CA2051417A1 - Lining of pipelines or passageways - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The invention provides that a rigid plastics material (preferably p.v.c.) pipe is provided with folds and is introduced into a pipeline or passageway and heat is applied to the pipe to soften same. The hot pipe is unfolded and using fluid pressure, is expanded onto the pipeline or passageway surface to line same. When the pipe cools or is cooled, it remains in position on said surface. The pipe is folded into petal or star shape in cross section, and it may be twisted for even bending and/or it may be everted into the pipeline or passageway. Several methods of insertion are disclosed.

Description

W' ~0/12~1 ~ 2 ~ 17 PCT~B90~00512 PASSAGEWAYS
Thi~ lnv~ntion relate~ to the lining of plpeline~ or pas~ageway~, in particular undarground pipelineR or passageway~ typically used ~or the ~ransportation of sew~ge .

Sewage ~y~tems compri~e main sewa~e pipas and lateral~
sewage pipe8~ the lataral ~ewage pipe~ conn~cting buildin~R ~uch as officeq and dw~lling hsu~e~ to ~ain ~ewage pip~#~ The present inven~ion ha~ appl~cation to main and lateral sewage pipes and initally it is expected that it is in connection with such pipe~ that the invention would be u~ed, but it is to be mentioned that the method can be used in connection with indu~trial pipes and water distribution pipes and indeed in connection with the lining of any pipeline or pa~sageway having the appropriate requirement. The lining of pipeline~ or pa~sageway~ may be effected for pr~venting the egress or ingre~s of liquid out of or into the pipaline or pasRagewayt or it may be for the purposes of changing the ~se of the pipeline or passageway or rendering it uitable for carrying a material Cuch a~ a chemical for which it may otherwise be unsuitable. The linlng may be effected furthermore in order to prevant or limi~ corrosion~ The lnvention is concerned with the lining of pipeline~ or passageways u~ing pla~tic pipe~ which are rigid when at ambient temperature, but which are capable of undergoing .
de~ormation in order either to effect a raduction in the overall diameter of the pipe and/or to effect an increase in overall diameter of the pipe ~o that the pla~tic pipe can be ~nserted into the pipeline or passageway in reduced diameter condition, and when in the pipeline or pa~sageway can be expanded up to tha diameter of a pipeline or pas ageway to be lined. ThiC
method of linin~ is of course already known, and example~ of the method have been disclo~d in the following published patent speclfication~-- British p~tent application 218869S, European patent ~_9OJI2~1 205~ 4~ ~ pcr/GBgo~oo5l2 specification 006s8a6, U.K. pa~ent speciflcation 2003576, British p~tent 1580438, British patent 1553408 and Briti~h patent 1437273.

The general concept of linin~ plpelines or passageways using pla~ticQ material pipe8 which are rigid at ambien~
temperature 1~ distingui~ed from the widely practiced 30 callad "soft-lining" m~thod~ of pipelining, whar~ln a flexible or "soft" liner i8 impregna~ed wlth ~ syn~ha~1~
) re~ln, and ~he soft l~ner in ~uch conditlon i~ shaped by fluid pressure to the wall of the pipeline or passageway to be lined, and then the re.~in ls cured or caused to cur~ ~o that the lining becomes a rigld plpe on ~ha wall o the pipellne or pas~ageway ~o be lined. The mo~t commonly practiced technique of soft lln~ng is di~cloQed in U.S. patent 4064211.
., The present invention i8 concerned wlth the lining method using pla~tics pipa whlch i~ rigld a~ ambisnt temperature.

As d~Ycribed in the prior art, various pla~tiGs material may be u3ed for the rigid pipe and malnly ~uch pl~ic8 material compri~es polyethylene, e~pecially hi~h density polyethylene or p.v.c. It is usual furthermore for the rlgid pipe to be as~ociated with heating to enable deformation of the pipe to a reduced diame~r or to ar. increa~ed diameter or both, and high density polyethyl~ne ha~ the advantage that it will Yoftsn generally speaking at a much lower tempera~ure than will p.v.c., for example in the order of 95 degree3 as comparad to 125 d~ree3, which makes h~gh den~ity polyethylane attractive in ~ome ca~es becau~e it will be easier at least on site to ~often the polyethylene.
However, p.v.c. ha~ the advantage that it i~ on a thickne~s for thlckna~s ba~i~ generally ~pe~king 4trongar material than poly~thylen~ and ~hereore when lt i3 itlQtalled i t will have be~ter strength characterl~tics than the polyethylene pipe.

~ Otl2241 2 0 ~ . 7 PCT/CB9OtO0512 Thi~ muke~ tha use of p.v.c. attrActlve.

Ano~her dlstlnguishing characteri~tic as ~etween polyethylene and p.v.c. i~ that lf a polyethylene pipe i8 deformed from clrcul~r cro~ ection by the u~e of heat and deformation forces, and then i~ cool~d in a deformed ~tate so a~ to retain the deformed shape, when it i~ subjected to r~heating, a~ 800n as it ~tart~ to soften, it tendq to return to the original circular shape, whereas if 8im$1ar Qperations are carrlad out on a p.v.c. pipe, as the p.v~c. pipe 3tarts to soften, ~t will not tend ~o return to the circular ~hape and in fact will ~imply become more floppy and pliable. Use can be made of the~e characteri~ticQ in connection wlth the utili3at~0n of pla~tic pipes for lining p~peline or passageways. Thus, in th~ case of the polyethylene plp~
which has been deformed from circular shape and ha~ been inserted in a pipeline or pa~sageway, the application of heat will assi~t the pipe in returning to the clrcular shape which mean~ that leq8 pre3~ur~ w~ll be used to shape the polyethylene pip2 to the plpellne or passageway ~urface. However, polyethylene does have the disadvantage that the temperature to which the plpe can be heated is somewhat critical and if the heatlng temperature `axc~sd~ a cert~ln value, for example in the order of 115 degrees C, then the integrlty of the polyethelene pipe can be destroyed and it wlll ~lmply mel~ and bscome unu~able. With p.v.c. p~pe howevsr it can be heated over a much wider ran~e ~nd stlll retain lts integrity ~o that lt can be lnflated whllst ho~
without any re~ulting loss in strength when the inflated pipe is eventualiy oooled and rigidifies in po~it~on on the pipeline or pa~ageway surface.

The above relâtes to th~ technical reasons a3 to why in ~ome cases polyethylene may be used wherea~ in other ca3es p.v.c. may be preferred, but in fac~ ~s regards the present invention any suitable ~her~al pl~stic pipe which ha~ th0 charact~rl~tic that the m~t~rial i~ ri9id w~ ,~/12~1 2 ~ 17 PCT/GB90/00512 at ambient temperature, can be used. Th~ present inventlon i8 concerned with a number of a paat~ which facillta~e and improve the basic rigid plastic pi~e lining proGe~s.

