Butt&Wrap Procedure

8/18/2019 Butt&Wrap Procedure

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GRP PIPE JOINING PROCEDURE: BUTT & WRAP JOI NT

The Butt & Wrap joint is perfore! for p"ain#en!e! GRP pipes an! fittin$s% The

pipefittin$s en!s are prepare!' a"i$ne! an! "ainate! (ith reinfor)in$ fi*ers an! resin%

Note: Interna" +ainations are $i,en for Pipe Diaeters a*o,e -..NB%

BUTT & WRAP JOINT

Before (or/ on "ainate! joint is starte!' a"" ne)essar0 e1uipent for )op"etin$ the

(or/ ust *e a,ai"a*"e% A ji$ or other ho"!in$ !e,i)e shou"! *e use! to ensure that the

pipes are aintaine! (ith joint fa)es he"! ti$ht"0 to$ether (ithout offset% The restraints

shou"! *e "eft in p"a)e unti" the joints has fu""0 )ure!%

The en!s of the pipe are )hafere! to "ea,e a root fa)e s1uare to the a2is of the

pipe an! 3 to 4 thi)/%

The pipe en!s are )hafere! (ith a taper not steeper than 5 in 6 75. 8a2iu9

Pipe en!s are he"! ri$i!"0 in position (ith a a2iu $ap of 4%

The )hafere!' a*ra!e! an! )ut surfa)es shou"! *e )oate! (ith the spe)ifie! resin

an! the $ap *et(een the en!s fi""e! (ith resin paste%

GRP Pipes: But & Wrap Procedure

Shriram SEPL Composies (P) Ld., Chennai


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Taper not steeper

than 5in 6 75. 8a29

ID

4 8a2iu

Pipe Ends for Butt & Wrap Joint

The se1uen)e of the joinin$ pro)e!ure is $i,en hereun!er%

1. Cutting

Gaps *et(een pipe se)tions shou"! not e2)ee! 4 % Therefore' a (rap#aroun! shou"! *e

use! to ensure s1uare )uts% Pipe )an *e )ut rea!i"0 (ith )ir)u"ar sa(s or a ha)/sa(%

A)hie,in$ a $ap of 4 or "ess a0 re1uire rotation or san!in$ of the pipe an!or fittin$%

2. urfa!e Preparation

The $"oss0 resin surfa)e ust *e reo,e! prior to a/in$ the joint% A san!er a)hine

(ith )oarse' 46 $rit san!paper shou"! *e use! to $rin! the surfa)es% The san!e! areas

shou"! *e s"i$ht"0 $reater than the (i!th of the "ast "a0er of at to *e app"ie! an! e1ua" in

!istan)e on *oth si!es of the *utt joint% Grease' oi"' !irt' paper' tape' oisture' so",ents'

et)% (i"" pre,ent proper a!hesion of the ateria"% Bon!in$ surfa)es that are !irt0 ust *e

re#san!e! to a fresh surfa)e% urfa)e ust *e )"ean an! free fro a"" $rin!in$ !ust

resi!ue' (hi)h (i"" a)t as a *arrier an! (ea/en the *on! of the o,er (rap% These surfa)es

ust *e prote)te! fro su*se1uent )ontaination if *on!in$ operation is interrupte!%

an!e! joints "eft for e2ten!e! perio!s' su)h as o,erni$ht' shou"! *e re#san!e!% A""

surfa)es ust *e free fro (ater or other so",ents prior to o,er (rappin$%

". Jigging

The pipe ust *e he"! se)ure"0 in p"a)e to pre,ent an0 o,eent !urin$ the *utt an!

(rap pro)e!ure% This a0 *e a))op"ishe! *0 )"apin$ the pipe into its han$ers or *0

usin$ stationar0 *"o)/s to pre,ent an0 pipe o,eent%


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Another etho! is to use teporar0 restrainin$ !e,i)es an! to app"0 ta)/#*on!s to

pre,ent pipe o,eent% Ta)/ *on!s are a!e *0 )uttin$ narro( strips 3;#;. of )hoppe! stran! at an! app"0in$ these strips saturate! (ith a sa"" i2ture of o,er#

)ata"0


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the resin% Do not attept to a/e an o,er#(rap (ith resin )ontainin$ "ups or partia""0)ure! resin in the i2in$ *u)/et%

Usin$ aounts of )ata"0st outsi!e of the re)oen!e! ran$e )an pro!u)e a poor joint%

After one or t(o i2es' the insta""ation )re( )an !eterine the proper resin#to#)ata"0st

ratio to o*tain the !esire! )urin$ tie% =or *est resu"ts' the ateria" shou"! *e app"ie! at

teperatures *et(een 3;>C an! ?3>C%

*. +a,ination

App"0 a thin )oat of )ata"0


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App! Resin #$Shaped seam

Laid up S% (Surace %a) Corrosion 'arrier %a ( La!er on!)

Prepare 'oh ends o he pipe appro *+ %% Grindin up o Rouh surace.

App! resin and aid up CS%$--* / a!er

App! resin and aid WR% (Wo0en Ro0in %a)

App! resin and aid CS%$1*+$a!er





2 amina3on hic4nesses no su5cien con3nue WR% and CS% 1*+ se6uence.

e-uen!e of i/er ,at insta$$ation0

Butt&Wrap Procedure

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