Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
WO 93/19322 ~ 7 0 1 PCI`/AIJ93/00121
The present invention relates to apparatus used in the process of refurbishing
damaged conduits, pipelines and sewer pipes through the application of a reinforced
lining to their inner walls by means of an inflatable form. The present invention is
5 particularly but not exclusively intended for use in the repair of y~rground pipelines
in situ to avoid the necessity of excavating the pipeline or re-routing flow from the
pipeline around the repair site.
Conventionally, two principal methods have been used for the refurbishment of
cracked, broken or eroded pipelines or sewer pipes through so-called soft lining methods
10 imoivin~ the application of a reinforced lining to 1heir inner walls. One of these methods
involves the eversbn ot a tube of themmosenin~ resin-impregnated reinforcement fabric
into a sectbn of pipe to be relined from an extemal position by means of a head of water.
An example of this method can be seen in U.S. Patent No. 4,581,085. This method has the
disadvantage that the pipe being repaired is necessarily blocked by the repair materials
15 durin~ the repair proc~ss and as a result, fhw through the pipeline must be re-routed
around the repair zone. A second method used involves carrying a layer of resin
impregnated reinfordn~ material on an intlatable form to the repair zone wilhin the pipe
and thereafter infbting the inflatabie brm to press and hold the repair layer against the
sectbn of 1he pipe requlring repair for a length of time sufficient to allow the resins to
20 cure. Examples of this type of repair can be seen in G.B. Patent No. 2136912, European
Patent No. 370193 and Swiss Patent No. 635181. A short coming of these known
systems Is that the inflatable forms used essentially fully block the pipe during the
repair process thereby intérrupting all flow in the pipeline. Bypassing of the section
being refu~bished or some other means of stopping flow in the pipeline beiing repaired is
25 1herehre a necessily.
A lhird torm ol pipeline repair is also shown in prbr art specification but thistypelot process isjnot intended to refurbish a length of pipeline but rather is intended to
repair bcalised defects, commonly cracks or gaps between discrete secthn lengths of a
pipellne. In thiS type of repair process a~ settable liquid or semi-liquid sealant is
30 pun~d or forced into a zone between two axially spaced inflated parts pressed agains1 the
inner wall of the pipeline. Examples of this type of device are shown in U.S. Palent Nos.
3,9058,607, 4,763,S11, 3,618,639, 3,762,446, 3,834,421, 3,958,607,
3,~46,761 and G.B. Patent No. 2169983. These prior art references do not permit
tefurblshment of a len~th of pipe as the repair material cannot include a resurfacing
W093/19322 'f~ ~ 3 ~ ~ O ~ Pcr/Aug3/00121 " I
malerial and canno1 reliably extend over any lenglh of an inner surface of a pipe as
opposed to a crack or gap between pipe section lengths.
In German Patent App ication No. DE 3922351 it has been proposed to provide an
annular form with an inflatable envelope on its outer surface such that fbw within the
5 pipeline being repaired may continue through Ihe annular formfiHhile Ihe repair process
Is being carried out. This avoWs the problem discussed above relating to re-routing or
stopping flow in the pipeline being repaired, however certain difficulties still exist. The
form discbsed is essentblly rigid makin~ it extremely difficulty to get the torm into an
underground repair positbn from an above ground bcation when the form length is above
10 a certain predetermined length. That is, above a certain length it is difficult or
impossible to manoeuvre a rbid form within the confines of a manhole or access pit.
Australian Patent Applicathn No. 54471/90 discloses an arrangement wherein
the inflatable form is formed by a plurality of individually rigid annular segments which
are pressed together by cable tensioning means to form a rigid annular form when in use,
15 Ihe cable tensioning means being capable of being relaxed to allow the individual segments
to be arrsnged at an angle to adjacent segments thereby facilitating introduction of the
brm into fhe pipeUne from an above ground position or movement through a pipeline to
the desired repair IJocatbn. Whib this arrangement does not have the same problem as
dlu~ud above in relation to German Patent Specificatbn No. DE 3922351, it does have
20 a problem in that it is complicated in construction and difficult to use where it is
nece~ary to tighteh lhe cable ~ensioning means underground at the repair location.
Whib this can be achi,eved, it is an added complicalion in cost of producing the repair
apparatus and in using ~he apparatus during a repair process.
