CA2170620A1 - Repair of drains and pipelines - Google Patents
Repair of drains and pipelinesInfo
- Publication number
- CA2170620A1 CA2170620A1 CA002170620A CA2170620A CA2170620A1 CA 2170620 A1 CA2170620 A1 CA 2170620A1 CA 002170620 A CA002170620 A CA 002170620A CA 2170620 A CA2170620 A CA 2170620A CA 2170620 A1 CA2170620 A1 CA 2170620A1
- Authority
- CA
- Canada
- Prior art keywords
- inflation
- drain
- sealing
- unit
- pipeline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/16—Devices for covering leaks in pipes or hoses, e.g. hose-menders
- F16L55/179—Devices for covering leaks in pipes or hoses, e.g. hose-menders specially adapted for bends, branch units, branching pipes or the like
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/16—Devices for covering leaks in pipes or hoses, e.g. hose-menders
- F16L55/162—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe
- F16L55/1645—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe a sealing material being introduced inside the pipe by means of a tool moving in the pipe
- F16L55/16455—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe a sealing material being introduced inside the pipe by means of a tool moving in the pipe a part of the tool defining, together with the inner wall of the pipe, an enclosed space into which sealing material is injected
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Pipe Accessories (AREA)
Abstract
For the in situ repair of drains and pipelines where damage or defects (6) have occurred in close proximity to incoming lateral drain or pipe connection (4), a tubular ejector body (10) is drawn or pushed into the drain or pipeline (2) to such a position that it extends to either side of the lateral connection (4). A pair of inflation sealing units (30, 32) at either end of the ejector body (10) are inflated to seal the body on either side of the lateral connection (4) and a further inflation unit (40) is inflated to close off the lateral side connection (4).
Then a sealing composition is pumped out of the body (10) through a plurality of ejector openings (140) to form, when set, a seal repair of the drain or pipeline (2), without a blocking of the junction with the lateral drain or pipe conection (4).
Then a sealing composition is pumped out of the body (10) through a plurality of ejector openings (140) to form, when set, a seal repair of the drain or pipeline (2), without a blocking of the junction with the lateral drain or pipe conection (4).
Description
W095/07433 ~ ; 2 1 ~ 0 62Q~ PCTIGB94/01932 REPAIR OF DRAINS AND PIPFTTN
FIELD OF THE INVENTION
This invention relates to the repair of drains and pip~l;nec, esrer~ y those which are located undelyLou~d or oc~ in surro~lnAIng material, such as concrete, and int~n~
to cc--vay fluids such as potable water, waste-water, certain semi-solids, solids susp~e~ in fluids, or gases. More particularly, the invention concerns an apparatus and method for the in situ repair of drains and pipel~n~ where damage or defects have occurred in close proximity to incoming lateral drain or pipe conn~r-tions.
BACKGROUND OF THE INVENTION AND PRIOR ART
For quite a number of years there have been known various devices for in situ repair of underground drains, pip~ c or the like. Convent;o~lly~ a carriage would be drawn or pushed into the drain or pip~l; n~ to reach the site at which repair was nee~A, and then a 8~Al ~ng el~ - t would be expanded r~A;~lly outwards so as to contact the pipe at each side of the leak, for example, and liquid grout would then be pumped to an outlet in the carriage so as to flow into the damaged region and form, once set and hardened, an effective sealed repair of the inner drain or pipeline wall.
In order to make it posc;hle to ut~l;C~ this basic idea for the repair of drain or pipel~n~ defects which are of substantial size, GB-A-2122300 proposes the employment of a tubular ejector body which is sited at the desired location in the drain or pip~l~ne and has a plurality of e~ector op~ni~gS
therein out of which sealant ._c ~lo~ition is pumped to fill the defect. The ce~l~nt rnmrocition is cont~i n~ at the required location over a limited length of the drain or pipeline by inflation, e.g. by ~,..~lessed air, of respective ~ ng rings disposed around the e~ector body at or near each of its ends.
Once the drain or pipeline defect has been filled and has been allowed to partially set, the se~ g rings are deflated, thereby allowing the ejector body to be removed from the repair site and SUBSTITUTE SHEET (RULE 26) -WO9S/07433 ; ~ ~ '~ 2 1 7 0 6 2 0 PCT/GB94/01932 full setting and har~ni ng of the sealant composition to take place, thus completing the repair of the drain or pip~l~nQ.
Reaming of the pA~Ageway before and/or after the repair has been effected may be carried out in order to enhAnce the ~uality and finish of the ~ob.
Prac~cAlly speAk~ng, the apparatus required to effect the above method of drain or pipe repair is relatively complicated and ~Yppncive and h~CAllce of the somewhat crude way in w~ich the ceAl~t composition is put in place at the site of the defect, the resulting accuracy and efficiency of the repair i8 not always as good as many types of practical application demand.
As an i,..~Lo~F - t to this known ~L~al, therefore, GB-A-2169983 proposes an apparatus and method for in situ drain or pip~l1ne repair, still based on the idea of employing an e~ector body which is drawn or pushed into the drain or pip~l~ne to the ~G~ location and providing a plurality of outlets through which ~lAnt composition is pumped to fill the defect, but in which the e;ector body is constructed such that it comprises a sleeve of flexible material which is uns~oL~ed internally along its length and has, between its ends, an intermediate portion wherein the ejector op~n~n~s are provided. The intermediate portion has less ext~slhility than the end portions on either side, so that for a given inflation pressure, a smoothly ~,lLoured inflated pressure sleeve is created whose end regions are more outwardly inflated than its central region, so that it seals the e~ector body against the intact walls of the drain or pip~l~ne either side of the defect and leaves an ~nnlll Ar gap around the central region of the e~ector body into whlch the S~Al Ant composition is pumped to fill the defect which i8 arranged to be located in that AnnlllAr cavity. EP-A-0259518 discloses a similar system to this, ùt~l~si ng much the same principle.
These known in situ pipe repair apparatuses and methods generally perfo~m satisfactorily where the damage or defect has occurred in a straight portion of the drain or pip~l~ne where SUBSTITUTE SHEET (RULE 26) W095/07433 ; - ~ 2 1 t ~ ~ 2 0 PCT/GBg4/Ul932 there is a substantially continuous pipe inner wall against which the various se~ g elements of the apparatus can abut and seal to generate the n~cpss~ry cl o~ region lnto which the -s~ nt composition can be pumped. Even if pipe damage exists over a wide area or along a relatively long section of pipe, s~-c~ful repair using these known systems is still po~C~ , as one can simply employ an e~ector body of increased length, for example.
There is, however, a problem A~o~Ated with these known systems, and that is when the pipe damage or defect has occurred at or near the ~unction of the main drain or pip~l~ne with an incoming lateral drain or pipe conn~Gtion. When the known apparatu~ is used to repair a defect in such a position, it is difficul~, if not impossible, to effect ~Lo~e~ repair of the damaged area by application of the sealant ~ tion to it without the incoming lateral con~ection itself becoming filled or blocked with the ~ Ant material. As will be appreciated, it can be extremely difficult and time-consuming to drill out such a lateral con~cting drain or pipe after repair of the main pip~l~ne is completed, but hitherto this has often been inevitable when the known systems as described above are ut~
for repairing damaged areas of pipe at locations in the n~ighho-lrhood of incoming side pipe ~o~ne~-tions.
Xt would be advantageous, therefore, if one was able to employ the ideas embodied in the above known pipe repair apparatuses and methods at damaged sites located in close proximity to ~nco~ ng lateral conn~ctions, but without the problem of the latter I h~ ves becoming filled or contaminated with the se~l~nt material with which the main drain or pipe defect is repaired.
SUMMARY OF THE INVENTION
Wlth this ob~ect in view, the present invention provides, in a first aspect, an apparatus for use in repairing a defect in a drain or pip~l~ne at or near a ~unction with a lateral drain or pipe ~-o~n~tion, the apparatus ~...~llsing:
a tubular e;ector body adapted to enable it to be drawn SUBSTITUTE SHEET (RULE 26) WO95/07433 , ~ . 2 1 7 0 6 2 0 PCT/GB~4/~1932 or pushed into the drain or pipeline to such a position that a 1 ~A~ ing end and a trAil~ng end of the body are disposed respectively to one side and the other side of the defect and lateral co~n~r,tion combination;
a pair of primary inflation ~ling units at or near the respective ends of the tubular body and which, when they are both inflated, seal the body against the drain or pir~l~n~ inner wall on each of the sides of the defect and lateral connection combination;
a C~cond~y inflation s~ ng unit situated between the primary inflation ~eAl~ng units and which, when it is inflated, substantially clocec off and/or seals from the main drain or pipeline the ~unction therewith of the lateral drain or pipe ~onnection; and means for ~o-~veying a settable s~ ng composition from within the tubular body to and out of at least one, preferably a plurality of, ejector op~nings in the body between the primary inflation ~A l~ng units and the -c~con~y inflation 5~1~ng unit, for forming, when set, a seal repair of the drain or p1pel1ne defect without a blo~k~ng of the junction with the lateral drain or pipe ~o~ection.
In a c~Qn~ aspect of the present invention, there i8 provided a method of repairing a defect in a drain or pi~ ne at or near a ~unction with a lateral drain or pipe conn~tion~ the method comprising:
drawing or p~sh~ng into the drain or pipel~ne a tubular e~ector body to such a position that a 1~A~ing end and a tr~ling end of the body are disposed respectively to one side and the other side of the defect and lateral conne~tion ~om~i n~tion;
inflating a pair of primary inflation ssAling units at or near the respective ends of the tubular body so that the body is sealed against the drain or pipeline inner wall on each of the sides of the defect and lateral co~nection combination;
inflating, either before, at the same time as or after the inflation of the primary inflation ~eAl~ng units, a s~co~A~y inflation ceAl ing unit situated between the primary inflation ling units, so as to substantially close off and/or seal from the main drain or pipeline the junction therewith of the lateral SUBSTITUTE SHEET (RULE 26) WO95/07433 '~ ?~ 2 1 7 0 62 0 PCT/GBg4/01932 drain or pipe conn~ction;
~ os-v~ylng a settable s~ ng comrosition from within the tubular body to and out of at least one, preferably a plurality of, e~ector op~ngs in the body ~etween the primary inflation s~Al~ng units and the cP~o~Ary inflatlon ~e~l~n~ unlt so that the composition is e~ected into the draln or pir~l~ne defect; and prior to complete setting of the ~ n~ composition but whilst it is in a coherent condition, diSpl~ n~ the eJector body along the drain or pipPl~ne, preferably ~lheP~uent to deflating at least the ~e~on~Ary inflation c~ ng unit and preferably also the pair of primary inflation sPAl~ units.
In a third aspect, the present invention provides a drain or pip~l~ne which has been repaired by the above-defined method or by use of the above-defined apparatus.
The PC~ce of the present invention, therefore, as presently contemplated in its broadest sense, lies in the modificatior. of the more recently generally known in situ pip~l~ne repair ~y~ell-s to include a cPcon~Ary~ preferably ~n~ n~ntly inflatable, inflation S~Al ~g means which acts to close off (or substant-ially so) and preferably also seal the ~unction of the incoming lateral drain or pipe ~o~ne~tion with the main drain or pipeline, thereby enAhl ~ng the region of the main drain or pipPl ~ n~ at or near the side ~onnection, where the defect is situated, to be repaired in a manner si mi l Ar to that which is already known, but without blo~k~ng that side co~n~ction where it ~oins the main pipe. Most i p~ Lantly, the ~y-L~ of this invention obviates the need for dr~ ng out of the incoming side ~onne~tion once the repair is complete, as would generally be required if the ~.,v~..t~onAl -y~L s were to be used in the repair of the particular sited defects with which we are here co~erned. Employment of this invention may also improve the overall quality and finish of a repair ~ob carried out on a defect in the neighbourhood of an ~ ncn~ ng drain or pipe side co~n~rtion, given the complete or substantial absence o ingress of ceAlAnt material into the side ~onn~tion and of build up of s~AlAnt composition around the edges of the co~n~tion junction.
SUBSTITUTE SHEET (RULE 26) W095/07433 ' ~ ~ ' 2 1 7 0 62 0 PCT/GB94101932 ~
In preferred ~ ho~ents of the apparatus of the invention, the primary inflation s~ ng units extend around the full circumference of the ejector body, so that when inflated they assume an ~nn~ r cross-section and seal the body against the inner wall of the pipe all the way round.
On the other hand, ho.ev~., the ~ A~Y inflation 8~ ng unit preferably eh Le~dS over only part of the ejector body circumference, and most prefe~ably it takes the form of an inflatable bubble which, upon inflation, presents a surface area sufficiently large to substantially close off and seal the incoming drain or pipe side ~onn~rtion~ generally with at least a small extension all the way round past the ~unction so as to ensure a good ~ ng action. It is, however, within the scope of the present invention for the c~on~y inflation c~ ng unit to have a similar circumferential s~ ng ring configuration like the primary inflation c~l ing units, for example in the case where application of ~e~llng composition to the damaged drain or pipel ~n~ iS to be restricted to a narrow region to one side only of the lateral pipe ~o~n~ction junction.
