Note: Descriptions are shown in the official language in which they were submitted.
:: WO 93/193~1 2 1 3 2 ~ 2 ~i) PCI/~U93/00114 1'
PP~RA~; FQR U$E ll~l REE~IRING A PIP~LIN~ AN~YI~THOD
FC3R CARRYING Q~IT ~CH REsC~AlRS
" ~
This invention relates to apparatus used in the process of refurbishing
dama~ed conduits, pipelines and sewer pipes through the ~pplication of a
5 reinforced lining to their inner walls by means of an inflatable form.
The refurbishrnent of cracked, broken or eroded pipelines or sewer pipes
through so-call0d soft lining methods involving the application of a r~inforced
lining to their inner walls is well known in the art. Two principal methods are
ernployed: the eversion of a tube of therrnosetting- resin - impregnated
10 reinforcernent fabric inlo a section to be relined from an external position by
m~ans of a head of water, and the application of a layer of th~rmosetting resin -
imprsgnated reinforcsment mat~rial ~o th~ inner walls of a s0ction to be relinedby means of a form inflatable by air or water pressure. In both cases, curing of~he thermosetting resin may be aecelerated by circulation of hct water, staam
15 through said inflatable form.
A shor~coming exists in the second method described in which an
inflatabl~ form is employed in that, particularly wi~h repsated use, the external
material of the form may develop an affinity for th~ resins smploy~d in the
reiinlng process and may thus bond to the new lining. This renders difficult the20 stripping and removal of the form after euring of the r~sins. It is of coursepossible to provide a separate layer or sheath between the r~sins and the
extP~rnal surface of the inflatable forrn to prev~nt the form being adhercd to the
resins, however, in tha prior ar~ such separate layers have been s~cured in
some way to the inflatabla form so that ~hey can be withdrawn from the pipe
25 being repaired. Such layers cannot b~ le~t in the pipeline as th~y may
eventually become detached and ultimately form a blockage in ~he pipeline On
the oth~r hand, if th~ layer is secured to the infiatable forn, ~t cre~t~s the same ~:
removal di~ficulty that existed with the infla~able form without suoh a iayer and 5
th~refor~ only serves to protect the inflatable form. !:
The present invention aims to pravide apparatus for the refurbishment of
pip~lines and sewer pipes through the application of a layer of therrnoset~ing
resin - impregnated reinforoement material to their inner walls by means of an
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2132~2~ ~
WO 93/19321 PCI`/AU93/00114 -. ~
2 ~ :
inflatable form which may be readily and reliably stripped from a refurbished
section and whieh embodies a coaxial duct capable of sustaining a ~Low of
liquid through the form whilst it is in use. '
Acoording to a first aspect of the present invention, there is provided
5 apparatus for applying in situ a repair matarial to a repair zone of an inn~r wall
of a conduit, sa~d apparatus for applying in situ a repair material to a repair zone
of an inner wall of a conduit, said apparatus comprising a radially expandable
device in use to extend over a predetermined axial length of the conduit to be
repaired and over at least a part of the inner circumference of said conduit, said
10 radially ~xpandable device having an outer s~rface means forming an outer
wall of an expandable oavity, means for supplying a pressure medium to said
expandable cavity or withdraw said pressure medium from said ~xpandabls
cavity to either move said outer surface means radially outwardly or to move
said outer surface m~ans radially inwardly, and a flexible sh~ath member
15 separate from said radially expandable device and arranged so as to be
capable of ~orming an outer layer extending along and at least partially
circumferentially around said radially expandable device, in use, between said
repair matsrial and said outer surface means, and withdrawat means eonn0cted
~o said sheath m~rnber adjac~nt one end whereby said sheath mernber can be
20 removed from said conduit with at least a portion of the sheath member
contacting said repair material eYerting as the sheath member is moved axially
along said oQndui~. Conveniently the radially expandable device may inelude
a c~re rnember which can inGlude a ~hrough flow passage. The core member
and said withdrawal means for removal of said flexible sheath member together
25 with said flexibl~ sheath member are by means of the present invention thus
a~apted for independent wi~hdrawal from said conduit by virtue of lhe fac~ tha~
th~ flexibie sheath member is independent of said eors rn~mber. Alternatively, ~ -
if it is desired to remove both the radially expandable devica and the flexible
sheath member simultaneously, the means for removal of said flexible sheath ~`
30 m~mber may be adapted so as to wi~hdraw or be withdrawn ~y ths radially
expandab!e device. In either case, the arrangement of the flexible ~heath
member enab3es it to be peeled away ~rom the repair material by at least partial
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:~.WO 93~19321 ~ 1~3 2 2 i, Pcr/AU93/noll4
eversion when the radially expandable device and/or the flexible sheath
member is withdrawn along the pipeline without affecting the bond betwe~en the
repair matsrial and the pipeline walJ.
