Trymer Installation Guidlines

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TRYMERPipe Insulation

Your Guide to Features, Installation and Use


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Choosing the right pipe insulation for your facilitysneeds depends on being able to distinguish the proper

insulation requirements for your specific application. Thisbrochure is designed to assist you in making that critical

selection, and to help guide you in proper installationpractices.

When looking for an insulation material you are con-cerned with:

Insulation efficiency

Moisture vapor permeability/water resistance

Weight of insulation

Damage resistance

Chemical and solvent compatibility

High product quality

Cost competitiveness

TRYMER* polyisocyanurate pipe insulation combines

all of these characteristics and presents them to you

as a cost-effective, high-quality choice for yourinsulation needs.

What is TRYMER pipe insulation? It is a polyisocyanurateinsulation, made in a continuous process in LaPorte,

Texas, by The Dow Chemical Company. TRYMER

polyisocyanurate pipe insulation has been used in thepipe insulation industry for more than 25 years.

How To Choose the RightPipe Insulation for YourFacilitys Needs

*Trademark of The Dow Chemical Company


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Insulation Efficiency

The k-factor is a measure of thermal(heat) conductivity. At a given thick-

ness, insulation with a lower k-factorreduces energy costs by providing

more resistance to heat transfer.TRYMER pipe insulation has a very

low average k-factor for temperaturesranging from -297F to 300F

(-183C to 148C).

The k-factor indicates the ability of

a material to conduct heat. Lower

k-factors indicate better thermalperformance. At a specified k-factor,TRYMER pipe insulation reduces

installed system costs and allowsyou to use thinner cross sections.This allows:

Use of less insulation, sealant,

vapor retarder and jacketing.

Insulated pipe to be installed intighter spaces.

Characteristics of TRYMERPipe Insulation

Light Weight

The weight of an insulation systemimpacts the static loading of the sup-

port structure, which could requirecostly design modifications. The

weight of an insulation material isdirectly related to its k-factor and

structural density.

How does TRYMER pipe insulationrate? Consider service temperaturesranging from -30F to 250F (-35C to

121C) with the required insulation

thickness, TRYMER pipe insulationwas the lightest, compared withother insulation materials, by up to

15.5 pounds per three-foot length.

Figure 1: k-Factor of TRYMER Pipe Insulation

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Moisture Resistance

Water has a thermal conductivity 10to 20 times greater than most insula-tion materials. As a consequence,

when moisture penetrates an insula-tion, it raises the insulations thermal

conductivity and lowers its long-term

effectiveness.

Water absorbed into insulation notonly reduces insulation efficiency, it

also adds weight to the line, increasesthe likelihood of corrosion and can

contribute to fungal and bacterialgrowth.

In cold service, water can freeze,causing the eventual destruction of

the insulation. In food and beverageplants, frequent wash downs with

scalding water are cause for concern.For these reasons, resistance to

water absorption is an importantfactor in the selection of insulationmaterial.

Choosing a moisture-resistant insula-

tion such as TRYMER pipe insulationhelps ensure long-term insulation

effectiveness in these types of services.

Low Moisture VaporPermeability

It is important to recognize that an

effective insulation system shouldnot wick or transport water from abreach in the jacket to the pipe sur-

face or along the pipe. In this sense,the insulation is a second line of

defense for the pipe against the entryof water.

The accumulation of water within the

insulation system often requiresmajor maintenance and repairs. Forthese reasons, resistance to water

absorption is an important factor inthe selection of an insulation material

for pipe and vessels. TRYMER pipeinsulation has a low moisture vapor

permeability that can provide a temp-orary, second line of defense shouldthe primary vapor retarder fail.

Compressive Strength

An insulations compressive strengthprovides support to the insulationsystem. Vapor retarders, sealants

and jacketing all function betterwith a firm, rigid base. Also, a high

compressive strength increases the

static load that can be applied to thepipe and jacketing. It also permitshanger installation on the outsideof the jacketing, eliminating direct

routes for moisture and heat transfer.Choosing an insulation with the right

compressive strength required foryour application is vital to ensure

long-term performance.

TRYMER pipe insulation is available

in grades that offer a compressivestrength from 19 to 140 pounds per

square inch.


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Wide Range of ServiceTemperatures

There are two reasons for specifying

an insulation with a wide service tem-perature range:

You can minimize the cost of usinga variety of insulation materials to

meet different temperaturerequirements.

You can eliminate the cost of

reinsulating due to insulationfailure caused by exposure totemperatures outside the

service range.

The wide service temperature rangeof TRYMER pipe insulation can help

you ensure better control of yourprocesses and high performance foryour applications (see figure 2).

Damage Resistance

There are two factors to considerwhen examining the damage resis-tance of TRYMER pipe insulation:

friability and breakage resistance.

