CA1282308C - Method of internal anticorrosive protection of pipelines - Google Patents
Method of internal anticorrosive protection of pipelinesInfo
- Publication number
- CA1282308C CA1282308C CA000493130A CA493130A CA1282308C CA 1282308 C CA1282308 C CA 1282308C CA 000493130 A CA000493130 A CA 000493130A CA 493130 A CA493130 A CA 493130A CA 1282308 C CA1282308 C CA 1282308C
- Authority
- CA
- Canada
- Prior art keywords
- hose
- pipeline
- pipe
- pressure
- internal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C63/00—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor
- B29C63/0065—Heat treatment
- B29C63/0069—Heat treatment of tubular articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C63/00—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor
- B29C63/26—Lining or sheathing of internal surfaces
- B29C63/34—Lining or sheathing of internal surfaces using tubular layers or sheathings
- B29C63/36—Lining or sheathing of internal surfaces using tubular layers or sheathings being turned inside out
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C63/00—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor
- B29C63/48—Preparation of the surfaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
- F16L58/02—Protection of pipes or pipe fittings against corrosion or incrustation by means of internal or external coatings
- F16L58/04—Coatings characterised by the materials used
- F16L58/10—Coatings characterised by the materials used by rubber or plastics
- F16L58/1009—Coatings characterised by the materials used by rubber or plastics the coating being placed inside the pipe
- F16L58/1027—Coatings characterised by the materials used by rubber or plastics the coating being placed inside the pipe the coating being a sprayed layer
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- Lining Or Joining Of Plastics Or The Like (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Protection Of Pipes Against Damage, Friction, And Corrosion (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
- Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
Abstract
METHOD OF INTERNAL ANTICORROSIVE
PROTECTION OF PIPELINES
ABSTRACT
A method of internal anticorrosive protection of a pipeline comprises the steps of introducing a fle-xible hose into a pipeline, pushing said hose forward and pressing said hose against the internal surface of the pipeline by building up excess pressure in the space between the hose and the pipe. The hose is pressed against the internal surface of the pipe and, simultaneously, the pipe is heated from inside, the pressure on both sides of the hose introduced into the pipeline being suitably regulated.
PROTECTION OF PIPELINES
ABSTRACT
A method of internal anticorrosive protection of a pipeline comprises the steps of introducing a fle-xible hose into a pipeline, pushing said hose forward and pressing said hose against the internal surface of the pipeline by building up excess pressure in the space between the hose and the pipe. The hose is pressed against the internal surface of the pipe and, simultaneously, the pipe is heated from inside, the pressure on both sides of the hose introduced into the pipeline being suitably regulated.
Description
MErrHO~ 0~ IN'~ERNAL ~JTICOi.~OSIY~
PROTECTION OF PII'ELII~S
~ his invention relates to construction and ope-ration of pipelines aad, in particular, to a method of internal protection of pipelines against corrosion.
This invention can be used most advantageously for protection of the internal surfacs of trunk a-nd distribution pipelines against corrosion. It can be used for anticorrosion protectio~ of deliv~ry and low-pressur~ pipelines utilized in land reclamation9 public and proces s water supply systems, and in h0at and power generation systems.
In addition9 the invention can be used for pro-tection of pipel~nes for water supply to gas and oil wells and ~or pumping o~ chemical products.
The invention can be used both during laying of new pipelines and ~or protectio~ of active pipe-lines .
At present protection of inside surface of pipe-lines is a pressing problem in many technical fields.
Particularly urqe~t is protection o~ active pip~lines since their internal sur~ace is constantly wetted by some liquid, ~ter, for example Conventionally1 the internal surface of a pipe has ~o be dried before applying a protective coating. ~he drying pxoc~ss has to immediately preceed the applic~tion process or~
otherwise the inter~al surface gets wet again by - 2 ~ 3V~;~q3~
moiqture preclpitated ~rom the atmosphere.
At present, there ar~ ~no~n variou~ methods a~d device6 far internal protection of pipelin~s ~gainst corrosion.
Known in the art is a method ~or coating the internal sur~`ace of a pipe b~ a cement-and-sand mi~ture (cf., ~or ex~npleg hMER0~ Co. pamphlet, New York 7 1978, pp 54~-601).
This method is de~icient in that it is inefficient .
si~ce one installation can coat 690 m o~ a 700 Dm pipe .
