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Mechanical Insulation Design Guide - Materials and Systems

by the National Mechanical Insulation Committee (NMIC)

Last updated: 08-16-2011

Within This Page

Introduction

Categories of Insulation Materials

Physical Properties of Insulation Materials

o Performance Property Guide for Insulation

Materials

Product Characteristics of Thermal Insulation

Materials

Categories of Weather Barriers, Vapor Retarders,

and Finishes

Physical Properties of Weather Barriers, Vapor

Retarders, and Finishes

Product Characteristics of Weather Barriers, Vapor

Retarders, and Finishes

Accessory Products

Fabrications of Insulation Products

Product Data Sheets

Glossary of Terms

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Example Bills of Materials

Insulation Textiles

INTRODUCTION

There are a wide variety of insulation materials, facings, and accessory products

available for use on mechanical systems. The list changes continuously as

existing products are modified, new products are developed, and other products

are phased out. The task for the insulation system designer is to select the

products or combination of products that will satisfy the design requirements at

the lowest total cost over the life of the project. This task is not easy. In most

cases, the designer will find there are a number of products or systems that will

work, and the final choice will depend on cost, availability, or other

considerations.

This section reviews the various commonly used materials and describes

important performance properties. Links to product data sheets for

commercially available products are provided.

Within theResource Section you can find listings of Mechanical Insulation;

Weather Barrier, Vapor Retarders and Finish; and Accessory ProductManufacturers—Associate Members of theNational Insulation Association (NIA)

categorized in the same format of materials contained in this Section.

BACK TO TOP

CATEGORIES OF INSULATION MATERIALS

Insulation materials may be categorized (Turner and Malloy, 1981) into one of five

major types 1) Cellular, 2) Fibrous, 3) Flake, 4) Granular, and 5) Reflective.

Cellular insulations are composed of small individual cells either interconnecting

or sealed from each other to form a cellular structure. Glass, plastics, and rubber

may comprise the base material and a variety of foaming agents are used.

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Cellular insulations are often further classified as either open cell (i.e. cells are

interconnecting) or closed cell (cells sealed from each other). Generally,

materials that have greater than 90% closed cell content are considered to be

closed cell materials.

Fibrous insulations are composed of small diameter fibers that finely divide the

air space. The fibers may be organic or inorganic and they are normally (but not

always) held together by a binder. Typical inorganic fibers include glass, rock

wool, slag wool, and alumina silica.

Fibrous insulations are further classified as either wool or textile-based

insulations. Textile-based insulations are composed of woven and non-woven

fibers and yarns. The fibers and yarns may be organic or inorganic. These

materials are sometimes supplied with coatings or as composites for specific

properties, e.g. weather and chemical resistance, reflectivity, etc.

Flake insulations are composed of small particles or flakes which finely divide

the air space. These flakes may or may not be bonded together. Vermiculite, or

expanded mica, is flake insulation.

Granular insulations are composed of small nodules that contain voids or hollow

spaces. These materials are sometimes considered open cell materials since

gases can be transferred between the individual spaces. Calcium silicate and

molded perlite insulations are considered granular insulation.

Reflective Insulations and treatments are added to surfaces to lower the long-

wave emittance thereby reducing the radiant heat transfer to or from the surface.

Some reflective insulation systems consist of multiple parallel thin sheets or foil

spaced to minimize convective heat transfer. Low emittance jackets and facings

are often used in combination with other insulation materials.

Another material sometimes referred to as "thermal insulating coatings" or

paints is available for use on pipes, ducts, and tanks. These paints have not

been extensively tested and additional research is needed to verify their

performance.

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Insulation materials or systems may also be categorized by service temperature

range.

There are varying opinions as to the classification of mechanical insulation by

the service temperature range for which insulation is used. As an example, the

word cryogenics means "the production of freezing cold"; however the term is

used widely as a synonym for many low temperature applications. It is not well-

defined at what point on the temperature scale refrigeration ends and cryogenics

begins. The National Institute of Standards and Technology in Boulder, Colorado

considers the field of cryogenics as those involving temperatures below -180 C.

They based their determination on the understanding that the normal boiling

points of the so-called permanent gases, such as helium, hydrogen, nitrogen,

oxygen and normal air, lie below -180 C while the Freon refrigerants, hydrogensulfide and other common refrigerants have boiling points above -180 C.

Understanding that some may have a different range of service temperature by

which to classify mechanical insulation, the mechanical insulation industry has

generally adopted the following category definitions:

Category Definition

Cryogenic Applications -50 F & Below

Thermal Applications:

Refrigeration, chill water and below ambient applications

Medium to high temperature applications

-49 F to + 75 F

+76F to +1,200 F

Refractory Applications +1,200 F & Above

BACK TO TOP

PHYSICAL PROPERTIES OF INSULATION MATERIALS

Selecting an insulation material for a particular application requires an

understanding of the physical properties associated with the various available

materials.

Use Temperature is often the primary consideration in the selection of an

insulating material for a specific application. Maximum temperature capability is4





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normally assessed using ASTMC 411 orC 447. These test method involve

exposing samples to hot surfaces for an extended time, and subsequently

assessing the materials for any changes in properties. ASTM C411 is specified

when exposing the insulation material to an ambient temperature surface and

then utilizing a specified heat up cycle. ASTM C447 requires the insulationmaterial to be installed on a surface which has been pre-heated to the maximum

operating temperature. Evidence of warping, cracking, delamination, flaming,

melting, or dripping are indications that the maximum use temperature of the

material has been exceeded. There is currently no industry accepted test method

for determining the minimum use temperature of an insulation material, but

minimum temperatures are normally determined by evaluating the integrity and

physical properties of the material after exposure to low temperatures.

Thermal Conductivity is defined inASTM C 168 as the time rate of steady state

heat flow through a unit area of a homogeneous material induced by a unit

temperature gradient in a direction perpendicular to that unit area. The term

apparent thermal conductivity is used for many insulation materials to indicate

that additional non-conductive modes of heat transfer (i.e. radiation or free

convection) may be present.

In the insulation industry, thermal conductivity is typically expressed as thesymbol k, in units of Btu·in/(h ft² °F) or λ, in units of W/(m·°C)

The apparent thermal conductivity of insulation materials is a function of

temperature. Many specifications call for insulation conductivity values

evaluated at a mean temperature of 75°F. Most manufactures provide

conductivity data over a range of temperatures to allow evaluations closer to

actual operating conditions. Conductivity of flat insulation products is measured

per ASTM Test MethodC 177 orC 518, while the conductivity of pipe insulation

is generally determined usingASTM Test Method C 335. At present, ASTM does

not provide a consensus test procedure for pipe insulation at below ambient

temperatures (i.e. heat flow in). Conductivity data for below ambient applications

is therefore obtained either by extrapolation from above ambient tests or via

tests on flat material. Note that in some cases tests on flat materials have yielded

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A number of other terms related to thermal conductivity are sometimes used

(also see the Glossary). These are not material properties, but are used to

describe the thermal performance of specific products or systems.

Thermal Conductance, or C-value, is the time rate of steady state heat flow

through a unit area of a material or construction induced by a unit temperature

difference between the body surfaces. Or a flat board or blanket insulation, C is

calculated as the thermal conductivity divided by the thickness (C=k/t).

Thermal Resistance, or R-value, is the quantity determined by the temperature

difference, at steady state, between two defined surfaces of a material or

construction that induces a unit heat flow rate through a unit area. For a flat

board or blanket insulation, R is calculated as the thickness divided by the

thermal conductivity (R=t/k). Thermal resistance is the inverse of thermal

conductance.

The thermal transmittance, or U-factor, is the heat transmission rate through unit

area of a material or construction and the boundry air films, induced by a unit

temperature difference between the environments on each side. Units of U are

typically Btu/(h·ft²·°F)

Density is the mass per unit volume of a material. For insulation we are normally

concerned with the "bulk" or the "apparent" density of the product. Bulk density

is the mass of the product divided by the overall volume occupied, and is an

average of the densities of the individual materials making up the product.

Density is denoted by the symbol ρ and expressed in units of lb/ft³ or kg/m³.

Historically, density was used as a proxy for other properties of insulation (e.g.

compressive resistance), and is still found in various insulation specifications. It

is useful in the design of support/hanger systems where the overall weight of the

system must be considered. It also becomes important in transient heat flowsituations.

Specific Heat is the amount of thermal energy required to raise the temperature

of a unit mass of a material by one degree. Normally expressed in units of

Btu/lb·°F or kJ/kg·°K.

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Thermal Diffusivity is the ratio of the conductivity of a material to the product of

its density and specific heat. It is an important property in transient situations.

Generally, the lower the diffusivity, the more "thermal flywheel" in the system.

Units are ft²/h or m²/s.

Alkalinity or pH describes the tendency of a material to have a basic or acidic

reaction. For insulation materials, it is measured on an extract of the material in

distilled water. Results are reported on the pH scale with readings above 7.0

indicating alkaline and below 7.0 indicating acidic.

Compressive Resistance is defined as the compressive load per unit of area at a

specified deformation. When the specified deformation is the start of complete

failure, the property is called Compressive Strength. Compressive strength is

measured in lb/in² or lb/ft² and is important where the insulation material must

support a load without crushing (e.g. insulation inserts used in pipe hangers and

supports). When insulation is used in an expansion or contraction joint to take

up a dimensional change, lower values of compressive resistance are desirable.

ASTM Test Method C 165 is used to measure compressive resistance for fibrous

materials andASTM Test Method D 1621 is used for foam plastic materials.

Flexural Resistance of a block or board insulation product is the ability to resist

bending. It is determined byASTM C 203 and is measured in lb/in² or lb/ft². Therelated term Flexural Strength is the flexural resistance at breaking.

Linear Shrinkage is a measure of the Dimensional Change that occurs in an

insulation material under conditions of soaking heat. Most insulation materials

will begin to shrink at some definite temperature. Usually the amount of

shrinkage increases as the exposure temperature becomes higher. Eventually, a

temperature will be reached at which the shrinkage becomes excessive, and the

material has exceeded its useful temperature limit. Linear shrinkage isdetermined byASTM C 356, which specifies soaking heat for a period of 24

hours.

Water Vapor Permeability is defined as the time rate of water vapor transmission

through unit area of flat material of unit thickness induced by unit vapor-

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and humidity conditions. For insulating materials, water vapor permeability is

commonly expressed in units of perm-in. A related and often confused term is

water vapor permeance (in perms), which describes the water vapor flux through

a material of specific thickness and is generally used to define the performance

of a vapor retarder. In below ambient applications, it is important to minimize therate of water vapor flow to the cold surface. This is normally accomplished by

using vapor retarders with low permeance, insulation materials with low

permeability, or both in combination.ASTM Test Method E 96 is used to measure

the water vapor transmission properties of insulation materials.

Water Absorption is generally measured by immersing a sample of material

under a specified head of water for a specified time period. It is a useful measure

when considering the amount of liquid water that may be absorbed due to waterleaks in weather barriers or during construction. Water absorption is measured

by a number of different immersion methods (ASTM C 209,ASTM C 240,ASTM C

272, andASTM C 610). These methods differ in length of immersion time (from

10 minutes to 48 hours) in the reported units (% by weight or % by volume) and

in the requirements for both pre-conditioning (i.e. heat aging) and post-

conditioning (specimen draining and pat-off). These differences make direct

comparison of water absorption data difficult.

Water Vapor Sorption is a measure of the amount of water vapor sorbed (either

by absorption or adsorption) by an insulation material under high-humidity

conditions. The test procedure (ASTM C 1104) involves drying a sample to

constant weight and then exposing to a high humidity atmosphere (120°F, 95%

RH) for 96 hours.

Wicking is the infiltration of a wetting liquid into a material by capillary action.

For insulation materials, wicking of liquid water is undesirable because it can

degrade the properties of the insulation. Wicking is measured byASTM C 1559

which involves inserting insulation samples in a pan of liquid water and

measuring the capillary rise after a one week period.

Typical physical properties of interest are given in Table 1. Values in this table

are generally taken from the relevant ASTM material specification. Within each

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material category, a variety in types and grades of materials exist. A

representative type and grade are listed in Table 1 for each material category, but

users are referred to the ASTM Material Standards or to manufacturers for

specific data.