The tubular ejector body of the apparatus preferably comprises an outer cylindrical sleeve which is rec~l~Pntly flexlhle so as to permit r~ ly outward ~Yp~ncion thereof into c~llng contact with the inner wall of ~he drain or pip~line upon inflation of the primary inflation s~l lng units. Each of these primary inflation sealing units may be constituted by an ~nn~ r (or short cylindrical) cavity formed within the sleeve wall towards the ends of the ejector body or, more preferably, each may be formed by virtue of a cylindrical section of the fl~Y~hle sleeve not being hon~ to an inner tube forming the core of the ejector body, as are portions of the sleeve which are not required to be ~yp~ncible outwardly from the core, e.g. the ends of the sleeve. The s~con~y inflation s~ g unit is preferably constituted by a cavity formed within the outer sleeve wall between the primary inflation s~Al~ng units. For the purpose of assisting correct outward ~Yp~ncion of the flex$ble sleeve to form the primary c~ ng rings at each end of the ejector body, the sleeve wall may, if desired, be constructed SUBSTITUTE SHEET (RULE 26) W095/07433 ~ ~ C 2 1 i 0 6 2 0 PCT/GBg4/01932 with a~Lu~ iate internal reinforcement or, alternatively, hond~
constriction rings to the outer and/or inner walls thereof in the regions where lesser extens~ h~ l~ty is required.
In one, less preferred embodiment of the apparatus of the invention the inner tube forming the core of the e~ector body is a rigid tube, e.g. a unitary steel (~srec~Ally st~nlesR ~teel) tube. In more preferred embodiments, ho. v~, the core comprises a tubular body which ls rPc~l~e~tly fl~Y~hl~, so as to ~n~hle it to deform and bend to assume a ~lved shape. This ~n~hl es the e~ector body to conform to deviations or bends in the drain or pipeline. Most suitably, for this ~L~osæ a most preferred ejector body core comprises a clocp~ coil spring, esp~c~Ally a hel~rAl closed coil spring, which preferably has formed around it a stretchable intermediate sheath which conforms to the outer shape of the core as it passes through the drain or pip~l~n~.
The shea~h is preferably made of rubber, e.g. nitrile rubber (which is particularly suitable for repair applicatlons involving pipes which oonv~ fuel gas) or natural rubber, and is preferably constructed and arranged so as to have a desired hardness and/or fl~x~b~lity ~ep~n~ng upon the degree of c~All~ required of the apparatus against the pipe or drain to be repaired and the amount of flexible deformability re~uired of the core. Generally speaking, bends in the drain or pipe of up to about 90 may be accommodated by use of this coil core with rubber intermediate sheath feature of the apparatus.
~ n a partic~ rly preferred ~-ho~ment of the apparatus of the invention, there is further provided a tertiary, ~n~er~n~nt inflation unit between the primary inflation c~Alin~
units and r~ lly beneath the s~con~Ary inflation S~Al ~n~ unit which is also situated between the primary inflation c~l ln~
units. The tertiary inflation unit is preferably constituted by an independently inflatable cavity beneath that which forms the ~on~A~y inflation s~Alin~ unit, i.e. between the central re~ion of the flexible outer sleeve and the inner tubular core of the e~,ector body and bounded on each side by the pair of primary inflation Ci~Al ~in~ units. The action of the tertiary inflation units is such that when it is inflated, there is a reduction in SUBSTITUTE SHE~T (RULE 26) WO95/07433 ~ ~ 2 1 7 0 6 2 0 PCT1GB94/01932 the depth of the headspace formed between the primary inflation 8~ n~ units and into which the SeR 1 ~ ng composition is pumped for the purpose of repairing the drain or pipe defect. In other words, inflation of the tertiary inflation unit r~ ~c the difference in diameter between the inflated primary inflation ~l 1n~ units constitut~ng the ~ ng rings at each end of the e~ector body and the central region of the flD~hl~ outer sleeve between the end s~ g rings. Inflatlon of the tertiary inflation unit, therefore, results in a reduction in the th~r-knecc of C~ ng composition e~ected from the body into the cavity defined between the primary inflation s~ ng units. This leads to a reduction in the amount of se~lAnt material used to repair a given area of defect and also means that once it is set and hardened, the se~l~ng material of the repaired site ~Lu~L~des less into the interior of the drain or pipeline, thereby re~ ng the n~ceC-~Ary extent or even need for post-repair reaming and giving an overall better finish to the repaired site.
As a means of controlling the r~ ly outward Pxp~nc~o~
of the section of wall of the cavity forming the tertiary inflation unit such that the wall remains substantially cylindrical, a~L~Liate internal reinforcement or outer and/or inner hon~ constriction rings may be employed, as already men~nne~ but in a different context. The cavity forming the tertiary inflation unit is preferably of ~nn~ r cross-section, such that it extends around the whole circumference of the e~ector body beneath the cavity into which the c~ n~
composition will be pumped.
In the apparatus of this invention, inflation of the various inflation units may be achieved by use of any suitable pressure medium, but is preferably cG...~Lessed air. Entry ports to each inflation unit can be conn~cted up and the supply of compressed air to all or any of them controlled by convent~ O~A 1 means, as will be known already in the art in the context of the prior art in situ pipe repair apparatuses described her~;n~hove.
It is preferred that both of the primary inflation s~l ~ng units are inflatable together, in which case they may be supplied and controlled by a common source, but it is preferable that the SUBSTITUTE SHEEr (RULE 26) ~ W095/07433 ~` ; ~ ` 2 1 7 ~ 6~2 0 PCTIGB94101932 c~s~y inflation s~l ing unit and the tertiary inflation unlt are both inflatable ~nd~p~n~ntly of each other and of the primary inflation $~ g units.
One exception, ho~e~, to the convent~o~l nature of the compressed air entry ports of the various inflation units of the apparatus is that in embodiments where the tertiary inflation unit is present, the entry port fee~i n~ the lnflation cavity of the Q~CO~Ary inflation c~ling unit ls preferably constituted by a special in~ection port which is constructed to allow supply of compressed air from inside the ejector body into the s~con~y inflation cavity independently of the degree of expansion of the cavity formed ther~h~neAth which constitutes the tertiary inflation unit and across which the compressed air supply duct for the sp~on~ry inflation cavity must therefore traverse.
This same requirement is true of the in~ection ports via which sealant material is ejected from within the ejector body into the ra~ially outer cavity against the inner wall of the drain or Pir~l i n~ under repair. Essentially, therefore, whilst compressed air injection ports for the primary and tertiary inflation units can be of known type, it is esp~c~ y preferred in practical embodiments of the preferred apparatus of the present invention that the compressed air inlet port of the c~CQn~ry inflation se~l Ing unit and each of the c~ n~
composition in~ection ports constituting the above defined e~ector op~ni~gs are all siril~ly constructed in accordance with what is a further definable aspect of the present invention, as will now be defined.
Accordingly, this invention also provides a fluid injection port for passage of fluid from a supply means to a first cavity across a C~con~ cavity which separates the first cavity from the supply means, the injection port ising co~ ;t means in communication with the fluid supply means and ext~ing across the second cavity and into the first cavity, the cQn~ t terminating in a headpiece fast with the wall separating the first and C~con~ cavities, and bush means fast with the wall separating the s~on~ cavity rom the supply means and through SUBSTITUTE SHEEr (RULE 26) , WO95/07433 ~ t'~ 2 1 7 0 6 2 0 PCT/GB94/01932 which the ~on~l~;t means extends and is sl 1 ~hl e with respect thereto, the bush means including ~ n~ means which forms a seal against the conduit means as it Q~ Q relative thereto, whereby inflation or deflation of the ~C~n~ cavity CAll~
piston-like cl~ng of the co~ t means through and with respect to the bush means, and whereby communication between the fluid supply means and the first cavity i8 maint~nAhle tn~p~ tly of the degree of inflation or deflation of th~ ~co~ cavity.
Thus, in the context of the preferred apparatus of the primary ob~ect of the present invention as defined above, ;c~tion between the supply of _ ,Lessed air or C~ nt composition, as the case may be, with, respectively, the cavity of the s~con~y inflation sealing unit and the external headspace region between the primary inflation ~e~l~ng units into which the sealant composition is to be ejected is preserved regardless of the degree to which the tertiary ~n~pe~nt inflation unit is inflated or deflated for the ~ e of altering the depth of that headspace surro~nA~ng the central region of the e;ector body.
A preferred construction of fluid in~ection port of the above defined aspect of the present invention will be described in detail further below in the context of an overall preferred embodiment of the apparatus of the present invention.
In practical embo~;~onts of the invention, to ~L~V~-~t the q~ ng composition bon~ng to the outer sleeve of the e~ector body during the repair process as the ~omro~ition sets and before the apparatus is ~ .ved from the repair site, there is preferably employed a release agent which is applied to at least the outer surface of the outer sleeve prior to the repair process being commenced. Suitable release agents are well known in the art and include for example oil-based or silicone-based rP~
agents such as MARLEASE 400 ex Marbo. The rPl~c~ agent may be applied by brush or spray to the sleeve before insertion of the apparatus into the pipeline to be repaired or may alternatively be impregnated into the sleeve material in a pre-soaking step, dep~n~;ng for example on the type of r~ C~ agent used.
SUBSTITUTE S~IEET (RULE 26) W095/07433 ~ r~! 2 i 7 0 62 0 PCT~GBg4~0l932 In practical e-ho~i~^nts of the apparatus of the invention the sealant com~poq~tion, which can be of a conventional type, e.g. single component or more preferably multi-component, (e.g. a resinous compound, such as an epoxy resin, and a hardener) is pumped from a ~o~L~e to the e~ector body through a supply line or lines using convent~snAl apparatus and in a conventional m~nn~ as is known in the art. The cc ~L~nts of a multi-~,4.L,o ~nt ~PAlA~t composition may be separately pumped to the ejector body and mixed in a cnn~ t or mixing chamber therein prior to injection of the ~D~ t composition into the h~AA~p~e defined by the apparatus. Alternatively, the components of a multi--o~Lo..~nt C~AlAnt composition may be mixed externally of the ejector body and pumped thereto as a pre-mixed composition.
Typically, when the settable sealing composition is ~o--veyed to and out of the ejector op~ningS in the e;ector body and it subsequently sets, the ejector or~nin~s will be substantially hl ock~d thereby. Con~uently, cl~An~ng or complete replacement of the ejector op~nings~ generally requiring removal of the apparatus from the drain or pipe, will usually be nec~s~y before further repair operations can be carried out using the apparatus. Therefore, and particularly where difficult ~c~c~ to a pipe is experienced, an apparatus which can be used for several repair operations, one straight after the other, without removal from the pipe, is highly desirable.
Accordingly, it is preferable that the means for ~o--veying the settable seAl~ng - ition to the e~ector body is constructed and arranged such as to be controllAhle to allow the ~Al1ng oQ~ ition to be conveyable to a first group of one or more ejector op~ni~gs independently of at least one other group of ejector op~nings, preferably two, three, four or even more - other such groups of ejector openings, whereby when one or more of the e~ector openings of the first group become(s) blocked by set or partially set sealing compocition~ the means for ~o.. -v~lng the ~Al ~ng composition to the ejector or~n~gs can be reconfigured to an alternative arrangement wherein the S~Al ~ng ~ompo~ition is ~o..v~y~d to a non-blocked group of ejector op~nings, and a further repair operation can thus be carried out SUBSTITUTE S~EET (RULE 26) WosS/07433 ~ 2 1 7 0 6 2 0 PCTIGB94/01932 -straightaway without the need for removal of thè apparatus from the drain or pipe for r.l ~n~ ng or replacement of the e~ector op~.n ~ ngS .
In preferred practical embodiments of the apparatus of the invention, therefore, the means for ~v~ying the settable ~e~ g composition may comprise a separate supply line for each group of ejector op~n~ngsr each supply line and hence each group of e~ector open~n~s being ~n~penApntly and selectively conne~-table to the source of ~eAl ~ng composition by use for exzmple of a "pne~ tic ratchet", which may thus form part of the ng composition supply means. A preferred construction of such a pneumatic ratchet is described further herP-~nhplow in the context of a specifically described preferred ~hoA~ment of the invention.
A preferred embo~l~ent of the present invention, and in particular, preferred features of the various aspects thereof, will now be described in detail, with reference to the A ~ ying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure l is a part-sect~ on~l view of the principal constructional features of the preferred apparatus of the invention as it is being trans~uLLed into the ~u.~ position in a pip~l~ne requiring repair, ready for the repair process to begin;
Figure 2 is a part-sectional view corresponA~ n~ to that of Figure l in which the apparatus is in posltion for the repair operation to begin, the primary inflation sealing units having been actuated by inflation to seal the e~ector body in place in preparation for the next stage of the repair process;
Figure 3 is a part-sectional view correspon~g to that of Figures l and 2, showing the apparatus with the s~con~ry inflation unit having been actuated by inflation to close off and seal the ~n~nm~hg lateral side connection of the pipel~e, in which condition the apparatus is ready for the introduction of SUBSTITUTE SHEET (RULE 26) WO9S/07433 ' ' ~ 2 1 7 0 6 2 0 PCT/GB94/01932 sealant composition into the region(s) of the pipe defect;
Figure 4 is a part-sect~o~l vlew on an increased scale of the left-hand end section of the appara~us shown in Figures l-3, in which the pr~nC~pAl construct~on~l features shown there are illustrated in further detail;
r Figure 5 is an enlarged cross-sect~on~l view of a preferred fluid in~ection port via which th~ ~on~y inflation 8~Al ~ng unit of the apparatus is actuated by inflation and also via which se~l~nt composition is eJected from the body of the apparatus into the headspace surro~ g the e~ector body; and Figure 6 is an enlarged part-sect~n~l view correspo~ng to that of Figure 3, showing the preferred apparatus in position in a curved drain or pipe.