In the prior speclfication~ referred to above, it i~
known to deform a circular cros~-.qection plastic pipa lnto U ~ection, H section or petal ~ection in order to reduce the ovarall di~meter of the pipe to en~ble lt to be in~erted into a suitable pipeline or paPsageway and in part~cular reference $8 made to European patent ~pecificatlon 0065886 in thi~ regard, but in fact deforming the rigid pipe ~n thi~ fashion re3ults in a deformed pipe which does not have ~imllar bending characteristics in all dlrections. For example if the pipe i8 deformed into U shape~ thsn bendiny about a plane parallel to but lying between the llmbs of the U
will be much simpl2r than bending in a plane at right angles ther~to. Becau~e of this, the feeding in of ~h~
pipe into a pipelina or pa-~ageway can be diffioul~ i the pa~ageway i8 not completely ~traight, and in any event it iq usually neces~ary for the ri~ld pipa to be cap~ble of some bending as it i~ fed from ground level into the end of the underground pipeline or pa ~agew~y.
It i8 known from the ~foresaid ~ritlsh pat~nt specification no. 2l88695A to prehe~t the rigid deformed pipe to enable it readily to be bent around various curvatures to anable it to be fed into the plpeline or pas~agew~y.

In the first aspect of the present invention~ a rigid plastic pipe of thermoplastic material ha4 folds therein and l~ capable of being heated and exp~nded to a larger diam~ter during which expan~ion the fold~ unfold, ~nd wherein the plpe i~ twi~ted ~o that axially of the plpe the fold line~ follow a helical path.
By this arr~ngament, the pipe ~xhiblt~ a better ~ ~90/12241 2 0 51~17 PCT/GB90toa5l2 5 ~

~ char~cteristlc o bendlng ln any dlractlon, bscause the cros~-aectlon of the p~pe ln ~ff~ct twl~ts al~ng th~ .
dlrectlon of th~ plpa AO ' th~t th~ ovarall r~slst~nce to bendlng in any direGtion i8 con~t~nt.
, The plastic pipe i~ pr~fer&bly folded ~o ~ to def ine petal shapes ln cros~-2~ction, And th~ olding 1~ suoh that ~he folded plpe in cross-sQctlon ha~ at least 3 axe3 of Rymmetry, By providlng that the cro~s-section has Rt le~t 3 axe~ of symmetry, then it can be arranged that, the bendlng effort r~qulred ~bout any of these .axes to giv~ t:he same amoun~ o bending i8 ~pproxim~tely equal, and ~ven by the folding dasign, i~ c~n be achleved that the pip~ will have a substantlally even bandlng ch~ract~ri~lc even i~ the ~fores~id ~wist were not. ! present. ~The presen~ lnv~ntion there~or~ cov~rs r~gld thermopl~stics pipe wlth foldlng ther01n, ~nd ~he pipe having at l~ast 3 axls of cymmetry, whlch prefer~bly are ofset by 1~0 degrees.
.
The pipQ m~y be ~ormed7to thc fold~d oondltion.0ith~r by belng directly extruded ~n ~uch conditlon, or lt may be he&ted wh~lst in clroula~ condition, and ~hen provided wlth radlal fold~ to provlde the de ired ~ro~a ~ectlon.
The twistlng, when provlded may be imparted durlng extruslon of the plp9~ or dur~ n0 ~ubs~quont foldln~ but it i8 unlikely that the twi~ting wlll be lmparted befor~
the pipe i3 provided wlth the said fol~s.

When th~. folded plpe i~ placed: in the pip~ o or pas~flgaw~y~ it il~ important to ensure that it unfold~ in a controllad fa~hlon, an~ in accordance wlth a ~eoond aspect of the lnvention j a method provid~ that the folded pipe 1~ plaoed in the pipeline .or ;passa~eway, and lt~ should be mentloned ln thls ~pact~ th~t 1~ 18 no~
necessary that th~ p1pe should b~ fold~d and~r twi~ted in aceordallce with the ir~t ~pect of thi~ inveneion, and then tha plpe 18 pro~re~slvely unfolded to clreul~r W~ 90/12241 - 6 - ~ O ~i ~ 4 ~. 7 Pcr/GBgo/oos~

form to bo ~ppll~d .to ~h3 plpellne or pa~sagewhy surfae3 by m~ns of ~n expandln~ device whlch urge~ the openlng plpe A~alnst ~ shleld lo~ted to the outslde of ~h~
pipe, ~nd whlch travel~ with the expanding davice along the pipellne or pa~ eway ~ the pla~tlc plpe 18 opened up, and the method al~o lncludln~ that thQ plfistlo plpe, at l~st ln the region whlch 18 openlng up, i~
heat~d to a 3uf lci2nt de~rae to en~ble the pipe to unf old . ; ^- :.
.: .. . . . .
The . shield may be deflned by a sleave whlch 1ts neatly to the pipeline or p~s~ageway ~urfaca and naatly receive~ the ~olded pla~tlc plpe ln lta bore or lt msy be a collar which~ ~urroundR tha folded rigld pip~. It could al~o bQ a steam ~cket t~hich ~urround~ the rlgld fcld0d pipe with clearanca to enabla steam to ba lntroduced betwaan the ~lcket and riyld plpQ, ~:he ~team ~ack~t leadlng to a b211 mouthad ~hleld of whlch th0 bell mouth li~ ~d~esnt the enfolding or openlng portion of the rlgld plpe, sald bell mouth ~erving to retaln ~ chamber of stQam ~round th~ openlng rl~ld plpe for the applicatlon of heat thereto, but ~o that steam can~ a~cape rom~th~ slearan~e be'cween the openlng rigid plpa ~nd the be~1 l mou~h i:c~ lng.
.
~n ~ome cai~es lt m~y ne~ be necei~sary to provide ~he reac~ion , shie~ld rQferrQd to ~bove, and in ~uch clrcum~t~nce~ th~ e~pan~ton device m~y comprlse ~
rolling plg or a buckot pig which i8 forced throu~h ~he rlgid pipe no 118 to lle slightly ujpitream of the region o the rigid p~pe whlch 18 for the time being, b~ing heaSed. . ~
-, ~ . . . ......... .
Whera th~ ~hield 18 provlded, lt i8 pr~ferably pulled along the plpaline or passageway ah~3ad of the openlng rlgld pipe.
., . : .
In y~t a furth~r: ~pect of th~ inventlon; Sha opening U!p ' of the r~gid pipe can be effacted by mearls of . ~90/12~1 2 0 5 14 17 PCT~GB90~00512 ~. - 7 -- progre~lve heatin~ uslng hot watar whlch i~ue8 from a hot wat~r feed tube whlch i8 in~er~d lnto the end of the rigl-d p~p~, and froM whlch hot w~t~r i~ue~ ln order to contAct the lnner. ~urface o~ the rigid pipe. Th~
fe~d plpe 18 progres~iv~ly ed ~long the inside of the openlng rigld pipQ thereby progr~Q~iv~ly to h~at and lnflate the rlgid plpe. The down~tream end of th~
rlgld ~ip~ may be.~Q~l~d by means of a 6topp~r wh~ch h~
~ bl~ed v~lv~ therein ln order ~o allow A sm~ ak~e of the ho~ water throu~h the inslde of the ri~id folded plpe for the pre-heatln~ of same prlor to unfolding.
~ , .
A3 to the ~ethod of lnsertin~ the rlgid plpe into the pipeline or pass~Q~way prlor to the opening up of sAme, thls may be effected by mean~ of ~ pulling or pu~hin~
action, and i~ may be pAs~ed over ~ heating box in ordsr to aoften, the pipe to en~ble it to be correctly po~l~ioned ~nd fed lnto the plpalins or pa~s~gew~y.

