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!!!!!!!!!!!!IMPORTANCE!OF!SPECIAL!FIBER!GLASS!REINFORCED!HSS3!COVALENCE!DIRAX!3!FOR!

FIELD!JOINT!COATING!!OF!PIPELINES!!INSTALLED!BY!HDD!METHOD!!!!

!!

!

www.crestcormix.com.auCREST CORMIX PTY LTDPh: 03 9945 2700 / Fax: 03 9945 2799Australian Exclusive Distributor

Background:!!Horizontal!Directional!Drilling!(HDD)!is#a#steerable#trenchless#method#of#installing#underground#pipes,#in#a#shallow#arc#along#a#prescribed#bore#path#by#using#a#surface7launched#drilling#rig,#with#minimal#impact#on#the#surrounding#area.###Directional#drilling#is#used#when#trenching#or#excavating#is#not#practical.#It#is#suitable#for#a#variety#of#soil#conditions#and#jobs#including#road,#landscape#and#river#crossings.###There#are,#however,#some#challenges#associated#to#HDD.#The#coating#of#the#pipe#may#be#damaged#when#pulling#it#through#the#drilled#hole.#Especially#the#girth#weld#joint#coatings#are#very#vulnerable#to#damages#as#the#field#joint#coating#has#the#step#at#the#overlap#portion#of#3LPE#Coating.##Coatings#are#subjected#to#extreme#abrasive#and#shear#load#when#the#pipe#is#pulled#through#the#drilled#hole,#especially#in#soils#containing#rocks#or#stones.##Since,#the#girth#weld#joint#coating#is#exposed#to#risk#of#getting#damaged#during#pulling#operation#in#HDD#method,#therefore#normal#Heat#Shrink#Sleeves#that#are#used#in#common#open#trench#method#cannot#be#used#in#the#HDD#method.###A#special#heavy#duty#Heat#Shrink#Sleeve#having#an#excellent#resistance#to#abrasive,#shear#and#peel#forces#is#required#for#this#purpose.##Covalence#(Formerly#Raychem)#designed#the#proprietary#Fiber!Glass!Reinforced#heat#shrink#sleeve#especially#for#field#joint#coating#of#pipeline#using#HDD#for#pipeline#installation.##Description!of!DIRAX!HDD!FJC!system:!!The#DIRAX#system#comprises#of#monolithic#heat7shrinkable#wraparound#sleeves#and#a#two7component#solvent#free#epoxy#primer.#Extra#protection#is#provided#using#a#wear#cone#on#the#leading#edge#in#the#direction#of#pipe#pulling.##The#main#sleeve#is#fabricated#from#a#thick#irradiation#cross7linked#thermally#stabilized,!fiberglass!reinforced#heat7shrinkable#woven#polyolefin#backing#that#is#coated#internally#with#a#high#shear#strength#hot#melt#adhesive.#Adhesion#to#bare#steel#pipe#surfaces#is#enhanced#by#application#of#the#primer.##The#main#sleeve#edge#profile#that#enters#the#soil#first#is#smoothed#by#the#application#of#an#additional#narrow#wraparound#sleeve#(wear#cone)#of#the#same#construction#as#the#main#sleeve.##The#system#is#installed#using#propane#gas#torches.#First#the#primer#is#mixed#and#applied.#While#the#primer#is#still#wet,#the#wraparound#sleeves#are#shrunk#down#onto#the#pipe#joint.#When#post#heated,#the#sleeves#shrink#tightly#around#the#substrate#onto#the#wet#primer.###During#recovery,#the#adhesive#softens#and#flows#to#form#an#intimate#bond#with#the#primer#and#curing#of#the#primer#is#initiated.#The#bond#strength#builds#up#during#cool#down#and#is#fully#retained#after#completion#of#the#job.##Having#excellent#peel#resistance#values#and#very#high#penetration#resistance,#DIRAX#system#has#been#the#best#choice#for#many#years#for#field#joint#coating#on#pipes#used#in#HDD#application.##

#Heat#Shrink#Sleeve#after#application#are#under#hoop#stress#and#in#case#of#any#cut#to#heat#shrink#sleeve#during!pull!through!operation,!the!sleeve!over!a!period!develop!the!tendency!to!split.!This!split!propagates!further!resulting!complete!tearing!of!heat!shrink!sleeve.!DIRAX!heat!shrink!sleeve!does!not!have!tendency!to!split!propagation!as!it!contains!fiber!glass!reinforcement!which!resist!the!sleeve!to!split!further.##In#the#same#way#during#pushing#or#pulling#operation,#any#obstacle#protruding#from#the#smooth#pipe#surface#is#loaded#by#the#surrounding#soil#that#passes#by#and#edge#of#the#installed#heat#shrink#sleeve#have#the#tendency#to#get#damaged#being#the#projected#part.##Specially#designed#wear#cone#of#DIRAX#sleeve#system#prevent#the#HSS#leading#edge#from#wear#&#tear.###

