Note: Descriptions are shown in the official language in which they were submitted.
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
- 3 -
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
- 4 -
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
-- 8 --
~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~
-- 10 --
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
-- 12 --
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
-- 13 --
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
-- 14 -
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
- 16 -
(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
- 17 -
-
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
19 -
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
22
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
- 23 -
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
- 24 -
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
- 26 -
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.