~ETAILED DESCRIPTION OF THE INVENTION AND ~K~K~ED EMBODIMENTS
Referring firstly to Figure l, a drain or pi~el~n~ 2, which will typically be cylindrical, has a lateral side drain or pipe co~n~ction 4 and in one or more of the illustrated regions 6 ad~acent to the junction of these two pipe sections, some form of damage or defect is present. TYP;CA11Y, cracking, or breaking away or even ma~or collapse or disintegration of the pipe wall at or near the junctlon with the lateral side qo~n~ction 4 will be the application to which the repair xyS~ of the present invention can be applied. The system is applicable to repair of the pipe walls in a region on one side only or on both sides of the lateral side ~-s~ne~tion 4 simultaneously. It is when damage or a defect of the drain or pip~l~ne has occurred in the region of a lateral side -o~n~ction, as illustrated here, that the prior art in situ repair systems face practical difficulties and it is to this application that the present invention is particularly, but not exclusively, directed.
The apparatus which is transported into the pipe 2 for positioning at the desired site of repair ~ , ises a tubular, preferably cyli~drical, ejector body lO which includes an inner core 20 ~u...~ising a closed coil spring 20a (Figure 4) surrounded SUBSTITUTE SHEET (RULE 26) W095107433 ; ~ 2 1 7 0 6 ~ O PCT/GB9~101932 by an intermediate stretnhAhle/resiliently fl~ hl e sheath 20b (Figure 4), for example of nitrile rubber, such that the core 20 is substantially rigid in the radial direction while being resiliently flexible out of the axial direction of the core, so as to be able to flex and deform as the e~ector body 10 Ll~v~.~es a bend in the drain or pipe 2. Surro~ln~ n~ the core 20 is an outer sleeve 22 in the form of a generally cont~nl~o~C tubular sleeve e~e"-l~ ng substantially over the whole length of the tubular body 10. The outer sleeve 22 is ~e~u~ely Ancho~ed to the core 20 at each of its ends, for example by ~ ve ho~n~, 1 ock~ ng rings or alternatively by any suitable form of invasive attachment between the two members. The outer sleeve 22 is generally of a fl~x~ hl e material such as rubber or other elastomer, so that it can be sub~ected to the required differential inflation along its longit~A~nAl length by the various inflation -s~ n~ units of the apparatus, as described further below.
The interior space within the tubular body 10 accommodates as much as is required of the various supply means, feed and control devices and any mixing apparatus which are used to supply compressed air to the various inflation units and ~AlAnt composition to the various ejector open~n~s le~ n~ to the exterior of the outer sleeve 22. These components are generally not shown in the Figures for clarity and will, in certain cases, be entirely ~u~ve~lt~onAl. End plugs 12 and 14 are conveniently provided at each end of the tubular body 10. One of these end plugs will generally include means by which the apparatus can be drawn or pushed along the pip~l~ne, for example, an eye for the attachment of a draw or push rod or cable, and the other of these end plugs will generally constitute a manifold for the r-o~nection to the above ment~ nn~ components of external compressed air andtor cAAlAnt composition supply means. The latter may, if desired, be provided by a separate unit introduced in the pip~l~ n~ along with the repair apparatus or may be supplied from above ground in a conventional ~-nne~.
Prior t~ insertion of the e;ector body 10 into the drain or pipe 2, the outer sleeve 22 is coated (or i,l,~Ley~ated in a SUBSTITUTE SHEET (RULE 26~
~ W095/07~33 ~ t~ 7 ~ ~ 2 0 PCT/GBg4/01932 pre-soaking step) with a rele~Q~ agent, e.g. MARLEASE 400 (ex Marbo). As shown by the arrow 100 in Figure 1, the e~ector body 10 is drawn or pushed into the pipe 2 until it rP~c~ec the longitl~Ain~l position shown in Figure 2, where the le~ng and trAi 1 in~ ends of the body 10 are disposed to either side of the damaged region 6 in the vicinity of the side co~n~ction 4. To assist ~AQs~e of the e~ector body along the p~r~l~ne during this posit~o~ n~ step, castors, ~'cel~ or other suitable rol 1 ~ n~
elements 27 may be provided at the ends of the e~ector body 10.
Towards each of the ends of the e~ector body 10 is provided one of a pair of primary inflation ~PAl ~ng units 30,32.
Each of these units is formed by an inflatable tube surro~n~ ng the core 20 of the e;ector body 10 rather like the inner tube of a vehicle tyre. Each of the primary se~l~n~ units 30,32 is shown in Figure 1 in its deflated condition (see also Figure 4 which shows one of these primary inflation -s~al~g units 32 in further detail in this deflated condition) and in their inflated condition in Figure 2. Each of the tubes forming the pair of primary inflation sP~l ~n~ units is situated in a space between the outer sleeve 22 and the inner tubular core 20, the two not being adhered or otherwise hon~ together in these regions. If desired, the upper and lower surfaces of the inflation units 30,32 may be ho~Pd such as by adhesive to the outer sleeve 22 and core 20 at the respective contact surfaces.
Each of the primary inflation c~l ;ng units is connected to a compressed air supply (not shown in the Figures) via respective ports 60,62 which may or may not themselves in~o-~olate valves, dep~ g upon the construction of the air supply hardware.
In the central region of the ejector body 10, in between the two primary inflation sealing units 30,32, is provided a single, c~OnAAry inflation s~ali~g unit 40 which is preferably inflatable and deflatable independently of the primary inflation Q~l ing units. In principle, the s~con~ry inflation s~al;~g unit 40 may be constructed and actuated in a similar ~qnner to the primary inflation s~ g units, except that instead of being SUBSTITUTE S)tET (RU~E 26) W095/07433 ~ 0 ~ ~ 2 1 7 0 6 2 0 PCT/GB94101932 situated in a gap between the outer sleeve 22 and the inner core 20, it is positione~ preferably in a cavity formed within the outer sleeve 22. This cavity may be formed as part of the integral construction of the outer sleeve 22, or it may be formed by a double-skin section of the sleeve formed by a patch-like attachment to the basic sleeve.
The function of the C~csn~Ary inflatlon S~Al ~ng unit 40 is to close off and seal the ~n~-s~g side ~onnection 4 of the pi~ ne and so the circumferential extent (relative to the e~ector body) of the se~on~ry inflation ~ ng unit i8 preferably only sufficient to fulfil that pUL~O~. It therefore does not need to extend around the whole periphery of the e~ector body and a bubble-like configuration is therefore typically the preferred form of se~-on~A~ry inflation sealing unit for most practical application. Of course, dep~n~ng upon the area of the pipe side ~onn~ction or the area re~uired to be ~lsC~ off and sealed during the repair process, any suitable size and shape of ~con~ry inflation R~Al ;ng unit may be employed within the scope of the invention.
The s~on~Ary inflation ~Al ~ng unit 40 is supplied for the purposes of its inflation by ~u,-~Lessed air via its own inlet port 70, which is fed and controlled independently of the ports 60,62 from which the primary inflation se~l~ng units are supplied. The construction of the ~e~on~ry inflation ce~l~ng unit's inlet port 70 is of a sp~ l form, as will be described in detail further below.
The central section 26 of the outer sleeve 22 between the primary inflation S~Al ~ng units 30,32 is not hon~ to the core 20 and there is thus formed beneath this central section 26 of the outer sleeve 22 between the primary inflation c~ n~ units 30,32 a cylindrical cavity 50 which constitutes a tertiary inflation unit. This tertiary inflation unit 50 is supplied, again preferably independently of the primary and S~on~Ary inflation units, by compressed air from an ~n~p~n~nt source via its own inlet port 80. This tertiary inflation unit 50 provides a means of altering the depth of the headspace outside of the SUBSTITUTE SHEET (RULE 26) WO9S/07433 ~ ` f ~ 2 1 7 0 6 2 0 PCT/GB94/01932 outer sleeve 22 between it and the walls of the pip~ e 2 and sealed off between the inflated primary inflation ce~l ing units 30,32. It is into thls headspace that c~al~nt composition will be ejected for the purpose of f~l1 ing the pipe defect or damaged area and thus by controlli~g the degree of inflation of the tertiary inflation unit 50, one is able to selectively control the depth of the headspace into which ~A 1 Ant will be pumped.
~ earing in mind that it is in the ~e-~L al section 26 of the outer sleeve 22 that the ~o~ y inflation C~Al~ng unit 40 iæ provided rA~i~lly outwardly of the tertiary inflation unit, for efficient operation of the Cp~on~ry inflation ~Al ~ng unit lt is preferred that the central region 26 of the outer sleeve 22 is constructed so that upon inflation it does not tend to bulge raAi~lly outwardly, but maintains a predominantly cylindrical configuration as it is inflated or deflated. This behaviour may be achieved by a~ro~Liate construction of the sleeve 22, for example by providing the ~e~-Llal section 26 with in-built reinfo ~ t or alternatively by internally or externally hnn~
constriction rings or the like. With this kind of construction, the end sections 24 of the outer sleeve 22 either side of the central section 26 are preferably not provided with any such reinforcement or constriction means, so that these sections of the outer sleeve 22 are in~PPA able to configure th~mCPlves somewhat convexly upon inflation of the primary inflation QP~l in~
units 30,32, SO that they form efficient seals against the inner pipe wall around the periphery of the apparatus.
A plurality of injection ports 140 are a ~l-yed in the central section of the apparatus in between the primary inflation ~ ng units 30,32 and it is these which form ejector op~n~ngs via which ~ a~t l_ osition is pumped from within the e~ector body lO to the outside of the apparatus into the headspace formed between the central region 26 of the outer sleeve 22 and the inner pipe wall once the various inflation s~l ing units have been actuated.
Preferably a plurality of the ejector opPnings 140 are arranged in a plurality of groups, each of which group is SUBSTITUTE SHEET (RULE 26) W095/07433 i~ ; 2 1 7 0 6 2 0 PCT/GB94101932 selectively and ;n~r~ntly connectable to the c~
composition supply means outside the apparatus. Any number of injection ports 140 may be provided in each group, but preferably a sufficient number are provided in an ~y~ ~ late distribution such that the ease and speed with which Q~l ln~ composition i8 pumped into the headspace to completely fill the pipe defect are optimised. The Figures show schema~lc~lly ~ust one pocs~hle arrangement of in~ection ports 140, namely an arrangement of at least two banks of such in~ection ports ~pAne~ from one another in the longit~ 1 direction of the apparatus and each bank comprising at least two, and preferably three or four or even more, in;ection ports evenly spaced from one another circumferentially around the e;ector body 10.
As already men~io~e~, the ceAlAnt composition in~ection ports 140 and the compressed air inlet port 70 of the s~Con~ry inflation ~ g unit 40 have in common that they are required to deliver fluid to a given cavity from a respective supply means which is separated from that given cavity by a se~on~ cavity, namely the tertiary inflation unit 50. During inflation of the tertiary inflation unit 50, there is relative movement between (i) the wall separating the given cavity (i.e. the headspace outside the outer sleeve 22 or the inflatable cavity forming the ~econ~y inflation s~ ng unit 40, as the case may be) and the cavity 50 of the tertiary inflation unit, and (ii) the wall (i.e.
the core 20) separating that tertiary cavity 50 and the interior of the ejector body 10 which accommodates the respective fluid supply means. For this reason, a spPc~l construction of port is preferable for the ports 140 and 70 and a preferred construction of such a port which constitutes a further aspect of the present invention will now be described with reference to Figure 5 of the drawings.
Figure 5 in fact shows a preferred port which forms one of the S~Al ;ng composition injection ports 140, but the compressed air inlet port 70 is of a correspnn~ ng construction.
The device comprises two principal cc ~po,~ents:
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Firstly, there is a conduit 142 which is in fluid SUBSTITUTE SHEET (RULE 26~
W095/07433 ~ 21 i 3 6 2 0 PCTIGB94/01932 communication at its lower end with the respective fluid supply and at its upper end terminates in a head piece 143 which is situated within the cavity into which the fluid is to be supplied, in this part~ r.~ r case this being the exterior headspace formed between the outer ~leeve 22 and the defective region 6 of the Pir~l ~n~ 2. In between these two extremities of the ~on~t~it 142, it L~avæ ~es the cavlty 50 of the tertiary inflation unit and penet~ates both the partit~o~g wall 22 (i.e.
the outer sleeve 22) which separates the tertiary cavity 50 ~rom the outside and also the partit~on~ n~ wall 20 (i.e. the inner core 20) which separates the tertiary cavity 50 from the interior of the ejector body 10. The upper end of the ~on~u~t 142 is held fast with the outer sleeve 22 by virtue of lock washer 148 which itself is clamped by piston tube 144 which is engaged for example, with screw threads on the exterior of the con~ t 142.
Thus, the piston tube 144 clamps the sleeve walls between the lock washer 148 and the h~A~p~ece 143. This fixing is sealed to ~e~e.lt leakage of fluid through the hole in the outer sleeve 22 by means of flanged s~ n~ washer 145. Thus, the upper end of the co~ t 142 is fast with the outer sleeve 22 and moves with it upon inflation or deflation of the tertiary cavity 50;
~ on~ly~ there is a the bush 146, for example of phosphor bronze, which is fitted into an aperture in the inner core 20, for example by screw threads or any other suitable mounting means, and the piston tube 144 which surrounds the conduit 142 pA-cs~s through this bush 146 into the interior of the e~ector body 10. The bush 146 is ~itted with a rubber seal 149, which is preferably an "0"-ring, so that whilst the piston tube 144 is slidable within the bush, there is a seal formed between the respective .cl i~lng surfaces in order to prevent leakage of fluid between the tertiary cavity 50 and the interior of the e~ector body 10.
Thus, upon inflation or deflation of the tertiary cavity 50, the elongate section of the conduit 142 slides in a piston-like manner within the bush 146~ A shoulder 147 may advantageously be provided on the exterior of the piston tube 144 to act as a stop against the lower face of the bush 146, thereby SUBSTITUTE SHEET (RULE 26) limiting its upward travel and thus defining a maximum inflation displacement of the sleeve 22 with respect to the metal core 20.