It will be appreciated that as regard~ the first aspect of the.lnventlon, which rela~es ~o the ~ ructure of the rigld pip~, then ~ny convenlent m~thod of ln~ertlon and lnflation may be adop~d.

Another known method of linln~ pas~ageway~ 18 referred to by the nam~ ~lip llnln~. In ~llp linin~ a ~eml-ri~ld pla3~ic~ mat~rlal ~ube ~pproxlmatln~ to the diame~er of the pas3ageway to be llned 1~ ~imply pulled lnto the passageway and any cle~rance between the pasQageway surf~ce and th~ outar 3urface of the lining tube may be d with ~routing material to ~omple~e the o~eratlon.
It will ba undar3tood;that 811p lining i~ llmlted in its U8~ lnsofar a3 tha p~ssa~sway which can be lined by the 31ip linin~ method h~ to be substantlally stralght.
Th~ soft lininq method~ can bc u~ed for p~a~ageways wh~h hav~ ~ub~tantial cur~0~ ~nd b~nd~ th~ln. Th~
~ot llnin~ me~hods furth~rmore pro~id~ ~h~ ~h~ inal linin~ wlll lie. closa to the pa~sa~eway ~urfacQ ~nd no ' WO 90/12~ 2~4~7 1 PCT/CB90/005~2 ~ddltlon~l gr~utlng ~t~p l~'r~qulr~. Th~ xIblo llnlng msthods al~o ~re' c~p~ble o~ being' c~rr'lsd out ln ~ingle shot~ over long langths of pfl~3ageways. Thl~
me~ns th~t a ln~le long len~th tube can be lnserted ln a p~s'sagQway to l~ ama: ~ith~ut th~re beln~ any ~oint~
ln th~ flnish0d lin~ "pipe. 'Slip llnlng h~s t~e advant~ge th~t 'the' lihln~ tube iB fabricat~d unde~
factory condltl'ons, and lts charactsr doeQ not ch~nge betwe'en'ln ertlon and ~o~ completlon wherea3 ln tha 80~t llnln'g procé's'~es, it 18 flOt alway~ possible to ~ 8ur0 that elther the bondln'g materlal h~s bsndad t~e ~oft linin~ tube to thc pa~sageway surface or tha reain ln the tube has cured evenly throughout it~ length.
. . .
The present inventlon in another aspect s~eks to provlde a method of llning pas~Ageways wh~ch has the advantage~
of both of ~he known system3 wlthout the di3advantage~.

In accordance with another aspect of the present lnv~ntion, a mathod of lln'ing a passagew~y compri-~ he' utiliQatlon of a rlgid or seml-rigi;d- 't:ube of ~harmoplastic~ m~terlal whlch in an lnltlaI condltion i~
of smaller overall dimenslons than the dlameter o~ the paQsagew~y to be lin~d, ~nd wherein the tube i~ f9d ln the' initlal condl~llon 'lnto -tha p~ ew~y, 'and lnsid~
th~ passageway'the tub~ everted t~ ~ final conditivn ' wher~ lt lies ~galnst the p~3sageway ~urfaca lining aame.

In the inl~lal- condition~ the tube may ha~e f'olds therein in order to reduce it~ overall di~meter or alt~rn~tively in th9 initial condltion lt may be circular and of s~allQr diamet~r th~n the p~s~g~way So be'`iln~d. In thi~'connection, the pl~8tic8 m~t~rlal of ehe tube may be of a type ha~lng ~ memory 80 that the tuba ig fir~t of ~ll'produced in the fln~l diamst~r ~lz~
and th~n ~ heated' to ~oft0n ~me ~nd th~ tube is atretched to the lni'tial diameter ~nd th~n cooled to W~ ~0/12~1 ~ 7 PCT/C~90/00512 _ ~ .

rlqldify the tube ln the lnitial diametar s~ze. In thi3 conditlon the tube retain4 8 "memory" 40 that when the tube i8 ~gain hsated lt will f reely expand to the fin~l diameter ~ize.

To enable the tube to evert rom the initial condltion to the final condition, heat i8 applied to ~often the thermoplastic material of the tube but only su~flc~nt heat to enabls the tube to be re~haped and 80 a~ to avold melting of same, The hest may be applied in any ~ultable manner. For example the everslon of th~ tube in~lde the pa~sagew~y m~y be effected by fluid under preq~ure, and that fluid may be heated. At the ~ame tlme heated fluid may be applied to the inside of the tube to give even heating and even softening of same.

In a pflrticul~rly preferred method, a heating means ~uch a~ a radiant heater or a stream he~ted bloek l~ provided in the passageway ah~ad of tha everting face 80 as loeally to heat the everting fa~e to ~llow the ever~lon to continue. With thl~ arrang~ment, it may be po~ible to cause the eversion ~imply by applying ~hrust to the inwardly travelltng plpe on the initial di~meter section of same without requiring the u~e of fluid pressure.

Where a ~team heated block i8 provided, the block may contact and be moved alon~ the pas~ageway by the avertin~ f~ce so tha~ heat i8 applied to ~he evertin~
face by conduction.

It i3 obviously most da~irable if the softening of ~he p~pe to permit ever~ion can take place locally and at tha evert~ng f~ce only a3 then th~re i~ no x0quir2ment to provide heat sources ~uch a~ boilar~ ~.or h~ating everting fluid~ Th~ eY~rting fluid when u~ed typioally wlll be w~ter or 3te~m.

W(,. ,0/12241 2 0 ~ l 7 PCr/G~go/oosl~

The procesR ~e~ordinçl to the ln~entlon, at leC18t ln its preferred form has ~he advantages of 811p linlng and th~
advantages of soft llning without the abovement~oned disadvantagss of these pro~es~es. That 1~ to s~y long lengths can be performed in a ~ingle ~hot, the pipe can be made to be a snug fit on the pa~sageway 8UrfAC~
without any requirement for grouting, and th~ even quality of the lining material oan be ~aintained by the utili~ation of a rigid pla tlcs material pipe.