Also Xno~Jn i~ the art is a method for i~ternal prot~ction of a pipeline agai~st corrosion, consisting in that a hose of a polymer material is fed lnto a pipeline, the pipe is heated and the polymer hose is pressed from i~side to the sur~'ace o~ the pipe, The devic~ realizing this method comprises a means for feedi~ the polymer hose into th~ pipeline, a system for ~eedi~g a working medium into the pipeline and a heater installed on the pipeline from outside (c~, for example, U~SR Inventor's Certi-~icate No. 1 018 729, IPC F16 L 5~/009 198~ ~n~ u.S.
Patent 4,135,958 issued January 23, 1979 to Insitu~orm International Inc.).
s~rious disadva~kage o~ ~his method consi6ta in that it cannot be uaed for coatin~ activ~ pipeli~es, This method can only be uaed by the.~acturer when the heater is mov~d alon~ ~he external su~face of the pipe.
.~
~ 2 It is an object of the invention to improve the quality of protective coatin~s in actin~ pipe-lines.
Another object o~ the invention is to ma~e the service life of acting pipelines lo~ger~
- One more object of this invention is to make the section of the active pipeline coated at one setting much lon~er~
Still another object of this invention is to make the pipeline more reliable.
And, finally, a further obaect of thi~ invention is to cut the cost of the protective coating applied on ac~ive pipelines.
q'hese and other objects of` the invention are ~chieved in ~hat in a method of internal anticorrosi~e protection of` pipelines, comprisin~ the steps of feedin~ a ~lexible hose into the pipeline, securin~
the end of said hose, whic~ is turned inside out~ to the internal wall of the pipeline, moving the hose along the pipeline, pressin~ said hose against the intern~l surface of the pipeline by producin~ an excessive pressure in the spac~ de~ined by the hose and the pipe, and heati~g the pipe, according to the inv~ntion, the pipe is heated ~rom inside and the hose is silnultaneously presse~ a~airlst th~ lnt~rnal surface of the pip~, the pressure differential on 3~
both si~es of the hose fed into the pipeline being suitably adjusted.
~ rlhis method provides a protective coating of active pipelines and those under construction. This is ~chiev-ed in that the pipeline is heated ~rom in~ide~ Simul-taneous pressin~ of the hose to the pipe wall and its heati~ produce a reliable bonding of the hose and pipe. The guali~y of the coatlng thus made is extremely high, which makes the service life of' the pipeline much longer.
This method can be used to provide a protective coatin~ o~ active pipelines and t~lose still being laidg both on the sur~ace and buried ones.
Since the pressure dif`ferenc~ o~ both sides of the hose fed into the pipeline can be adjusted, the feeding speed can be controlle~, and the ~orce with which the hos~ is pres~ed against the wall of the pipe can be regulated~ This rules out ruptures of the hose and adds to the better qual~ty of the pipe coat-ing~
In the pre~erred embodiment o~ the i~ventio~
the pipeline is heated simultarleously with the hose being fed lnto the pipe. The guality of the coating this formed i~ much better because the temperature in the zone where the hose i8 pr~ssed against the internal sur~ace o~ thc pipe is constant.
It is advis~ble that the pxessure dif~erential is re~ulated by re~ulatin~ the pressure ol' the working medium in the pipeline before the hose fed into the pipe.
~ his permits prevention o~ hydraulic and pheumatic shocks on the hose in the pipeline~
ln one o~ the embodiments of the invention the pressure differential is regulated by lowering the pressure in the pipeline be~ore the moving hose and simultaneous communication of the space between the hose and pipe with atmosphere. In thiS manrler ruptures of the hose can be prevented, if they are due to irregular movement of the hose. Ilhe vacuum produced in the pipeline in front of the hose provides better conditions for ~rying the walls of the pipe, th~ ad-hesion of the hose to the wall of the pipe is substan-tially improved. ~ower is also sa~ed since the pressure crop is localized ~ithin the pipeline.
~ hîs protects the hose against ruptures and improves the quality of th~ protective coati~g.
It is ad~isable that protectors made of a material capable of prod~cing9 in combination with the pipe metal, an electrochemical potential are installed into the annular gap between the hose and p~pe ~imultaneously with the feddin~ o~ the hose into this pipe.
~3 This makes the pipelin~ more reliable since the mechanical protection of the pipeline is supplemented by the additional electrochemical protection ~hich can ward off corrosion ~ven wh~n the hose is not tight.
In one OI` the embodiments of the invention, after the polymer hose is introduced into thc ~ipe-line, anotner hose made of a no~-ther~oplastic material is introduced in this pipeli~e. ~hen the pipe is heated, the polymer ho.se melts.
'l'his produces a durable and corrosion-proof`
protective coating made o~, for example a carbon-filled plastic or glass ~iber.