The lower end of the conduit 142 is mounted in a base 154 which provides connecting means for coupling to the respective fluid supply via access port 150.
Advantageously, this preferred construction of the injection port is simple enough to allow it to be readily dismantled and removed from the apparatus for cleaning, etc, as and when required, which may typically be after each repair operation. The parts of the device can simply be unscrewed from each other and the conduit removed for cleaning, and subsequently it is easy to reassemble the port in the same simple manner.
Referring now to Figure 4, this shows diagrammatically in slightly greater detail the construction of one end of the ejector body 10 and in particular the spacial relationships between the various components of the primary inflation sealing unit 32 and the neighbouring parts of the apparatus. Towards the right-hand side of Figure 4 is seen one of the sealant material injection port 140. The conduit 142 leading to the outside is connected at its lower end via base 154 to a respective supply conduit 88 through which the sealant composition, preferably a multi-component sealing composition which is supplied to the supply conduit 88 in a pre-mixed state, passes prior to ejection through the injection port 140 into the headspace surrounding the ejector body where the pipe repair is to be effected. Known means may be employed for coupling the respective supply conduits 88 with the necessary sealing composition supply line or lines via manifold 90.
In the preferred construction shown Figure 4, it is desirable for there to be a flexible connectio, e.g. by a length of flexible hose, between the supply conduit 88 and the injection port 140 (or constituting the supply conduit 88), because the latter moves relative to the ejector body core 20 as the tertiary inflation unit 50 is inflated or deflated, so such a flexible connection prevents any hindrance to such movement of the port WO95/07433 '~ 2 1 7 ~ 6 2 a PCTIGB94/01932 140.
The in~ectlon ports 140 in the apparatus are arranged in groups, each group having an ~n~ep~ t supply ConAl~t 88 such that the c~ n~ composition may be pumped from its source to each group of injection ports 140 ~n~p~nApntly and selectively.
The source may be selectively conn~cted to each of the supply co~A~l~ts 88 using a pneumatic ratchet. Such a device is already known in the art in various forms in the ~.ele~ and related arts and essentially allows for selectiv~io~ ~Lion of a fluid supply ~o~,~e to one of a plurality of outlets, each of which is co~nectable to a given supply co~A~t 88 supplying a part~Cl~
group of ejector op~nings 140 in the apparatus. Examples of constructions and operations of such devices are well described in the patent and ~chn1 C~ 1 literature, and will be readily av~lAhle to pe ~GllS skilled in the art. In one preferred form, however, two hoses supplying the two ~ .L~,ents of the preferred ng composition are ~-onnected to a stat~on~ry plate with a ~e~ e shaft e~ ng to another stat~onAry plate approximately 60mm apart. The C~o~A stationary plate has conne~tions for attachment to the plurality of ~Y~ng ~-on~ t outlets and is removable from the centre shaft by means of for er~ a screw thread. Between the two plates is a revolving section whose bearing is mounted on the centre shaft. On the first stationary plate are a plurality of stops in the form of teeth and the revolving section contains a pn~ tic plunger which, after one in~ectionr will withdraw sufficiently to pass over the first index stop. Compressed gas, e.g. air, will then spin the revolving section. Once the plunger has p~Cs~A over the first ~ndex stop, the gas supply is automatically shut off, hence forcing the plunger out. This will then stop at the next index tooth. The two components of the composition will pass separately through the first plate and the revolving section, meeting only where the ceco~A plate and revolving section interface.
The overall repair process using the apparatus of the invention may `be repeated up to for example a maximum of approximately six repair cycles, since the release agent used to SUBSTITUTE SI~EET (RULE 26) W095/07433 ~ 5~ 2 1 7 0 6 2 0 PCT/GB94/01932 prohibit the sealant resin adhering to the outer sleeve 22 will generally no longer function subsequent to that number of repair operations.
The operation of the above described apparatus for effecting repair of the defective area or areas 6 of the drain or pipe 2 will now be outl ~n~, though this will to a large e~L~
already be clear from the foregoing descrlption of the apparatus.
Initially, the e~ector body 10 (with releAs~ agent already applied to the outer sleeve 22) is drawn or pushed into the pipe 2 to such a position that its l~A ~ ng and tr~l1ng ends 12,14 straddle the defect 6 and ~ nCQ~ ng side ronn~tion 4 combination. This lateral positioning is shown already completed in Figure 2.
Next, the pair of primary inflation s~ g units are inflated, preferably together, but not nec~cc~ily so, so as to form inflated end c~ ng rings 24 at each end of the ejector body 10. Each of these end c~ ng rings, as illustrated in Figure 2, forms a circumferential seal against the intact (i.e.
undamaged or undefective) inner wall of the pipe 2 so as to define between them a cylindrical cavity ad~acent to the damaged or defective region or regions 6.
If desired, the tertiary inflation s~ ng unit may also be inflated to reduce the depth of the headspace into which the s~lAnt composition is to be in~ected.
In order to seal off that cylindrical headspace cavity from the lateral pipe side ~o~nection 4, the C~con~ry inflation c~l~g unit 40 is now inflated into the configuration aq shown in Figure 3. The bubble-like inflated cavity 40 cloces off and seals the lateral side connection 4 from the main drain or pip~ 2 and therefore now completely seals the generally cylindrical headspace cavity between the outer sleeve 22 and the inner wall of the pipe 2 between the inflated end seal rings 24.
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The apparatus may be used to repair damaged sections in SUBSTITUTE SHEET (RULE 26) W095/07433 ~ 2 1 7 0 6? o PCTIGB94l01932 both straight pipes, e.g. as shown in Figures l to 3, and curved pipes, e.g. as shown in Figure 6. In Figure 6, like parts as in Figure 3 are identified with like reference numerals.
With the apparatus in the fully ~ n~ condition as shown in Figures 3 or 6, the sealant composition, which can be of conventi~nAl type, e.g. single com~G--e--~ or (more preferably) multi-com~onen~ (e.g. epoxy re~in plU8 hardener), can now be pumped through the multiple walls of the apparatus via a s~ ngl e group of in~ection ports 140, ln~eren~ntly selected by the pneumatic ratchet, into the headspace cavity between the outer sleeve 22 and the pipe defect region or regions 6. The s~ nt composition is forced into the defect(s) and is allowed to partially set so as to be able to maintain its shape before the next sta~e of the process.
Once sufficient setting of the ~ nt co~pn~;tion has taken place, the various inflation units of the apparatus can be at least partially deflated and the e~ector body removed from the repair site, this being assisted by the r~lp~ce agent. Rather than comrlete removal, however, it is poc-s~bl~ within the scope of the invention for the apparatus to be tranY~olLed incrementally along the pipeline to effect multiple repair operations at ad;acent sites, for example where a particularly large section of pireline requires repair. Each step of such an incremental repair process can be carried out individually in the manner just described with the addit;onAl step of co~ne~ting the ~Al~t composition source to the supply line of a clean group of in~ection ports between each incremental repair step, by means of the pne~ tic ratchet.
As is known in prior art in situ pipe repair systems, reaming apparatus may be employed either before or after, or even both, the repair operation, in order to on the one hand clear the pipe of debris for example and clean the repair site ready for the repair operation and on the other hand for removing ~xc~ss seAl~t material, or cleAning or polish;ng it, following the repair operatioh. Suitable r~ ; ng apparatus is well known in the art, for example in GB-A-2122300, so will not be described SUBSTITUTE SHEET (RULE 26) ~ ~ ~ r ~
W095/07433 ~ 2 1 7 0 6 2 0 PCT/GB94/01932 further here.
The preferred embodiments of the various aspects of the ev~lt invention described above are by way of example only and it will be appreciated by those ~k~ 11 e~ in the art that many variations and modifications can be made to what has been specifically described within the scope of the present invention as ~ e~.
SUBSTITUTE SHEET (RULE 26)
FIELD OF THE INVENTION
This invention relates to the repair of drains and pip~l;nec, esrer~ y those which are located undelyLou~d or oc~ in surro~lnAIng material, such as concrete, and int~n~
to cc--vay fluids such as potable water, waste-water, certain semi-solids, solids susp~e~ in fluids, or gases. More particularly, the invention concerns an apparatus and method for the in situ repair of drains and pipel~n~ where damage or defects have occurred in close proximity to incoming lateral drain or pipe conn~r-tions.
BACKGROUND OF THE INVENTION AND PRIOR ART
For quite a number of years there have been known various devices for in situ repair of underground drains, pip~ c or the like. Convent;o~lly~ a carriage would be drawn or pushed into the drain or pip~l; n~ to reach the site at which repair was nee~A, and then a 8~Al ~ng el~ - t would be expanded r~A;~lly outwards so as to contact the pipe at each side of the leak, for example, and liquid grout would then be pumped to an outlet in the carriage so as to flow into the damaged region and form, once set and hardened, an effective sealed repair of the inner drain or pipeline wall.
In order to make it posc;hle to ut~l;C~ this basic idea for the repair of drain or pipel~n~ defects which are of substantial size, GB-A-2122300 proposes the employment of a tubular ejector body which is sited at the desired location in the drain or pip~l~ne and has a plurality of e~ector op~ni~gS
therein out of which sealant ._c ~lo~ition is pumped to fill the defect. The ce~l~nt rnmrocition is cont~i n~ at the required location over a limited length of the drain or pipeline by inflation, e.g. by ~,..~lessed air, of respective ~ ng rings disposed around the e~ector body at or near each of its ends.
Once the drain or pipeline defect has been filled and has been allowed to partially set, the se~ g rings are deflated, thereby allowing the ejector body to be removed from the repair site and SUBSTITUTE SHEET (RULE 26) -WO9S/07433 ; ~ ~ '~ 2 1 7 0 6 2 0 PCT/GB94/01932 full setting and har~ni ng of the sealant composition to take place, thus completing the repair of the drain or pip~l~nQ.
Reaming of the pA~Ageway before and/or after the repair has been effected may be carried out in order to enhAnce the ~uality and finish of the ~ob.
Prac~cAlly speAk~ng, the apparatus required to effect the above method of drain or pipe repair is relatively complicated and ~Yppncive and h~CAllce of the somewhat crude way in w~ich the ceAl~t composition is put in place at the site of the defect, the resulting accuracy and efficiency of the repair i8 not always as good as many types of practical application demand.
As an i,..~Lo~F - t to this known ~L~al, therefore, GB-A-2169983 proposes an apparatus and method for in situ drain or pip~l1ne repair, still based on the idea of employing an e~ector body which is drawn or pushed into the drain or pip~l~ne to the ~G~ location and providing a plurality of outlets through which ~lAnt composition is pumped to fill the defect, but in which the e;ector body is constructed such that it comprises a sleeve of flexible material which is uns~oL~ed internally along its length and has, between its ends, an intermediate portion wherein the ejector op~n~n~s are provided. The intermediate portion has less ext~slhility than the end portions on either side, so that for a given inflation pressure, a smoothly ~,lLoured inflated pressure sleeve is created whose end regions are more outwardly inflated than its central region, so that it seals the e~ector body against the intact walls of the drain or pip~l~ne either side of the defect and leaves an ~nnlll Ar gap around the central region of the e~ector body into whlch the S~Al Ant composition is pumped to fill the defect which i8 arranged to be located in that AnnlllAr cavity. EP-A-0259518 discloses a similar system to this, ùt~l~si ng much the same principle.
These known in situ pipe repair apparatuses and methods generally perfo~m satisfactorily where the damage or defect has occurred in a straight portion of the drain or pip~l~ne where SUBSTITUTE SHEET (RULE 26) W095/07433 ; - ~ 2 1 t ~ ~ 2 0 PCT/GBg4/Ul932 there is a substantially continuous pipe inner wall against which the various se~ g elements of the apparatus can abut and seal to generate the n~cpss~ry cl o~ region lnto which the -s~ nt composition can be pumped. Even if pipe damage exists over a wide area or along a relatively long section of pipe, s~-c~ful repair using these known systems is still po~C~ , as one can simply employ an e~ector body of increased length, for example.
There is, however, a problem A~o~Ated with these known systems, and that is when the pipe damage or defect has occurred at or near the ~unction of the main drain or pip~l~ne with an incoming lateral drain or pipe conn~Gtion. When the known apparatu~ is used to repair a defect in such a position, it is difficul~, if not impossible, to effect ~Lo~e~ repair of the damaged area by application of the sealant ~ tion to it without the incoming lateral con~ection itself becoming filled or blocked with the ~ Ant material. As will be appreciated, it can be extremely difficult and time-consuming to drill out such a lateral con~cting drain or pipe after repair of the main pip~l~ne is completed, but hitherto this has often been inevitable when the known systems as described above are ut~
for repairing damaged areas of pipe at locations in the n~ighho-lrhood of incoming side pipe ~o~ne~-tions.
Xt would be advantageous, therefore, if one was able to employ the ideas embodied in the above known pipe repair apparatuses and methods at damaged sites located in close proximity to ~nco~ ng lateral conn~ctions, but without the problem of the latter I h~ ves becoming filled or contaminated with the se~l~nt material with which the main drain or pipe defect is repaired.