In an al~ernative form of the invention, the flexible sheath member
5 comprises inner and outer layers, the inner layer being connected to the mear1s
for rsmoval of the flexible sheath member and to the outer layer at ends of the
inner layer which are axially remote from each other.
Preferably, the means for removal of the ~lexible sheath member and the
oore member of tha apparatus are coaxial and define an axially extending
1 Q passage so as to permit ~low through ~he conduit whilst the apparatus is in use.
Conveniently, the means for removal of the flexible sheath member defines an
annulus.
In this embodimen~ of the invention, the radially expandable device may
comprise an infla~able element defining an annular or part annular enclosed
1~ space extending axially along the core member. Inflating medium inleVoutlet
m~ans may b~ provided intemally of said cor~ member so as to enable inflation
and deflation of the inflatable elernent.
According to a second aspect of the invention, a method o~ applying a
repair material In situ to a repair ~one of an inner wall of a conduit to be
20 repaired, said process comprising:
providing a radially expandable device adapted in use ~o extend over a
preJatermi.ted axial length of the conduit to be repaired and over at Isast part of
the inner circumferenoe of said conduit, said radially expandabl~ devica having
an out~r surface means forming an outer wall of an expandable cavity, msans
25 for supplying a pressure medium to said expandable cavity or withdrawn said
pressure medium from said expandable oavity; .-
providing a flexible sheath member, seoarate from said radially
expandable device, over said outer surface means wi~h withdrawal means
enabling wi~hdrawal of said sheath member from thP conduit means;
,croviding a structural repair material outwardly of said sheath member;
2132~2~
WO 93/19321 PCr/AU93/00114
,
moving said radially ~xpandable device with said sheath member and
repair material into said conduits to be repaired and thereby positioning said
repair material adjacent the repair zone;
introducing a pressure medium to said expandable cavity to move said
5 ~uter surfaoe means radially outwardly to press said repair material against
said repair zone;
subsequently withdrawing said pressure medium from said expandable
ca\fity to move said outer surface radially inwardly; and
withdrawing said radially expandabls device from sai~ conduit, said
10 flexîble sheath member being remoYed from said conduit either simultaneously
with said radially expandable devic0 or separately therefrom with at least a
portion of said shaath member contacting the repair material everting as the
sheath member is moved axially along said conduit during remoYal.
In a preferred method, according to this aspect of the invention, the
15 radially expandable dQvice and said flexible sheath member toge~her with said means for r~moval Qf said flexible sheath member are withdrawn
simultaneously or sequentially from said conduit by moving the radially
expandable devic~ and:the means for removal of the flexible sheath member
simultaneously or sequentially along the conduit in a direction towards an axial2û end of said flexible sh~ath member opposite to an end conn0cted to said
withdrawal means for removal of said fiexible sheath member.
In an al~ernative embodiment of this aspect of the invengion, there is
provided a method wh~rein said flexibl~ sheath member comprises an inner
and outer layer, said inner layer b~ing connected to said msans for ramoval of
25 said flexible sheath m~mbcr and to said outer layer at ends of said inner layer
axially remote from each other, said radially expandable device and said
flexible sheath member tog~ther with said means for ramoval of said flexible
sheath member being withd~awn from said conduit in a mann~r such as to allow
the flexible sheath member to be peeled away ~rom said repair matarial by at
30 least partial ~version.
.. WO 93~19321 21 3 ~ S 2 G PCr/AU93/00114
1,
Preferably the radially expandable device comprises an inflatable
elemant defining an annular or part annular enclosed spacs forming said
~xpandabl~ cavity, extending axially aleng said core member.
In a further preferred embodiment of this aspect of the invention, fluid is
5 directed into said inflatable element so as to radially expand it. C:onveniently
the fluid is heated and th~ repair material includes a th~rmosettlng material orsubstanc~.
Various preferred aspects of the pres~nt invention will be more readily
understood by reference to the following description of preferred embodiments
10 given in rela~ion to the accompanyin~ drawings in whioh:
Figure 1 is a longitudinal cross-sectional view of an inflatable ~orm
according to the invention in situ in a pipeline to be repaired.
Figure 2 is a longitudinal cross-sectional view of an inflatable form
according to a s~cond embodiment of the invention in situ in a pipeline to be
1 5 repaired.
Figure 3 is a longitudinal cross-sectional view of the infiatable form of
Figur~ 1 in an inflated condition in situ in a pipeline being repaired.