In another embodiment oY this invention, blip is applied on ~he internal su~face of the pipe before the hose is fed into it, and, after the glass cloth hose has been placed into the pipe, it is heated until the slip ~elts.
This embodiment provides a stronger and more reliable coating ~or protection of the pipeline agains t corrosi on in ~;re ss ive me di a .
When the ~lip melts, pores are f ormed i~ the coatin~, But the pressure buil~ up in the glass cloth hose in the process of heating the slip comple-tely prevents ~ormation oY pores in the coatin~ andt consequently 7 improves the reliability of the pipeline .
It is advi~able that the pipeline is h~ated from inside by purnpin~ heated gas thro~h the internal hose made from a non-thermoplastic rnateri~l.
In this manner the processes of drying and heating the internal surface o~ the pipellne can be combined and made simplier.
It is also advisable that the heated gas should be fed in the pipeline to meet the hose introduced into the pipe and released throu~h the pipe into atmosphere. This embodiment of the invention makes drying of the pipe and regulation of the pressure di~ferential on both sides of the hose a much ~implier task.
In accordance with another embodiment of the invention, the pipe is heated simultaneously with the introductio~ of the hose into it by ~eedi~g a co~bu~-tible mixture into the pipe and igniting it khereafter.
I'his method pxovi~es a built-up o~ pressure inside the pipeline. '~his ma~es the device realizing the method much simplier.
The hose i5 heated and pressed against the pipe wall at the same ti~e. '~he guality of the coating becomes better since the ho~e fills all pores and pits in the pipe wall. The wall of the pipeline cools o~ practically simultaneously throughout the leng~h o~ the pipeline. Relaxation stresses in the coating are reduced and its guality becomes better. In this way the cost of the coatin~ is cut down and the coat-in~ application process becomes mole e~fective sinc~
the hose is pushed forward and pressed against the pipeline walls by the force o~ the combustible mixture~
In accordance with one of the embodiments of the invention a protective alloy is applied onto the internal surface o~ the pipeline before the hose is pressed thereto, This provides an a~ditional electrochemical protection of the pipeline in case the hos~ is ruptur -ed. Besides, t~he dissolution products of the prot~ctive alloy, for example~ an ~l~minum-Gallium allo~, are deposited on the wall o~ the pipeline and form an oxide film which protects the pipeline a~ainst corrosi-on for many years-to come.
Other objects and advanta~es of the invention will become apparent from the following description of preferred embodiments theresf, ta~en in conju~ction with the accompanying drawings.
A method of internal anticorrosion protection of pipelines consists in introducing a flexible hose into the pipeline, securing the forward end o~ the hose, which is turned inside ou~, on the internal surface o~ the pipeline, and then moving the hose and pressing it against this internal surface of the pipeline. The hose is pushed along the pipeline and ~ 3~
pressed against its walls by the excess pressure built up i~ the space between the turncd out end o~
the hose and the pipe. ~lhe pipeline is heated at the same time as the hose is presse~ against the wall thereo~`~
~xample 1 A polyethylene hose i5 introduced into a pipeline~
the leadin~ end of the hose being tur~ed inside out and secured to the internal surface of the pipeline.
Air compres~ed to 0.3 ~a is pumped into the space between the hose and the pipe. A heater is installed into the pipe in front of the hose which pushes it alon~ the pipe. In this way the hose and the heater are moving simultaneously in the pipe.
The internal surface o-~ the pipeline is heated to 150C. Compressed air presses the hose to the wall o~ the pipe and welds it reliably to this wall. As the hose is pushed along the pipeline, a pressure of 0.15 MPa is produced in the space before the hoso.
This pressure is produced by compressed air fed into the pipe space be~ore the hose end. '~he air is re-leased to atmosphere through an opening made in the pipe at the end of the coated se~tion. '~he pressure can be built up by pumpin~ the air out of the pipe space i~ ~ront of the hose. Prior to installation?
the hose is rein~orced with wire made of an alumi~um 30~3 alloy. The pip~line is hr~ated by supplying a not ~as through the hose a~d, consequently, the pipeline. The hot gas can be either supplied at the end of the pipe-line in the direction opposite to the movement of the hose or at the beginnirlg o~` the pipeline in the same direction. In botr. cases the hot gas is released to atmosphere throu~h the hose.
Example 2.
A polyethylene hose is introduced into a pipeline, a carbon-~illed plastic hose bein~ inserted inside the ~irst hose. The leadin~ ends of both hoses are turned inside out and secured to the internal surface of the pipeline. After that, air heated to 150C at a pressure o~ 0.2 MPa is pumped into the hose and it starts moving along the pipeline drying and heating the walls. The polyethylene hose melts as it is heated further o~ and, ~hen cooling, it welds tlle internal hose to the wall of the pipeline.