SUMMARY OF THE INVENTION
Wlth this ob~ect in view, the present invention provides, in a first aspect, an apparatus for use in repairing a defect in a drain or pip~l~ne at or near a ~unction with a lateral drain or pipe ~-o~n~tion, the apparatus ~...~llsing:
a tubular e;ector body adapted to enable it to be drawn SUBSTITUTE SHEET (RULE 26) WO95/07433 , ~ . 2 1 7 0 6 2 0 PCT/GB~4/~1932 or pushed into the drain or pipeline to such a position that a 1 ~A~ ing end and a trAil~ng end of the body are disposed respectively to one side and the other side of the defect and lateral co~n~r,tion combination;
a pair of primary inflation ~ling units at or near the respective ends of the tubular body and which, when they are both inflated, seal the body against the drain or pir~l~n~ inner wall on each of the sides of the defect and lateral connection combination;
a C~cond~y inflation s~ ng unit situated between the primary inflation ~eAl~ng units and which, when it is inflated, substantially clocec off and/or seals from the main drain or pipeline the ~unction therewith of the lateral drain or pipe ~onnection; and means for ~o-~veying a settable s~ ng composition from within the tubular body to and out of at least one, preferably a plurality of, ejector op~nings in the body between the primary inflation ~A l~ng units and the -c~con~y inflation 5~1~ng unit, for forming, when set, a seal repair of the drain or p1pel1ne defect without a blo~k~ng of the junction with the lateral drain or pipe ~o~ection.
In a c~Qn~ aspect of the present invention, there i8 provided a method of repairing a defect in a drain or pi~ ne at or near a ~unction with a lateral drain or pipe conn~tion~ the method comprising:
drawing or p~sh~ng into the drain or pipel~ne a tubular e~ector body to such a position that a 1~A~ing end and a tr~ling end of the body are disposed respectively to one side and the other side of the defect and lateral conne~tion ~om~i n~tion;
inflating a pair of primary inflation ssAling units at or near the respective ends of the tubular body so that the body is sealed against the drain or pipeline inner wall on each of the sides of the defect and lateral co~nection combination;
inflating, either before, at the same time as or after the inflation of the primary inflation ~eAl~ng units, a s~co~A~y inflation ceAl ing unit situated between the primary inflation ling units, so as to substantially close off and/or seal from the main drain or pipeline the junction therewith of the lateral SUBSTITUTE SHEET (RULE 26) WO95/07433 '~ ?~ 2 1 7 0 62 0 PCT/GBg4/01932 drain or pipe conn~ction;
~ os-v~ylng a settable s~ ng comrosition from within the tubular body to and out of at least one, preferably a plurality of, e~ector op~ngs in the body ~etween the primary inflation s~Al~ng units and the cP~o~Ary inflatlon ~e~l~n~ unlt so that the composition is e~ected into the draln or pir~l~ne defect; and prior to complete setting of the ~ n~ composition but whilst it is in a coherent condition, diSpl~ n~ the eJector body along the drain or pipPl~ne, preferably ~lheP~uent to deflating at least the ~e~on~Ary inflation c~ ng unit and preferably also the pair of primary inflation sPAl~ units.
In a third aspect, the present invention provides a drain or pip~l~ne which has been repaired by the above-defined method or by use of the above-defined apparatus.
The PC~ce of the present invention, therefore, as presently contemplated in its broadest sense, lies in the modificatior. of the more recently generally known in situ pip~l~ne repair ~y~ell-s to include a cPcon~Ary~ preferably ~n~ n~ntly inflatable, inflation S~Al ~g means which acts to close off (or substant-ially so) and preferably also seal the ~unction of the incoming lateral drain or pipe ~o~ne~tion with the main drain or pipeline, thereby enAhl ~ng the region of the main drain or pipPl ~ n~ at or near the side ~onnection, where the defect is situated, to be repaired in a manner si mi l Ar to that which is already known, but without blo~k~ng that side co~n~ction where it ~oins the main pipe. Most i p~ Lantly, the ~y-L~ of this invention obviates the need for dr~ ng out of the incoming side ~onne~tion once the repair is complete, as would generally be required if the ~.,v~..t~onAl -y~L s were to be used in the repair of the particular sited defects with which we are here co~erned. Employment of this invention may also improve the overall quality and finish of a repair ~ob carried out on a defect in the neighbourhood of an ~ ncn~ ng drain or pipe side co~n~rtion, given the complete or substantial absence o ingress of ceAlAnt material into the side ~onn~tion and of build up of s~AlAnt composition around the edges of the co~n~tion junction.
SUBSTITUTE SHEET (RULE 26) W095/07433 ' ~ ~ ' 2 1 7 0 62 0 PCT/GB94101932 ~
In preferred ~ ho~ents of the apparatus of the invention, the primary inflation s~ ng units extend around the full circumference of the ejector body, so that when inflated they assume an ~nn~ r cross-section and seal the body against the inner wall of the pipe all the way round.
On the other hand, ho.ev~., the ~ A~Y inflation 8~ ng unit preferably eh Le~dS over only part of the ejector body circumference, and most prefe~ably it takes the form of an inflatable bubble which, upon inflation, presents a surface area sufficiently large to substantially close off and seal the incoming drain or pipe side ~onn~rtion~ generally with at least a small extension all the way round past the ~unction so as to ensure a good ~ ng action. It is, however, within the scope of the present invention for the c~on~y inflation c~ ng unit to have a similar circumferential s~ ng ring configuration like the primary inflation c~l ing units, for example in the case where application of ~e~llng composition to the damaged drain or pipel ~n~ iS to be restricted to a narrow region to one side only of the lateral pipe ~o~n~ction junction.
The tubular ejector body of the apparatus preferably comprises an outer cylindrical sleeve which is rec~l~Pntly flexlhle so as to permit r~ ly outward ~Yp~ncion thereof into c~llng contact with the inner wall of ~he drain or pip~line upon inflation of the primary inflation s~l lng units. Each of these primary inflation sealing units may be constituted by an ~nn~ r (or short cylindrical) cavity formed within the sleeve wall towards the ends of the ejector body or, more preferably, each may be formed by virtue of a cylindrical section of the fl~Y~hle sleeve not being hon~ to an inner tube forming the core of the ejector body, as are portions of the sleeve which are not required to be ~yp~ncible outwardly from the core, e.g. the ends of the sleeve. The s~con~y inflation s~ g unit is preferably constituted by a cavity formed within the outer sleeve wall between the primary inflation s~Al~ng units. For the purpose of assisting correct outward ~Yp~ncion of the flex$ble sleeve to form the primary c~ ng rings at each end of the ejector body, the sleeve wall may, if desired, be constructed SUBSTITUTE SHEET (RULE 26) W095/07433 ~ ~ C 2 1 i 0 6 2 0 PCT/GBg4/01932 with a~Lu~ iate internal reinforcement or, alternatively, hond~
constriction rings to the outer and/or inner walls thereof in the regions where lesser extens~ h~ l~ty is required.
In one, less preferred embodiment of the apparatus of the invention the inner tube forming the core of the e~ector body is a rigid tube, e.g. a unitary steel (~srec~Ally st~nlesR ~teel) tube. In more preferred embodiments, ho. v~, the core comprises a tubular body which ls rPc~l~e~tly fl~Y~hl~, so as to ~n~hle it to deform and bend to assume a ~lved shape. This ~n~hl es the e~ector body to conform to deviations or bends in the drain or pipeline. Most suitably, for this ~L~osæ a most preferred ejector body core comprises a clocp~ coil spring, esp~c~Ally a hel~rAl closed coil spring, which preferably has formed around it a stretchable intermediate sheath which conforms to the outer shape of the core as it passes through the drain or pip~l~n~.
The shea~h is preferably made of rubber, e.g. nitrile rubber (which is particularly suitable for repair applicatlons involving pipes which oonv~ fuel gas) or natural rubber, and is preferably constructed and arranged so as to have a desired hardness and/or fl~x~b~lity ~ep~n~ng upon the degree of c~All~ required of the apparatus against the pipe or drain to be repaired and the amount of flexible deformability re~uired of the core. Generally speaking, bends in the drain or pipe of up to about 90 may be accommodated by use of this coil core with rubber intermediate sheath feature of the apparatus.
~ n a partic~ rly preferred ~-ho~ment of the apparatus of the invention, there is further provided a tertiary, ~n~er~n~nt inflation unit between the primary inflation c~Alin~
units and r~ lly beneath the s~con~Ary inflation S~Al ~n~ unit which is also situated between the primary inflation c~l ln~
units. The tertiary inflation unit is preferably constituted by an independently inflatable cavity beneath that which forms the ~on~A~y inflation s~Alin~ unit, i.e. between the central re~ion of the flexible outer sleeve and the inner tubular core of the e~,ector body and bounded on each side by the pair of primary inflation Ci~Al ~in~ units. The action of the tertiary inflation units is such that when it is inflated, there is a reduction in SUBSTITUTE SHE~T (RULE 26) WO95/07433 ~ ~ 2 1 7 0 6 2 0 PCT1GB94/01932 the depth of the headspace formed between the primary inflation 8~ n~ units and into which the SeR 1 ~ ng composition is pumped for the purpose of repairing the drain or pipe defect. In other words, inflation of the tertiary inflation unit r~ ~c the difference in diameter between the inflated primary inflation ~l 1n~ units constitut~ng the ~ ng rings at each end of the e~ector body and the central region of the flD~hl~ outer sleeve between the end s~ g rings. Inflatlon of the tertiary inflation unit, therefore, results in a reduction in the th~r-knecc of C~ ng composition e~ected from the body into the cavity defined between the primary inflation s~ ng units. This leads to a reduction in the amount of se~lAnt material used to repair a given area of defect and also means that once it is set and hardened, the se~l~ng material of the repaired site ~Lu~L~des less into the interior of the drain or pipeline, thereby re~ ng the n~ceC-~Ary extent or even need for post-repair reaming and giving an overall better finish to the repaired site.
As a means of controlling the r~ ly outward Pxp~nc~o~
of the section of wall of the cavity forming the tertiary inflation unit such that the wall remains substantially cylindrical, a~L~Liate internal reinforcement or outer and/or inner hon~ constriction rings may be employed, as already men~nne~ but in a different context. The cavity forming the tertiary inflation unit is preferably of ~nn~ r cross-section, such that it extends around the whole circumference of the e~ector body beneath the cavity into which the c~ n~
composition will be pumped.
In the apparatus of this invention, inflation of the various inflation units may be achieved by use of any suitable pressure medium, but is preferably cG...~Lessed air. Entry ports to each inflation unit can be conn~cted up and the supply of compressed air to all or any of them controlled by convent~ O~A 1 means, as will be known already in the art in the context of the prior art in situ pipe repair apparatuses described her~;n~hove.
It is preferred that both of the primary inflation s~l ~ng units are inflatable together, in which case they may be supplied and controlled by a common source, but it is preferable that the SUBSTITUTE SHEEr (RULE 26) ~ W095/07433 ~` ; ~ ` 2 1 7 ~ 6~2 0 PCTIGB94101932 c~s~y inflation s~l ing unit and the tertiary inflation unlt are both inflatable ~nd~p~n~ntly of each other and of the primary inflation $~ g units.
One exception, ho~e~, to the convent~o~l nature of the compressed air entry ports of the various inflation units of the apparatus is that in embodiments where the tertiary inflation unit is present, the entry port fee~i n~ the lnflation cavity of the Q~CO~Ary inflation c~ling unit ls preferably constituted by a special in~ection port which is constructed to allow supply of compressed air from inside the ejector body into the s~con~y inflation cavity independently of the degree of expansion of the cavity formed ther~h~neAth which constitutes the tertiary inflation unit and across which the compressed air supply duct for the sp~on~ry inflation cavity must therefore traverse.
This same requirement is true of the in~ection ports via which sealant material is ejected from within the ejector body into the ra~ially outer cavity against the inner wall of the drain or Pir~l i n~ under repair. Essentially, therefore, whilst compressed air injection ports for the primary and tertiary inflation units can be of known type, it is esp~c~ y preferred in practical embodiments of the preferred apparatus of the present invention that the compressed air inlet port of the c~CQn~ry inflation se~l Ing unit and each of the c~ n~
composition in~ection ports constituting the above defined e~ector op~ni~gs are all siril~ly constructed in accordance with what is a further definable aspect of the present invention, as will now be defined.
Accordingly, this invention also provides a fluid injection port for passage of fluid from a supply means to a first cavity across a C~con~ cavity which separates the first cavity from the supply means, the injection port ising co~ ;t means in communication with the fluid supply means and ext~ing across the second cavity and into the first cavity, the cQn~ t terminating in a headpiece fast with the wall separating the first and C~con~ cavities, and bush means fast with the wall separating the s~on~ cavity rom the supply means and through SUBSTITUTE SHEEr (RULE 26) , WO95/07433 ~ t'~ 2 1 7 0 6 2 0 PCT/GB94/01932 which the ~on~l~;t means extends and is sl 1 ~hl e with respect thereto, the bush means including ~ n~ means which forms a seal against the conduit means as it Q~ Q relative thereto, whereby inflation or deflation of the ~C~n~ cavity CAll~
piston-like cl~ng of the co~ t means through and with respect to the bush means, and whereby communication between the fluid supply means and the first cavity i8 maint~nAhle tn~p~ tly of the degree of inflation or deflation of th~ ~co~ cavity.
Thus, in the context of the preferred apparatus of the primary ob~ect of the present invention as defined above, ;c~tion between the supply of _ ,Lessed air or C~ nt composition, as the case may be, with, respectively, the cavity of the s~con~y inflation sealing unit and the external headspace region between the primary inflation ~e~l~ng units into which the sealant composition is to be ejected is preserved regardless of the degree to which the tertiary ~n~pe~nt inflation unit is inflated or deflated for the ~ e of altering the depth of that headspace surro~nA~ng the central region of the e;ector body.
A preferred construction of fluid in~ection port of the above defined aspect of the present invention will be described in detail further below in the context of an overall preferred embodiment of the apparatus of the present invention.