A still tunher probiem~with many prior art repair devices is that the inflation
25 envebpe or bag is commonly~produced from a stretchable or expandable material such as
rubber'or rubber like m ~ ~bl. In some siluations a plpeline may be broken with a
reasonably lar~e washed out cavity in the earth around the break. Where this hasoccurred, iI is posslble for the pressure of an elastic inflatable form to displace a broken
~on, distend into the caviq and burst. If the repair is only partially cured it may, as
30 resun, be a hilure snd be impossible to remove without excavating the whole section of
the p4eline.
G.B. Patent Specification No. 2136912 discbses an inflatable form of the same
general type as discussed above wherein the intlatable bag is produced from a non
stretchable materlal such as nybn coated internally with Neoprene (for waterproofing).
35 The diameter ot this bag is selected to be generally equal to the diameter of the pipe being
Pcr/~u~3 / 001 ~1
RECEIVED 16 fEB 1994
repaired less twiee lhe lhickness of the repair malerial. This G.B. patent does not,
however, disclose any melhod of conlaeling lhe inflalable bag after the repair proeess has
been completed to enable the repair device to be removed from the pipeline beingrepaired which is normally aehieved by making the bag from an elastic material.
The objective of the present invention is generally to provide repair apparatus
and a malhod of operating sueh repaTr apparatus whbh will solve~all or at least some of
1he dlffieulties assoeiated with prior ar~ deviees as discussed above. In partieular, in a
first aspect, the present invention aims at providing repair apparatus which can be
posilbned as desired within a pipe to be repaired from an above ground position without
10 signifieant complications in construction or use of the apparatus and without preventing
normal fbw in the pipeline being repaired while the repair process is carried out. In a
seeond aspect, the present invention aims at providing apparatus which will prevent the
intlalable hrm expanding into a cavily surrounding lhe repair zone beyond a
predetermined limil lhereby ensuring against the inflation malerial bursling with the
15 possible consequent effect of the repa~r material and repair apparatus becoming
irretrievably sluck al the repair site, while at the same time allowing contraction cf the
intlatable form upon eompletion of the r~pair process.
According to the present invention, apparatus adapted to achieve the
aforemenffoned objectives is provided having fealures corresponding lo those defined in
20 cbims 1 and 5 annexed herelo. Similarly, lhe invention also provWes a method of repair
having the features deflned in claims 11 and 12 annexed hereto. Prsferred aspects are as
denned in daims dependent from lhe aforesaid daims.
By these methods and apparatus, a pipe or conduit may be repaired in situ without
danger of the infiatabh member expanding into a cavity around the repair zone to a stage
25 where bursting mbht oeeur.
In accordanee with another aspeet, the present case discloses apparatus for
applying In situ a repair material in the form of a sleeve or sheet including a settable
mat,eflal to a repair zone of an inner wall of a eonduit or pipeline, said apparatus
comprisin~ a eore member having a radially expandable deviee loeated outwardly of said
30 eore member and exlending axialb aiong and at least partially circumferentially around
said eore member, said eore member ineluding a holiow flexible tube of a non perforate
material and having a fixed axial length capable of transverse bending but adapted to
eslst inwatd deformatbn eaused by internal pressure within said expandable device
during a repair operation.
A~D~ s~r
lPWAV
P~/AU 93 / 001 2 1
~ RECEIVED 16 ~E~ 1994
- h ~ 2 ~Oi
Preferred embodiments of the present invention will now be described with
reference to the accompanying drawings, in which:
Fi~ure 1 is a longiludinal cross-sectional view of a first embodiment of the
present invention;
Figure 2 is a longitudinal cross-sectional view of a secon,d embodiment of the
present invention;
Figure 3 is a view sharing the embodiment of Figure 2 in a position of use;
Figure 4a is a cross-sectional view along line A-A of Figure 2;
Figure 4b is a partial section view of the end of lhe apparatus adjacent section10 A-A wnh the sheath member removed for the sake of clarity;
Figure 5 is a cross-sectional view along line B-B of Figure 2; and
Figure 6 is a cross-sectional view along line- C-C of Figure 2; and
~ND~D ~BEr
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W093~19322 f~ 0 1 PCI`/AU93/00121
Fi~ure 7 is a view similar to Figure 6 except Ihat the expandable cavity has been
expandsd.