Insulation with a high friability

level is more easily damaged duringinstallation. Fortunately, TRYMERpipe insulation is formulated toprovide a balance between toughness

and the ability to fabricate detailedshapes at an economical rate.

Damaged insulation creates path-

ways for direct heat transfer, therebywasting energy and money. TRYMERpipe insulation offers a product that

is tough and durable, resists damageand yet is friable enough to cut and

shape with ease.

Due to its toughness, TRYMER pipeinsulation can even be applied tohot systems that are at operating

temperatures without interruptingor shutting down the service, or

damaging the insulation. This qualityallows you to keep your process

running, or if you are startingup from a shutdown, to startrunning sooner.

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Electrical TracingInsulation Systems

TRYMER pipe insulation is an ideal

choice for your electrically tracedinsulation system.

Due to its moisture resistance andlow moisture vapor permeability,

TRYMER pipe insulation helpsprotect your investment in an

electrical tracing system fromthe damage water creates when it

migrates through the insulation tothe electrical tracing.

Additionally, due to its excellentk-factor at a given insulation thick-

ness, compared to other insulationproducts, you can realize a 25 percent

savings in insulation value, therebyreducing your system cost by reduc-ing the wattage necessary to maintain

a desired temperature.

Figure 2: Service Temperature Range of TRYMER Pipe Insulation


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Recommended Practices for All Applications

This guideline covers recommended

requirements and design featuresfound in typical above-grade pipeapplications of TRYMER pipe

insulation. It may be followed unless

state and/or local building codesdictate otherwise. Instructions fromthe insulation accessory manufacturer

supersede recommendations con-tained in this guideline for thoseaccessory materials.

Because TRYMER pipe insulation

is a closed-cell material, it providesexcellent moisture resistance.

However, the primary purpose of theinsulation in a system is to providethermal protection, not moisture

protection. The other parts of thesystem, including primers, vapor

retarders and jackets, are necessary tocreate an effective barrier to moisture.

Insulation Material

A qualified engineer should specify

both the TRYMER pipe insulationproduct and thickness based on designcriteria. Design criteria include service

temperature, ambient conditions,

jacket type, etc. Desired service lifeand economics are also important toconsider. Physical properties can be

found in individual technical datasheets published for each TRYMERpipe insulation product. The insulation

thickness is chosen to prevent conden-sation on the outside pipe surface,

reduce heat flow rates to a specifiedvalue or provide personal protection.

Fabricated pipe, valve and fittingcoverings should have dimensions

and tolerances in accordance withASTM C 585 and ASTM C 450.

Insulation Job SiteStorage and Protection

Prolonged storage at the job site is

discouraged. The insulation must be:1) kept off the ground, floor or deck,and 2) completely covered (top and

sides) by a waterproof materialdesigned to prevent formation of con-densation on the inside surface.

Preparation of the OuterPipe Surface

The outer surface of the pipe shouldbe properly prepared before

installing the insulation. The pipeshould be free of oil, corrosion, loose

particles, moisture and frost at thetime of installation. With any insula-

tion, corrosion can be a concern inservice temperatures above 25F. Inservice temperatures between 25F

and 300F, recommendations in theinsulation industry call for coatings

on austenitic stainless steel equip-ment. Consult a coating/primer

manufacturer in the selection of

appropriate protective coatings.

Maintenance ofInsulation Systems

Insulation systems must be main-tained to ensure the system operatesas designed. The presence of mois-

ture in any insulation system willlower the thermal efficiency, often

destroying the insulation package.Corrosion can develop on the exterior

surface of the pipe if moisture ispresent and the temperature isabove 32F (0C).

The frequency of inspection should

be determined by the critical natureof the process, the external environ-

ment, and the age of the insulationsystem.

During a routine inspection of the

insulation system:

Look for signs of moisture or ice

on the lower part of horizontal

pipe, at the bottom elbow of avertical pipe, and around pipehanger/saddles as moisture will

migrate to low areas.

Look for any jacketing penetra-

tions, openings or separations.

Check the jacketing to determineif loose banding or screws are

present.

Look for bead caulking failure,

especially around flange andvalve covers.

Look at jacketing integrity around

all intersecting points such as pipetransitions, branches and tees.

Look for cloth visible throughthe mastic if the pipe is protected

by a reinforced mastic weatherbarrier.

During an extensive inspection of aninsulation system:

Use thermographic equipment

to isolate areas of concern.

Design a method to close anycut into the insulation so that apositive seal can be maintained

throughout the entire system.

Examine the pipe surface forcorrosion if the insulation is

physically wet.

The extent of moisture present within

the insulation system and (or) thecorrosion to the pipe will determine

the need to replace the insulation.Generally, all wet parts of the insulation

system are replaced.