In practical embo~;~onts of the invention, to ~L~V~-~t the q~ ng composition bon~ng to the outer sleeve of the e~ector body during the repair process as the ~omro~ition sets and before the apparatus is ~ .ved from the repair site, there is preferably employed a release agent which is applied to at least the outer surface of the outer sleeve prior to the repair process being commenced. Suitable release agents are well known in the art and include for example oil-based or silicone-based rP~
agents such as MARLEASE 400 ex Marbo. The rPl~c~ agent may be applied by brush or spray to the sleeve before insertion of the apparatus into the pipeline to be repaired or may alternatively be impregnated into the sleeve material in a pre-soaking step, dep~n~;ng for example on the type of r~ C~ agent used.
SUBSTITUTE S~IEET (RULE 26) W095/07433 ~ r~! 2 i 7 0 62 0 PCT~GBg4~0l932 In practical e-ho~i~^nts of the apparatus of the invention the sealant com~poq~tion, which can be of a conventional type, e.g. single component or more preferably multi-component, (e.g. a resinous compound, such as an epoxy resin, and a hardener) is pumped from a ~o~L~e to the e~ector body through a supply line or lines using convent~snAl apparatus and in a conventional m~nn~ as is known in the art. The cc ~L~nts of a multi-~,4.L,o ~nt ~PAlA~t composition may be separately pumped to the ejector body and mixed in a cnn~ t or mixing chamber therein prior to injection of the ~D~ t composition into the h~AA~p~e defined by the apparatus. Alternatively, the components of a multi--o~Lo..~nt C~AlAnt composition may be mixed externally of the ejector body and pumped thereto as a pre-mixed composition.
Typically, when the settable sealing composition is ~o--veyed to and out of the ejector op~ningS in the e;ector body and it subsequently sets, the ejector or~nin~s will be substantially hl ock~d thereby. Con~uently, cl~An~ng or complete replacement of the ejector op~nings~ generally requiring removal of the apparatus from the drain or pipe, will usually be nec~s~y before further repair operations can be carried out using the apparatus. Therefore, and particularly where difficult ~c~c~ to a pipe is experienced, an apparatus which can be used for several repair operations, one straight after the other, without removal from the pipe, is highly desirable.
Accordingly, it is preferable that the means for ~o--veying the settable seAl~ng - ition to the e~ector body is constructed and arranged such as to be controllAhle to allow the ~Al1ng oQ~ ition to be conveyable to a first group of one or more ejector op~ni~gs independently of at least one other group of ejector op~nings, preferably two, three, four or even more - other such groups of ejector openings, whereby when one or more of the e~ector openings of the first group become(s) blocked by set or partially set sealing compocition~ the means for ~o.. -v~lng the ~Al ~ng composition to the ejector or~n~gs can be reconfigured to an alternative arrangement wherein the S~Al ~ng ~ompo~ition is ~o..v~y~d to a non-blocked group of ejector op~nings, and a further repair operation can thus be carried out SUBSTITUTE S~EET (RULE 26) WosS/07433 ~ 2 1 7 0 6 2 0 PCTIGB94/01932 -straightaway without the need for removal of thè apparatus from the drain or pipe for r.l ~n~ ng or replacement of the e~ector op~.n ~ ngS .
In preferred practical embodiments of the apparatus of the invention, therefore, the means for ~v~ying the settable ~e~ g composition may comprise a separate supply line for each group of ejector op~n~ngsr each supply line and hence each group of e~ector open~n~s being ~n~penApntly and selectively conne~-table to the source of ~eAl ~ng composition by use for exzmple of a "pne~ tic ratchet", which may thus form part of the ng composition supply means. A preferred construction of such a pneumatic ratchet is described further herP-~nhplow in the context of a specifically described preferred ~hoA~ment of the invention.
A preferred embo~l~ent of the present invention, and in particular, preferred features of the various aspects thereof, will now be described in detail, with reference to the A ~ ying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure l is a part-sect~ on~l view of the principal constructional features of the preferred apparatus of the invention as it is being trans~uLLed into the ~u.~ position in a pip~l~ne requiring repair, ready for the repair process to begin;
Figure 2 is a part-sectional view corresponA~ n~ to that of Figure l in which the apparatus is in posltion for the repair operation to begin, the primary inflation sealing units having been actuated by inflation to seal the e~ector body in place in preparation for the next stage of the repair process;
Figure 3 is a part-sectional view correspon~g to that of Figures l and 2, showing the apparatus with the s~con~ry inflation unit having been actuated by inflation to close off and seal the ~n~nm~hg lateral side connection of the pipel~e, in which condition the apparatus is ready for the introduction of SUBSTITUTE SHEET (RULE 26) WO9S/07433 ' ' ~ 2 1 7 0 6 2 0 PCT/GB94/01932 sealant composition into the region(s) of the pipe defect;
Figure 4 is a part-sect~o~l vlew on an increased scale of the left-hand end section of the appara~us shown in Figures l-3, in which the pr~nC~pAl construct~on~l features shown there are illustrated in further detail;
r Figure 5 is an enlarged cross-sect~on~l view of a preferred fluid in~ection port via which th~ ~on~y inflation 8~Al ~ng unit of the apparatus is actuated by inflation and also via which se~l~nt composition is eJected from the body of the apparatus into the headspace surro~ g the e~ector body; and Figure 6 is an enlarged part-sect~n~l view correspo~ng to that of Figure 3, showing the preferred apparatus in position in a curved drain or pipe.
~ETAILED DESCRIPTION OF THE INVENTION AND ~K~K~ED EMBODIMENTS
Referring firstly to Figure l, a drain or pi~el~n~ 2, which will typically be cylindrical, has a lateral side drain or pipe co~n~ction 4 and in one or more of the illustrated regions 6 ad~acent to the junction of these two pipe sections, some form of damage or defect is present. TYP;CA11Y, cracking, or breaking away or even ma~or collapse or disintegration of the pipe wall at or near the junctlon with the lateral side qo~n~ction 4 will be the application to which the repair xyS~ of the present invention can be applied. The system is applicable to repair of the pipe walls in a region on one side only or on both sides of the lateral side ~-s~ne~tion 4 simultaneously. It is when damage or a defect of the drain or pip~l~ne has occurred in the region of a lateral side -o~n~ction, as illustrated here, that the prior art in situ repair systems face practical difficulties and it is to this application that the present invention is particularly, but not exclusively, directed.
The apparatus which is transported into the pipe 2 for positioning at the desired site of repair ~ , ises a tubular, preferably cyli~drical, ejector body lO which includes an inner core 20 ~u...~ising a closed coil spring 20a (Figure 4) surrounded SUBSTITUTE SHEET (RULE 26) W095107433 ; ~ 2 1 7 0 6 ~ O PCT/GB9~101932 by an intermediate stretnhAhle/resiliently fl~ hl e sheath 20b (Figure 4), for example of nitrile rubber, such that the core 20 is substantially rigid in the radial direction while being resiliently flexible out of the axial direction of the core, so as to be able to flex and deform as the e~ector body 10 Ll~v~.~es a bend in the drain or pipe 2. Surro~ln~ n~ the core 20 is an outer sleeve 22 in the form of a generally cont~nl~o~C tubular sleeve e~e"-l~ ng substantially over the whole length of the tubular body 10. The outer sleeve 22 is ~e~u~ely Ancho~ed to the core 20 at each of its ends, for example by ~ ve ho~n~, 1 ock~ ng rings or alternatively by any suitable form of invasive attachment between the two members. The outer sleeve 22 is generally of a fl~x~ hl e material such as rubber or other elastomer, so that it can be sub~ected to the required differential inflation along its longit~A~nAl length by the various inflation -s~ n~ units of the apparatus, as described further below.
The interior space within the tubular body 10 accommodates as much as is required of the various supply means, feed and control devices and any mixing apparatus which are used to supply compressed air to the various inflation units and ~AlAnt composition to the various ejector open~n~s le~ n~ to the exterior of the outer sleeve 22. These components are generally not shown in the Figures for clarity and will, in certain cases, be entirely ~u~ve~lt~onAl. End plugs 12 and 14 are conveniently provided at each end of the tubular body 10. One of these end plugs will generally include means by which the apparatus can be drawn or pushed along the pip~l~ne, for example, an eye for the attachment of a draw or push rod or cable, and the other of these end plugs will generally constitute a manifold for the r-o~nection to the above ment~ nn~ components of external compressed air andtor cAAlAnt composition supply means. The latter may, if desired, be provided by a separate unit introduced in the pip~l~ n~ along with the repair apparatus or may be supplied from above ground in a conventional ~-nne~.
Prior t~ insertion of the e;ector body 10 into the drain or pipe 2, the outer sleeve 22 is coated (or i,l,~Ley~ated in a SUBSTITUTE SHEET (RULE 26~
~ W095/07~33 ~ t~ 7 ~ ~ 2 0 PCT/GBg4/01932 pre-soaking step) with a rele~Q~ agent, e.g. MARLEASE 400 (ex Marbo). As shown by the arrow 100 in Figure 1, the e~ector body 10 is drawn or pushed into the pipe 2 until it rP~c~ec the longitl~Ain~l position shown in Figure 2, where the le~ng and trAi 1 in~ ends of the body 10 are disposed to either side of the damaged region 6 in the vicinity of the side co~n~ction 4. To assist ~AQs~e of the e~ector body along the p~r~l~ne during this posit~o~ n~ step, castors, ~'cel~ or other suitable rol 1 ~ n~
elements 27 may be provided at the ends of the e~ector body 10.
Towards each of the ends of the e~ector body 10 is provided one of a pair of primary inflation ~PAl ~ng units 30,32.
Each of these units is formed by an inflatable tube surro~n~ ng the core 20 of the e;ector body 10 rather like the inner tube of a vehicle tyre. Each of the primary se~l~n~ units 30,32 is shown in Figure 1 in its deflated condition (see also Figure 4 which shows one of these primary inflation -s~al~g units 32 in further detail in this deflated condition) and in their inflated condition in Figure 2. Each of the tubes forming the pair of primary inflation sP~l ~n~ units is situated in a space between the outer sleeve 22 and the inner tubular core 20, the two not being adhered or otherwise hon~ together in these regions. If desired, the upper and lower surfaces of the inflation units 30,32 may be ho~Pd such as by adhesive to the outer sleeve 22 and core 20 at the respective contact surfaces.
Each of the primary inflation c~l ;ng units is connected to a compressed air supply (not shown in the Figures) via respective ports 60,62 which may or may not themselves in~o-~olate valves, dep~ g upon the construction of the air supply hardware.
In the central region of the ejector body 10, in between the two primary inflation sealing units 30,32, is provided a single, c~OnAAry inflation s~ali~g unit 40 which is preferably inflatable and deflatable independently of the primary inflation Q~l ing units. In principle, the s~con~ry inflation s~al;~g unit 40 may be constructed and actuated in a similar ~qnner to the primary inflation s~ g units, except that instead of being SUBSTITUTE S)tET (RU~E 26) W095/07433 ~ 0 ~ ~ 2 1 7 0 6 2 0 PCT/GB94101932 situated in a gap between the outer sleeve 22 and the inner core 20, it is positione~ preferably in a cavity formed within the outer sleeve 22. This cavity may be formed as part of the integral construction of the outer sleeve 22, or it may be formed by a double-skin section of the sleeve formed by a patch-like attachment to the basic sleeve.
The function of the C~csn~Ary inflatlon S~Al ~ng unit 40 is to close off and seal the ~n~-s~g side ~onnection 4 of the pi~ ne and so the circumferential extent (relative to the e~ector body) of the se~on~ry inflation ~ ng unit i8 preferably only sufficient to fulfil that pUL~O~. It therefore does not need to extend around the whole periphery of the e~ector body and a bubble-like configuration is therefore typically the preferred form of se~-on~A~ry inflation sealing unit for most practical application. Of course, dep~n~ng upon the area of the pipe side ~onn~ction or the area re~uired to be ~lsC~ off and sealed during the repair process, any suitable size and shape of ~con~ry inflation R~Al ;ng unit may be employed within the scope of the invention.
The s~on~Ary inflation ~Al ~ng unit 40 is supplied for the purposes of its inflation by ~u,-~Lessed air via its own inlet port 70, which is fed and controlled independently of the ports 60,62 from which the primary inflation se~l~ng units are supplied. The construction of the ~e~on~ry inflation ce~l~ng unit's inlet port 70 is of a sp~ l form, as will be described in detail further below.
The central section 26 of the outer sleeve 22 between the primary inflation S~Al ~ng units 30,32 is not hon~ to the core 20 and there is thus formed beneath this central section 26 of the outer sleeve 22 between the primary inflation c~ n~ units 30,32 a cylindrical cavity 50 which constitutes a tertiary inflation unit. This tertiary inflation unit 50 is supplied, again preferably independently of the primary and S~on~Ary inflation units, by compressed air from an ~n~p~n~nt source via its own inlet port 80. This tertiary inflation unit 50 provides a means of altering the depth of the headspace outside of the SUBSTITUTE SHEET (RULE 26) WO9S/07433 ~ ` f ~ 2 1 7 0 6 2 0 PCT/GB94/01932 outer sleeve 22 between it and the walls of the pip~ e 2 and sealed off between the inflated primary inflation ce~l ing units 30,32. It is into thls headspace that c~al~nt composition will be ejected for the purpose of f~l1 ing the pipe defect or damaged area and thus by controlli~g the degree of inflation of the tertiary inflation unit 50, one is able to selectively control the depth of the headspace into which ~A 1 Ant will be pumped.