Suitable materials which c~n be u~ed for the procesR are the thermopla~ticR materlal~ PVC and polyethylene, but the invention is to be considered as being theretoO

Various embodiments of the present in~ention will now b~
described, by way of example, with r~farence to the accompanying diagramatic drawings, whereinS-Fig 1 is a sectional view of ~ pipe of thermal pla~ticmaterial surrounded by A heAter for the heating of same;

Fig 2 shows the heated plpe o~ Fi~ 1 when subj~cted ~o deformation rolling and foldlng;

Fig 3 is a view similar to ~i~ 2 but showing a ur~her ~tage in the proce~s;

Fig 4 is a seotional view of a rigid therma~ plastic pipe folded lnto a petal con~iguration;

Fig 5 is a p2rsp~ctive view of the pipe shown in Fig 4, but also illustrating the longitudinal twist therein;

Flg 5 show~ the end of an extru~ion dye suitable for producing the rigid pipe of section ~hown ln Fig 4S

Fig 7 ~hows a ri9id folded and twi~ted thermopla~ie W~90/12~1 2 ~ ~141 7 PCTtCB90/00512 ~ pipe accordlng to another smbodlment o~ ths ln~entlon7 Fig a i9 a ~ectional elevation showing how the fold ln the pipe of Fig 7 are formed;
.
Flg 9 ~8 a sid~ ~ec~ional ~lev~tion lllu~tr~ting ~he method of forming the pipe ~hown ~n Flg 7 rom a circular pla~tic pipe to the folded and twisted form shown in Fig 7, the flgure al80 ~howinq th~ folded and twlsted pipe being wound onto a collecting drum Fig 10 iQ a per3pective elevation of the apparatus ~hown in Fig 9:

Fig 11 iB a sectional elevation illu~trating the lnstallation of a rigid and folded pla3tlc3 material pipe into a pipeline or passageway;

Fig 12 is a vlew ~im~lar to Fig 11 but howln~ an advanced ~tage of the lining opera~ionJ

Fig 13 is a per~pective elevation of the rigid llning pipe being expanded in the pipeline or pa3sageway Again~t a steam Rhield;

Fig 14 i~ a perspective cutaway s2ction~1 vlaw illuctrating another method of ri~id pipe in.Qtallation , Fig 15 i8 A view similar to Fig 14 but showing th~
operation a~ an advanoed ~age;

Fig 16 i8 a sectional elevation ~howing part of the installation oper~tion in Fig 15;

Fig 17 is ~ view similar to Fig 14 but ~howing an alternative method of installation;

Fig 18 i~ a view similar to Fl~ 17, but ~howing ~n O~ 12241 ~ 0 51 ~1 7 PClr/(:~lB9()/00512 advanced ~taga of the in~t~llatlon procs3~ ~

F~g 19 i3 a ~ectional ~ide view of the arrangement shown in Fig 18;

Fig 20 i8 a ~ctional vl~w of the arragngernent Qhown in Fig l9 and in p~rticular ~ detail thereof to an anlarged scale and 8howing a modif ication ~

Fig 2l i~ a vi~w ~ilnllar to Fi9 18 but ~h~win~ an al~ernative method of in~tfillation;

Fig 22 i~ a ~iew slm~l~r 'co Fig 21 bu~ ~howin9 an advanced s~cage of the inoitallation;

Fi~ 23 is a view similar to Fig 21 bu~ relate8 to a modif ied method of in~tallationS

Fi~ 24 shows the arrangement of Fig 23 but ln ~n advanced stage of in~t~llation.

25, 26 and 27 ~how a modification in the method for repairing imparfection~ in the linin~ operatlon7 Fig 28 3hows the equlvalent u~ed in the modlied method of FigR 28, 26 ~nd 27 ~

Flg~ 29 and 30 how two further modification~ of the method;

Fig. 31 i~ a ~eetional e.levation through an underground pas~geway showing a lining method a~cording to another embodiment in operation;

Fig. 32 i~ a ~ectional elevation taken on the llne II -II in Flg a 31 and~ Fi~. 33 i~ a ~ectional elevation similar to ~ig. 1 but ~howing a modified ~hape.

90/l2241 2 0 ~ 17 PCI/CB90/00512 R3ferrlng to the drawing~, it 18 'co be mentioned that All notss and wording and additional dlagrams on ~he drawlngs ar~ to be con~idered as part of the ~pecification and the applic~nt may ~ish to refer thereto for su~ining any particular di~clo~ure.

Referrlng now to the drawing ln more detai~, in Pi~ 1 a thermal plastlcs material pipe (10~, Apecificslly U . p V . C, pip~ ~ 8 surrounded by mean~ of a h~Mter ~12) whlch may be an electrlc re~i~tance heater. The pipe i8 of indefinlte length, and th~ len~th wlll ln fact be related to the length of the pipeline or pa~ageway to be lined u~ing pipe ~10). Plpe (10) is passed through the heater in the direction of its length 80 that ik will be heat~d throu~hout i~ ngth ~nd progra~ivelyt and ~he hot pipe 1~ then passed through a forming d~es aR shown in Fig~ 2 and 3 to form the pipe ~10) lnto H
conf igurationD As ~hown in Fig 2, a pair of deforming rollcrs ~14) and (16) compress the pipc radially, whll~t the pair of tucking knive~ or ormers (18) and ~20) orm inwardly directed fold~ giving the deformed pipe the H
confirguration.

A~ the pips prOgreQses in its movemant lt mQves to poQltlon between the nip de~ined by fl~tening rollers (22) and (24) which form the pipe to the folded flattened condit~on a~ shown in Fig 3.

A3 ~he flattQnad and fold~d tube (10) emarge~ ~rom ~he roller~ (22) and (24); it i8 pas9ed directly to a large re~ling drum which i~ best illustraSed in Fig g and ln Fig 10 and referance wi}l be made thereto ~ubsequently~
The flattened and folded tub~ (10) may be cooled prior to rcelin~ if de ired, but ~t i8 not believed tha~ such cooling will be neces~ary.

Fig3 2 ~nd 3 illustrate only one form to which th~ tub~
may be folded, ~nd in ~act thQ foldln~ o a tubQ to the .

U )0/12241 ~ O ~ 7 p~r/c;B9o/ol)s12 H coniguration ~hown in Flg 3 i8 known in the prior art. It is al~o ~nown from ~he prlor art ~o fold the tube into U 3ection And horse shoe ~ec~ion and indQed lnto petal ~ectlon, but a fir~t a~pect of the presQnt inven~ion provide~ that the tube ~lQ) i8 fold~d into a ~peclflc configuration. One example of this specific configuration i~ ~hown in Fig 4 .

The tubs ~10) ~ made up of c~rcul&r arcs B0 a~ to define 3 deep folds ~26) and 3 shallow fold~ ~28). The folded tube in fact ha~ 3 axes of symmetry (30) (32) and ~4) which are angularly offs~t by 120 deg~ee~. The various circular dim~n~ions Dl~ D2 and D3 ~re of the proportlon shown, the di~tAncQ D being ~he ovarall diameter of the folded ~ube. A tube formed into this configuration has excellent bending characteristic~
insoar as it ~ill hAve the same re~istance or su~ceptlbility to bending in virtual~y ~ny direction, 80 th~t the tube c~n be readily bent ln b~ing fed round corners ln the pipeline or pa~sagsway or ln being fed into the pipeline or pa~sageway aQ will be de~cribed.
The folded tub~ (10) may be extruded in this form, or it may a~ described in relation to F$g~ 2 and 3 be heatad and deflected ~o ~his RhAp~.

Ftg 5 ~how~ that the tube (10) shown in Fig 4 in ~ddition to having the petal cro~s ~ection shs:~wn also 18 twisted longitudinally which eYen further enhances the c~pability of the pipe to bend evenly in any direction. Because of this capability, whsn the plpe i8 being inser~ed into a pip01ine or p~ag~way it i~ not nece-~s~ry to control the attitude of a pipe having re~ard to the direction in which i~c IllU8t: bend., ~igR 7 to lO illu3trate another :Eolded and twisted pipe conf igur~tion. A~ be3t shown in Fig 7, 'che pipe l~
folded ~o as to def lne 6 pe~al~ ~ 36 ) which have rad~al ~ides and curved outer ~urfaceQ of whlch ~che curva~ure ~0~2~1 '~ P~T/C~90/00512 - 15 ~

- 1Q equal to the lniti~l curv~ture of the elrcular undeflected pipe. The fold line~ ~38) which arise a~ a result of the longitudinal foldQ twist helically along ths length of the plpe.