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Role of Specifiersand Design Engineers

The information in this guideline is

intended to serve as examples oftypical installations and practices.It is not intended to be used as precise

specifications for any and everyapplication. A design or specification

engineer will be able to create precisespecifications tailored to particular

owners and contractors. Theseengineers are familiar with the key

attributes of an application, includingits environment, the desired lifeexpectancy of the installation and

the budgetary or time constraintsof the owner. Dow has used both

internal and external resources andcan provide contacts for interested

owners and contractors.

Advisement

Every installation system has a finite

service life that depends on the typesof materials used, the quality of the

installation, and the exact conditionsof the surrounding environment.

Dow believes the information in thisdocument can help installers andowners build insulation systems that

will increase the service life of thesystem, but proper installation,

inspection and maintenance of theinsulation system are always necessary

to achieve the maximum potential ofits service life. Dow recommends that

you consult a design or specificationengineer regarding the use of

TRYMER pipe insulation in specific

applications. In addition, Dowrecommends a review of applicable

building codes and constructionregulations in order to determine

if TRYMER pipe insulation isan acceptable material in theintended application.

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TRYMER Pipe Insulation in a Dow Plant Facility.

TRYMER Pipe Insulation in a Double- and Single-layer Application.


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Installation GuidelinesCommon to All Temperature Ranges

Now that you are familiar with themany benefits TRYMER pipe insula-

tion offers, it is important to note theinstallation guidelines common to all

temperature ranges.

General:

Complete all welding, hot work,hydrostatic and performancetesting before installing the pipe

insulation.

Keep insulation dry at all timesbefore and during the installation.

Any vapor retarder and weatherbarrier must be installed only overdry insulation and dry piping.

All insulation joints (except for con-

traction/expansion joints) mustbutt together tightly.

Insulate all valves and flanges tothe same thickness as the adjacent

pipe insulation. If the valve designpermits, insulate valves to the

packing gland.

Secure the insulation sectionsusing a filament tape with a 3/4"minimum width. In general, each

3' section should be taped 3" fromthe end with all other banding

occurring on 9" to 12" maximumcenters. Do not use wire to secure

the insulation.

Pipe support areas: Supporting

the pipe outside of the protectivejacket eliminates the need to insulate

over the pipe clamps, hanger rodsand cut holes. This support method

minimizes the potential for vapordrive and thermal shorts within thesystem as a continuous envelope sur-

rounds the pipe.

Hangers will need to be spaced sothat the insulation will not collapse

under static loading if located onthe exterior surface of the jacket. Adesigner can specify a higher com-

pressive strength TRYMER pipeinsulation product for the section

supporting the hanger if necessary.The formula in figure 3 can be used to

calculate the minimum spacingrequired to prevent TRYMER pipe

insulation collapsing under differentload requirements.

Insulation protection saddles should

be provided and installed at all pipehangers and supports for insulatedlines. All insulation saddles should be

rolled with a true radius to suit theinsulation outside diameter. Sheet

metal is typically used for all saddles.

The saddles should be sized to wrapthe insulation in an arc between 120

degrees and 180 degrees dependingon the load. Pipes greater than or

equal to 8'' in diameter should onlyuse an arc of 180 degrees.

High-compressive-strength rigid

insulation, like TRYMER 4000 or6000 pipe insulation, can be used atthe saddle supports. High-compressive

strength insulation can be used on anydiameter pipe, but is typically used on

all pipe approximately 12" in diameteror greater.

Figure 3: Formula for Pipe Support Spacing

S =(Comp. Str.) x (Pipe O.D.) x (Saddle Length) x (Safety Factor)

(Weight of Pipe + Weight of Fluid)

Where S = Minimum spacing in feet

Pipe O.D. = Pipe outer diameter in inches

Saddle Length = Saddle (support) length in inches

Safety Factor = Typically 0.33 (for a 3-fold safety factor)

Weight of Pipe = Empty weight in pounds per foot

Weight of Fluid = Fluid weight in pounds per foot

Effective Method to Maintain a

Staggered Joint Configuration

through the Pipe Support.

Pipe Support Installation with High-dens

TRYMER Pipe Insulation on Saddles and

TRYMER 2000 Pipe Insulation.


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Vapor Stops

Vapor stops are used in insulationdesign to isolate potential sources ofmoisture infiltration from migrating

throughout your insulation system.Potential areas of infiltration include:

pipe supports and collars, problem

fittings, fittings that are removed orreplaced regularly, or an uninsulateddrain valve or stub end.

The vapor stop is designed to limitthe infiltration to a small area and iso-

late the rest of the piping systemfrom being exposed to moisture

through migration.

An effective vapor retarder barrier

design is shown in figure 4. Using amastic with fabric support to form a

vapor stop at each end of this flangedconnection will reduce the chance

that moisture infiltrating through thevalve flange (see figure 5) willmigrate out from the valve through

the rest of the system.

Vapor stops are standard practice inapplications where moisture drive

into the system is high or in areaswhere a good moisture seal is notpossible.