Table 1: Performance Property Guide for Insulation Materials

This tool provides the reader with physical properties as specified in ASTM

material specifications and is a guide to material properties, but may not be

sufficient for writing specifications.

Enter the operating temperature in F° below.

BACK TO TOP

PRODUCT CHARACTERISTICS OF THERMAL INSULATION MATERIALS

The following information describes the commonly available materials used as

insulation on mechanical systems. Note that much of this discussion

summarizes information in the appropriate ASTM material specification. These

material specifications are the responsibility of ASTM Committee C 16 on

Thermal Insulation and are published in the Annual Book of ASTM Standards,

Volume 04.06, available, in book or CD format fromASTM International.

Individual standards in downloadable pdf format are also available.

Note that these ASTM Standard Specifications are industry consensus

standards. Compliance with the requirements of these industry standards is

voluntary. Standards become legally binding only when a government body

references them in regulations, or when they are sited in a specification that is

part of a contract. Manufactures who claim compliance to these standards are

required to have the appropriate documentation supporting their claim.

Also note that the property requirements of these standards are generally stated

as minimums or maximums. Most insulation manufacturers will claim to "meet

or exceed" these requirements. In some cases, the performance of specific

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products may significantly exceed the minimum or maximum requirements.

Check manufacturer's specific product data sheets for specific product

performance.

A brief discussion of imported insulation materials is appropriate. Ever since two

catastrophic fiberglass manufacturing facility fires occurred in 2003, the

importing and acceptance of foreign manufactured materials have been more

amiable to all North American industry participants. The end-user, in many

cases, does not place primary importance on where the product is made if the

product meets the specification. There in lies a very important question, does

the foreign manufactured material meet the applicable ASTM material

specification? It may look and feel the same and is in a similar wrapper but is the

composition, health and safety aspects, quality and its performance standardsmeasured on the same basis as domestic manufactured materials?

This is not suggesting that imported materials are inferior to those manufactured

in the North America. It is simply raising a caution flag to those individuals and

companies that are considering the use of imported materials. Are they tested

and is performance being measured on the same basis? The burden of proof and

ownership of the material ultimately lies with the end user but all channel

participants involved in the decision making process will shoulder some degreeof responsibility if a failure were to occur. A failure of any magnitude and

regardless of the cause is detrimental to the industry. Assumption of

equivalence and warranty support could be costly.

Cellular Insulations

Elastomeric

Elastomeric insulations are defined byASTM C 534, Type I (preformed tubes) andType II (sheets). There are three grades in the ASTM standard which are widely

available.

GradeBasic description Temperature

Limits

Flame Spread Index/Smoke

Developed Index

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1 Widely used on typical

commercial systems

-297°F to 220°F 25/50 through 1–½"

thickness.

2 High temperature uses -297°F to 350°F Not 25/50 Rated

3 Use on stainless steelapplications above 125 °F

-297°F to 250°F Not 25/50 Rated

Elastomeric Insulation Products

All three grades are flexible and resilient closed-cell expanded foam insulation.

The maximum water vapor permeability is 0.10 perm-inch and the maximum

thermal conductivity at 75°F temperature is 0.28 BTU·in/(h·ft²·F) for grades 1 and

3 and grade 2 is 0.30 BTU·in/(h·ft²·F). Grade 3 formulation does not contain any

leachable chlorides, fluorides or polyvinyl chloride or any halogens.

The preformed tubular insulation is available in ID sizes from 3/8" to 6 IPS and in

wall thickness from 3/8" to 1–1/2" and in typical length of 6 feet. The tubular

product is available with and without pre-applied adhesive. The sheet insulation

is available in continuous lengths of 4 feet widths or 3'x 4' and in wall

thicknesses from 1/8" to 2". The sheet product is available with and without pre-

applied adhesive.

These materials are normally installed without additional vapor retarders.Additional vapor-retarder protection may be necessary when installed on very-

low-temperature piping or where exposed to continually high humidity

conditions. All seams and termination points must be sealed with manufacturer

recommended contact adhesive. For outdoor applications a weatherable jacket

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or manufacturer recommended coating must be applied to protect against UV

and ozone.

View Product Sheet - MTL Product Catalog

Cellular Glass

Cellular Glass is defined by ASTM as insulation composed of glass processed to

form a rigid foam having a predominantly closed-cell structure. Cellular glass is

covered byASTM C552, "Standard Specification for Cellular Glass Thermal

Insulation" and is intended for use on surfaces operating at temperatures

between -450 and 800°F. The Standard defines two grades and four types, as

follows:

Cellular Glass Insulation Products

Type Form and Grades Available

I Flat Block, Grades 1 and 2

II Pipe and Tubing, Fabricated, Grades 1 and 2

III Special Fabricated Shapes, Grades 1 and 2IV Board, Fabricated, Grade 2

Cellular glass is produced in block form (Type I). Blocks of Type I product are

typically shipped to fabricators who produce fabricated shapes (Types II, III, and

IV) that are supplied to distributors and/or insulation contractors.

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The maximum thermal conductivity is specified, by grade, as follows (for

selected temperatures):

Temperature, F Grade 1 Grade 2

Type I, Block-150 F 0.20 0.26

-50 F 0.24 0.29

50 F 0.30 0.34

75 F 0.31 0.35

100 F 0.33 0.37

200 F 0.40 0.44400 F 0.58 0.63

Type II, Pipe

100 F 0.37 0.41

400 F 0.69 0.69

The standard also contains requirements for density, compressive strength,

flexural strength, water absorption, water-vapor permeability, combustibility, andsurface burning characteristics.

Cellular glass insulation is a rigid inorganic non-combustible, impermeable,

chemically resistant form of glass. It is available faced or un-faced (jacketed or

un-jacketed). Because of the wide temperature range, different fabrication

techniques are sometimes used at various operating temperature ranges.

Typically, fabrication of cellular glass insulation involves gluing multiple blocks

together to form a "billet" which is then used to produce pipe insulation orspecial shapes. The glue or adhesives used vary with the intended end use and

design operating temperatures. For below-ambient applications, hot melt

adhesives such asASTM D 312 Type III asphalt are usually used. On above-

ambient systems, or where organic adhesives could pose a problem (i.e., LOX

service) an inorganic product such as gypsum cement is often used as

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fabricating adhesive. Other adhesives may be recommended for specific

applications. When specifying cellular glass insulation, include system operating

conditions to ensure proper fabrication.


Polystyrene

Extruded Polystyrene Foam (XPS) Insulation Products

Polystyrene thermal insulation is rigid, cellular foam insulation. It is commonly

classified as either Expanded Polystyrene Foam (EPS) or Extruded Polystyrene

Foam (XPS). XPS is a closed cell material manufactured as rectangular billets

typically 20 in wide x 9 ft long x 10 in tall. Prior to actual installation, billets are

fabricated into various shapes including preformed pipe half-shells 3 ft long

designed to fit NPS pipe and tubing. Complex shapes can also be fabricated to fit

valves, fittings, and other equipment. ASTM material specification C 578 covers

several types of polystyrene insulation, but Type XIII is usually specified for

mechanical applications and covers service temperatures from -297°F to +165°F.

The standard contains requirements for compressive resistance, flexural

strength, thermal conductivity, water absorption, water vapor permeability, and

dimensional stability. For comparison purposes, the thermal conductivity of theType XIII XPS is a maximum of 0.259 Btu-in/hr-ft²-°F at 75°F.

Key applications for XPS insulation are on pipe, equipment, tanks, and ducts

operating at temperatures below ambient. These include food and beverage

lines, and refrigeration lines.

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Polyisocyanurate

Polyisocyanurate Insulation Products

Polyisocyanurate thermal insulation (PIR) is rigid foam insulation with a closed

cell structure. It is usually manufactured as large rectangular buns typically 4 ft

wide x 3-24 ft long x 1-2 ft tall and in a range of densities and compressive

strengths. Prior to actual installation, buns are fabricated into various shapes

including flat boards and preformed pipe half-shells 3-4 ft long designed to fit

NPS pipe and tubing. Complex shapes can also be fabricated to fit around

valves, fittings, and other equipment. ASTM material specificationC 591 covers

PIR at service temperatures from -297°F to +300°F ASTM C 591 contains

requirements for density, compressive resistance, thermal conductivity, water

absorption, water vapor permeability, dimensional stability, closed cell content,

and hot-surface performance. This ASTM specification lists two grades and six

types with the types identifying the various densities as noted below. The mostcommonly used densities are in the 2-2.5 lb/ft³ range (types IV and II). For

comparison purposes, the thermal conductivity of the Grade 2, Types IV and II

PIR is a maximum of 0.20 Btu·in/(hr·ft²·°F) at 75°F.

Type Minimum Density (lbs/ft³) Minimum Compressive Resistance (lbs/in²)

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I 1.8 20

IV 2.0 22

II 2.5 35

III 3.0 45

V 4.0 80

VI 6.0 125

The two Grades, 1 and 2, identify PIR designed for different temperature ranges.

Grade 1 has a temperature range of -70°F to +300°F while Grade 2 has a

temperature range of -297°F to +300°F.

Key applications for PIR insulation are on pipe, equipment, tanks, and ductsoperating at temperatures below ambient. Examples include commercial chilled

water, refrigeration, and liquefied natural gas lines. It is also used as the core

material in the manufacture of foam core panels for various applications

including transportation, building construction, and temporary shelters.


Polyurethane

Polyurethane insulation, commonly called PUR, is a closed-cell foam insulation

material. It is typically either spray-applied or poured-in-place. Spray applied

polyurethane Foam (SPF) requires specialized equipment to apply the material

and proper technical training is important in order to get the best results. SPF is

used in a wide variety of applications including industrial applications like pipes,

tanks, cold storage facilities, freezers, and walk-in coolers.

ASTM C 1029 Standard Specification for Spray-applied Rigid Cellular

Polyurethane Thermal Insulation covers the types and physical properties for

use as thermal insulation between -22°F and 225°F. The standard classifies

materials into four types by compressive strength as follows:

Type Compressive Strength, psi

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I 15

II 25

III 40

IV 60

The standard covers requirements for thermal resistance of 1.0 inch thickness,

compressive strength, water vapor permeability, water absorption, tensile

strength, response to thermal and humid aging, and closed cell content. For

comparison purposes, the max thermal conductivity for all types is 0.16 Btu-in/(h

ft²°F)

ASTM C 945 Standard Practice for Design Considerations and Spray Application

of a Rigid Cellular Polyurethane Insulation System on Outdoor Service Vessels

covers substrate preparation, priming, selection of the polyurethane system, and

the selection of the protective covering for outdoor service. The Spray

Polyurethane Foam Alliance (www.sprayfoam.org) is a trade organization of SPF

producers and contractors who can provide additional assistance on SPF.

Polyurethane foam is also available as one or two component poured-in-place

systems in disposable containers.


Phenolic

Phenolic Insulation Products

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Phenolic insulation is rigid foam insulation with a closed-cell structure. It is

manufactured as large rectangular buns typically 4 ft wide x 3-12 ft long x 1-2 ft

tall at a density of 2 lbs/ft³. Prior to actual installation, buns are fabricated into

various shapes including flat boards and preformed pipe half-shells 3 ft long and

designed to fit over NPS pipe and tubing. More complex shapes can also befabricated to fit around fittings, elbows, and other equipment. ASTM material

specificationC 1126, Type III, Grade 1 covers this type of insulation at service

temperatures from -290°F to +257°F. The specification defines requirements for

density, compressive resistance, thermal conductivity, water absorption, water

vapor permeability, and dimensional stability. While this ASTM spec lists two

grades and three types, only the Type III, Grade 1 is appropriate for use in pipe

insulation. The other types are boards either faced with a vapor retarder or not

and used for building sheathing and roofing, respectively. Grade 2 is an open

cell product. For comparison purposes, the maximum thermal conductivities at

75°F for the Type III, Grade 1 phenolic insulation is 0.13 Btu-in/hr-ft²-°F.

Key applications for this phenolic insulation are on pipe, equipment, tanks, and

ducts, especially those operating at temperatures below ambient.