Refening tirst to Figure 1 the apparatus 10 is shown within a pipe 11 lo be
repaired having a repair zone 12. The apparatus 10 comprises a pair of longitudinal
5 spaced end members 13 14 whbh may be formed from solid metal or fabricated from
sheet metal such as aluminium or an aluminium alloy. Each member 13 14 has a
bn~itudinal through flow passage 15 and connectbn means 16 to permit connection of
cabbs 30 or the like (Figure 3) to albw positbning of the member within the pipe to be
repaired. A flexible tube 17 interconnects the two end members 13 14. The tube 17 is
10 convenhnt~ formed from a rubber or other elastomeric material and is reinforced so
Ihat deflectbns or deformations inwardly are resisted but the tube 17 is sufficiently
Uexible to albw transverse bending to albw the apparatus to be moved around bends in
the pipe 11 to be repaired. Fbxible cables or chains 18 are provided interconnecting the
two end members 13 14 to ensure that they do not separate under the loads required to
15 winch same into positbn or to withdraw same aner a repair process has been completed.
The thhugh flow passages 15 and the interior of the tube 17 provide a longitudinal
pa~oe that albws continued fbw through the pipe 11 durin~ positioning or withdrawal
ot the apparatus 10 and during the repair process itself.
P~adbl~ outwardb of the tube 17 is a flexible and expandable tube 19 which is
20 oonnected by any~suitable means 26 27 at either end to the end members 13 14. The
flexlble~and expandabb tube 19 defines an expandable cavity Z0 essentially between
ll~elf- and the~ outer wrface of the tube 17. Access is provided through one or more
pa~ e means 21 ~n at~ bast one of the end members 13 14 to albw introduction or
~ wi~l ol~a pressute~medium (liquW or air - preferab~y heated) to the cavity 20 to
25 th*~y~expand this~cavity~and~move the tube 19~radially outwardly. If the tube 19 is
eb~tb and therefore st ~t0abb then upon withdrawin~ the pressure medium from thecavi~ 20 the tube~will oontract radiallx inwardly. ~Located radially outwardly from 1he
t~lb~ 19 is a ~hea1h member 22 which is oonnected at one end 231O one of the endrs 13~ The ~heath- member 22 ~s ~provided ~to assist removal of the apparatus from
30 tl~ ~plpelhe upon completb~n ~of ~a repair operation as is explained in Australian Patent
~tbn No. 54771~/90.~ The sheath member 22 may alternatively be constructed as a
sepsra1e unit as di~closed in Aus1ralisn Provisbrlal Pa!ent Application No. PL 1466 filed
on the 20th l~lardl 1992. The subject matbrs of these co-pending paten1 applications
are includ~d herein~ by this cross reterence thereto. The shea1h member 22 carries to
35 lhe repai-~zone 12 (Fi~ure 3) a repair ma1erial 24 in 1he h~m of a reinforcement
WO 93/19322 h i ~ PCI'/AU93/00121
Impregnated with a settable material such as a thermosetting resin. Advantageously. the
senable material will not readily set at normal temperatures but will set upon an
eleva~ed pressure medium (such as hot water) being introduced into the expandable
eavity 20.