~ earing in mind that it is in the ~e-~L al section 26 of the outer sleeve 22 that the ~o~ y inflation C~Al~ng unit 40 iæ provided rA~i~lly outwardly of the tertiary inflation unit, for efficient operation of the Cp~on~ry inflation ~Al ~ng unit lt is preferred that the central region 26 of the outer sleeve 22 is constructed so that upon inflation it does not tend to bulge raAi~lly outwardly, but maintains a predominantly cylindrical configuration as it is inflated or deflated. This behaviour may be achieved by a~ro~Liate construction of the sleeve 22, for example by providing the ~e~-Llal section 26 with in-built reinfo ~ t or alternatively by internally or externally hnn~
constriction rings or the like. With this kind of construction, the end sections 24 of the outer sleeve 22 either side of the central section 26 are preferably not provided with any such reinforcement or constriction means, so that these sections of the outer sleeve 22 are in~PPA able to configure th~mCPlves somewhat convexly upon inflation of the primary inflation QP~l in~
units 30,32, SO that they form efficient seals against the inner pipe wall around the periphery of the apparatus.
A plurality of injection ports 140 are a ~l-yed in the central section of the apparatus in between the primary inflation ~ ng units 30,32 and it is these which form ejector op~n~ngs via which ~ a~t l_ osition is pumped from within the e~ector body lO to the outside of the apparatus into the headspace formed between the central region 26 of the outer sleeve 22 and the inner pipe wall once the various inflation s~l ing units have been actuated.
Preferably a plurality of the ejector opPnings 140 are arranged in a plurality of groups, each of which group is SUBSTITUTE SHEET (RULE 26) W095/07433 i~ ; 2 1 7 0 6 2 0 PCT/GB94101932 selectively and ;n~r~ntly connectable to the c~
composition supply means outside the apparatus. Any number of injection ports 140 may be provided in each group, but preferably a sufficient number are provided in an ~y~ ~ late distribution such that the ease and speed with which Q~l ln~ composition i8 pumped into the headspace to completely fill the pipe defect are optimised. The Figures show schema~lc~lly ~ust one pocs~hle arrangement of in~ection ports 140, namely an arrangement of at least two banks of such in~ection ports ~pAne~ from one another in the longit~ 1 direction of the apparatus and each bank comprising at least two, and preferably three or four or even more, in;ection ports evenly spaced from one another circumferentially around the e;ector body 10.
As already men~io~e~, the ceAlAnt composition in~ection ports 140 and the compressed air inlet port 70 of the s~Con~ry inflation ~ g unit 40 have in common that they are required to deliver fluid to a given cavity from a respective supply means which is separated from that given cavity by a se~on~ cavity, namely the tertiary inflation unit 50. During inflation of the tertiary inflation unit 50, there is relative movement between (i) the wall separating the given cavity (i.e. the headspace outside the outer sleeve 22 or the inflatable cavity forming the ~econ~y inflation s~ ng unit 40, as the case may be) and the cavity 50 of the tertiary inflation unit, and (ii) the wall (i.e.
the core 20) separating that tertiary cavity 50 and the interior of the ejector body 10 which accommodates the respective fluid supply means. For this reason, a spPc~l construction of port is preferable for the ports 140 and 70 and a preferred construction of such a port which constitutes a further aspect of the present invention will now be described with reference to Figure 5 of the drawings.
Figure 5 in fact shows a preferred port which forms one of the S~Al ;ng composition injection ports 140, but the compressed air inlet port 70 is of a correspnn~ ng construction.
The device comprises two principal cc ~po,~ents:
\
Firstly, there is a conduit 142 which is in fluid SUBSTITUTE SHEET (RULE 26~
W095/07433 ~ 21 i 3 6 2 0 PCTIGB94/01932 communication at its lower end with the respective fluid supply and at its upper end terminates in a head piece 143 which is situated within the cavity into which the fluid is to be supplied, in this part~ r.~ r case this being the exterior headspace formed between the outer ~leeve 22 and the defective region 6 of the Pir~l ~n~ 2. In between these two extremities of the ~on~t~it 142, it L~avæ ~es the cavlty 50 of the tertiary inflation unit and penet~ates both the partit~o~g wall 22 (i.e.
the outer sleeve 22) which separates the tertiary cavity 50 ~rom the outside and also the partit~on~ n~ wall 20 (i.e. the inner core 20) which separates the tertiary cavity 50 from the interior of the ejector body 10. The upper end of the ~on~u~t 142 is held fast with the outer sleeve 22 by virtue of lock washer 148 which itself is clamped by piston tube 144 which is engaged for example, with screw threads on the exterior of the con~ t 142.
Thus, the piston tube 144 clamps the sleeve walls between the lock washer 148 and the h~A~p~ece 143. This fixing is sealed to ~e~e.lt leakage of fluid through the hole in the outer sleeve 22 by means of flanged s~ n~ washer 145. Thus, the upper end of the co~ t 142 is fast with the outer sleeve 22 and moves with it upon inflation or deflation of the tertiary cavity 50;
~ on~ly~ there is a the bush 146, for example of phosphor bronze, which is fitted into an aperture in the inner core 20, for example by screw threads or any other suitable mounting means, and the piston tube 144 which surrounds the conduit 142 pA-cs~s through this bush 146 into the interior of the e~ector body 10. The bush 146 is ~itted with a rubber seal 149, which is preferably an "0"-ring, so that whilst the piston tube 144 is slidable within the bush, there is a seal formed between the respective .cl i~lng surfaces in order to prevent leakage of fluid between the tertiary cavity 50 and the interior of the e~ector body 10.
Thus, upon inflation or deflation of the tertiary cavity 50, the elongate section of the conduit 142 slides in a piston-like manner within the bush 146~ A shoulder 147 may advantageously be provided on the exterior of the piston tube 144 to act as a stop against the lower face of the bush 146, thereby SUBSTITUTE SHEET (RULE 26) limiting its upward travel and thus defining a maximum inflation displacement of the sleeve 22 with respect to the metal core 20.
The lower end of the conduit 142 is mounted in a base 154 which provides connecting means for coupling to the respective fluid supply via access port 150.
Advantageously, this preferred construction of the injection port is simple enough to allow it to be readily dismantled and removed from the apparatus for cleaning, etc, as and when required, which may typically be after each repair operation. The parts of the device can simply be unscrewed from each other and the conduit removed for cleaning, and subsequently it is easy to reassemble the port in the same simple manner.
Referring now to Figure 4, this shows diagrammatically in slightly greater detail the construction of one end of the ejector body 10 and in particular the spacial relationships between the various components of the primary inflation sealing unit 32 and the neighbouring parts of the apparatus. Towards the right-hand side of Figure 4 is seen one of the sealant material injection port 140. The conduit 142 leading to the outside is connected at its lower end via base 154 to a respective supply conduit 88 through which the sealant composition, preferably a multi-component sealing composition which is supplied to the supply conduit 88 in a pre-mixed state, passes prior to ejection through the injection port 140 into the headspace surrounding the ejector body where the pipe repair is to be effected. Known means may be employed for coupling the respective supply conduits 88 with the necessary sealing composition supply line or lines via manifold 90.
In the preferred construction shown Figure 4, it is desirable for there to be a flexible connectio, e.g. by a length of flexible hose, between the supply conduit 88 and the injection port 140 (or constituting the supply conduit 88), because the latter moves relative to the ejector body core 20 as the tertiary inflation unit 50 is inflated or deflated, so such a flexible connection prevents any hindrance to such movement of the port WO95/07433 '~ 2 1 7 ~ 6 2 a PCTIGB94/01932 140.
The in~ectlon ports 140 in the apparatus are arranged in groups, each group having an ~n~ep~ t supply ConAl~t 88 such that the c~ n~ composition may be pumped from its source to each group of injection ports 140 ~n~p~nApntly and selectively.
The source may be selectively conn~cted to each of the supply co~A~l~ts 88 using a pneumatic ratchet. Such a device is already known in the art in various forms in the ~.ele~ and related arts and essentially allows for selectiv~io~ ~Lion of a fluid supply ~o~,~e to one of a plurality of outlets, each of which is co~nectable to a given supply co~A~t 88 supplying a part~Cl~
group of ejector op~nings 140 in the apparatus. Examples of constructions and operations of such devices are well described in the patent and ~chn1 C~ 1 literature, and will be readily av~lAhle to pe ~GllS skilled in the art. In one preferred form, however, two hoses supplying the two ~ .L~,ents of the preferred ng composition are ~-onnected to a stat~on~ry plate with a ~e~ e shaft e~ ng to another stat~onAry plate approximately 60mm apart. The C~o~A stationary plate has conne~tions for attachment to the plurality of ~Y~ng ~-on~ t outlets and is removable from the centre shaft by means of for er~ a screw thread. Between the two plates is a revolving section whose bearing is mounted on the centre shaft. On the first stationary plate are a plurality of stops in the form of teeth and the revolving section contains a pn~ tic plunger which, after one in~ectionr will withdraw sufficiently to pass over the first index stop. Compressed gas, e.g. air, will then spin the revolving section. Once the plunger has p~Cs~A over the first ~ndex stop, the gas supply is automatically shut off, hence forcing the plunger out. This will then stop at the next index tooth. The two components of the composition will pass separately through the first plate and the revolving section, meeting only where the ceco~A plate and revolving section interface.
The overall repair process using the apparatus of the invention may `be repeated up to for example a maximum of approximately six repair cycles, since the release agent used to SUBSTITUTE SI~EET (RULE 26) W095/07433 ~ 5~ 2 1 7 0 6 2 0 PCT/GB94/01932 prohibit the sealant resin adhering to the outer sleeve 22 will generally no longer function subsequent to that number of repair operations.
The operation of the above described apparatus for effecting repair of the defective area or areas 6 of the drain or pipe 2 will now be outl ~n~, though this will to a large e~L~
already be clear from the foregoing descrlption of the apparatus.
Initially, the e~ector body 10 (with releAs~ agent already applied to the outer sleeve 22) is drawn or pushed into the pipe 2 to such a position that its l~A ~ ng and tr~l1ng ends 12,14 straddle the defect 6 and ~ nCQ~ ng side ronn~tion 4 combination. This lateral positioning is shown already completed in Figure 2.
Next, the pair of primary inflation s~ g units are inflated, preferably together, but not nec~cc~ily so, so as to form inflated end c~ ng rings 24 at each end of the ejector body 10. Each of these end c~ ng rings, as illustrated in Figure 2, forms a circumferential seal against the intact (i.e.
undamaged or undefective) inner wall of the pipe 2 so as to define between them a cylindrical cavity ad~acent to the damaged or defective region or regions 6.
If desired, the tertiary inflation s~ ng unit may also be inflated to reduce the depth of the headspace into which the s~lAnt composition is to be in~ected.
In order to seal off that cylindrical headspace cavity from the lateral pipe side ~o~nection 4, the C~con~ry inflation c~l~g unit 40 is now inflated into the configuration aq shown in Figure 3. The bubble-like inflated cavity 40 cloces off and seals the lateral side connection 4 from the main drain or pip~ 2 and therefore now completely seals the generally cylindrical headspace cavity between the outer sleeve 22 and the inner wall of the pipe 2 between the inflated end seal rings 24.
\
The apparatus may be used to repair damaged sections in SUBSTITUTE SHEET (RULE 26) W095/07433 ~ 2 1 7 0 6? o PCTIGB94l01932 both straight pipes, e.g. as shown in Figures l to 3, and curved pipes, e.g. as shown in Figure 6. In Figure 6, like parts as in Figure 3 are identified with like reference numerals.
With the apparatus in the fully ~ n~ condition as shown in Figures 3 or 6, the sealant composition, which can be of conventi~nAl type, e.g. single com~G--e--~ or (more preferably) multi-com~onen~ (e.g. epoxy re~in plU8 hardener), can now be pumped through the multiple walls of the apparatus via a s~ ngl e group of in~ection ports 140, ln~eren~ntly selected by the pneumatic ratchet, into the headspace cavity between the outer sleeve 22 and the pipe defect region or regions 6. The s~ nt composition is forced into the defect(s) and is allowed to partially set so as to be able to maintain its shape before the next sta~e of the process.
Once sufficient setting of the ~ nt co~pn~;tion has taken place, the various inflation units of the apparatus can be at least partially deflated and the e~ector body removed from the repair site, this being assisted by the r~lp~ce agent. Rather than comrlete removal, however, it is poc-s~bl~ within the scope of the invention for the apparatus to be tranY~olLed incrementally along the pipeline to effect multiple repair operations at ad;acent sites, for example where a particularly large section of pireline requires repair. Each step of such an incremental repair process can be carried out individually in the manner just described with the addit;onAl step of co~ne~ting the ~Al~t composition source to the supply line of a clean group of in~ection ports between each incremental repair step, by means of the pne~ tic ratchet.
As is known in prior art in situ pipe repair systems, reaming apparatus may be employed either before or after, or even both, the repair operation, in order to on the one hand clear the pipe of debris for example and clean the repair site ready for the repair operation and on the other hand for removing ~xc~ss seAl~t material, or cleAning or polish;ng it, following the repair operatioh. Suitable r~ ; ng apparatus is well known in the art, for example in GB-A-2122300, so will not be described SUBSTITUTE SHEET (RULE 26) ~ ~ ~ r ~
W095/07433 ~ 2 1 7 0 6 2 0 PCT/GB94/01932 further here.
The preferred embodiments of the various aspects of the ev~lt invention described above are by way of example only and it will be appreciated by those ~k~ 11 e~ in the art that many variations and modifications can be made to what has been specifically described within the scope of the present invention as ~ e~.