Melamine

Flat Melamine Insulation

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Melamine Pipe Insulation

Melamine insulation is a low density, semi-rigid, open-cell foam intended for use

as thermal and sound absorbing insulation at temperatures between -40°F and

+350°F.ASTM C 1410 covers this material and defines the following insulation

types and grades:

Type I - flat slab

Grade 1 - Regular (core foam with no facing)

Grade 2 - Faced foam

Type II - pipe and tubing insulation

Grade 1 - Regular (core foam with no facing)

Grade 2 - Faced foam

Type III - special shapes

The specification defines requirements for oxygen index, optical smoke density,

surface burning characteristics, density, tensile strength, % elongation,

indentation force deflection, thermal conductivity, water vapor sorption, linear

shrinkage, and smoke toxicity.

For comparison purposes, the maximum thermal conductivity at 75 F mean

temperature is 0.30 Btu-in / h·ft²·F

Melamine insulations find application to a variety of industrial and process

applications, including pharmaceutical, food-grade, and clean room applications.

The product is available unfaced or with a number of different factory-applied

jacketing systems.


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Polyethylene/Polyolefin

Polyethylene and Polyolefin Insulation Products

Polyethylene/Polyolefin insulations are defined byASTM C 1427. Type I

(preformed tubes) and Type II (sheets). Note: the designations polyolefin andpolyethylene refer to the same type of material and are considered synonymous.

Polyethylene/polyolefin are flexible, closed cell insulation products. The

maximum water permeability values are 0.05 perm-inch and the maximum

thermal conductivity is 0.35 BTU-in/hr sq ft°F at a mean temperature of 75°F.

The preformed tubular insulation is available in ID size range from 3/8" to 4 IPS

and in wall thicknesses from 3/8" to 1". The tubular product is available with and

without pre-applied adhesive. They are suitable for domestic plumbingapplications where the maximum temperature is below 200°F. The

polyethylene/polyolefin insulations are formulated to meet the flame spread

index of less than 25 and smoke developed index of less than 50.

These materials are generally applied without additional vapor retarder facings.

All seams including termination points must be sealed with manufacturer

recommended contact adhesive. For outdoor applications a weatherable jacket

must be applied to protect against UV and ozone.


Polyimide

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Polyimide (PI) insulation is defined by ASTM as lightweight, flexible, open-cell

foam for use as thermal and sound-absorbing insulation in commercial and

industrial environments. PI is manufactured as large rectangular buns, typically

4 ft wide x 8 ft long x 5-30 inches tall, in a range of densities. Prior to actual

installation, buns are fabricated into various shapes, including flat sheets andpreformed pipe half-shells designed to fit over NPS pipe and tubing. Complex

shapes can also be fabricated to fit tightly around fittings, elbows, and other

equipment. ASTM material specificationC 1482 covers PI insulation at service

temperatures from -328°F to +572°F.

ASTM C 1482 defines the requirements for density, thermal conductivity,

acoustic absorption, thermal stability, flammability, smoke density, smoke

toxicity, chemical resistance, corrosiveness, and mechanical properties. ThisASTM spec lists two grades and four types of PI foam, but the following three

types are most commonly used for commercial and industrial applications.

Type Maximum Density

(lbs/ft³)

Maximum Thermal

Conductivity at 75°F

(Btu-in/hr-ft²-°F)

Upper Temperature

Limit

I, Grade

1

0.48 0.32 400°F

IV 0.37 0.34 400°F

VI 0.50 0.34 572°F

Key applications for PI foam include thermal and acoustic insulation for HVAC

and industrial equipment, acoustic duct liner, high temperature pipe insulation,

and expansion joints for cryogenic facilities.

The use of an appropriate vapor retarder is required in all applications wherecondensation could occur. There are a wide variety of vapor retarders, both films

and coatings, that can be specified.


Fibrous Insulations21







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Fiberglass Board and Blanket Insulation Products

Fiberglass Pipe Insulation Product

Fibrous insulations are composed of small diameter fibers that finely divide the

air space. The fibers may be organic or inorganic and they are normally (but not

always) held together by a binder. Typical inorganic fibers include glass, rock

wool, slag wool, and alumina silica.

Mineral Fiber (Fiberglass and Mineral Wool)

Mineral Fiber insulations are defined by ASTM as insulations composed

principally of fibers manufactured from rock, slag, or glass, with or without

binders. Fiberglass and Mineral Wool products fall in this category. There is

some confusion concerning the nomenclature used for these materials.

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Fiberglass products (sometimes called "fibrous glass" or "glass wool") and

mineral wool products (sometimes called "rock wool" or "slag wool") are

covered by the same ASTM "Mineral Fiber" specifications, and sometimes by the

same type and grade. Specifiers are cautioned to call out both the specific

material and the ASTM Type and Grade when specifying these products. Forexample "Fiberglass pipe insulation meeting the requirements of ASTM C 547

Type I, Grade A" or "Mineral Wool pipe insulation meeting the requirements of

ASTM C 547 Type II, Grade A".

A number of ASTM material standards cover mineral fiber products.

Mineral Fiber Pipe

Mineral Fiber Pipe insulation is covered inASTM C 547. The standard contains

five types classified primarily by maximum use temperature.

Mineral Fiber Pipe Insulation Products

Type Form Maximum Use

Temp, F

I Molded 850 F

II Molded 1200 F

III Precision V-groove 1200 F

IV Molded 1000 F

V Molded 1400 F

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The standard further classifies products by grade. Grade A products may be

"slapped-on" at the maximum use temperature indicated, while Grade B

products are designed to be used with a heat-up schedule.

The specified maximum thermal conductivity for all types is 0.25 Btu·in/(hr·ft²·°F)

at a mean temperature of 100°F.

The standard also contains requirements for sag resistance, linear shrinkage,

water-vapor sorption, surface-burning characteristics, hot surface performance,

and non-fibrous (shot) content. Further, there is an optional requirement in

ASTM C 547 for stress corrosion performance if the product is to be used in

contact with austenitic stainless steel piping.

Mineral Wool Insulation Products

Fiberglass pipe insulation products will generally fall into either Type I or Type

IV. Mineral wool products will comply with the higher temperature requirements

for Types II, III, and V.

These pipe insulation products may be specified with various factory-applied

facings, or they may be jacketed in the field. Mineral fiber pipe insulations

systems are also available with "self-drying" wicking material that wraps

continuously around pipes, valves, and fittings. These products are intended to

keep the insulation material dry for chilled water piping in high-humidity

locations.

Mineral fiber pipe insulation sections are typically supplied in lengths of 36 inch,

and are available for most standard pipe and tubing sizes. Available thicknesses

range from ½" to 6".

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Mineral Fiber Blanket

Mineral Fiber Blanket Insulation for Commercial and Industrial Applications is

covered inASTM C 553. The standard contains seven types classified by

maximum use temperature and thermal conductivity.

Type Maximum Use Temperature,

°F

Maximum k at 75°F,

Btu-in./(h ft² °F)

Maximum k at 300°F,

Btu·in/(hr·ft²·°F)

I 450 0.36 0.76

II 450 0.31 0.60

III 450 0.26 0.46

IV 850 0.25 0.43

V 1000 0.31 0.60

VI 1000 0.26 0.46

VII 1200 0.25 0.43

The standard also contains requirements for flexibility, water-vapor sorption,

odor emission, surface-burning characteristics, corrosiveness, and shot content.

These insulations are flexible and are normally supplied as batts or rolled

blankets. Dimensions vary but thicknesses from 1" to 6" are typically available.

The products may be specified with various factory-applied facings, or may be

ordered unfaced.


Mineral Fiber Block and Board

Mineral Fiber Block and Board insulation is covered inASTM C 612. This

standard contains five types classified by maximum use temperature and

thermal conductivity.

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Type Maximum Use Temperature,

°F

Maximum k at 75°F,

Btu·in/(hr·ft²·°F))

Maximum k at 300°F,

Btu·in/(hr·ft²·°F))

IA 450 0.26 0.46

IB 450 0.26 0.42II 850 0.25 0.44

III 1000 0.25 0.44

IVA 1200 0.25 0.44

IVB 1200 0.24 0.36

V 1800 0.45 0.49

Mineral Fiber Block and Board Insulation Products

Each of these types is further classified by compressive resistance. Category 1

materials have no requirement for compressive resistance, while Category 2

materials require a minimum compressive resistance value be met. Density is

not a performance measure and has been removed as a requirement in ASTM C

612.

The standard also contains requirements for linear shrinkage, water-vapor

sorption, surface-burning characteristics, odor emission, corrosiveness to steel,

rigidity, and shot (non-fibrous) content. Further, there is an optional requirement

in ASTM C 612 for stress corrosion performance if the product is to be used in

contact with austenitic stainless steel.

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Fibrous glass boards will generally meet Types I, II, or III. Mineral wool products

will generally comply with the higher temperature requirements for Types IVA,

IVB.

These products are supplied in rigid and semi-rigid board form. Dimensions will

vary, but typical available thicknesses range from 1" to 4". The products may be

specified with various factory-applied facings, or may be ordered unfaced.


Textile Glass

Textile Glass (E-glass) fibrous thermal insulation is produced from textile glass

fibers (e-glass) and is needled into insulation felts without the use of binders.The material is used as thermal insulation component in the fabrication of

insulation systems for use on machinery and equipment at temperatures up to

1200 F. These products are covered inASTM C 1086 and inMIL-I-16411F.

The standard contains requirements for thickness, mass per unit area, apparent

thermal conductivity, hot surface performance, tensile strength, and

combustibility. For comparison purposes, the thermal conductivity of the

material is a maximum of 0.29 Btu·in/(hr·ft²·°F) at 75°F.


High Temperature Fiber

High Temperature Fiber insulations are fibrous insulations, varying in flexibility,

density, and composition, with or without binders. These insulation products are

available in flat sheets, rolls, boards, or loose fibers. The insulation products are

used as the thermal insulation component in the fabrication of insulation

systems for use at temperatures up to 3,000°F.

This category of products is comprised of Refractory Ceramic Fibers (RCF),

including a recently developed class generally referred to as Alkaline Earth

Silicates (AES). These AES fibers are designed to be bio-soluble (i.e. they have

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enhanced in-vitro solubility characteristics which enable these products to meet

European regulatory requirements (Directive 97/69/EC) for man-made vitreous

fibers).

The RCF products in mat and blanket form are covered inASTM C 892. Products

are classified into five types (by maximum use temperature) and five grades (by

density).

Type Maximum Use Temp, °F

I 1350 F

II 1600 F

III 2400 F

IV 2600 F

V 3000 F

Grade Density, nominal, pcf

3 3

4 4

6 6

8 8

12 12

The standard contains requirements for thermal conductivity, density, maximum

use temperature, non-fibrous (shot) content, linear shrinkage, and tensile

strength. For comparison purposes, the maximum thermal conductivity of Grade

3 material is 0.66 Btu·in/(hr·ft²·°F) at 400°F. It should be noted that not all

manufacturers of high temperature fiber products utilize the ASTM C 892standard for their products.

High temperature insulation products are often used as an alternative to fire

resistance rated shaft enclosures. Applications include kitchen exhaust grease

ducts, ventilation ducts, stairwell pressurization ducts, smoke extraction,

chemical fume exhaust ducts, and refuse and trash chutes. They may be used to

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cover plastic pipe and cables to limit flame spread and smoke generation in fire

rated air plenums. These insulation systems are listed and labeled by nationally

recognized laboratories.

Pneumatically applied high temperature fibers are typically used on applications

where it would be difficult to adhere blankets to a surface. These typically are

internal surfaces such as furnace interiors or outer surfaces that are convoluted

and / or difficult to access, such as boiler tube walls on a coal fired furnace.

While they are yet covered by an industry specification, an ASTM specification is

in development.

The composition can be described as follows: The basic types of materials are

loose inorganic fibers (either RCF or AES) combined with a liquid, water based

chemical binder. The fibers are made from mineral substances such as silica,

alumina, calcium, and magnesium processed from the molten state into fibrous

form. The liquid binder is made from inorganic materials: water, colloidal silica

and less than 2% of an organic foaming agent.