Figure 4: Cutaway View of Vapor Stop at Flange

Fabric mesh support sandwiched between two layers of mastic spread over and

under entire end of butt joint.

Figure 5:Vapor Stop System to Allow for Valve Access

Vapor stops at each end of valve protect insulation system from moisture infiltration

while allowing access for maintenance.


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Composite Insulation

SystemsComposite insulation systems allowthe system designer to take advantage

of the best properties of two differentinsulation materials. Following is one

example of a composite system, avail-able from several distributors, which

incorporates TRYMER pipe insulation.

High-temperature steam lines:

A composite of mineral wool and

TRYMER pipe insulation can with-stand service temperatures of 400F(204C), or about 200 psig saturated

steam. The inner layer of mineral

Sealants and Joints

There are many types of sealantsavailable for use with TRYMER pipeinsulation products. Sealants are

specified for service temperature,perm ratings, type of application

(troweled, brushed, sprayed), color,

etc. Contact your sealant manufac-turer for choosing the right productfor your application.

Where sealants are applied on joints(see figure 6), it is important that the

entire joint is buttered using a puttyknife to ensure a seal that is free of

voids that may be a source of waterinfiltration in the future. A layer ofsealant should also be buttered

over the seam once the two sectionshave been joined. This will mitigate

moisture infiltration through the joint.

In double-layer applications the firstlayer should not be sealed to itself norto the second layer, to allow free move-

ment of the inner layer of insulation asit cycles between ambient temperature

and its operating temperature.

Ship-lap and tongue-and-groovesystems can be designed for thisinner layer to ensure maximum joint

integrity for the life of the insulationsystem. (Refer to the Special JointConfigurations section on page 10for more information.)

Joint sealants are not required on

systems operating above 80F.Because the pipe surface is generallyhotter than ambient temperatures,

moisture is typically driven awayfrom the pipe.

In a double-layer insulation system

the longitudinal joints between theinner and outer layer should be 90degrees to each other. Additionally,

the butt joints should be staggeredbetween the inner and outer layer.

This installation technique will makemoisture migration through joints

more difficult. This same principlewould be applied when designing atriple-layer insulation system.

Figure 6: Non-setting Joint Sealants

Applied to butt joints and longitudinal joints of a single layer.

wool provides an initial layer of heat

resistance that keeps the polyiso-

cyanurate insulation below its servicetemperature of 300F (148C). Inreturn, the TRYMER pipe insulationmaintains its normal properties of

water resistance and rigidity, and itssuperior k-factor allows the pipe to be

insulated with less overall thicknessthan if the mineral wool were used

by itself.

Multiple-layer systems of cellular

glass, calcium silicate and mineral

wool with TRYMER pipe insulationcan provide an effective compositeinsulation system.

Figure 7: Composite Material Insulation System

Outer layer of TRYMER pipe insulation,

inner layer of other insulation material.

Joint sealants are optional.


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Special JointConfigurations/Fittings

The ease of fabrication of TRYMER

pipe insulation allows economicalproduction of special joints, elbowsand fittings. Two types of joint config-

urations that can be fabricated foradditional joint integrity are the ship-lap

(figures 8 and 9) and tongue-and-groove(figure 11). Both systems are offered

as an upgrade from the standard flatface offered on fabricated pipe rounds.

Figure 9: Ship-lap Butt JointFigure 8: Ship-lap Longitudinal Joint

Special joint configurations can be used to improve the seal of a single-layer system. In many cases,

ship-lap longitudinal joints (fig. 8) and butt joints (fig. 9) are used together (fig. 10).

Figure 10: Ship-lap Elbow

Since elbows and tees are usually single layer,

ship-lap joints are a more effective sealing system.

Ship-lap and tongue-and-groove

joints are ideally suited for use as afirst-layer application in a two-layer

insulation system, where the first-layer joints are not sealed. This

upgrade can help further reducewater penetration through the jointswhen compared to a standard butted

joint. Additionally, elbows (figure 10)and prefabricated fittings can be

matched with these fabricated jointsfor a complete system.

Due to the manufactured size and ease

of cutting TRYMER pipe insulation,flanges, elbows, tees and valve stations

can be prefabricated as one piece andshipped to the job site in two half sec-

tions for easy installation. These fabricatedtechniques can be used on a variety ofdifferent fittings and can be cut to your

specification. Contact your Dow repre-sentative for further information.

All joint and fitting fabrication work is

cut according to ASTM C 585 andC 450 specifications.

Figure 11: Tongue-and-groove Longitudinal Insert Joint

For straight pieces, this configuration can be used with a multi-layer application

in cryogenic systems. The tongue-and-groove is usually in the

first of a double-layer arrangement. Elbows and

tees can also be made similarly.