S Figure 2 illustrates in longitudinal uoss-seetion an alter~tive embodiment to
the apparatus shown in Figure 1. Like features in Figure 2 have been given the same
rebrenee numerals as ~n Figure 1 and are not further deseribed hereafler. The essential
differenee between the two arrangements lies in the confi~uration of the member 19
forming Ihe outer wall of ~he expanding cavity 20. In this ease the wall is formed by a
10 non-elaslb non-stretehable flexible material which is capable of containing the
pressure of the hjeetbn medium used. A knitted polyester fibre yarn coated wnh vinyl
material to provide a seal has been found satisfactory. Other materials that are non-
ebstie under normal operating pressures, that are flexible, and that are capable of
retaining the pressure medium during use, may equally be used. As can be seen in15 Fi~ures 4a and 4b, the end of the tubular member 19 is wrapped about the end member
13 ~or 14) and is seabd thereto with a suitable alant and elamping bands 26. As a
te8ùlt, in the position where there is no pressure medium in the cav;ty 20 or
l~dkient medium to expand the eavity 20 (as illustrated schematieally in Fi~ure 2,
4b, 5 and 6), the material torming the wall 19 is folded ~in on itself to form a trough 27
20 and Is maintained~b~thiS~oontræled position by~a plurality of elàstic bands 25 spaced
abn~the hll~i i~bal i Ih~of the~ai alus. The bands 25 may be secured to the
tube 19 ~o axialb iwale~same às desired. The bands 25,~ il suit~y secured lo the tube
19 could sl~o-be i slhoned inwa~ly of,1he~tube 19. It~will of,eourse be appredated that
sb~ive;~00uld,slso~be~used~in~substitutbn~for 1he elastie bands 25. ~en
25 ~Uu~ me,dbm~is;~lntroduced throu~h passa~e means 21, the~folds in the material
~ thé~ wall, 19 mo~ oui ardly~ that, the wall~as a whole moves radially ouiwa diy
to thé po~ltbn Ulustralec in~ Fi~7ures 3 -~and 7. ~ ~er, ~as ~shown in Figure 7, there may
remdn some extra materia~ as f,oWs 8 in Ihe~lube 19 that is retained oenetally within
1he,sheath 22 even~when~i~the zone~ 20 is operationally~infla!ed. Thus, in abnormal
ao -drcums~ai ces,~ ube~ 19~may~ stil~expand radial~y~outwardly unlil all the material of
the ~ube 19 is~used h~Ps~cir:c,umferènce and~al~this~ sta~e~no further outward movement is
~ble.~ The r~adial~outwad,~mov,ement occurs, against radially inward *rces provided
; by~lhe b~nds~ whbl~ a~Qàin~con!raa me~wall l9~when the~pressure medium is removed
- ~ Irom 1he Gavlty 20. The~ material of the wall 19, being essenUally non-extensible itself,
35 ~n~s Ihe ~ fl~y 20 expanding lo such a condllion Ihal wall 19 may distend into a
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WO 93/19322 PCI`/AU93/00121 '
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washed out cavity around 1he repair zone of the pipe being repaired and. as a result,
burst.
In an alterna1ive embodiment it may be possible to mould the material forming
the tube 19 so that it has a greater diameter along its central iongitudinal dimensions and
a narrower diameter approximatin~ the outer diameter of the end,rrlembers 13i 14, at its
ends.
In a slill further alternative embodiment it is poss~ble to manufacture the
flexible material tube 19 from an elastic material which is capable of stretching
outwardly under pressure applied trom within the expandable cavity 20. In this case it
10 is preferred to provide one or more circumferenlially extending mem~ers of a non-
ebstic material co-operating with the tube 19 having an infia1ed d~ameter generally
conesponding to the maximum desired Inflation diameter of 1he 1ube 19. These non-
elaslic circumferentially extending members may be in the form of a plurali1y of bands
(simllar to bands 25) or perhaps a single sleeve member. Advan1ageously the members
15 would be secured at one or more circumferential bcatbns to the tube 19 and if desired
could be bcated inwardly or outwardly ot the tube 19.
In operatbn, both embodiments of Fi~ure 1 and 2 are moved in10 posi1ion adjacen1the repair zone 12 by apparatus not shown. The embodimen1 of Fi~ure 2 is shown in
Figure 3. In this positbn, the cavity 20 is expanded by in1roduc1ion of a pressure
20 medium so that the wall 19 moves !adially outwardly 10 press the repair material 24
against the pipe wall 11 on op~sed;axial sides of the repair zone 12. In lhe case of the
emi iiment d Figures 2 and 3,-lhe repair material is not extended into the cavity behind
the repair zone beyond a cenain limh: as discussed above. It there is no deep cavi1y a1 the
epai- zone, Ihe epair material~ might be~ pre&sed against lhe entire repair zone it5 de~ired. After the repair material ~is sufficiently ;set, the cavity 20 is deflated and the
s is relr~ed by~withdrawing in a~drectbn SUch ~ha! the sheath member 22 will
pee! trom ~he repair malerial by~ at~ least panial eversion. In the illustrated
embodiments, the apparatus would be withdrawn by movement towards the right in
F bu-e 1, 2 and 3.
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