can be used up to
temperatures of 1400 °F (760 °C) when using
ProRox® PS 980NA Type V insulation. They are
supplied ready split and hinged for quick and easy
snap-on assembly and are suitable for thermal
and acoustical insulation of industrial pipe work.
Due to their excellent fit and high compression
resistance, pipe sections can often be applied in
asingle layer without any additional spacers.
If multiple layers are required, ROXUL® can also
supply double layered - ‘nested’ - pipe sections.
This reduces installation costs considerably. Also
the number of thermal bridges, which have a
negative influence on the insulation, is greatly
reduced, while a lower thickness may be applied
compared to wired mats.

Using pipe sections for the insulation of pipes
results in considerably reduced installation time
and costs. The lack of spacers and “unforeseen”

gaps minimizes heat losses and the risk of
personal injuries due to hot spots on the cladding.
At temperatures above 550 °F (300 °C), the
provisional application of spacers must be
determined in each individual case.

Pipe sections are always precisely tailored to the
corresponding pipe diameter to minimize the risk
of convection and processing defects. ROXUL pipe
sections are available in diameters of
NPS 1/2" (23 mm) to NPS 28" (713 mm).

Insulation with load-bearing pipe wraps
(mats)

Load-bearing pipe wraps (mats), such as
ENERWRAP® MA 960NA are the latest development
in the insulation sector. ENERWRAP® MA 960NA is
a stone wool (mineral wool) insulation wrap
available with a black mat or reinforced foil facing
and is designed for easy installation of large
diameter pipes. Typical applications include:

pipe diameters >NPS 12" (326 mm), or;
piping with a high number of shaped pieces

such as elbows or T-joints.

ENERWRAP® MA 960NA can be applied up to
temperatures of 1200 °F (650 °C). It is highly
compression resistant and can be applied without
any additional spacers.

24

Consequently the number of thermal bridges,
which have a negative influence on the insulation,
is greatly reduced.

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 piping. Wired mats are ideal for
application in situations where the use of pipe
sections or load bearing wraps (mats) is difficult
or impossible. Historically this included large
diameter pipes and high temperatures (where the
wired mat provided structural integrity to the
insulation at high temperatures), but advanced
modern ProRox® pipe section and ProRox® pipe
wraps (mats) have provided a suitable alternative
to wired mats. Wired mat is still used today in
piping with a high number of shaped pieces such
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 or
support structures. 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).

of piping

Insulation

The result is considerably reduced installation
time and costs. The lack of spacers and
“unforeseen” gaps minimizes heat losses and the
risk of personal injuries due to hot spots on the
cladding.
corresponding length of the pipe circumference
on site and are fastened with clamps.

Pipe wraps (mats) are tailored to the

Insulation with wired mats

Wired mats, are lightly bonded stone wool wraps
(mats), usually stitched with galvanized wire onto
a galvanized wire mesh. For more details on
ProRox® wired mat insulation products, contact
your ROXUL® representative.

25

1.2 Insulation of piping

Comparison of the different insulation
systems

The particular advantage of pipe sections and pipe
wraps (mats) lies in the fact that support
structures are not required and therefore thermal
bridges caused by the insulation are minimized or
removed. On the other hand, wired mat systems
have their advantages due to their ability to be
structurally sound when insulating around
irregularly shaped pipe sections.

The advantages of pipe sections and load-bearing
pipe wraps (mats) at a glance are:

It is not necessary to install spacers or support

structures.

Faster application without the interference of

spacers.

Both products offer an even, firm surface for

installing the sheet cladding.

Insulation system with a spacer ring

The lack of spacers gives rise to lower heat

losses.

It yields an even surface temperature across

the sheet cladding.

In comparison to wired mats, a more shallow

insulation thickness can be applied. Theoperating
costs of the installation decrease as a result of
lower heat loss.

Generally speaking, a spacer or support structure
functions as a thermal bridge, as a result of which
theheat loss in the total insulation is increased
considerably.

1. Pipe - 2. Insulation: ProRox® Wired Mats - 3. Cladding - 4.Spacer ring

Insulation system without a spacer ring

1. Pipe - 2. Insulation: ProRox® Pipe Sections or Pipe Wraps (Mats): ENERWRAP® MA 960NA - 3. Cladding

26

Required insulation thicknesses

If the three insulation systems are compared,
taking into consideration similar heat losses,
clear advantages are seen with regard to the
insulation thicknesses with systems using pipe
sections or pipe wraps (mats). These do not use
spacers, in contrast to insulation systems made
using wired mats. The table below shows the
required insulation thicknesses taking into
account the following boundary conditions:

Medium temperature: 480 °F (250 °C)
Ambient temperature: 50 °F (10 °C)
Wind speed: 1.1 mph (5 m/s)
Cladding: Aluminum
Heat loss: 150 BTU/ft.hr (150 W/m)
Application of spacers in the case of wired mats

of piping

Insulation

Minimum Insulation Thickness

NA

ENERWRAP® MA 960

NA

Wired mats

NPS

(inch)

Pipe Diameter

Nominal diameter

Ø DN

Pipe diameter

(mm)

Pipe sections Pipe wraps (mats)

®

PS 960

ProRox

inch inch inch

2 50 60 1" n.a. n.a.

3 80 89 1" n.a. n.a.

4 100 108 1.5" n.a. n.a.

6 150 159 2" n.a. n.a.

8 200 219 2.5" n.a. 5"

10 250 273 3" n.a. 6"

12 300 324 4" 4" 7.5"

14 350 356 4.5" 4.5" 8"

Multiple layer insulation n.a. = not applicable

27