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Figure 13: Trench Detail

Tape Pattern forStaggered Insulation

While every installation is unique,

the tape pattern shown in figure 12provides ample physical support forthe insulation during installation,

before applying vapor retarders orjacketing.

Two wraps (or more) of tape, rather

than one, add assurance and integrityto the fit of the pieces. The nylon fila-

ment tape used in installing TRYMERpipe insulation has no effect onthermal or moisture performance

of the system.

Underground Insulation

Systems

Low-pressure Steam, ChemicalProcessing Lines, Hot Water,Chilled Water and Chilled Brine

Due to the compressive strength

and water absorption properties,TRYMER pipe insulation products

are ideally suited for use in under-ground insulation systems.

Principles

(1) Insulation must be used in con-

junction with a waterproof membraneto protect the insulation from ground

water infiltration. Jacketing is nottypically used in undergroundapplications.

(2) The trench must be designed to

keep the insulation system frombeing immersed in ground water

(see trench detail, figure 13).

(3) An experienced engineer/designer

should be consulted to determinesoil conditions, frost depths, anchor

details, wall penetrations, requiredcompressive strength, etc.

Contact your Dow representativefor help in determining the proper

product selection.

Figure 12:Typical Tape Pattern

Backfill detail for high water table area.


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Industrial Chemicals,

Hydrocarbons andNatural Gas

Principles

(1) Two or three layers of insulationare needed at these temperatures to

mitigate moisture infiltration and toallow for expansion and contraction

of the system. Using more than onelayer allows the joints between piecesof insulation to be staggered so that

thermal conduction paths and moistureentry paths are kept to a minimum.

Typically, the inner layer is notadhered to the outer layer (or layers)

so that the layers can move relativeto each other. The outer layer shouldbe sealed tightly. Sealing the inner

layer is sometimes recommended inthis service, depending on the pipe

operating conditions.

(2) Stagger all joints where possible.Staggering joints will improve theintegrity of the insulation system and

reduce thermal shorts within thesystem.

Guidelines for Cryogenic Servicein the Temperature Range of -297F to -100F(-183C to -73C)

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Figure 14: Double-layer System

Showing vapor retarder and protective outer jacket.

Figure 15: Double- or Triple-layer System, Showing Staggered Joints

Typically 3" - 6" (or more) of TRYMER pipe insulation.

These low-temperature systems require experienced engineers and/or specifiers for their design.Likewise, trained installers are recommended to attain the best, long-lasting results.

(3) Elbows should be prefabricated, notmitered, eliminating many unnecessary

seams, except for large diameter fittingsthat cannot be made any other way.

The insulation surrounding an elbowshould be the same thickness as the

adjacent pipe insulation.

TRYMER Pipe Insulation Installation on an

Off-shore Liquefied Natural Gas Facility.

(4) Cryogenic temperatures requireproper vapor retarders with very low

perm ratings to resist the vapor driveof warm, moist air to the cold surface

of the pipe. It is also imperative that thevapor retarder be completely sealed

throughout the entire installation. Anypenetration of the vapor retarder can

lead to rapid icing and eventualsystem failure.


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Design

Some other features that can beincorporated in a good design:

Pipe support areas: Foam insertsare short sections of insulation that

support the pipe at a pipe hanger.The top section of insulation should

be removed to maintain a staggeredorientation of the insulation pieces.

This also will help ensure adequatestructural tie-in between insulationpieces. Wood or scrap foam can be

used as temporary support.

Joint sealants: It is important thatthe joint sealant is spread across the

whole joint to ensure a full bed ofsealant. This full bed will help miti-gate moisture due to vapor drive

and ensure a good bond at the joint.

Vapor stops are necessary in this ser-vice temperature range; for example,

pipe supports, standoffs, frequentlyremoved fittings and uninsulateddrains are all spots where the high

vapor drive in this type of service willattack your insulating system. Vapor

stops can be used in these locations toisolate your problem area and stop the

moisture infiltration from continuingthroughout your insulating system.

Voids in all valve and flange coversshould be packed with glass fiber

insulation. Foam-in-place polyurethanecan be used in conjunction with a

prefabricated valve cover if the valveis covered with a poly film (in casethe valve has to be opened for main-

tenance). Valves and instrumentsthat necessarily have exposed pieces

need extra care during installation.Vapor stops should be used to isolate

valves from the rest of the system.

Every installation is unique. Whilecertain engineering principles apply to

all insulation jobs, it is best to contact

an experienced contractor, distributor

or fabricator. Design engineers may be

required, especially for the tempera-

ture applications described here.

Figure 18: Expansion/Contraction Joints

Dow product literature states that the lower service

temperature limit for TRYMER pipe insulation is

-297F (-183C), which is the boiling point of

oxygen. TRYMER pipe insulation does not haveany inherent physical or thermal properties that

would preclude its use at this temperature or below.