Flg 8 show~ how the pipe of Fig 7 i~ ~ormed from an originally cireular pipe (~0). The pipe (40) i8 heated ov~r segmental and evenly ~paced portion~ (42) of wh~ch the altornate region~ ~42) are longar than th~ r2maining regions And a plurality of radial ~orm~r~ ~44) and (46) deflect the heated portions inwardly a~ shown in Flg 8, ~he form~rs (44) deflec~in~ the heated portions inwardly to a greater extent than the form~rs ~46~. The formQrs (44) and (46) may in f~ct a~ ~hown in ~ig 10 be circular discs which rotate ~s the ~ube (40) i~ fed lnto ~he eye formed by the edgeR of the disc3, as better descrlbed in relation to Fig lO. The unheated port~on (4S) of ~he pip~ ~40) remain of the same radius but are moved progres8ively inwardly with the foldin~ of the heatad portions untll the resultlng d~formed tube ~lO) a3 ~hown ln Fi~ 8 r~sults. As the pipe ~qO) i~ 30 heated and deformed it i~ a}~o twisted into the configuration ~hown in Fig 7 and aventu~lly i8 wsund onto ~ take-up drum.
..
Figq 9 and 10 ~how the ~pparatus or deformln~ and kwisting the heated pipe ~40~. A~ shown in Flg 9, ~he pipe ~40) enter~ a heating pedestal (50) havlng a heating tube ~52) in whlch the r~spective clrcumferential portions t42) and (48~ ~re heated and maintained cold re3pectively. Hot and cold chambers (52) and (54) are created by radial dividing partitions ~56) and Aot alr is ~upp~i~d to ~he ohamber~ ~54) through p~pe ~58~ and 18 raturned through a cold ~ir pipe ~60). A~ the pipe (40) pa~e~ through the pedest31 ~50) therefore it i~ heated a illustrated in Fi9 8. A
driva motor (62) ~nd ~ drlve belt ~64j drlv~ a die plata through which th9 hea~ed pipe i~ p~s~ed in order ~o imp~rt a tWiBt th~r~to, ~nd the forming di~cs (44) ~nd w~ ~Otl2241 2 ~5~ 4 1 7 PCI/GBgO/00512 (46) engage the movln~ pipe (40) to form the eventual twisted pipe ~10 ) which i~ wound onto the take-up reel (66) for Qtora~e. The resulting pipe (10) may be cosled if de~ired, but ln any ca~e it will cool when on the reel ~66) and the hot portlons of the plpe will eventually rigidl~y . The reeled pipe is qtored unti 1 1 t ls to be uQed for lining a pipeline or pas~ageway.

Reference will now be made to Figs 11 and 12 whlch show a fir~t embodiment of in~erting a folded rigid thermoplaqtic pipe into a pipeline or pa~ageway followed by the expansion of same onto the pipeline or passageway ~urface. In the example of Fi~ 10 and 11l an underground sewer ~68) ls connected by a pair of manholes (70) and (72). The distance betw~en the manholes (70) and (72) wlll be greater than that shown, but only a ~hort distance ls illustrated in the interest~ of clarity. The reel ~66) carrying the plpe ~10) to form the lin~ng i~ encased in a ~ultable caslng (74) which may be a tarpaulin or the like, and trunking (76) leading from the reel to the bottom of man-hole (72) conects with the ca~ing (74). The trunking (76) i3 open at ~he bottom, and ~team ~8 is3ued from a s~eam generation apparatus ~75) through a supply plpe (78) to cause the ~team to flow into the trunking ~76) which has the effect of pre-heating the pipe (10) as it i8 unwound a3 ~hown from the reel (66) and i8 pulled into and along the sewer (68) by means of a winch ~80) and a cable (82) connected to the free end of ~he pipe ( 10 ) by mean~ of a coupling t 84 ) .

When the pipe (10) has bean placed in position as shown in Fig 12, it i~ cut to length, and then a rolling pig d~vice (86) de~cribed in greater detail hereinafter i8 introduced into the right hand end of the pipe ( 10 ) after it has been h~ted, and a pre~ur~ coupling ~88) *nables ~he supply of air under pr~ure f rom a compressor (90) via a pipe t92) to a location behind W~ ~0/~2~1 ~0 ~1~17 p~r/cB9o/oosl2 -the pi~ ~86) ln order to force same along the inslde of the pipe ~10) to expand ame onto the -~ewer surface.
The pipe (10) ls heated from a steam gen~ration apparatus (94) through ~a feed pipe (96) and a ste~m heating collar of the type 8hown in ~i~ 13.

Referring to Fig 13, thç end of the pipe (10) is 6hown a3 projectln~ through a coupllng (98), and connected to the coupllng i8 ~ heat resi~tant flexlble ho~e ~lO0) to the opposite end of which ~ 3 connected a bell Qh~ped houslng or shield (102). The steam hoQe ~96) i~
connected to the coupling ( 98 ) ~o as to supply steam to the interior of the hose (100) and to the ~xterior of the pipe (10) and also to the interior of th~ ~hield ~102) 80 th~t the pipe (10) inside the ho~e (100) and the shield (102) is heated to softened condition so that it wlll expand upon the forcing of the plg ~a6) along the interior of the expanded pipe tlO). The steam ho3e i9 also u~e~ to pull the a~sQmbly comprising coupllng (98) hose (100) and shield (102) in the direction of arrow (104) as the expan lon of th~ tube (lO) continues.
It i~ to be noted from Fig 13 that as ragards a lateral sewer pipe (106~ which meet~ the main s~war (68) ~he expanded tube ~10) will be dimpled into the lateral pipe ~106) (~ tsd~ s~eEe~6~ O~and ~uch dimple wlll be clearly vi~ibly when the interior of the lined sewer ic ~ubsequently inspected by a T.V. camera or ~he l~ke. When the dimple i8 idantified, it i8 then a simple matter of cutting the dimple out by a ~uitable cutter to re~establish a connection between the lateral sewer (106) and the main ~ewer (68).

Thsr~fore aR the expansion progre3se~, 80 the pipe (10) is heated only over A ~ection precedin~ the pi~ (86).
The pig furthermore react~ against the ~hield ~102), and 80 1~ pr~vented from pro9re~sin~ ~t too guickly a ra~e and th~ who}e as~mbly move-Q ~lon~ the pipe ~10) expanding same as lt proceed~. In ~he arran~emen~ of U ~0/12t4l - 18 _ 2 ~ 51~17 PCT/GB90/005l2 ~ig 13, the rlgid foldsd pipe ~10) is shown as having the H configuration illustrated in Fig 3, but ebvlou~ly lt ls not neeessary that this should be the cas~.