! !!Figure!1:!Installed!DIRAX!HSS!system!!!Advantage!of!DIRAX!over!normal!HSS!system!(two!HSS!on!top!of!each!other):!#There#is#no#reliable#alternative#other#than#DIRAX#for#HDD#applications.#However,#some#manufacturers#offer#two#normal#heat#shrink#sleeves#(Without!fiber!glass!reinforcement)#on#top#of#each#other.#This#kind#of#system#does#not#provide#enough#resistance#to#peel,#shear,#abrasion#&#penetration.#Therefore#it#carries#a#high#risk#of#getting#damaged#during#pulling#process.#

#######

Fiber Glass Reinforced backing

Additional sacrificial wear cone to protect leading edge of HSS during pulling

Following#are#the#notable#advantages#of#DIRAX#HSS#system#over#normal#HSS#system.##

•# High#resistance#to#shear#&#peel#forces#induced#by#soil#and#thermal#movement.#•# Being#a#fiber#glass#reinforced#pose#very#high#abrasion#and#penetration#resistance#

equivalent#to#mil#coating#which#protect#the#coating#form#damage#due#to#impact#of#sharp#rock#and#stone#particles.#

•# Resistance#to#split#propagation,#circumferential#edge#loading.#•# Being#a#single#layer#HSS#system#provides#a#monolithic#coating.#•# Additional#wear#cone#protect#the#leading#edge#of#sleeve#during#pull#–through#

forces.#•# Sleeve#applied#over#wet!epoxy!forms#a#strong#chemical#bond.#There#is#no#curing#

/#waiting#time#and#therefore#it#allows#fast#application#and#ensures#high#performance.#This#reduces#overall#cost#of#ownership.##

•# Superior#cathodic#disbondment#and#hot#water#resistance.##FJC!Specifications!overview!for!HDD!section:!!In#general,#field#joint#coating#specifications#mention#application#of#normal#Heat#Shrink#Sleeves#for#pipelines#laid#by#open#trench#method#as#most#of#the#pipeline#section#is#comprise#of#open#trench#laying#technique.###However,#most#of#the#end#users#/#laying#contractors#are#aware#of#the#special#field#joint#coating#requirements#for#pipeline#used#in#HDD#section.##To#avoid#any#risk#of#failure#due#to#wrong#selection#of#field#joint#coating#material#for#HDD#section,#most#of#the#end#users#categorically#mention#fiber!glass!reinforced!sleeve#for#HDD#in#their#specifications,#drawings/#data#sheets#&#procedures.###DIRAX#is#the#special#product#of#the#Covalence#and#is#the#only#sleeve#available#worldwide#which#has#the#fiber#glass#reinforcement#and#was#especially#designed#for#field#joint#coating#of#HDD#section.##Below#is#the#extract#from#one#of#the#FJC#specification#of#PERTAMINA!(Indonesia)#which#categorically#state#to#use#“Fiberglass!Reinforced!HSS”.##

###########

#

Box 1 – excerpt from PERTAMINA (Indonesia) specification

PTT!Thailand#specifically#issue#separate#specification#for#field#joint#coating#for#HDD#section.#Extract#for#the#same#is#mentioned#below#which#also#state#to#use#“Fiberglass!Reinforced!HSS”.#

########################################

#

Box 2 – excerpt from PTT (Thailand) specification

###########Comparison!of!COVALENCE!DIRAX!system!V/S!competitor!normal!HSS!system!!#

S.NO% PROPERTY% COVALENCE%/%DIRAX% OTHER%HSS% %%%%%%%%%%%%%%REMARKS%

1%%CONSTRUCTION%%%%%%%

1.1! First!Layer! S13010M! Two!component!epoxy!! !!

1.2! Second!Layer!High!Shear!Strength!Co0polymer!Adhesive!

Heat!sensitive!hot!melt!!adhesive!!

DIRAX!!adhesive!being!a!!high!shear!strength!poses!very!high!peel!and!shear!resistance!values!!

1.3! Third!Layer!Fiber!Glass!Reinforced,!radiation!cross0linked!Heat!Shrinkable!HDPE!backing!

Heat!Shrinkable!HDPE!backing!