The limit of -297F (-183C) is cited to caution

end-users that there are significantly different

design concerns when dealing with service temper-

atures this cold.

The design concerns center on the fact that at

service temperatures below -297F (-183C), oxygen

from the air can begin to condense on the cold pipe

surface or in the cells of the insulation, resulting

in local regions of higher liquid oxygen concentra-

tion. Also, if the pipe subsequently warms above

Figure 16: Cross Section of a

Double-layer Installation

-297F (-183C), there will be a thin region of air

within the insulation system with higher than

normal levels of oxygen. Either situation poses a

flammability and reactivity concern regardless ofthe type of insulation, sealant, vapor retarder or

jacket used.

Special care must be given to the design and

installation of cryogenic insulating systems. A

qualified and experienced design engineer should

be consulted when designing these types of

insulating systems. Furthermore, the quality of the

workmanship assumes greater importance when

dealing with the vapor drives that will be present

when operating at these very cold temperatures. It

is generally prudent to employ contractors who are

experienced in multi-layer systems.

Figure 17: Cross Section of aTriple-layer Installation

Use of TRYMER Pipe Insulation in Critical Low Temperature Service (Below -297F or -183C)

The detail above is for a Liquefied Natural Gapipeline constructed in harsh conditions (90Ftemperatures with 90 percent humidity). Atriple-layer system with a double vapor barrierdesign was used to ensure long-term insulatiointegrity over several miles of pipeline.


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Ammonia, Brines,

Glycols and CoolantsPrinciples(1) The temperature range of -100F

to 0F (-73C to -18C) is a verycommon service condition for ammo-

nia and other refrigerant lines. Thistemperature range can be considered

a transition range. At temperaturesbelow -100F (-73C), multiple layersof insulation are virtually a necessity.

Above 0F, a single layer is often ade-quate. In the range of -100F (-73C)

to 0F (-18C), however, the designmay or may not call for multiple lay-

ers, depending on the pipe diameter,service temperature, ambient condi-tions and desired service life.

(2) While there is no hard and fast

rule, double layers of TRYMER pipeinsulation are usually advisable when

the insulation thickness is about 3"or more. Relative humidity is an

important consideration. Highhumidity environments should be

double layered if possible, becauseof greater vapor drive.

(3) Staggered joints: Longitudinaland circumferential joints are stag-

gered between layers where possible.While joint sealant is generally notused on the inner layer of insulation,

the second layer requires a full bed-ding coat of non-setting elastomeric

joint sealer.

(4) Cold temperatures require

proper vapor retarders with lowperm ratings to resist the vapor drive

of warm, moist air to the cold surfaceof the pipe. It is also imperative that

the vapor retarder be completelysealed throughout the entire installa-

tion. Any penetration of the vaporretarder can lead to rapid icing andeventual system failure.

(5) Vapor stops can also be used in

this temperature range. Vapor stopscan help isolate a failure of the vapor

retarder to a small portion of theinsulation, and are particularly usefulon either side of problem fittings,

pipe supports, pipe collars, exposeddrains, valve boxes, etc.

Every installation is unique. While

certain engineering principles apply to






For material suppliers of jacketing,

joint sealants, vapor retarders, etc.,

see your fabricator or distributor.

Guidelines for Very Cold Servicein the Temperature Range of -100F to 0F(-73C to -18C)

Figure 19: Double-layer System

Showing vapor retarder and protective outer jacket over a double layer of

insulation. A single layer of insulation can be used if servicetemperatures and ambient conditions are not severe.

14


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(6) Voids in all prefabricated valve

and flange covers should be packedwith glass fiber insulation. Foamed-

in-place polyurethane can be usedinstead of fiberglass. This will

require drilling both fill and ventholes in the prefabricated valvecover, and filling after the valve is in

place. Valves and instruments whichnecessarily have exposed pieces

need extra care during installation.Vapor stops should be used to isolate

valves from the rest of the system.

Because of the need to have a valve stem accessible to operators, it is difficult to completely isolate a valve in cold service. Vapor stops on eitherside of the valve can help restrict ice build-up to the small area of the valve itself, and protect the line in either direction from the valve from moisturemigration.

Figure 20:Valve Insulation Procedure

For cold service (welded or screwed valves).

TRYMER Pipe Insulation Valve Cover Fabricated to ManufacturersSpecifications for Exact Fit.


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Ammonia, Brines,

Glycols and CoolingFluids

Principles

(1) Since this service temperature isbelow freezing, condensation and

icing are concerns. Vapor retardersand a sturdy jacket are necessary.

However, moisture vapor drive is notas severe as with colder service tem-peratures. The moisture vapor drive

is less severe as the service tempera-ture increases, so less elaborate

vapor retarders and jackets areacceptable.