The pneumatically applied product is separated into three types based on the

chemistry and upper use temperature use limit:

Type Chemical Composition Upper Use Temperature ,°FI Calcium Magnesium Silicate 2012

II Magnesium Silicate 2300

III Aluminum Silicate 3000

The liquid binder consists of a mixture of both organic and inorganic (colloidal

silica) materials and is typically added in sufficient quantity to provide the fibers

with necessary adhesion to the applied surface, cohesion to one another, and

the required physical properties of the installed, dry insulation. Also, this type of

fiber insulation is typically dimensionally stable with exposure to the maximum

rate temperature for the particular Type I, II, or III. When first heated above a

temperature of about 500° F, most or all of the organic binder decomposes,

leaving only the colloidal silica binder.

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The surface to which pneumatically applied high temperature fiber insulation is

typically prepared with weld pins and wire mesh, the latter being applied a

distance off the surface 1 inch less than the finished thickness. The pins and

wire mesh assure the insulation material is firmly applied and will resist the

effects of vibration and external forces.


Granular Insulations

Calcium Silicate

Calcium Silicate thermal insulation is defined by ASTM as insulation composed

principally of hydrous calcium silicate, and which usually contains reinforcing

fibers.

Calcium Silicate Pipe and Block Insulation are covered inASTM C 533. The

standard contains three types classified primarily by maximum use temperature

and density.

Type Maximum Use Temp (°F) and Density

I Max Temp 1200°F, Max Density 15 pcfIA Max Temp 1200°F, Max Density 22 pcf

II Max Use Temp 1700°F

The standard limits the operating temperature between 80° to 1700°F.

Calcium Silicate Insulation Products

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Calcium Silicate pipe insulation is supplied as hollow cylinder shapes split in

half lengthwise or as curved segments. Pipe insulation sections are typically

supplied in lengths of 36 inch, and are available in sizes to fit most standard pipe

sizes. Available thicknesses range from 1" to 3" in one layer. Thicker insulation

is supplied as nested sections.

Calcium Silicate block insulation is supplied as flat sections in lengths of 36",

widths of 6", 12", and 18" and thickness from 1" to 4". Grooved block is available

for fitting block to large diameter curved surfaces.

Special shapes such as valve or fitting insulation can be fabricated from

standard sections.

Calcium Silicate is normally finished with a metal or fabric jacket for appearanceand weather protection.

The specified maximum thermal conductivity for Type 1 is 0.41 Btu-in/(h·ft²·°F) at

a mean temperature of 100°F. The specified maximum thermal conductivity for

Types 1A and Type 2 is 0.50 Btu-in/(h ft² °F) at a mean temperature of 100°F.

The standard also contains requirements for flexural (bending) strength,

compressive strength, linear shrinkage, surface-burning characteristics, and

maximum moisture content as shipped.

Typical applications include piping and equipment operating at temperatures

above 250°F, tanks, vessels, heat exchangers, steam piping, valve and fitting

insulation, boilers, vents and exhaust ducts.


Molded Expanded Perlite

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Molded Expanded Perlite Insulation Products

Molded Expanded Perlite insulation is defined by ASTM as insulation composed

principally of expanded perlite and silicate binders. It may also contain

reinforcing fibers.

Perlite Pipe and Block Insulations are covered byASTM C 610. The standard

covers the material for operating temperature between 80° to 1200°F.

Perlite pipe insulation is supplied as hollow cylinder shapes split into half or

quarter sections or as curved segments. Pipe insulation sections are typically

supplied in lengths of 36 inch, and are available in sizes to fit most standard pipe

sizes. Available thicknesses range from 1" to 4" in ½" increments. Thicker

insulation is supplied as nested sections.

Perlite block insulation is supplied in lengths of 36" and 1 meter, widths from 24"

and in thickness from 1–½" to 6" in increments of ½". Perlite molded fitting cover

insulation is available for a wide variety of standard elbow and tees.

Scored and V-Groove sections are also available. Special shapes such as valve

or fitting insulation can be fabricated from standard sections.

Perlite is normally finished with a metal or fabric jacket for appearance and

weather protection.

The specified maximum thermal conductivity both block and pipe insulation is

0.48 Btu-in/(h ft² °F) at a mean temperature of 100°F.

The standard also contains requirements for flexural (bending) strength,

compressive strength, weight loss by tumbling, moisture content, linear

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shrinkage, water absorption after heat aging, surface-burning characteristics,

and hot surface performance. In addition, the standard requires compliance with

the standard for insulation for use in contact with austenitic stainless steel.

Typical applications include piping and equipment operating at temperatures

above 250°F, tanks, vessels, heat exchangers, steam piping, valve and fitting

insulation, boilers, vents and exhaust ducts. Perlite insulation is often used

where water entering an insulation system may cause corrosion problems or

process problems. Examples of this would be wash down areas, deluge testing,

pipes that cycle in temperature, stainless steels that are susceptible to stress

corrosion cracking.


Microporous Insulation

Microporous insulation is defined as a composite material in the form of

compacted powder or fibers with an average interconnecting pore size

comparable to or below the mean free path of air molecules at standard

atmospheric pressure. Microporous insulation may contain opacifiers to reduce

the amount of radiant heat transmitted.

The resulting blend of materials and pore structure produces a thermal

insulation with extremely low thermal conductivity across a broad temperature

range. The Microporous core material is completely inorganic making it non-

combustible and suitable for passive fire protection applications.

An ASTM specification for Microporous insulation is under development with the

following Grades and types:

Grade Temperature of use,

°C (°F), max

1 900 (1652)

2 1000 (1832)

2 hydrophobic 250 (482)

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3 1150 (2102)

Type Brief Definition

I Rigid Board

II Flexible Panels

III Pipe Sections

Grade 2 Hydrophobic has been chemically treated to make the insulation water

repellant. The water repellency is maintained up to its grade operating

temperature of 250°C. Above this temperature it performs as standard Grade 2.

Microporous Board Insulation

Microporous Rigid Boards (Type I) are supplied in two primary forms. The first,

typically identified as block or board, is an un-faced flat section of Microporous

insulation compressed to a density of typically 18-25 pcf. The second type,

identified as panel, is a flat section of Microporous insulation which has been

encapsulated with a high temperature glass facing to minimize dust and improve

handling. Normal densities are 14-18 pcf. Rigid Boards have superior

compressive strength but normally cannot be flexed without cracking or

breaking the material. Boards are produced in thicknesses from 1/8" to 4"

depending on the specific type.

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Microporous Flexible Panel Insulation

Flexible Microporous Panels (Type II) are manufactured at a lower density of

approximately 8-16 pcf. They are also faced with a high temperature glass facing

but also are often stitched through, in 1 or 2 directions, using a high temperature

thread. The lower density and the segregation caused by the stitching allows thematerial to be flexed to cylindrical or contoured surfaces. Thicknesses range

from 1/8" to ¾".

Microporous Pipe Sections (Type III) are supplied as hollow cylinder shapes split

in half lengthwise or as curved segments. Pipe insulation sections are typically

supplied in lengths of 19.7" (½ meter), and are available in sizes to fit most

standard pipe sizes. Microporous Pipe Sections are faced with a high

temperature glass facing to improve handling. The thickness is always 1"

nominally (25mm). Thicker insulation can normally be supplied as nested

sections for most pipe sizes. Pipe sections can also be used in combination with

Type II Flexible Panels to meet specific thickness requirements.

With the exception of Hydrophobic Grade, all Microporous Insulation is

permanently damaged by liquid water. Therefore protective jacketing must be

used when the application is subjected to potential environmental conditions or

water spray. Likewise, care must be taken during transportation, storage, and

installation to prevent contact. Humidity does not degrade Microporous

Insulation.

The standard facings for most Microporous Insulations are high temperature

glass fabrics which have a use temperature which is below the maximum use

temperature of the core. In the majority of applications, the Microporous

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Insulation is further jacketed, encapsulated, or sandwiched with other materials

in a static environment. In these environments the facing provides mainly a

handling and installation benefit. In applications where the product must

function dynamically at temperatures above 800°F the product should be

encapsulated in materials appropriate for the environment.

Typical values for thermal conductivity in Btu·in/(hr·ft²·°F) are 0.15 at 392°F, 0.17

at 752°F, and 0.19 at 1112°F. Microporous Insulation has compressive strength of

80 psi for a 10% deflection in a typical board product.

Microporous Insulation is most often used where a maximum amount of thermal

resistance is needed with minimal thickness and weight. Typical applications

include piping and equipment operating at temperatures above 250°F, tanks,

vessels, heat exchangers, valve and fitting insulation, exhaust ducts, electronic

instruments, and fire protection.


Flexible Aerogel Insulation

Silica Aerogel Insulation

Flexible aerogel insulation is a composite of an amorphous silica-based aerogelcast into a fiber reinforcement. The fiber reinforcement may consist of a batt, a

needled felt blanket, or other configurations of fibers. The fibers themselves may

be inorganic, such as glass fibers, or organic, such as polyethylene. The flexible

aerogel insulation typically contains hydrophobic agents and may also contain

opacifiers.

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The ASTM material specification for this insulation material has not yet been

developed. Flexible aerogel insulations have thermal conductivities (of about 0.1

Btu·in/(hr·sq ft·°F) at room temperature. They are flexible and resilient (down to

cryogenic temperatures) and are hydrophobic, with water vapor absorption

below 4%, and water retention below 4%. Some flexible aerogel insulations arerated Class A for flammability / smoke developed and some have a temperature

rating as high as 1200°F.


Poured-In-Place

Granular Poured-In-Place insulation for underground piping, ducts, and tanks is

available. These are granular materials generally made from engineered blends

of inorganic materials or calcium carbonate and require no mixing or curing. The

hydrophobic materials provide thermal insulation, corrosion protection, and load

bearing properties. Product is sold by the cubic foot and is available in a variety

of packaging options. The material is installed around underground pipes, ducts,

or tanks before backfilling. Currently no ASTM Standard material specifications

have been developed for these products.


Reflective Insulations

Reflective insulations are defined by ASTM as insulation depending for its

performance upon reduction of radiant heat transfer across air spaces by use of

one or more surfaces of high reflectance and low emittance. Reflective

insulations utilize low-emittance foil (usually aluminum) or foil coated facings to

reduce the amount of radiant heat flux occurring at the surface.

While reflective insulations obey the same laws of physics as any insulation

system, they are typically relatively thin (usually less than ½"). Thus they present

little resistance to conduction heat transfer through the material. They operate

primarily by reducing the radiant heat flux to and from the surface of the

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insulation. Reflective foils are often used as facing on other more conventional

insulations to provide additional thermal resistance. The Reflective Insulation

Manufacturers Association (www.rima.net) is a source of additional technical

information on reflective insulation products.

ASTM C 667 Standard Specification for Prefabricated Reflective Insulation

Systems for Equipment and Pipe Operating at Temperatures Above Ambient Air

covers prefabricated, multi-layer reflective insulation systems for equipment and

piping.

BACK TO TOP

CATEGORIES OF WEATHER BARRIERS, VAPOR RETARDERS, AND FINISHES

Most mechanical insulation systems require a covering or finish material. The

primary reason is to protect the insulation from damage. Weather, mechanical

abuse, water vapor condensation, chemical attack, and fire are all potential

sources of damage. Additionally, appearance coverings are utilized to provide

the desired aesthetics. Depending on the location and application, various terms

have been used to describe these functions:

Weather Barriers are materials which, when installed on the outer surface of

thermal insulation, protects the insulation from the weather such as rain, snow,

sleet, dew, wind, solar radiation, atmospheric contamination, and mechanical

damage.

Vapor Retarders are materials which retard the passage of water vapor into the

insulation.

Mechanical Abuse Coverings are materials that protect the insulation from

damage by personnel, machinery, etc.

Condensate Barriers (sometimes called moisture retarders) are materials,

normally used as an inner lining for metal weather barriers, which will bar the

condensate which tends to form on the inner surface of the metal jacket from

contacting the metal portion of the jacket.

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Appearance Coverings are materials used over insulation systems to provide the

desired color or appearance.

Hygienic Coverings are materials used to provide a smooth, cleanable, surface

for use in food processing, beverage, or pharmaceutical facilities.