DIRAX!HSS!has!a!fiber!glass!reinforcement!which!provides!excellent!resistance!to!abrasion!&!penetration,!split!propagation!&!circumferential!edge!loading!!Whereas!other!do!not!have!any!fiber!glass!!!!!!!!!!!!!!reinforcement!integrated.!They!are!normal!heat!shrinkable!sleeves.!

1.4!Additional!Component!

Narrow!width!sacrificial!wear!cone!!for!extra!protection!against!pull!through!forces!!of!the!same!construction!as!the!main!sleeve!

Entire!HSS!installed!on!top!of!previous!HSS!as!Sacrificial!layer!

!

2%%COMPATIBILITY%AND%OPERATING%CONDITIONS%%%%%%%

2.1!Compatible!Line!Coatings!

PE,!FBE! PE,!FBE! !!

2.2! Pre0Heat!Temp.! 60!070!⁰C! 60!070!⁰C! !!

2.3!Temperature!of!Force!Curing!of!epoxy!

Not!required! 90!+/0!5!⁰C!

DIRAX!HSS!lead!to!fast!installation!due!to!the!elimination!of!force!curing!step!pf!epoxy!primer.!This!also!save!cost!as!it!does!not!require!induction!heating!system!for!curing!of!epoxy!primer!!

2.4!Recommended!Pipe!Prep!

SA0!2½! SA0!2½! !!

%3%

%%FUNCTIONAL%AND%MECHANICAL%PARAMETERS%%%%%%%

3.1!Bursting!Strength!of!the!Backing!

2350!N!(DN!30672)! NA!! !

3.2!Softening!Point!of!the!Adhesive!!

94!⁰C!(ASTM!E028)! 95⁰C!(ASTM!E028)! !!

3.3!Lap!Shear!of!the!Adhesive!

40!N/cm²!@!60⁰C!C!No!shear!strength!is!mentioned!in!data!sheet!at!60!⁰C!

DIRAX!poses!very!high!shear!strength!comparative!to!other!HHS!systems!!

3.4!Peel!to!Steel!Typical!value!!

>11!N/mm!@!23⁰C!!(!EN!12068!)!

6.8!N!/!cm!@!23⁰C!!!ASTM!D!1000!

DIRAX!poses!very!high!peel!resistance!value!!comparative!to!other!HSS!systems!!

3.5! Impact!Resistance!Pass!15J,!No!Holidays!@!20KV!(EN!12068!Class!C)!

Pass!holiday!detection!!No!value!is!mentioned!in!data!sheet!!

!!

3.6!

Indentation!Resistance!!(!Residual!thickness)!

Pass!3.1mm!@!60⁰C!(EN!12068!Class!C)!

No!value!is!mentioned!in!data!sheet!!!

DIRAX!indentation!resistance!values!are!superior!compared!to!other!HSS!

3.7!Cathodic!

Disbondment!

4.3!mm!ASTM!0!G42!! 7.5!mm!,!ASTM!0!G42! DIRAX!Cathodic!Disbondment!resistance!values!are!superior!!!0!mm!@!60!⁰C!(EN12068,!30!

days)!<!15!mm!rad!@!80⁰C!!G!42!!

3.8!

Resistance!to!UV!radiation!followed!by!Bursting!strength!

Reduction!in!Bursting!Strength!<!25%!of!the!original!value!(ASTMD02565!/!EN!12068)!

Poor!!UV!resistance!!DIRAX!have!good!UV!resistance!performance!!

4% Application% %% %% %%

4.1!Pre0Heating!prior!to!application!of!epoxy!

60070!⁰C! 60!070!⁰C! !!

4.2! Sleeve!Application!On!wet!epoxy!(S1301M).!No!need!to!cure!the!epoxy!

Force!Curing!of!epoxy!is!required!by!heating!it!to!a!temperature!of!95!+/0!5!⁰C!!

The!recommended!method!for!force!curing!is!indirect!heating!through!induction!generator!and!coil.!Exposure!of!naked!flame!on!the!epoxy!can!contaminate!the!same.!!DIRAX!HSS!do!not!require!force!curing!!

5% Track%Record% %% %% %%

5.1! World!Wide!Extensive!track!record!worldwide.!!

No!Track!Record!or!!minimal!track!record!for!HDD!application!!

DIRAX!HSS!has!extensive!worldwide!track!record!and!most!of!the!FJC!specification!categorically!mention!to!use!"!Fiber!Glass!Reinforced!HSS!for!HDD!applications!.!Only!DIRAX!has!a!Fiber!Glass!integrated!reinforcement!!

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