In the insertion arrangement illu~trated in Flgs 14, 15 and 16, the method is bacically the same as already described in 80 far aq ~team is introduced through the man hole t70) via a steam in9ertlon pipe (96). The pipe (10) is pre-in~erted into the sewer (68~. A pig (86) is used for the openlng up ~ the plpe ( 10 ), but in this case a device sometimes referred to as a poly-pig (110) lq u~ed as a ~leeve around the portion of the pipe (10) immediately ahead of the pig (86). The sleeve ~110) acts as a reaction member for the rolling pig to prevent 3ame from progres~ing too quickly, but the slaeve (110) ~s shown in Fis 16 does not provide for the ~team heatlng. The steam heating is efected by means of a pair of nozzle~ (112) connected to the poly-pl~ (110), but arrange to supply steam into the folds ~28) and (26) as shown ln Fig 4 for the heating of the section of the pipe (10) ahead of the rolling pig (86). Fig 16 a~ain shows the dimpling effsct (108) and the pig is shown ln sllghtly more detall. It will be seen to comprlse a valve ~112) through which air or water undex pre ~ure can be introduced or eqtabli~hed in the correct pres~ure lnside the plpe.

The steam supply plpes (~6) are also used for dragging the noæzles (112) and the poly-pig (liO~ along the 4ewer ahead of the rolling pig. The poly-pig provide~ an excellent of means of preventing cold water from coming into contact with the ~ection of the pipe (10) which ls being heated. It is important that water be kept clear of this heating zone, as water ha3 ~he effect of chillin~ the pipe and preventing the effect of ~oftening of same. Where the plpe i9 dry, it i~ not nece~sary to use a poly-pi~ and in fact a flared ~leeve can be used, the flaxed sleeve Qimply provlding the feature of 90/1224~ 2 ~ 17 P~r/GBgotoos~2 housin~ the rigid pipe ~lO) and provid~ng a reaction surface ~gainst which the rolllng pig can react.

The polypi~ has an inn@r ~le~ve (116) of p.v.c. or polyurethane but certainly of low friction ma~erlal such as p.t.f.e. felt. The poly-pig in fac~ tends to reduce ln thickn~s~ a~ it is put under ten~ion a~ a result of ~ ing on the steam pipes ~96). It may be fill~d with a liquid or solld fllm and preferably h~s an outer ca~ing of polyurethane.

The pig (86) may be driven through the opening pipe ~lO) by water or air pre~sure, and Fig 14 shows that w~ter is used and is drawn from the mains (118) and supplied through a flow and pressure control device ~120) via a supply pipe ~122) whlch couples with a casing ~124) from which the pig can be driven.

In the lining method of Fig 17, again the pipe ~10) i5 placed in th~ sewer (68), bu~ the pipa end in man-hole (72) is provided with an end formatlon ~126) for receipt of a plug which subsequently wlll effect expansion of the pipe (lO). The plug act~ like a plston and ln fact has rubber or the like seals, best illustrated ln Fig (20) which contact the inslde of the expanded pLpe ~}0) a~ will be explalned. The special pi3ton i~ lndlcated b~ reference ~128), and connected to the piston 1~ a steam ~upply ho~e (130). In order to expan~ the pipe (10) water from the mains (118) i8 coupled ~o a control valve (~20) on an in~tallation vehicle (121), and the water output ho e (122) is coupled to a gland (1273 to which ls connected a coupling hose ~132). A hose connects with the coupling (126), so th~t water undèr controlled pre3sure can be supplied to the rear side of the piston ~128) 80 th~t it can be forced through ~he expanding pipe (lO). At the s~me time, ~ 3hown be~t ln Fig 19, the ~team ~pe (134) whlch reoeive~ steam from ~

W~ 0/12~1 2 0 51~17 PCT/CB90/005l2 - 20 ~

st~am ~ener~tor (136) mounted on the vehlcle ~121), and the steam plpe passeq through the gland ~l27) and through the lnterior of the hose (132) and eventually throu~h the piston (128~ ~o ~ to is~ue lnto the ~pace between the expanding pipe (lO) and the pi~ton (128) The hot stsam ~oftan9 the pipe ~lO) and allowq lt ~o exp~nd a~ shown, ~nd ~he conden9ation i8 allowed to p~38 through the unexpanded portion of the pipe ( lO) out of ~n overqpill pipe (138) ~o ~8 to disch~r~e at a level of controllad head indicated by reference (140) in Flg l9 in the man-hole ~70). An inQulation sleeve (142) surrounds the pipe (lO) where it expandQ and ~lightly downstsam of same, and the sleeve ls pull~d along paq~ageway (68) by a winch (80) and winch cable (82) as described in relation to Flg ll.

In the illu~tration of Fi9 20, tha method illus~rated i~
essentially ~imilar to that shown in Fig l9, exc~pt that a poly-pig ~llO) is used ln place of the ~leeve (142), and in addition the piston ~128) comprises a pair of f lexible disc9 ~144 ) t I4~ ) between ~hich i8 fur~her poly-pig ~148) in order to ~orm a good seal be~ween the inner wall of the expander pipe (lO) and the pi~ton.

In the ~rrangement ~hown in ~lgs 21 and 22, no ~pec~fic ~xpandin~ mean~ 18 used, and the rigid pipe tlO) whlch 18 inserted in the sewer (68) as shown in Fig 21 is provided with a water co~plin~ (lS0) which a~ shown ln Flg 22 i~ coupled to a h~t resistant drop tube ( 152 ) lying in the man-hole t72), and which is ~upported ~rom ground level by meanA of a gland assembly (lS4). The gland assembly is coupled to a supply truck (156) 80 that hot water from tank (158) in the t~nk can b~ pumped through a central supply pipe ~160~ lnside ~he drop tube ~152), tha ~upply plpa ~ein~ loeated ~o that it8 ou~let end lie in the ~iolnlty of whers the pipe ~lO) i8 expandin~. In this connection ~he tube ~160) i~ ~eeled . . .

~_ 90/12241 ~ 7 pcr/c~B9o/oo5l2 on a driv~ reel (l62~ whlch i9 rotated a~ the sxp~nslon of ths tube ~ lO ) progresAes . In the operation of th~s method the length of pipe ~10) ~s placed ln the pa3sag~way ~68) and then af ter couplin~ the couplln~
(150) to the tube (160), hot water 1~ pumped out o~ the end of the ~ube (160) when it is located at the coupling tl50) end of the tube (10) o that end is heated by the incoming hot water. As the heated end axpands due to ~ha wa~er prss8ure, 80 the water in~ection tube tl60) i~
progressiv~ly fed along the inside of the expanding pipe a~ ~hown in Fig 22. When the expanQlon has been completed, the hot water can be pumped back up the tube ~160) and lnto the tank ~158) by couplln~ an air pump (162~) and hose ~164) to the gland (154), the hot wat~r oAn be tak~n to another lnstallation looatlon~ ~ai~ing ~he temperature of the returned hot water to lts former lsvel will requlre le~ than would be required if the hot watar were ~imply discarded~

The arran~ement of Fi~s 23 and 24 i~ ess~ntially slmllar to that shown in Fig3 21 and 22 with the exception that the pipe ~10) i8 provided with a cont~ol collar or ~lee~e (166) in the reglon where the pipe i~ expanding in order to perform an in~ulation function. The poly-pig~ and reaction sleeves and shiel~ reerred ~o hereln can all be arranged to per~orm an lnsulating unc~ion.