These functions are performed by a number of different materials or material

systems. In many cases, a single material can provide multiple functions (for

example, a metallic jacketing often serves as protection from both the weather

and from mechanical abuse).

There is some inconsistency in the nomenclature used for these materials. The

terms jacketing, lagging, and facings are sometimes used interchangeably to

describe the outer covering of an insulation system.

Adding to the confusion, the term vapor retarder has evolved. Historically, the

term vapor barrier was used, but this has been generally replaced with the term

vapor retarder in recognition of the fact that an absolute barrier to water vapor

flow is difficult if not impossible to achieve. There is also movement toward the

use of the term vapor diffusion retarder (VDR) to generically describe these

materials.

BACK TO TOP

PHYSICAL PROPERTIES OF WEATHER BARRIERS, VAPOR RETARDERS, AND

FINISHES

Depending on the application, weather barriers, vapor retarders, and finishes are

subject to certain requirements that must be considered when selecting a

system:

Internal Mechanical Forces - Expansion and contraction of the pipe or vessel

must be considered because the resulting forces are transferred to the external

surface of the weather barrier. An ability to slide, elongate or contract must be

accommodated for.

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External Mechanical Forces - If a pipe, vessel or a specific area thereof is subject

to mechanical abuse i.e. tools being dropped, abrasion from wind driven sand or

personnel walking on the system, then these need to be considered in the

design. This may impact insulation type used, as well as the weather barrier

jacketing type.

Chemical Resistance - Some industrial environments may have airborne or

spilled corrosive agents that accumulate on the weather barrier and cause

chemical attack of the pipe or vessel jacketing selected. Elements that create

corrosive issues must be well understood and accounted for. Insulation design

of coastal facilities of course should account for chloride attack.

Galvanic Corrosion - The use of one metal in contact with a different metal must

be considered for galvanic corrosion potential. Similarly water can act as an

electrolyte and galvanic corrosion can happen due to the different potential of

the pipe and vessel and a metal jacketing.

Insulation Corrosivity - Some insulation materials can cause metal jacket

corrosion. Some insulation materials can chemically attack some polymer films.

Both of these situations shorten service life.

Thermal Degradation - Hot systems are typically designed so that the surface

temperature of the insulation and jacketing material do not exceed 140 degrees

F. The long term effect of 140 degrees F on the jacketing material must be

considered. Additionally, there may be solar radiation load and perhaps parallel

heat loss from an adjacent pipe. This is a critical design consideration,

particularly if a non-metal jacket is being considered.

Installation and Application Logistics - A common occurrence is that the

insulation contractor installs more insulation in a day, than can be protected with

jacket. If it rains, the exposed portion of insulation gets saturated and the next

day the jacket is installed over the wet insulation. This creates an obvious

potential corrosion issue before the installation is operational. If this occurs it

must be corrected immediately. It should also be understood that the size, shape

and adjacent space available to work may dictate the type of weather barrier

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barrier option must be utilized. If this is the case, the maintenance schedule

must recognize and accommodate for this.

Maintainability - The importance of a maintenance and inspection plan cannot be

over emphasized to achieve the service life expected of the design.

The physical properties of importance to jacketings and facings are summarized

below:

Water Vapor Permeance is defined byASTM C 168 as the time rate of water vapor

transmission through unit area of flat material or construction induced by unit

vapor-pressure difference between two specific surfaces, under specified

temperature and humidity conditions. For facing materials, water vapor

permeance is commonly expressed in units of perms. In below ambientapplications, it is important to minimize the rate of water vapor flow to the cold

surface. This is normally accomplished by using vapor retarders with low

permeance, insulation materials with low permeability, or both in combination. In

above ambient applications, it is often desirable to have a "breather" facing that

allows water vapor to escape without condensing. In either case, it is important

to know the permeance of the facing materials. ASTM Test Method E 96 is used

to measure the water vapor transmission properties of insulation materials.

Emittance of a surface is the ratio of the radiant flux emitted by a specimen to

that emitted by a blackbody at the same temperature. For personnel protection

and condensation control applications, a high emittance is desirable. For

minimizing heat flow, a lower emittance surface is generally desirable.

Surface Burning Characteristics are generally determined byASTM Standard

Test Method E 84 which measures the relative burning behavior of materials by

observing the horizontal flame spread along the specimen surface. Flame spread

and smoke developed index are reported. However, there is not necessarily a

relationship between these two measurements. Many other fire test are also

used to characterize these materials. For example, textile products utilize ASTM

D 6413 (Standard Test Method for Flame Resistance of Textiles) and NFPA 701

(Standard Methods of Fire Tests for Flame Propagation of Textiles and Films).

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Tensile Strength of facings and jacketing materials is a measure of the damage

resistance of the facing. For facing materials, tensile strength is typically

measured per ASTMD 828 orD 882 with results reported in units of lbs/in of

width. ASTM D 828 is designed for paper while ASTM D 882 is designed for thin

plastic sheeting. For woven fabrics, ASTM D 5035 is the predominate test. Somespecifications require testing in both machine direction and cross machine

direction.

Dimensional Stability at elevated temperatures is measured in % usingASTM

Standard Test Method D 1204. Specimens are exposed to temperatures of 150 F

for 24 hrs.

Fungi Resistance of insulation facing materials is typically evaluated using

ASTM C 1338, which calls for inoculating specimens with 5 different strains of

fungi spores and then incubating them at 86 F, 95% RH for 28 days. The growth

is then evaluated relative to a comparative material to assess the fungi

resistance of the sample.

Thermal Integrity of the facing materials must match the application requirement.

Flexible vapor-retarder facings are generally evaluated perASTM C 1263, which

subjects specimens to temperature extremes of -20 F to + 150 F, bends the

specimens around a 1 in. OD mandrel, and then evaluates for any cracking ordelamination.

Bursting Strength is a measure of the force required to rupture the facing in psi.

It is measured in accordance withASTM D 774 (up to 200 psi) orASTM D 3786

(up to 500 psi).

BACK TO TOP

PRODUCT CHARACTERISTICS OF WEATHER BARRIERS, VAPOR RETARDERS,AND FINISHES

Metal Rolls or Sheets

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Metal Rolls or Sheets at various thicknesses are commonly used for weather

protection and abuse resistance. They are available with embossing,

corrugation, moisture barriers and different banding and closure methods.

Elbows, tees, valve and flange covers, beveled collars and end caps, wire, straps

and screws are also available from manufacturers and fabricators.

In North America, the most common metal jacketing materials are:

Bare aluminum

Coated aluminum

Stainless steel

Additional metal jacketings include:

Painted steel

Galvanized steel

Aluminum-zinc coated steel

Common metal jacket thicknesses available in aluminum include 0.016, 0.020,0.024, 0.032 and 0.040 inch. Those available in stainless steel include 0.010,

0.016 and 0.020 inch. Not all thicknesses are available in all material offerings

from all manufacturers. The minimum thickness recommended for aluminum

installed indoors is 0.016 inches; for stainless steel installed indoors, 0.010

inches. For outdoor installations, increase thickness on non-rigid insulations to

at least 0.024 for aluminum and to 0.16 inch for stainless steel. Consult

manufacturer's product data for available offerings.

Aluminum is weather resistant but susceptible to corrosive chemicals. Coated

aluminum can be used to provide additional corrosion protection and to provide

higher values of surface emittance where needed. Stainless steel offers the best

chemical resistance and is commonly offered as Type 304 and 316. Type 316

offers greater chemical resistance than Type 304. Corrugated and stucco-

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embossed materials are better suited for applications exposed to physical abuse

because they disguise surface imperfections.

For unprotected insulation exposed to severe weather, jackets are available with

continuous longitudinal Z-shaped locking seams and weather resistant butt

straps that offer the ultimate in weather protection.

Metal jackets should be specified with a moisture retarder on the inside surface

to provide 100% coverage and resist galvanic corrosion. Common offerings

include a 3-mil thick polysurlyn coating (which is most suited for below ambient

and cyclical operating temperatures), kraft paper coated with a 1-mil thick

polyethylene film, and kraft paper coated with 3- mil thick polyethylene film.

For vertical tanks and vessels greater than 48 inches (1200 mm) in diameter,consider using either nominal 1–¼ or 2–½ inch (31 or 63 mm) deep, corrugated

sheets or 4 by 1 inch (100 by 25 mm) box rib sheets for improved durability.


Polymeric (plastic) rolls or sheets

Polymeric (plastic) rolls or sheets are available at various thicknesses. These

materials are glued, solvent welded, or taped depending on the polymer. Elbows

and tees are also available for piping for some type of polymers. Typical

polymeric (plastic) jacketing materials are:

Polyvinyl Chloride (PVC)

Polyvinyliedene Chloride (PVDC)

Polyethylene Terephthalate (PET)

Polyvinyl Flouride (PVF)

PVC Jackets

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PVC jackets are durable, attractive, and an easy-to-clean material that is typically

field-applied over unfaced insulation and most factory-applied jackets where

additional protection is necessary. PVC jackets are covered by ASTM Standard

Practice C 921, Types I Grade 4 and Type II, Grade 2.

PVC jackets are available in several thicknesses and colors. Standard

thicknesses are 10, 15, 20, 30, and 40 mils, with 20 and 30 mils being the most

common thicknesses. Thicknesses of 30 mils are recommended for outdoor

applications. Jacketing for outdoor use should be UV stabilized. White is the

predominant color used; however PVC jackets are available in a variety of colors

(colored jacketing is normally not available with UV stabilization).

Several manufacturers and fabricators offer PVC "cut and curl" jacketing

products. Fitting covers are also available for covering elbows, tees, valves,

flanges, mechanical couplings, drain bodies, strainers, end caps, and other

common piping products. Accessory products (solvent adhesive, tapes,

stainless steel thumbtacks, etc) are also available from manufacturers.

PVC jacketing up to 30 mil thicknesses generally meet 25/50 flame-spread and

smoke-developed indexes. Jacketing temperatures should be kept below 150°F

for hot services. PVC jackets can be used in areas requiring frequent washdown

and are used extensively for applications requiring USDA and FDA approval. Toachieve USDA and FDA approval, PVC jackets should be installed with

continuous solvent welded joints and seams. PVC jackets and fittings, when

applied over an intermediate vapor retarder and properly sealed, can be used on

cold systems.


PVDC Film

PVDC Film is a flexible and tough vapor-retarder facing that is applied to the

exterior of pipe, vessel, and equipment insulation systems. This vapor retarder

consists of a biaxially oriented homogeneous opaque white polymer film. It can

be factory or field applied to the surface of the insulation and is available in two

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thicknesses, 4 and 6 mils, both at 35.5" wide and more than 250 ft long. When

factory applied to insulation, the lap joint of the vapor retarder is sealed in the

field using a self-sealing lap (SSL). The PVDC tape is the same type of

homogeneous white film to which an adhesive backing that does not require

release paper has been applied. The tape is available at 2 and 6 mil thicknesses,widths of 1, 2, and 3 inches, and 150 ft length. PVDC films are not intended for

exterior applications unless protected by a suitable weather barrier.

ASTM Standard Specification C 1136-06, Type V and VI covers this type of vapor-

retarder facing for use where insulation outer surface temperatures are -20 to

150°F. This ASTM standard specification establishes requirements for

permeance, burst strength, tensile strength, dimensional stability, flame/smoke

performance, zero fungal growth, and lack of cracking or delamination.

ASTM Standard Practice C 921, Type II, Grade 2 covers this type of film for use

as a vapor retarding outer jacket on thermal insulation over mechanical

equipment such as tanks, pipe, and vessels. The 6 mil PVDC film meets the

permeance requirements of Class A, "Extremely low permeance" or 0.01 perms

maximum. The 4 mil PVDC film meets the permeance requirements of Class B,

"Very low permeance" or 0.02 perms maximum.

Key applications for PVDC vapor retarder is in insulation systems for pipe,equipment, tanks, and ducts, especially those operating at temperatures below

ambient such as food and beverage lines, refrigeration, ammonia refrigeration,

and LNG pipe. PVDC film is applied to the insulation on straight sections of pipe

or to large surfaces like tank or duct walls. PVDC tape is used to seal joints in

the film, at vapor retarder butt joints on pipe insulation, can be wrapped around

complex insulation shapes such as fittings and elbows, and can be used to

repair physical damage to the vapor retarder film.