(2) Depending on the relative humidity,a single layer of insulation is probably

sufficient. (Jacket type, wind andambient temperature will also have

an effect.) Single layers of insulation

insulation should be used regardlessof service temperature. See charts on

pages 21-23, or consult your Dow rep-resentative for computer calculations

of recommended thickness.

are usually adequate because expan-sion and contraction forces are not as

great as at lower service temperatures.However, if the required insulation

thickness for condensation control isgreater than about 3", double layers of

Guidelines for Cold Servicein the Temperature Range of 0F to 35F(-18C to 1.6C)

Figure 21: Single-layer System

Typically 1" - 3" of TRYMER pipe insulation.

Stagger the end joints by beginning a length of pipe with half- and full-length sections of insulation.If the system is installed with a factory-applied vapor retarder, you will not be able to stagger theupper and lower butt joints.

Typical Outdoor Installation of TRYMER Pipe Insulation on a Rooftop

Ammonia Line.

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Figure 22: Single-layer System With Factory-applied SaranVapor Retarder Film

Typical TRYMER pipe insulation with Saran vapor retarder

film for a chilled water line.

Figure 23: Double-layer Contraction Joint in a Single-layer Application

Inner layer milled to half thickness of single-layer insulation.

Second layer milled to fit over first layer. Seal inner

and outer layers to single layer at butt joints.

Low temperatures require proper

vapor retarders to resist the vapordrive of warm, moist air to the cold

surface of the pipe. It is also imperativethat the vapor retarder be completely

sealed throughout the entire installa-tion. Any penetration of the vapor








retarder can lead to rapid icing and

eventual system failure.

TRYMER pipe insulation can bespecified with a factory-applied

Saran* vapor retarder film and tapealready adhered to the insulation

*Trademark of The Dow Chemical Company

(see figure 22). This product reduces

installation time and is ideal forammonia lines, chilled water lines,

brine systems and other chilled orcold systems. Contact your Dow

representative for more details.


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Guidelines for Chilled Servicein the Temperature Range of 35F to 60F(1.6C to 16C)

Primarily Chilled Water

Lines in the 40F (4C)Temperature Range

Principles

(1) Although there is only a smalldifference between ambient

temperature and the pipessurroundings, in humid areas

condensation will still occur andcreate problems with sweatingor water build-up.

(2) Except for the very highest

humidity areas, the excellentk-factor of TRYMER pipe

insulation means that only asmall thickness (1" - 2") ofinsulation should be required

for this temperature range.

(3) Elbows should be prefabricated,not mitered, eliminating many

unnecessary seams, except for verylarge diameter fittings that cannot bemade any other way. The insulation

surrounding an elbow should be thesame thickness as the adjacent pipe

insulation.






required, especially for low tempera-

ture applications.

Consult local building codes and your

Dow representative for appropriateuse of TRYMER pipe insulation in

applications where 25/50 flame and

smoke ratings apply.

Figure 24: Single-layer Elbow Tie-in

Insulation surrounding the elbow should be the same thickness

as the adjacent pipe insulation.

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Figure 25: Cross Section of a Single-layer Installation

Insulation for chilled water lines in low-humidity environments.

Contact your local TRYMER pipe insulation fabricator or Dow representative for informationabout factory-applied Saran vapor retarder films.


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Guidelines for Hot Servicein the Temperature Range of 80F to 300F(27C to 149C)

Chemical Industry,

Food/Beverage, Low-pressure Steam andCondensate Lines

Principles

(1) There are three reasons toinsulate hot service lines:

1. Protect personnel from injury2. Energy savings

3. Process control

Commonly, the personnel

protection thickness requirementdrives the others, although additional

insulation may be used to achieve adesired rate of heat loss. In the

United States, a surface temperatureof 140F (60C) is often specified.

(2) Because the pipe surface is hotterthan ambient, moisture is generally

driven away from the pipe. Vaporretarders and staggered joints are

not needed for high temperatureservice. However, water entry is

still an issue, especially in wash-downareas or outdoors. An effective jacketis still required.

(3) A vapor retarder might be requiredfor some lines that cycle aroundmoderate temperatures, especially

if the ambient temperature is higherthan the pipe temperature. However,

in most hot service applications a

vapor barrier is not required.

Figure 26: Single-layer System

Vapor retarders are not necessary for higher temperatures unless the pipe

temperature cycles to temperatures near or below the dew point.

Figure 27: Single-layer System in Hot Service

Typically 1" - 2" (or more) of TRYMER pipe insulation.

Above 300F (149C), the portion ofthe insulation next to the pipe can

begin to char and/or discolor. Theimmediate effect is a reduction of the

insulating ability of the insulation.Therefore, TRYMER pipe insulation

is not recommended for continuousservice above 300F (149C).

Use an aluminum or plastic (PVC) jacket,depending on indoor or outdoor application.


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Figure 29: Expansion Joints in a Hot Service Application

Spacing of the joints depends on length of pipe run, temperature, etc.