In eaoh of the embodiment of Fi~ 21 ~nd 22 and Fi~ 23 and 24, the down~tream end of the rigid pipe ~ lO ) i~
provided wlth a ~topper ~16~ ) which 18 de~ign~d ~co hav~
a Rmall leaksge characteristlc in~ofaras some of the water supplied to the interior of the pipe tlO) to heat and expand ~ame can al~o leak out of the down~tream end.
This ensure~ a good flow of hot watQr through the antire pipe tlO) and a certain amount of pre-heating of the plp~ llO) before the expan~ion of ~ame.

~e~erring to Flgs ?5 to 28, the~e ~igure~ ~how a w~ o/12241 2 0.~1~1 7 Pcr/GB90/005l2 modlf ied method compared to the methodq alraady de~cribed herein. The method of Figs 2S ~o 28 19 e~sentlally Qlmilar, ~ubject to the ~ollowing modlf ication. A~ ~hown in Fig 28, at ~round level provided a televlelon truck ~200) whlch i~ provided with a steam supply and a ~q'ceam hose ( 202 ) extends f rom the truck to the vlcinity of the llnin~ opera'cion.
Additlonally, the T.V. cable ~204) extends from the truck to a T.V. camera (206) in the plpellne or passageway following behind the rolling plg ~ 208 ) .

A 3econd vehicle (210) connects via the other man hole to the shield ~220) whlch i9 qimilar to the ~hieldR
described herein via a team hos~ (222) and a wlnching cable ~224). The cable (224) alQo connects with a wlnching drum ln vehicle (200). ~i~s 25 to 27 show the detail of tha compon~nt~ ln the pipelin0 or passagew~y.
The winch cable (224) ls shown, and it will be ~een to pa8~ through the rolling pig ~20B). The camera (205) is al~o shown as i5 the steam ho~e (204). The 3team hose t204) has an end t204A) adjacent the T.V. camera. F19Q
25 to 27 illustrate the effect when the T.V. camera which can view ~he operatlon view~ an imperfection in the lining application as indica~ed by reference (230).
Should thiq occur, and should it be required that the linlng procedura be temporarily rever~ed, the winch ropa (224) i~ pulled ln the opposite direction causing the plg to move backwards as indlcated ln Fig 26 whlch has the effect of exposlng the portion of the lining to be re-applled. The pig ~208) travel3 over the end (204A) of the steam hose, 80 that steam can be in~ected in~o ~he region of the imperfectly applied portion (23~) of the llner to soften ~ame, ~nd thi~ is followed by causing the piy once more to travel ln the forwards dlrection a3 indic~ted by arrow (232) in Fi~ 27 in order ~o properly apply the lining. If nece~ary the llnin~
operation c~n then procead at a slowar ra~e, U _90/12~1 2 0 ~1417 PCT/GB90/00512 A~ regard~ the modiflcation shown in Figs 23 and 30, ln the arrang~ment of Fig 29, a~aln the pig (2-OB) i~
lllu~trated, ~g i~ the towing rope (224). This rope i9 arranged to travel at twlce the spaed of the wlnching rope l234) wh~ch ~erves to pull the Rhield (236), the shlald ~236 ) having the same function as the shields h~reinbefore deQcribed. Again a T.V. camera (206) is provlded to complete the a~cent and ~he T.V. c~mera is used to observe the linlng proce!o~s .
~o In the arrangement of Fig 2~9, two pigs (208) and (208A) are used and the~e are linked by the winching rope (224). A steam hose ~204) ~lmilar to ~he hose described ln rel~tion to Fi~ 25 is u~ed for lnjectlng ~team into the space betw~n the pigs ~208 ) ~nd ~208A) in order to repair a secti~n t230) of ~mperfectly applied liningO

The pra~ent inventlon provide~ a u~eful and effsctive method for the lining of pipeline~ or p~ssa~eways, and also provldes improvements in the ba~ic material~ us~d for the lining operation. The heatlng of the rlgid pipe can take place at any appropriate tlme, and for the formatlon of the pipe into folded condltion, the ~oldlng may take place durlng extru9 lon or may ba performed ~f~er ~xtrusion. The pipe may be heated in order to dsform sam~ to the folded condition but it will require heat in ord0r to move lt to the round contltion in which lt lines th~ p~pellne or pas ageway.

When the rigid pipe 1~ in~erted lnto the pipellne or pa~sa~way as shown in Fig 11, it i heated be~ore it 1~
introduced into the pipeline or pa3~ageway and th$~ may apply in each embodiment. In the alternative it ~ay not b~ ncce~ ary to pre~heat the pipe in order to place it in the pipe1ine or pa~sag~way.

As r~gard~ the embodiment of the lnventl~an u~ln~ a rolling pi~, if water i8 u~ed to propel the pl~ throu~h W~ ,0/12~ P~`/CB90/005l2 the expandlng plpe~ it is provlded the c~pabllity of having excellent ~peed control for ~he expan~ion process.

Referring now to Fl99 31 - 33 of the drawlng~, an und~rground pa89ag~way i6 defined by a pipe 10. The pip9 ha~ a bell mouth joint 12, and it i~ jolned by a lateral pipe 14. The pa8~agewa~ may be a ~ewer, and the lateral pipe 14, may define a connection for example to a dome~tic d~elllng.

The figure shows that the pa~ageway is lnitially lined by a prellner tube 16, of pla~tic coated fabric or the like which 3erves to keep the interior of the plpeline or pa~sageway dry and prevents ingres~ of moi~ture f rom the surrounding ground 18..

The figure al80 3hows that the pa~sageway is lined by means of a pla3tic pipe 20 of a thermoplastic materlal which i8 fed in~o the pi~eline or pa8sageway and everted as indicated at an evertlng face 22~ In thiQ connection ~he pipe 20 i~ fed into the p~ssa~eway in an ini~ial condi~ion a~ indica'ced by refarence 24, and in whlch condltion the pipe ia of les~er overall dimension th~n the diamet~r of the pas~ag~way to b~ lined so thst the cver~ion 22 can take place. In the initial condltion as shown in Fig 32 the plpe 20 iq in star conflguration having been formed into thia configuration by any ~ul~cable mean~, for example ~ di~closed hereln before.
To change the pipe 20 from the ln~tial condition to evert same as indicated at 22 and to apply sam~ to the pa~sageway surface require~ the otherwi~e rigid pipe to be heatcd 90 that it will ~often ~nd deform to the correc~ configur~tion which a5 8hown ln Fig 32 is circular. To thi~ end the pipe may be everted by fluid prassure and the fluid ~upplyin~ the pres~ure may be hot wat~r or ~r and will fill the spac~ 26 between the pip~
$n ~he initi81 condition 24 and ln it9 linin~ po~itlon.

U ~0/12241 ~ 7 P~r/GB90/00512 -- 25 ~

- That water or ~ir (or steam) may be heat~d to esntrlbuta to the ~of tening of the pipe .