Laminates

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Laminates are, in general terms, materials made by bonding (through the use of

heat, pressure, adhesives or any combination thereof) two or more layers of

materials. The layers can be comprised of similar or dissimilar materials.

Laminates used for protective jacketing may be comprised of metal foils, plastic

films, papers, nonwovens, scrims, etc. and may or may not contain a topcoat ofsome kind for coloration, UV resistance, contain varying degrees of

configurations, etc.

For vapor retarder applications, at least one component must be a material that

offers significant resistance to vapor passage. Laminates may be classified into

three categories:

Laminated Foil Jacketing (ASJ/ASJ+/FSK/PSP/FSP)

Synthetic Rubber Laminates

Multi-ply Laminates

Laminated Foil Jacketing (ASJ/ASJ+/FSK/PSP/FSP)

A commonly used pre-formed jacket for pipe, tank, and equipment vapor retarder

applications is the lamination of white paper, reinforcing fiberglass scrim, andaluminum foil. Of secondary prominence is the same basic structure, with

substitution of metallized polyester film for the foil component and/or a polymer

film for the white paper component. These products are generally referred to as

ASJ or ASJ+ (for all-service-jacket), and meet the requirements of ASTM C1136,

Standard Specification for Flexible, Low Permeance Vapor Retarders for Thermal

Insulation. These ASJ or ASJ+ facings are commonly used as the outer finish in

low abuse, indoor areas; elsewhere, they are covered by a protective metal or

plastic jacket. A similar facing material (FSK, for foil-scrim-kraft) has the samebasic structure except with the aluminum foil layer facing outward. Numerous

variations (e.g. FSP for Foil-Scrim-Poly, PSP for Poly-Scrim-Poly, and PSK for

Poly-Scrim-Kraft, etc.) are available. Many types of insulation products are

supplied with factory-applied ASJ, FSK, or FSP vapor retarders.

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Synthetic Rubber Laminates

Synthetic rubber based laminates typically consist of aluminum facing laminated

to a synthetic rubber membrane and a peel-and-stick application. These

laminates are used on pipes, ducts, and tanks for both interior and exterior

applications and may be used in direct burial applications. A variety of weights

are available. Perm values of less than 0.02 are reported and the materials are

generally considered to be "self-healing" in that small punctures and

penetrations will re-seal.


Multi-ply Laminates

Multi-ply laminates consist of multiple layers of aluminum with alternating layers

of polyester or polyethylene film with a peel-and-stick adhesive system. These

laminates are used on pipes, ducts, and tanks for both interior and exterior

applications. They cut easily and install easily in the field. Perm values of zero or

near zero are reported. They are available in smooth or embossed surface finish

in a variety of thicknesses. Several colors and chemical resistant films are also

available.


Fabrics

Fabrics are often coated and used as insulation jacketing materials, particularly

for removable/reusable insulation covers. The fabrics are woven from a widevariety of textile fibers including but not limited to:

Canvas

Fiberglass (Type E)

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Amorphous Silica fibers

Ceramic fibers

Aramid fibers

Stainless Steel

Inconel

Coatings and laminate membranes are usually applied to these fabrics to

provide increased protection and abrasion resistance. Coatings used include but

are not limited to:

Acrylic

Silicone

Polytetrafluoroethylene (PTFE)

Polychloroprene

Vermiculite

The selection of the fabric/coating combination for a particular application

depends on the temperature, abuse, chemical compatibility, and combustibility

requirements.Click here to view additional information on fabrics or consult

manufactures of fabrics or removable/reusable covers for guidance.


Mastics and Coatings

Mastics are available in numerous formulations designed to provide protection

of the insulation from physical, chemical, water and weather damage. They can

be broken-up into special use classes as described below, and the selection of

the proper mastic will depend on the insulation type, equipment, piping or duct

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operating temperature, fire hazard classification required, expected service life

and other conditions. Mastics can be applied to protect the entire insulation

system surface, facing materials over insulation or over irregular insulation

surfaces such as sprayed polyurethane foam systems, bends and elbows,

protrusions such as flanges, valves, supports or insulation terminations wheresheet materials can not be effectively applied. They are most often applied by

brush, trowel or spray in two coats at the manufactures recommended

application rate with a reinforcing mesh embedded between the first two coats.

Typical reinforcing meshes are made of synthetic fibers, fiberglass scrim or

cloth and canvas cloth. The mastic manufacturers application guide should be

consulted for selection of the proper reinforcement to use with the mastic

chosen.

Properties and tests commonly considered in the selection of a mastic are given

in ASTM C 647, Standard Guide to Properties and Tests of Mastics and Coating

Finishes for Thermal Insulation.

Mastics are broken-up into the following types and sub-types:

Vapor Retarder (vapor barrier) Mastics and Coatings

o Solvent based thermoplastic rubber/resintypes

Common uses

Cryogenic applications (below

-40°F)

Severe chemical environments

Other benefits

Fire resistive - meet Class A flame

and smoke

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Highest performance of vapor

retarders

Lowest permeance

o Water based synthetic polymers types

Common uses

Low temperature piping and

equipment (-40°F to Ambient)

Sealing seams, punctures and

terminations of vapor retarderfacings

Chilled water, air conditioning duct,

brines

Other benefits

Fire resistive - meet Class A flame

and smoke

Low Hazards during application and

shipment - low toxicity and no fire

hazard

Permeance: dependent on type -

below 0.5 perms

o Solvent based asphaltic types

Common uses

Buried pipes

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Exterior low service temperature

piping

Other properties

Chemical resistant

Poor fire resistivity

Weather Barrier (Breather) Mastics and Coatings

o Water based synthetic polymer type

Most common type on the market

Provide weather protection

Keep liquid water out

Allow water vapor to pass through

over hot equipment

UV resistance

Protect vapor retarder facings (FSK, ASJ)

Exterior ductwork and piping

Weather protection

Physical protection against

puncture

o Water based asphalt emulsions

Older technology

Low material cost, but high labor cost

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Mastic Characteristics: When selecting the mastic to be used the following

general characteristics and uses should be considered:

Vapor Retarder Mastics are designed to prevent the ingress of water vapor into

cold insulation systems in addition to protection against mechanical abuse,

liquid water intrusion and weather. Permeance of vapor retarder mastics will vary

greatly ranging from 0.5 perms to <0.01 perms depending on the mastic type and

performance requirements. Most manufacturers will provide information on the

mastic's permeance on their product data sheets. When comparing permeance

of a mastic the test temperature, test relative humidity and film thickness must

be considered. Changes in any of these properties will affect the permeance of

any mastic.

Cold insulation systems with respect to mastics can be further defined by:

cryogenic service (operating below -40°F)

low temperature service (-40°F to 32°F)

cool/cold service (33°F to ambient).

Cryogenic insulation systems require specialized engineering beyond the scope

of this document. Mastics and coatings for these uses have very low

permeability (<0.02 perms) and include specialized vapor stop coatings with

extremely low service temperature limits (down to -320°F) and solvent based

thermoplastic rubber (Hypalon) mastics. Contact the mastic manufacturer for

assistance in selecting these materials.

Low temperature service mastics should have permeance of <0.02 perms. These

products include solvent-based thermoplastic rubber and water based synthetic

rubber mastics. The solvent based mastics will typically have the lowest

permeance, highest chemical resistance and longest service life, however, they

may be restricted for use in some regions, are combustible during application

and require solvents for clean-up. Some water based mastics have permeance

values below 0.02 perms, can be used in all regions and have the added

advantage of being non-flammable during application and easy water clean up.

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Cool or cold service insulation includes insulation of chilled water piping, air

conditioning ductwork and other systems operating between 33°F and ambient.

The proper mastic and permeance requirements for these systems will depend

on whether or not the system is interior or exterior, the facing on the insulation,

the likelihood of physical or mechanical abuse, the climate (high vs. lowhumidity environment) and insulation type. There are still some solvent-based

mastics used for these applications however in most cases water based mastics

will meet the required performance and are preferable. The vapor retarder

system, including any sheet facing materials and mastics, should have

permeance <0.05 perms per ASTM C 755.

In many cases insulation for duct systems or piping in warm humid climates will

be faced with a FSK, ASJ or other vapor retarder jacket. In this case a waterbased mastics with permeance <0.5 perms are typically acceptable for vapor

sealing punctures (from hangars or pins) and seams in the facing on interior

applications. These mastics can also be applied over the entire facing surface to

provide additional physical protection if required or physical and weather

protection of the facing on outdoor insulation. If the insulation is not faced with a

vapor retarder jacket or at insulation terminations or over bare insulation the

mastic should have a permeance less than 0.05 perms. Reinforcing mesh

embedded in the mastic is typically required per manufacturers guidelines.

Weather barrier mastics and coatings are also commonly referred to as

"breather" coatings. They are specifically designed to provide protection of the

insulation from physical abuse and/or weathering. They are normally water

based synthetic polymer coatings. These mastics have higher permeance, > 1.0

perm, than vapor retarders and will allow water vapor to pass through them while

repelling liquid water. This is particularly important when used over hot

equipment or piping where trapped moisture must be allowed to pass throughthe mastic to avoid blistering of the coating. Weather barrier coatings also find

use on dual temperature systems; such as rooftop HVAC ductwork used for

cooling and heating or dual temperature water piping, where the insulation

contains a vapor retarder facing that requires weather protection. On exterior

applications the insulation should always be sloped to avoiding ponding water.

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On interior applications on hot pipes specialized lagging adhesives and coatings

may be used with fiberglass cloth or canvas cloth to create an insulation cover.

The lagging adhesive is used to both bond the cloth to the insulation as well as

to provide a protective finish.

Inspection, Maintenance and Repair of Mastic Systems

Mastics are a key component in the protection of many insulation systems and

need to be inspected, maintained and quickly repaired to function properly.

Regular inspection of the mastic, as part of an overall insulation system

maintenance program, should be conducted. Inspection should include visual

observation for any cuts, tears, punctures, chemical breakdown, embrittelment

from chemical attack or other damage to the mastic or reinforcement. Any buildup of dirt or other chemical contaminants should be removed to ensure that

underlying damage has not occurred and to prevent deterioration of the mastic.

Surface wear should be repaired by thoroughly cleaning the surface before

applying a new finish coat of mastic. The use of reinforcing mesh may be

required if there was damage or exposure of the previous reinforcement. If

damage includes a breach of the mastic such as a puncture, tear or through cut

the insulation system should be closely examined to ensure that water or

contaminants have not entered the insulation system. If the insulation is wet or

damaged it must be removed and replaced prior to re-applying any mastic. Any

newly applied mastic should be reinforced per the manufacturers

recommendations and extend at least three inches over the previously sealed

and cleaned surface.

Coatings generally need to be re-coated every 2—3 years. If applied to flexible

insulation products or insulation materials that will expand and contract during

service, they may "egg shell / crack" but will not flake or peel off. This eggshelling effect may detract from the appearance of the application; it will not

generally affect the UV performance of the product. It can be re-coated for

extended service life.


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Insulating and Finishing Cements

Insulating and Finishing Cements are mixtures of various fibers, powders and

binders sometimes used to insulate and finish irregular surfaces. ASTM C 195

covers Mineral Fiber Thermal Insulating Cement (for use up to 1900 F), ASTM C196 covers Expanded Vermiculite Thermal Insulating Cement (for use up to 1800

F), and ASTM C 449 covers Mineral Fiber Hydraulic Setting Thermal Insulating

and Finishing Cement. (for use up to 1200 F).

These materials are typically mixed with water to the consistency of a paste and

then troweled on to the surface to be covered.


BACK TO TOP

FABRICATIONS OF INSULATION PRODUCTS

Most mechanical insulation systems require some degree of fabrication. The

degree required will vary depending on the complexity of the job and the

materials used. Some mechanical insulation products can be ordered directly

from insulation manufacturers in standard sizes with factory-applied facings.These products still require some fabrication in the field to accommodate valves

and fittings, etc. Other insulation materials (i.e. cellular glass, phenolic,

polyisocyanurate, and polystyrene) are manufactured in relatively large size

blocks or buns, and must be cut into the appropriate size and shape. While this

fabrication is sometimes done in the field, the work is more often done by

insulation fabricators and/or distributor/fabricators that specialize in this work.