Consult an engineer or specifier for details.

Figure 28: Electrical Tracing System

Contact your fabricator, distributor or Dow representative for information onmultiple-material systems.

Figure 30: Example of a Composite Material System

Outer layer of TRYMER pipe insulation: provides water resistance, k-factor and rigidity.Inner layer of mineral wool: provides heat resistance.

While design and typical service

temperatures may be less than 300F(149C), occasional purges or clean-

ings may exceed this temperature forbrief periods with some effect on the

insulation. In applications such as this,or in applications at the high end of

TRYMER pipe insulation service

temperatures, refer to figure 7 or 30and the section on Composite InsulationSystems on page 9, or contact your Dowrepresentative for more information.




an experienced designer, contractor,

distributor or fabricator. Design engi-

neers may be required, especially for

these temperature applications.


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To help determine required thicknessfor controlling condensation, Dow

representatives can provide calculationsusing the NIA 3EPLUS program, which

uses heat flow algorithms based onASTM C 680-95. Estimations of requiredthickness call for the following data:

Service temperature, ambient relativehumidity, ambient temperature, wind

velocity, pipe diameter (nominal) andjacket material.

Condensation Control Thickness

Note for hot service: Service

temperatures for hot service do notrequire relative humidity. A maximum

allowable surface temperature of

140F (60C) is generally assumedas a default for personnel protection.Greater thickness of insulation isoften used to reduce heat loss.

For convenience, Dow has prepared

charts based on the 3EPLUS pro-gram that include some common

design conditions. Tables 1 - 4 can be

used to give an estimate of minimuminsulation thickness required toprevent condensation underthese conditions.

This table is based on ASTM C 680-95 heat transfer algorithms. The suggested insulation thickness values assumeproper system design and installation, do not include a safety factor and are applicable only for the specified scenario.

Dow recommends that the user consult a qualified design engineer familiar with this type of construction for propersystem design and specification.

Table 1: Condensation Control Thickness for Typical Indoor Applications Using TRYMER 2000 Pipe InsulationConditions: 80F, 70% Relative Humidity, No Wind, PVC or Mastic Jacket (Emittance 0.9)


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Table 2: Condensation Control Thickness for Typical Indoor Applications Using TRYMER 2000 Pipe Insulation

Conditions: 80F, 80% Relative Humidity, No Wind, PVC or Mastic Jacket (Emittance 0.9)

Table 3: Condensation Control Thickness for Typical Outdoor Applications Using TRYMER 2000 Pipe InsulationConditions: 80F, 80% Relative Humidity, 8 mph Wind, PVC or Mastic Jacket (Emittance 0.9)

This table is based on ASTM C 680-95 heat transfer algorithms. The suggested insulation thickness values assumeproper system design and installation, do not include a safety factor and are applicable only for the specified scenario.

Dow recommends that the user consult a qualified design engineer familiar with this type of construction for propersystem design and specification.

This table is based on ASTM C 680-95 heat transfer algorithms. The suggested insulation thickness values assume

proper system design and installation, do not include a safety factor and are applicable only for the specified scenario.Dow recommends that the user consult a qualified design engineer familiar with this type of construction for proper

system design and specification.

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Table 4: Condensation Control Thickness for Typical Outdoor Applications Using TRYMER 2000 Pipe Insulation

Conditions: 80F, 80% Relative Humidity, 8 mph Wind, Aluminum Jacket (Emittance 0.2)

Table 5: Additional Guidance in Selecting Insulation Thickness

This table is based on ASTM C 680-95 heat transfer algorithms. The suggested insulation thickness values assumeproper system design and installation, do not include a safety factor and are applicable only for the specified scenario.Dow recommends that the user consult a qualified design engineer familiar with this type of construction for proper

system design and specification.

This chart is based on the ASTM C 680 algorithm for thickness of insulation required to control condensation on the surface

of a line or vessel, as used in NIA 3EPLUS program. It is not intended for use in design calculations, but rather to give an ideaof the relative importance of variables that influence the amount of insulation needed on a cold application.


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NOTICE: No freedom from any patent owned by Dow or others is to be inferred. Because use conditions and applicable laws may differ from one location to anotherand

may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customers use and

for ensuring that Customers workplace and disposal practices are in compliance with applicable laws and other government enactments. Dow assumes no obligation

or liability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A

PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.

COMBUSTIBLE: Protect from high heat sources. For more information, consult MSDS and/or call Dow at 1-866-583-BLUE (2583). In an emergency,call 1-989-636-4400. Local building codes may require a protective or thermal barrier. Contact your local building inspector for more information.

The Dow Chemical CompanyBuilding Materials

200 Larkin Midland, MI 48674

For Technical Information: 1-866-583-BLUE (2583)

For Sales Information: 1-800-232-2436www.dowpipe.com

Trymer Installation Guidlines

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