SUBSTITUTE SHEET (RULE 26)
Claims (29)
1. Apparatus for use in repairing a defect in a drain or pipeline at or near a junction with a lateral drain or pipe connection, the apparatus comprising:
a tubular ejector body adapted to enable it to be drawn or pushed into the drain or pipeline to such a position that a leading end and a trailing end of the body are disposed respectively to one side and the other side of the defect and lateral connection combination;
a pair of primary inflation sealing units at or near the respective ends of the tubular body and which, when they are both inflated, seal the body against the drain or pipeline inner wall on each of the sides of the defect and lateral connection combination;
a secondary inflation sealing unit, being part of the said tubular ejector body, and situated between the primary inflation sealing units, and which, when it is inflated, substantially closes off and/or seals from within the main drain or pipeline the junction therewith of the lateral drain or pipe connection; and means for conveying a settable sealing composition from within the tubular body to and out of at least one, preferably a plurality of, ejector openings in the body between the primary inflation sealing units and the secondary inflation sealing unit, for forming, when set, a seal repair of the drain or pipeline defect without a blocking of the junction with the lateral drain or pipe connection.
a tubular ejector body adapted to enable it to be drawn or pushed into the drain or pipeline to such a position that a leading end and a trailing end of the body are disposed respectively to one side and the other side of the defect and lateral connection combination;
a pair of primary inflation sealing units at or near the respective ends of the tubular body and which, when they are both inflated, seal the body against the drain or pipeline inner wall on each of the sides of the defect and lateral connection combination;
a secondary inflation sealing unit, being part of the said tubular ejector body, and situated between the primary inflation sealing units, and which, when it is inflated, substantially closes off and/or seals from within the main drain or pipeline the junction therewith of the lateral drain or pipe connection; and means for conveying a settable sealing composition from within the tubular body to and out of at least one, preferably a plurality of, ejector openings in the body between the primary inflation sealing units and the secondary inflation sealing unit, for forming, when set, a seal repair of the drain or pipeline defect without a blocking of the junction with the lateral drain or pipe connection.
2. Apparatus according to claim 1, wherein the primary inflation sealing units extend around the full circumference of the ejector body, so that when inflated they assume an annular cross-section and seal the body against the inner wall of the drain or pipeline all the way therearound.
3. Apparatus according to claim 1 or claim 2, wherein the secondary inflation sealing unit extends over only part of the ejector body circumference.
4. Apparatus according to claim 3, wherein the secondary inflation sealing unit takes the form of an inflatable bubble which, upon inflation, presents a surface area sufficiently large to substantially close off and seal the incoming drain or pipe side connection.
5. Apparatus according to claim 1 or claim 2, wherein the secondary inflation sealing unit extends around the full circumference of the ejector body.
6. Apparatus according to any preceding claim, wherein the tubular ejector body comprises an outer sleeve which is resiliently flexible so as to permit radially outward expansion thereof into sealing contact with the inner wall of the drain or pipeline upon inflation of the primary inflation sealing units.
7. Apparatus according to claim 6, wherein the ejector body comprises an inner tubular core within the outer sleeve and united therewith at the ends thereof.
8. Apparatus according to claim 7, wherein the inner tubular core is a closed coil helical spring.
9. Apparatus according to claim 7 or claim 8, wherein the inner tubular core is surrounded by an intermediate sheath of resiliently flexible material.
10. Apparatus according to any one of claims 6 to 9, wherein the primary inflation sealing units are constituted by an annular cavity formed within the outer sleeve wall towards the ends of the ejector body.
11. Apparatus according to any one of claims 6 to 9, wherein the primary inflation sealing units are formed by virtue of a cylindrical section of the outer sleeve not being bonded to the inner core of the ejector body.
12. Apparatus according to any one of claims 6 to 11, wherein the secondary inflation sealing unit is constituted by a cavity formed within the outer sleeve wall between the primary inflation sealing units.
13. Apparatus according to any preceding claim, wherein there is further provided a tertiary inflation unit between the primary inflation sealing units and radially beneath the secondary inflation sealing unit, such that when it is inflated, there is a reduction in the depth of the headspace formed between the primary inflation sealing units and into which the sealing composition is pumped for the purpose of repairing the drain or pipeline defect.
14. Apparatus according to claim 13, wherein the tertiary inflation unit is constituted by an independently inflatable cavity beneath that which forms the secondary inflation sealing unit.
15. Apparatus according to claim 14, wherein the cavity forming the tertiary inflation unit is of annular cross-section, such that it extends around the whole circumference of the ejector body beneath the cavity into which the sealing composition will be pumped.
16. Apparatus according to any preceding claim, wherein the means for conveying the settable sealing composition are configurable in a first arrangement, wherein the sealing composition is conveyable to a first group of one or more ejector openings, and at least one alternative arrangement, wherein the sealing composition is conveyable to a respective at least one alternative group of one or more ejector openings.
17. Apparatus according to any preceding claim, wherein inflation of the various inflation units is achieved by use of compressed air.
18. Apparatus according to any preceding claim, wherein both of the primary inflation sealing units are inflatable together.
19. Apparatus according to any one of claims 13 to 18, wherein the secondary inflation sealing unit and the tertiary inflation unit are both inflatable independently of each other and of the primary inflation sealing units.
20. Apparatus according to any one of claims 13 to 19, wherein means for supplying inflation fluid from within the tubular body to the secondary inflation sealing unit comprises a fluid injection port, the injection port comprising conduit means in communication with the inflation fluid supply means and extending across the tertiary inflation unit and into the secondary inflation sealing unit, the conduit means terminating in a headpiece fast with a wall separating the tertiary and secondary inflation units, and bush means fast with a wall separating the tertiary inflation unit from the inflation fluid supply means and through which the conduit means extends and is slidable with respect thereto, the bush means including sealing means which forms a seal against the conduit means as it slides relative thereto, whereby inflation or deflation of the tertiary inflation unit causes piston-like sliding of the conduit means through and with respect to the bush means, and whereby communication between the inflation fluid supply means and the secondary inflation sealing unit is maintainable independently of the degree of inflation or deflation of the tertiary inflation unit.
21. Apparatus according to any one of claims 13 to 20, wherein the means for conveying the sealing composition from within the tubular body into the headspace between the primary inflation sealing units comprises at least one fluid injection port, the or each injection port comprising conduit means in communication with the sealing composition supply means and extending across the tertiary inflation unit and into the headspace, the conduit means terminating in a headpiece fast with a wall separating the headspace and tertiary inflation unit, and bush means fast with a wall separating the tertiary inflation unit from the sealing composition supply means and through which the conduit means extends and is slidable with respect thereto, the bush means including sealing means which forms a seal against the conduit means as it slides relative thereto, whereby inflation or deflation of the tertiary inflation unit causes piston-like sliding of the conduit means through and with respect to the bush means, and whereby communication between the sealing composition supply means and the headspace is maintainable independently of the degree of inflation or deflation of the tertiary inflation unit.
22. A method of repairing a defect in a drain or pipeline at or near a junction with a lateral drain or pipe connection, the method comprising:
drawing or pushing into the drain or pipeline a tubular ejector body to such a position that a leading end and a trailing end of the body are disposed respectively to one side and the other side of the defect and lateral connection combination;
inflating a pair of primary inflation sealing units at or near respective ends of the tubular body so that the body is sealed against the drain or pipeline inner wall on each of the sides of the defect and lateral connection combination;
inflating, either before, at the same time as or after the inflation of the primary inflation sealing units, a secondary inflation sealing unit, being part of said tubular ejector body, and situated between the primary inflation sealing units, so as to substantially close off and/or seal from within the main drain or pipeline the junction therewith of the lateral drain or pipe connection;
conveying a settable sealing composition from within the tubular body to and out of at least one, preferably a plurality of, ejector openings in the body between the primary inflation sealing units and the secondary inflation sealing unit so that the composition is ejected into the drain or pipeline defect; and prior to complete setting of the sealing composition but whilst it is in a coherent condition, displacing the ejector body along the drain or pipeline, preferably subsequent to deflating at least the secondary inflation sealing unit and preferably also the pair of primary inflation sealing units.
drawing or pushing into the drain or pipeline a tubular ejector body to such a position that a leading end and a trailing end of the body are disposed respectively to one side and the other side of the defect and lateral connection combination;
inflating a pair of primary inflation sealing units at or near respective ends of the tubular body so that the body is sealed against the drain or pipeline inner wall on each of the sides of the defect and lateral connection combination;
inflating, either before, at the same time as or after the inflation of the primary inflation sealing units, a secondary inflation sealing unit, being part of said tubular ejector body, and situated between the primary inflation sealing units, so as to substantially close off and/or seal from within the main drain or pipeline the junction therewith of the lateral drain or pipe connection;
conveying a settable sealing composition from within the tubular body to and out of at least one, preferably a plurality of, ejector openings in the body between the primary inflation sealing units and the secondary inflation sealing unit so that the composition is ejected into the drain or pipeline defect; and prior to complete setting of the sealing composition but whilst it is in a coherent condition, displacing the ejector body along the drain or pipeline, preferably subsequent to deflating at least the secondary inflation sealing unit and preferably also the pair of primary inflation sealing units.
23. A method according to claim 21, further comprising the step of inflating a tertiary inflation sealing unit prior to the ejection of the sealing composition, so as to reduce the depth of the headspace formed between the primary inflation sealing units and into which the sealing composition is pumped for the purpose of repairing the drain or pipe defect.
24. A method according to claim 21 or claim 22, further including the step of applying, prior to insertion of the ejector body into the drain or pipeline, a release agent to the surface(s) of the ejector body which will contact the sealing composition ejected therefrom.
25. A method according to any one of claims 21 to claim 23, wherein the drain or pipeline has deviations or bends in its internal shape.
26. A method according to any one of claims 21 to 24, further comprising the steps of incrementally transporting the apparatus along the drain or pipeline and repeating the repair process to effect multiple repair operations at different sites.
27 . A method according to claim 25, wherein the plurality of ejector openings in the apparatus are arranged in a plurality of groups, each said group being independently and selectively connectable to the source of sealing composition.
28 . A method according to claim 25 or claim 26, wherein the apparatus remains in the drain or pipeline between individual repair operations.
29. Apparatus or a method for the repair of drains and pipelines substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9318446.3 | 1993-09-06 | ||
| GB939318446A GB9318446D0 (en) | 1993-09-06 | 1993-09-06 | Repair of drains and pipelines |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2170620A1 true CA2170620A1 (en) | 1995-03-16 |
Family
ID=10741579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002170620A Abandoned CA2170620A1 (en) | 1993-09-06 | 1994-09-06 | Repair of drains and pipelines |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0717825A1 (en) |
| AU (1) | AU7618294A (en) |
| CA (1) | CA2170620A1 (en) |
| GB (1) | GB9318446D0 (en) |
| WO (1) | WO1995007433A1 (en) |
| ZA (1) | ZA946844B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19644466A1 (en) * | 1996-10-25 | 1998-04-30 | Herbert Dietrich | Renovation equipment |
| DE202008004685U1 (en) * | 2008-04-03 | 2008-07-10 | Js Kanalrobotik Gmbh | Injection packer for pipe and sewer rehabilitation |
| FR3016952B1 (en) | 2014-01-28 | 2016-09-09 | Gdf Suez | TOOL FOR INTERVENTION ON THE WALL OF A PIPELINE - ASSOCIATED METHOD. |
| US10295103B1 (en) | 2018-03-08 | 2019-05-21 | Car-Ber Investments Inc. | Inflatable isolation tool with enhanced monitoring unit |
| BR102018013965B1 (en) * | 2018-07-09 | 2022-03-29 | Petróleo Brasileiro S.A. - Petrobras | Device and method for umbilical hose repair |
| CN112682823B (en) * | 2020-12-18 | 2023-04-07 | 江苏恒建元建筑工程技术有限公司 | Non-invasive maintenance method for flue damage and smoke leakage |
| CN113819335A (en) * | 2021-08-26 | 2021-12-21 | 中山大学 | Pipeline repairing device and pipeline repairing method |
| CN114087455A (en) * | 2021-11-05 | 2022-02-25 | 湖北润贯通环保科技有限公司 | Waterproof frock of drain pipe maintenance |
| CN114382166B (en) * | 2021-12-06 | 2023-08-25 | 济南市市政工程设计研究院（集团）有限责任公司 | Drainage pipeline detecting system |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1982004086A1 (en) * | 1981-05-12 | 1982-11-25 | Rice Nigel Leonard | Pipe connecting method |
| GB8314209D0 (en) * | 1983-05-23 | 1983-06-29 | British Gas Corp | Sealing joints and leaks in mains |
| CH676495A5 (en) * | 1988-11-21 | 1991-01-31 | Himmler Kunststoff Tech | |
| FR2659720B1 (en) * | 1990-03-16 | 1992-07-24 | Devin Lemarchand | IMPROVEMENT IN UNDERGROUND PIPE SEALING APPARATUS. |
| DE4115563C2 (en) * | 1991-05-13 | 1994-01-20 | Linck Hans Peter | Process for lining a pipe with a branch-side branch line and device for carrying out the process |
| DE4207038C2 (en) * | 1992-03-06 | 1994-12-01 | Mueller Hans | Packer for lining the transition area between a main water pipe and a confluent house connection pipe |
-
1993
- 1993-09-06 GB GB939318446A patent/GB9318446D0/en active Pending
-
1994
- 1994-09-06 AU AU76182/94A patent/AU7618294A/en not_active Abandoned
- 1994-09-06 CA CA002170620A patent/CA2170620A1/en not_active Abandoned
- 1994-09-06 EP EP94926286A patent/EP0717825A1/en not_active Withdrawn
- 1994-09-06 WO PCT/GB1994/001932 patent/WO1995007433A1/en not_active Application Discontinuation
- 1994-09-06 ZA ZA946844A patent/ZA946844B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| GB9318446D0 (en) | 1993-10-20 |
| ZA946844B (en) | 1995-09-11 |
| AU7618294A (en) | 1995-03-27 |
| WO1995007433A1 (en) | 1995-03-16 |
| EP0717825A1 (en) | 1996-06-26 |
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