Insulation Fabrication Standards

Insulation Fabrication Standards and guidelines are generally developed by the

insulation manufacturers based on experience with their products. These

standards provide specifics on the dimensions to be used and the allowable

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tolerances. In some cases, industry standard specifications are available. They

are:

ASTM C 585Standard Practice for Inner and Outer

Diameters of Rigid Thermal Insulation for NominalSizes of Pipe and Tubing

ASTM C 450Standard Practice for Fabrication of

Thermal Insulating Fitting Covers for NPS Piping,

and Vessel Lagging

ASTM C 1639-07Standard Specification for

Fabrication of Cellular Glass Pipe and Tubing

Insulation

Specifiers are encouraged to utilize these standards when specifying fabricated

products, or to specify fabrication to the insulation manufacturers' instructions.

This can be particularly important in regards to the type of adhesives used.

Removable and Reusable Insulation Covers

Removable and reusable insulation covers are fabricated insulation productsused in industrial and commercial applications where insulation must be

periodically removed for inspection and maintenance. Equipment with irregular

or complex surfaces such as turbines, pumps, and valves can be insulated with

removable covers. The covers are generally fabricated from flexible insulation

materials enclosed in fabric or metal mesh containment. The seams are sewn

(usually machine) with thread, staples, or metal rings. The covers are designed

to fit closely with tight joints on the valves, piping, or equipment. A suitable

attachment system is incorporated and the covers are easily removed and

replaced. Requirements will vary with the application, with commercial

applications generally less demanding than industrial sections.

Removable covers should be designed for acceptable thermal performance,

compatibility with operating temperature, weather and atmospheric conditions,

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fire endurance, and sound attenuation. Covers can be classified into the

following categories:

Flexible insulation blankets or pads

Formed and shaped insulation covers

Fabric finish

Metal encased

Metal canning and framing

Removable elastomeric insulation covers

Flexible insulation blankets or pads are made in flat form, designed to wrap on

specific contour with slots or notches provided for nozzles or interference

points. The blankets can be provided with flaps or overlap edges to prevent wind

and rain penetration. Blankets can be made in any thickness but thicknesses

over 2 inches are usually made in two or more layers.

Formed or shaped insulation covers are made to conform to the shape of the

fitting, valve, or equipment, having the same curvature built into the insulationand fabric or metal canning.

Metal canning and framing covers are used where physically strong removable

insulation enclosures are required. Canning consists of metal sheets formed to

shape, and lined with insulation. An inside metal lining may be required.

Removable Elastomeric insulation covers are constructed from insulation

materials, adhesives, bands, and light metal frames.

The materials used to make removable covers are generally standard products

and can be classified into the following:

Insulation materials

Encasement materials

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Stitching materials

Attachment system

Identification system

Click here to view a glossary of frequently used terms for removable/reusable

insulation covers and example bills of material for these products.

ASTM C 1094 Standard Guide for Flexible Removable Insulation Covers provides

guidance in specifying removable insulation covers for surfaces operating in air

at temperatures above ambient.


BACK TO TOP

ACCESSORY PRODUCTS

Adhesives

A variety of adhesives types are available for many different applications

including insulation attachment, insulation fitting fabrication and facing.Adhesives are available in water based, solvent based, hot melts, reactive cure,

pressure sensitive adhesives and aerosol formulations for application by

numerous methods including brush, spray, trowel and roll coater. When

selecting an adhesive the insulation type, service temperature limits, application

method and required adhesive strength should all be considered. Refer to the

adhesive manufacturer's product selection guides for assistance in choosing

adhesives for specific uses. In all cases, regardless of the type of adhesive used

to secure the insulation, it is important to prepare the surface being adhered to.

It must be free of dirt, rust, loose particles, and oil. Wiping the surface with

denatured alcohol is often recommended. Ambient and surface temperature are

also important factors in selecting an adhesive. When considering ambient

temperatures, it is important to factor in the temperature over the entire curing

time. The surface being bonded to must also be considered. Steel (coated or

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painted), plastic (such as polypropylene) or others may require special

preparation work or special adhesives.

For attachment and fabrication, in general, rigid insulations will require thicker,

high-bodied adhesive capable of filling small gaps while flexible insulations such

as fiberglass, mineral wool, or elastomeric use thinner higher coverage rate

adhesives. Attachment or fabrication of impermeable insulations will require

contact adhesives, pressure sensitive, or reactive cure adhesives to avoid

trapping vapors. Water based adhesives are not recommended. When using

contact adhesives, it is important to coat both surfaces with a thin coat of

adhesive (a thin coat is better than a thick coat) and to allow the solvents to

evaporate before combining the two surfaces. This may vary with installation

conditions (temperature and humidity). When using pressure sensitiveadhesives, it is important to apply pressure to insure the adhesive is wetted out

between the two surfaces being adhered. As the installation temperature gets

colder, the amount of pressure to wet out the adhesive increases.

Other specialty adhesive includes cryogenic adhesives for very cold operating

systems (down to -320°F) and high temperature inorganic adhesives for hot work

(up to 800°F). When used for attachment most adhesives are used in conjunction

with mechanical fasteners.Duct liner adhesives include water and solvent types as well as pressure

sensitive adhesive and hot melts. They can be applied in a sheet metal shop

either as part of a coil line or on fabrication tables. Typical duct liner

specifications require two forms of attachment that generally are weld or stick

pins and an adhesive. On coil lines the adhesives is often water based to allow

for immediate weld pin placement without concern for flash fire. Water based

adhesives do not work well with closed cell foam duct liner materials because

the water can't evaporate. Hot melt, spray adhesives or pressure sensitive

adhesives are often used on these products.


Reinforcements for Cements and Mastics

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Reinforcing fabrics for cements and mastics are critical to prevent cracking over

seams or areas of movement and to improve the overall strength of the finish.

They come in a variety of types and sizes. The reinforcement chosen must be of

the correct type and size and be compatible with the mastic or cement to ensure

proper function. Refer to the mastic or cement manufacturers product data sheetfor compatible reinforcements. Fiber fabrics include open weave fiberglass and

synthetic fiber meshes and woven canvas and fiberglass cloth. Mastics are

typically reinforced with "10x10" open weave cloths for most applications.

Heavier duty, 5x5 mesh, cloths are sometimes used with heavier coats of

mastics. Reinforcements should always be embedded within the wet mastic or

cement and be fully covered. All seams in the fabric should be overlapped by a

minimum of two inches to avoid potential for cracking.


Sealants

Sealants can be broken up into the following general categories:

Duct Sealants

o Sheet metal sealants

o Duct board sealants

Flashing Sealants

Joint Sealants

Duct sealants come in a variety of formulations. Typically the sealant is a high-

bodied water or solvent-based formulation applied by brush or cartridge gun.

UL-181 A-M for duct board and UL-181 B-M for flexible and rigid metal duct give

standard requirements for duct sealants that may be used to specify them. In

addition for metal duct they should meet the SMACNA pressure class for the

duct system being sealed. Refer to the duct sealant manufacturers product data

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Flashing sealants are used to seal insulation terminations, penetrations and

protrusions such as around valves, gauges and other areas where the insulation

is broken. They may also be used to seal metal jacketing seams. Flashing

sealants protect the exterior of the insulation system from the ingress of liquids

and/or vapors. The flashing sealant must be compatible with all surface incomes in contact with including the insulations and insulation finishes. It should

be applied per the manufacturers instruction such that it forms a complete

watertight seal.

Joint sealants are used to seal the longitudinal and circumferential butt joints of

rigid insulation against moisture penetration. Joint sealants are of particular

importance in cold temperature systems to lock out water vapor penetration

between blocks of insulation. Formulations are of high solids and are available ina variety of types. The joint sealant should remain flexible after application to

allow for movement in the insulation system without cracking or splitting.

Selection of the proper joint sealant will depend on the operating temperature at

the point where the sealant is applied, the insulation type being sealed and the

finishes being applied over the top of the insulation. Refer to the manufacturers

product data sheets and product selection guides for more information on

selection and application of joint sealants.


Other Accessory Products

There are a wide variety of additional accessory products required for

successful installations of mechanical insulation, including:

Securments

o Studs and Pins

o Staples, rivets, and screws

o Clips

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o Wire or Straps

o Self-adhering laps

o Tape

Flashing

Stiffening

Supports

o Heavy density insulation inserts

o Pipe support saddles and shoes

o Wood blocks and dowels

o Pre-insulated pipe supports

Caulking

Expansion/contraction devices

These accessory products are readily available from a number of vendors. (see

Product Data Sheets below)

BACK TO TOP

PRODUCT DATA SHEETS

Cellular Insulation

o Elastomeric

o Cellular Glass

o Polystyrene

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o Polyisocyanurate

o Polyurethane

o Phenolic

o Melamine

o Polyethylene/Polyolefin

o Polyimide

Fibrous Insulation

o Mineral Fiber Pipe

o Mineral Fiber Blanket

o Mineral Fiber Board

o Textile Glass

o High Temperature Fiber

Granular Insulation

o Calcium Silicate

o Molded Expanded Perlite

o Microporous Insulation

o Silica Aerogels

o Poured-In-Place Insulation

Weather Barriers, Vapor Retarders, and Finishes

o Metal Rolls and Sheets64





































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o PVC Jackets

o PVDC Film

o Laminated Foil jacketing (ASJ/FSK/FSP)

o Synthetic Rubber Laminates

o Multi-ply Laminates

o Fabrics

o Mastics and Coatings

o Insulating and Finishing Cements

Fabrication of Insulation Products

o Fabricated Insulation

o Removable/Reusable Insulation Covers

Accessory Products

o Adhesives

o Reinforcements for Cements and Mastics

o Sealants

o Securements

o Flashing

o Stiffening

o Supports

o Caulking65







































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o Expansion/contraction devices

BACK TO TOP

GLOSSARY OF TERMS

For Removable/Replaceable Insulation Covers

Hot Face - The inside surface area of a removable/reusable insulation cover. The

materials in direct contact with the item being covered.

Cold Face - The outside surface area of a removable/reusable insulation cover.

The materials exposed to atmospheric and ambient temperature conditions.

One Piece Construction - A removable/reusable insulation cover designed andfabricated to be installed as one unit, rather than two or more components

requiring separate installations to comprise the finished cover.

Inside Seam - A sewn seam which is turned to the inside of a cover shell, so as

not to show on the outside.

Outside Seam - A sewn seam which is not turned to the inside of a cover shell,

but remains exposed to the outside.

Closing Seam - The final seam sewn on a cover after the shell has been filled

with the core insulation.

Parting Faces - The edges of a removable/reusable insulation cover which butt

together when the cover is installed and secured.

Terminal Ends - The ends or tops of a removable/reusable insulation cover which

are drawn down around adjacent insulation, valve packing stems, pump flange

nozzles, etc.

Gusset Construction - Fabricatio of a removable/reusable insulation cover using

inside seams to achieve square edges on the cover rather than rounded edges.

Core Unit - The insulating material(s) inside a removable/reusable insulation

cover.

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Tie-Down/Anchor Straps - Straps used in conjunction with buckles to secure

removable/reusable insulation covers in place when they are installed on the

items being insulated.