The evertin~ faee 22 of the plpe prafer~bly iQ hea~ed to a~si8t eversion and ln thi3 connec~clon heatlng may ~e effected by mean~ of a hot block 28 which i5 ~ block of ~teel or the like having passages 30 thsrein through which steam i~ supplled. It l~ noted that the block haa a contoured face whlch will in fact by compllmentary to the star shape ~hown in Fig 32 so that the ~vertln~ face 18 heated a evenly as po~sible. Some of 'che passage~ys 30 open to the portion of the block whlch engages ln the centre of th~ plpe in it~ inltlal condition 24 ~o that -~teAm i8 ~ed lnto the interior 34 of the pipe whlch also contributes to ~he hsating and softening of same.

The block may be mov~d along the pas~ageway a~ lndcated by arrow 38 by a tractor device 40 controlled from ground level. The tractor device may al~o embody a T~V.
camera 50 that the everslon operation can be obeerved to en~ure that the lining i~ beln~ correctly placed in posltion.

Becau~e the ~pace 26 i8 pres~urised, the lining 20 uill bulge $nwardly where the lining meet~ tha l~teral pipe 14 80 that a dimple 42 wlll be formed enabling subsequent identification of the locations of the lateral~ ~o that the dimple c~n be cut out to re-establl~h the latersl connection with the main passageway .

The bloek 28 will be ma~ntained at the appropria~e temperature to facilit~te the eversion without melting the plasties mAterial of the pipe ~0. The ~orce for ~verting the pipe may be e~fected ~lmply by pu~hln~ on th~ pips in it~ initlal conditlon 24 ~g indicated by arrow 44 or such a force may be u3ed in combln~tion with W~ ,Otl2~1 ~ 4 ~ 7 Pcr/cBgo/oos12 the fluid pressure.

Where the pipe 20 ln the initlal condition has to be fed down a manhole and then turned at a 3harp angle lnto the pa~sagaway, i~ may be de~irable to soften the pipe 80 that it can be effectively fed round the sharp corn~r.
Softening wlll be effected b~ sultable hea~ing of ~amel It i8 bel~eved that it may be possible to achieve the everslon ~imply by applying he~t only to ~he everting face 22 and th~s may be done either by the block ~ llustrated or in a preferred ca~e by a radiant heater whlch is spaced from the everting face ln order to ellmina~e possible frictlon.

To commence the eversion operation lt may be ne~e~sary to apply heat to the leading end of the pip~ and to turn it back upon it~eif ~o that aversion can be commended but once commenced, everslon ~hould proceed ~moothly and evenly resulting in the application of an even thickn~s and predeterm~ned 3trength lining tube on ~he 3urface of the passageway~

Fig 33 show~ an alternative shape for the pipe cro~4-~ection whereln the pet~l~ 21 are wider on the cre~t~
than the grooves 23 msking the pipe almo~ round in cross ~ection. This enables the pipe more rellably to be wound on a ~torage reel and prevents interlocking of the coll~ of the plpe wh~n on such reel.

Claims (16)

1. l. A rigid plastic pipe comprising folds therein which is capable of being heated and expanded to a larger diameter during which expansion the folds unfold, and wherein the pipe is twisted so that axially of the pipe the fold lines follow a helical path.
2. 2. A pipe according to Claim 1 or 2, wherein the pipe is folded so as to define petal shapes in cross-section, and the folding is such that the folded pipe in cross-section has at least 3 axes of symmetry.
3. 3. A rigid pipe according to Claim 1 or 2, wherein the pipe is folded either by being directly extruded in such condition, or it may be heated whilst in circular condition, and then provided with radial folds to provide the desired cross-section.
4. 4. A method of lining a pipeline or passageway wherein folded, rigid plastics material pipe is used to line the pipeline or passageway and wherein the pipe is placed in the pipeline or passageway and then the pipe is progressively unfolded to circular form to be applied to the pipeline or passageway surface by means of an expanding device which urges the opening pipe against a shield located to the outside of the pipe, and which travels with the expanding device along the pipeline or passageway as the plastic pipe is opened up, and the method also including that the plastic pipe, at least in the region which is opening up, is heated to a sufficient degree to enable the pipe to unfold.
5. 5. A method according to Claim 4, wherein the shield is defined by a sleeve which fits neatly to the pipeline or passageway surface and neatly receives the folded plastic pipe in its bore or the shield may be a stream jacket which surrounds the rigid pipe with clearance to en introduced between the jacket and rigid pipe, the steam jacket leading to a bell mouthed shield of which the bell mouth lies adjacent the enfolding or opening portion of the rigid pipe, said bell mouth serving to retain a chamber of steam around the opening rigid pipe for the application of heat thereof, but so that steam can excape from the clearance between the opening rigid pipe and the bell mouth casing.
6. 6. A method according to Claim 4, wherein the expansion device comprises a rolling pig or a bucket pig which is forced through the rigid pipe so as to lie slightly upstream of the region of the rigid pipe which is for the time being, being heated.
7. 7. A method of lining a pipeline or passageway wherein a folded rigid plastics material pipe is used to line the pipeline or passageway and wherein the pipe is placed in the pipeline or passageway wherein the opening up of the rigid pipe can be effected by means of progressive heating using hot water which issues from a hot water feed tube which is inserted into the end of the rigid pipe, and from which hot water issues in order to contact the inner surface of the rigid pipe.
8. 8. A method according to Claim 7, wherein the feed pipe is progressively fed along the inside of the opening rigid pipe thereby progressively to heat and inflate the rigid pipe and the downstream end of the rigid pipe may be sealed by means of a stopper which has a bleed valve therein in order to allow a small leakage of the hot water through the inside of the rigid folded pipe for the pre-heating of same prior to unfolding.
9. 9. A method according to any of the Claims 4 to 8, wherein the pipe is inserted into the pipeline or passageway by means of a pulling or pushing action, and it may be passed over a healing box in order to soften the pipe to enable it to be correctly positioned and fed into the pipeline or passageway.
10. 10. A method of lining a passageway comprising the utilisation of a rigid or semi-rigid tube of theremoplastics material which in an initial condition is of smaller overall dimensions than the diameter of the passageway to be lined, and wherein the tube is fed in the initial condition into the passageway, and inside the passageway the tube is everted to a final condition where it lies against the passageway surface lining same.
11. 11. A method according to Claim 10, wherein the tube has folds therein in order to reduce its overall diameter or alternatively in the initial condition it may be circular and of smaller diameter than the passageway to be lined.
12. 12. A method according to Claims 10 or 11, wherein the tube is of a type having a memory so that the tube is first of all produced in the final diameter size and then is heated to soften same and the tube is stretched to the initial diameter and then cooled to rigidify the tube in the initial diameter size.
13. 13. A method according to Claims 10, 11 or 12, wherein to enable the tube to evert from the initial condition to the final condition, heat is applied to soften the thermoplastic material of the tube but only sufficient heat to enable the tube to be re-shaped and so as to avoid melting of same.
14. 14. A method according to Claim 13, wherein the eversion of the tube inside the passage may be effected by fluid under pressure, and that fluid may be heated.
15. 15. A method according to Claims 13 or 14, wherein heated fluid is applied to the inside of the tube to give even heating and even softening of same.
16. 16. A method according to Claim 13 wherein a heating means such as a radiant heater or a steam heated block is provided in the passageway ahead of the everting face so as locally to heat the everting face to allow the eversion to continue.