Figura 4 is a longitudinal cross-sectional view of a repaired pipeline from
which a flexible sh~ath member is to be rernoved by eversion. --
With r~ference to Figure 1, an inflatable f~rm ~1~ is made by forrning an
inflatable element (2) axially along and circum~erentially around ~ core member
(3). The inflatable elem~nt is fixed at its ends (2a and 2b~ to the c~re member
(3). InleUoutlet duct (4) is provided throu~h said core member (3) ~nd in~o saidinflat~bla ~lement ( ) ~o enable an inflating medium to be delivered to and
25 wi~hdrawn from the inflatable element (2). The inflatable ~orm (1) is also
provided with a separat~ flexible sheath (~ which is connected to means for its
r~moval ~6) in ~he forrn of an annulus at one axial end of the core member (3). ~-
The separate flexibie sheath (5) is !ocated axially along and circu mfere ntiaily
around the inflatable elemen~ (2) loe~ted ~xternally of th~ c~r~ rn~mber (3). Th~
30 fact that the flexible sheath ~5) is separa~ed from ~he core memb~r (3) and
inflatable ~lement (2) enables it to be withdrawn from the pipelin~
independently of the core member (3) and inflatable elem0nt (2) if so desired.
wo 93,l9322 ~ 3 2 S 2 ~ PCI/AU93/00114 ~
. .
However, it is also possible, if the means for removal of the ~lexible sheath is of
substantial enough form, that the two parts could be removed simultaneously.
With reference to Figure 2, a second embodiment of th~ invention is
illustrated in which the flexible sheath (5~ comprises an inner layer ~5a) and an
5 outer layer (5b). The inner layer (~a) is connected to the means for removai of
the flexible sheath (~) and to the outer layer (5b) at ends of the inner layer (5a)
axially remote from ~ach other. This embodiment merely enables an alternate
onentation of the inflatable form which may be more conv~niant than the
embodiment of Figure 1, depending on the orienta~ion of the pipeline to be
1 0 repaired.
In use, repair material in the form of a sheet or tube of reinforcement
material (7) impregnated with thermosetting resin is placed over the inflatable
form ~1). The whole assembly including the core member (3) with attached
inflatable elemen~ ~2) and the separate flexible sheath (5) tog~ther with the
15 maans for removal of the flexible sheath (6) is then simul~aneously introduced
into the section of a pipPline or sewer pipB required to be refurbished. Ths
appara~us may be orianted according to either Figures 1 or 2. Correct
positioning may be verified through the use of closed circuit television.
Referring ~o Figur~ 3, an inflation medium at a suitable ~emparature and
20 pressure is than in~roduced through inleVoutlet duct ~4) causing th~ inflatable
~lement (2) to expand and force th~ resin - impregnated reinforcement material
into intimate contact with the inner wall surfaces of the pipelin~ or sewer pipe.
The inflating medium circulates at a suitable pressure and t~mperaturs and is
preferably continued until full curing of the resin of the resin - impregnated
25 reinforcemen~ material isobtained. Conveniently,th inflating medium might be
water, air or some oth~r suitable gas or fluid.
Following tull euring of thP thermosetting resin with which the
reinforcement material is impregnated, inf~ating medium circulation is s~opped
and the inflatable elements (2) are deflated by remov~ of the infla~ing medium
30 frem the apparatus. The inflatable form (1) include the core member (3~ and the
inflatable element (2) is then withdrawn from the pipeline or sewer pipe section.
H the core rnember (3) is ~o be withdrawn independently and before the flexible
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- ~ WO 93/19321 213 ~ ~ 2 ~ PCI/AU93/00114
sheath ~5~ and the means for removal of the flexible sheath (6) withdrawal
should occur in ~n axial direction away from the means for removal of the
flexible sheath (6). Referring to Figure 4, when wit~drawal of the core member
(3) and inflatable element (2) oceurs independently of the flexible sheath (5),
5 withdrawal of the l~tter occurs subsequent to withdrawal of the former and is
conducted so tha~ e flexible sheath everts and peels cleanly away from the
reinforcement material (7). In this way, as the inflatable form exits the section
which has been refurbished, it is, more or less, completely avert~d. This
peeling action has been shown ~o be extremely efficient at overcoming any
10 residual adhesion be~ween the flexible sheath and the resin with which the
reinforcement m~terial is impregnated.
Alternatively, the flexible sheath (~), means for removal of the flexible
sheath (6) and the inflatable forrn (13 comprising core member (3) and inflatable
element ~2), may b~ withdrawn from ~he pipeline simultaneously. In this
15 instanc~, it is necessary that, aecording to tha smbodirnent sf Figur~ 1, thcmeans for removal of the flexible sheath be of sufficient size to bear the forcerequired to withdraw the core member (3) and inflatable element (2). Again,
howeY~r, simuttaneous withdrawal of the core member (3), inflatable element
(2), flexible sheath (5) and means ~or removal of the ~lexible sheath (6~ mus~ be
20 in a direction such that the nexible sheath (5) is caused to evert thus paeling
away from the resin Impr~gnated reinforcement material as previously
deseribed.
in another alternate withdrawal method which may be used with respect
~o th~ embodimcnt of Figure 2, the flexibla sheath (5) and means for r~moval of
2~ thc same (6) may be carefully wi~hdrawn prior to withdrawal of the cor~ member
(3) and the inflatable element (2). Care must be taken to ensure that eversion of
the flexible sheath (5) occurs such that it is peeled away from the resin
impregnated reinforcement material.
3û