BACK TO TOP

EXAMPLE BILLS OF MATERIALS

For Removable/Reusable Insulation Covers

BILL OF MATERIALS #1

For insulation of fittings, valves and equipment operating indoors or outdoors

with operating temperatures of up to 500°F

Inner

Jacketing

17oz./cu.ft PTFE Coated Fiberglass cloth,

Outer

Jacketing

17oz./cu.ft PTFE Coated Fiberglass cloth,

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Side Gussets 17oz./cu.ft PTFE Coated Fiberglass cloth,

Insulation

Core

2" Thk.—6#/Cu.Ft. Density "ET" blanket

Seam ClosurePTFE coated fiberglass threadSeam

Fasteners

PTFE cloth straps with stainless steel double D-rings and Type

304 Lacing hooks & 16Ga S.S. tie wire

I.D. Tags Type 304 Stainless steel with embossed lettering

(*) — for service temperatures up to 350°F — 1"thk. — (3" to 1") should be used


For insulation of fittings, valves and equipment operating indoors or outdoors

with operating temperatures from 501°F to 750°F

Inner Casing 0.008" x 60# Dens. Type 304 Stainless Steel wire mesh

Inner

Jacketing

Hi-temperature/Pure Fiberglass Cloth

Outer

Jacketing

17oz./cu.ft PTFE Coated Fiberglass cloth

Side Gussets Hi-temperature/Pure Fiberglass Cloth & 011" x 60# Dens Type 304

Stainless Steel wire mesh

Insulation

Core

2" Thk.—9-11#/cu.ft Dens Needled Mat

Seam Closure10-ply type 304 Stainless steel thread

Seam

Fasteners

PTFE cloth straps with stainless steel double D-rings and Type

304 Lacing hooks & 16Ga S.S. tie wire



For chilled water applications

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Inner

Jacketing

17 oz./sq. yd. PTFE Coated Fiberglass Cloth.

Outer

Jacketing

7 oz./sq. yd. PTFE Coated Fiberglass Cloth.

Insulation

Core

2" Thick, 6# Density Blanket Fiberglass.

Seam

Closure

Pure PTFE Thread

Seam

Fasteners

Both Straps and Hook and Loop Fasteners Shall be used for

securing the blankets. Hook & Loop Fasteners shall be Fire

Retardant

Quilting To Prevent Insulation from Shifting within The cover, Quilt Pins of

12 GA stainless steel shall be used. The pins shall not Penetrate

the inner face of the covers.



Turbines and hi-temperature equipment

1ST LAYER — HOT SIDE

Inner

Jacketing

Outer

Jacketing

& Gusset

Inconel type Wire Mesh

Insulation

Core

2" Thick – 8# Density Ceramic Wool

Seam

Closures

½" Stainless Steel Hog-Rings, 1" O.C.

Seam Type 304 Stainless Steel 12 Gauge T-type Lacing Anchors with Self-

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FastenersLocking Washers and 12" Stainless Steel Annealed Tie Wire.

I.D. Tags Type 304 Stainless Steel with Embossed Lettering

2ND LAYER — COLD SIDE

InnerCasing &

Gusset

Hi-temperature/Ceramic type Cloth

Outer

Jacketing

17 oz./sq. yd. PTFE coated Fiberglass Cloth

Insulation

Core

2" Thick – 9-11# Density, Type "E" Needled Glass Mat

SewingThread

Type 304 Stainless Steel, 10 Strand Thread

FastenersType 304 Stainless Steel, 12 Gauge J-type Lacing Anchors with Self-

Locking Washers and 16 Gauge Annealed Stainless Steel Tie Wire

I.D. Tags Type 304 Stainless Steel with Embossed Lettering

Fabrication Requirements

Removable/Reusable covers shall meet the following requirements:

A.All covers for all piping, fittings and equipment shall

be manufactured pre-formed creating a close

contour fit and conform to the configuration of the

items being insulated, utilizing a "separate inner and

outer skin" method of design to create a finished

pre-shaped cover.

B.All valve covers shall be designed and manufactures

with sewn-in bonnets with proper allowances for

packing gland opening.

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C.All covers shall utilize gussets to provide a full

extent of insulation thickness throughout the cover.

Gussets shall be made of the same materials as the

inner skin fabric and be a separate piece of fabric

joining the inner and outer skins. All covers shall bemanufactured inside-out, then turned correct side

out before inserting the insulation.

D.All seams shall be machine sewn, double lock-

stitched with 8-10 stitches per inch from 1/8" to 1/2"

apart.

E.The insulation core should be secured within thejackets with 12 GA stainless steel quilting pins,

backed with 12 GA stainless steel self-locking

washers. Hand tufting with cross type stitch thru the

entire thickness through the blanket using 10 strand

stainless steel thread can be used instead of pin

quilting.

F.No substitution of specified materials shall be madewithout written permission from the Engineers and

Purchasers of the client.

Construction Specifics for the Turbine on Double Layer Blankets

A.All covers shall repeat the shape of the turbine as

close as possible.

B.The outer, 2nd layer covers shall be staggered over

the inner layer covers by a minimum of 6" for the

ultimate in thermal performance.

C.Detailed installation drawings on CD-ROM's along

with installation instructions, (3 sets), must be

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supplied with shipments of blankets. The drawings

shall show the shape of each blanket in both layers

and their exact location on the turbine.

BACK TO TOP

INSULATION TEXTILES

Applications

Insulation textiles are used in a variety of applications including:

1.Removable/Reusable insulation jackets or blankets

to insulate high maintenance/high temperatureequipment

2.Removable/Reusable fireproofing jackets and

blankets

3.Lagging fabrics and tapes to insulate for freeze and

personal protection or reinforce insulation jacketing

4.Tapes and tubing to insulate electrical, hydraulic and

air hoses and tubing

5.Welding blankets to protect personal or valuables

from sparks, spatter or slag

6.Fire blankets to help extinguish fires

7.Apparel for hot work and radiant heat protection

Textile Materials for Insulation

Insulation textiles, fabrics, threads, tapes, tubing and blanket are available

untreated, treated, coated, impregnated or laminated. Aramids, fiberglass, high

purity silica, ceramic fiber and stainless steel are the primary base materials

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from which textile materials are manufactured. There are a variety of coatings

and laminate materials to apply to these textiles. Coating and laminate

membranes are usually applied to these textiles to create a process, weather or

moisture barrier and abrasion resistance at low or elevated temperatures. These

textiles are available in a variety of widths, thickness and densities. In addition,these textiles are available with various thermal conductivity, temperature and

chemical compatibility limits.

Temperature Limits

Continuous Maximum

Untreated Fabrics, Threads, Tapes, Tubing, Blanket

1) Aramids 600 F 850 F2) Fiberglass (Type E) 800 F 1200 F

3) Fiberglass w/ SS wire insert 1000 F 1200 F

4) High Purity Silica Glass (96+%) 1400 F 1800 F

5) Ceramic Fiber w/ E glass insert 1000 F 2300 F

6) Ceramic Fiber w/ SS wire insert 1800 F 2300 F

7) Stainless Steel ( 304 ) 1500 F 2300 F8) Inconel 1800 F 2300 F

Coatings

1) Acrylic 250 F 250 F

2) Silicone 500 F 500 F

3) PTFE 550 F 700 F

4) Neoprene 400 F 400 F5) Vermiculite 2000 F 2300 F

Fabric Laminates

1) Polyester/Mylar 350 F 350 F

2) Aluminum Foil 750 F 900 F

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3) 304 SS Foil 1500 F 2300 F

4) Inconel Foil 1800 F 2300 F

Untreated Fabrics, Threads, Tapes, Tubing and Blanket

Aramids

Arimids were developed in the 1960s and 1970s as a high heat resistant fiber that

does not melt, has good solvent resistance, very low flammability, is non

conductive, has a good thermal conductivity and a high temperature limit of 850

degrees F. This product is sensitive to acids, salts and ultraviolet radiation.

Fiberglass (Type E)

Fabrics, Threads and Tapes - See Mil C 20079 H

Fabrics, Tapes and Tubing - See Mil Y 1140

Blanket or Felt - See Mil I 16411 F

Incombustibility - See USCG 164.009

Corrosion Potential - See Mil I 24244 or NRC 1.36

Type E fiberglass is the primary yarn used to produce textile grade fabrics,

threads, tapes tubing and blanket. This material is incombustible and has good

strength to 800 F., where it still retains 60% of its tensile strength. At 1200 F., the

strength retained is 20% and the melt point is 1530 F. When used with a SS

insert, the yarn retains much of its strength to 1000 F. Type E fiberglass yarn has

a low thermal conductivity and is resistant to many solvents and acids. This

product is sensitive to high alkalinity and bases.

High Purity Silica Glass (96+%)

Fabrics - See Mil C 24776A (SH)

Incombustibility - See USCG 164.009

Corrosion Potential - See Mil I 24244 or NRC 1.36

High purity silica yarn made into fabrics, tapes, tubing and blanket is a very

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products have relatively low strength and abrasion resistance. Silica textiles

have good fabrication properties when coated with silicone (for temperatures to

500 F) and vermiculite (for temperatures to 1400 F). The maximum use

temperature is 1800 F. High purity silica has a low thermal conductivity. Silica

textiles are sensitive to high alkalinity and bases.

Ceramic Fiber w/ E glass and SS inserts

Ceramic fiber yarn is produced with Type E fiberglass and SS inserts into each

yarn strand. This yarn is then woven, knitted, braided into fabrics, tapes, or

tubing. Ceramic fiber blanket is made by spun or blown fiber which is then

directly needled or felted into various thickness and densities of blanket.

Ceramic fiber textiles have use temperatures of 1000 F for glass inserted yarn;1800 F. for SS inserted yarn; and 2300 F., 2600F and 2800 F. for various

chemistries of ceramic fiber blanket. Ceramic fiber is sensitive to high alkalinity

and bases.

Stainless Steel or Inconel Knitted and Woven Fabrics

Stainless steel wire of various diameters are woven, knitted and braided into flat

fabrics and sleeves of various widths and thicknesses for high temperature

applications. These products are used as the hot face in composites and

coverings to reinforce the tensile strength losses at high temperature. The wire

type used should be specified to match the application.

Coatings

Acrylic

Acrylic coatings are applied as a weave set or light coating to allow the textilesto stay together during and after fabrication. This light coating will also keep

potential air born fiber to a minimum. Acrylic is inherently flammable, so a good

flame inhibitor is needed in many applications. Acrylic is a low temperature

coating that melts at 250 F.

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Neoprene (Synthetic Rubber)

Neoprene rubber makes an excellent water proof and fire resistant coating for

high temperature textiles. In addition, due to neoprene's non-flammability

characteristics, it is widely used to coat high temperature textiles to weatherproof and for welding or fireblanket applications. Neoprene has a maximum use

temperature of 400 F and is resistant to many acids, bases and solvents.

Silicone (Synthetic Rubber)

Silicone is a widely used high temperature rubber coating that is applied to

fiberglass fabrics to create a weather proofing and used as the cold face and hot

face liners for making removable reusable insulation jackets or blankets.

Silicone is also applied to tapes and tubing to waterproof and protect these

textile products from abrasion and chemical spills. Silicone has a maximum

used temperature of 500 F. and is chemically resistant to most acids, bases and

solvents.

PTFE

PTFE is a high temperature thermoplastic that is applied to fiberglass and other

high temperature textiles for protection against weathering and hostile chemical

attack. PTFE coatings do not melt however soften at a temperature of 630 F. and

starts decomposing at above 800 degrees F. PTFE is the most chemically inert

liquid or vapor proof coating that man has ever made which is why this coating

is used in chemically hostile applications. Since PTFE is a thermoplastic, this

film can also be heat patched or sealed with another PFA appropriate film. As

with frying pans, since nothing sticks to PTFE , the surface can also be easily

cleaned.

Vermiculite

Vermiculite is a mineral that is emulsified into a high temperature coating.

Vermiculite coatings are used on high temperature textiles to help spread heat

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energy throughout the coating minimizing the localization of heat and the

temperature rise in localized areas.

Vermiculite is also an excellent binder and weave set for high temperature

textiles. The maximum use temperature is 2000 F.

Fabric Laminates

Fabric laminates play an important role in the use of insulation textiles in

industry. The three major film materials used are polyester, aluminum foil and

304 SS foils. A 1-2 mil, aluminized polyester is a popular reflective film that is

laminated to a variety of fabric materials for radiant heat reflection applications

such as fire entry suits or other hot applications where radiant heat protection is

needed. Mylar has a max temperature of 350-400 degrees F., however the films

reflective property help to keep the film below this temperature.

Aluminum and 304 SS foils are also used mostly as a vapor or moisture barrier

with the fabrics acting as reinforcement for strength purposes. The maximum

use temperature is usually determined by the adhesive if not sandwiched

between another membrane.

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