~ ot air can also be pumped into the pipeline in the opposite directio~ to tne movement of the hose and released throu~h the internal hose.
E~ample 3 Initially, slip is pumped through the pipeline.
~fter that~ using the method described in EXample 2 9 two hose~ are introduced into the pip~line. 'I`he external hose is made o~ polyethylene, the intcrnal one of glass cloth.
v~hen two hoses are introduced into the pipeline, the i~ternal ~Jall thereof is heated to 500C.
Tne heat- melts the .51ip and welds both hoses to the wall of the pipe.
~ xample 4, lnitially, slip is pulQped throu~h the pipeline.
'l`herl, t~o hoses are introduced into the pipeline es described in Example 3. 'l'he workin~ medium pumped into the pipeline i~ a mixture of oxygen and propane taken in ~ proportion 1 to 4 by wei~ht. After tne hoses are in the pipeline, the mixture is ignited.
`The heat produced by the burnin~ mixture heats the internal ~all of the ~ipeline ~nd the hoses are welded thereto.
Example 5 A polyethylene hose is introduced into the pipe~
line as in Example 1.
Prior to introducing the polymer hose into the pipeline, a layer of a protective alloy is sprayed over the internal su~face of the pipe~ 'l'he protective alloy comprises the ~olloY/in~, parts bg weight:
Magnesium 1 ;
Gallium - 0,5 ;
The balance - Aluminum~
This alloy is preheated to a temperature of 950C.
~hen the melt i~ sprayed over the wall of thc p~peline ' .
3~8 1~ --usin~ approximately 80 ~ o~ the melt for one syuare meter o~ the internal surface. 'llnen a polyethylene hose is introduced into the pipelin~. The ho~e is melte~
and a protective coating i9 formed through the heat of ~he wall o~ the pipeline.
~xample 6 A polyethylene hose is introduced into the pipe-line as described in Exampl~ 1~
i~hen the hose is manuf~ctux~d~ it is rein~orced with wire made of a protective alloy, Al-Ga alloy, for example, as described in Example 5.
ln case the hose is ruptured, an electrochemical potential is produced between the metal of the pipe wall and the wires. ~his potential protects the pipe-line against corrosio~
The wire in the place of rupture is dissol~ed and the dissolution products are deposited on the pipe wall as an oxide ~ilm which protects the pipeline against corrosion.
PROTECTION OF PII'ELII~S
~ his invention relates to construction and ope-ration of pipelines aad, in particular, to a method of internal protection of pipelines against corrosion.
This invention can be used most advantageously for protection of the internal surfacs of trunk a-nd distribution pipelines against corrosion. It can be used for anticorrosion protectio~ of deliv~ry and low-pressur~ pipelines utilized in land reclamation9 public and proces s water supply systems, and in h0at and power generation systems.
In addition9 the invention can be used for pro-tection of pipel~nes for water supply to gas and oil wells and ~or pumping o~ chemical products.
The invention can be used both during laying of new pipelines and ~or protectio~ of active pipe-lines .
At present protection of inside surface of pipe-lines is a pressing problem in many technical fields.
Particularly urqe~t is protection o~ active pip~lines since their internal sur~ace is constantly wetted by some liquid, ~ter, for example Conventionally1 the internal surface of a pipe has ~o be dried before applying a protective coating. ~he drying pxoc~ss has to immediately preceed the applic~tion process or~
otherwise the inter~al surface gets wet again by - 2 ~ 3V~;~q3~
moiqture preclpitated ~rom the atmosphere.
At present, there ar~ ~no~n variou~ methods a~d device6 far internal protection of pipelin~s ~gainst corrosion.
Known in the art is a method ~or coating the internal sur~`ace of a pipe b~ a cement-and-sand mi~ture (cf., ~or ex~npleg hMER0~ Co. pamphlet, New York 7 1978, pp 54~-601).
This method is de~icient in that it is inefficient .
si~ce one installation can coat 690 m o~ a 700 Dm pipe .
Also Xno~Jn i~ the art is a method for i~ternal prot~ction of a pipeline agai~st corrosion, consisting in that a hose of a polymer material is fed lnto a pipeline, the pipe is heated and the polymer hose is pressed from i~side to the sur~'ace o~ the pipe, The devic~ realizing this method comprises a means for feedi~ the polymer hose into th~ pipeline, a system for ~eedi~g a working medium into the pipeline and a heater installed on the pipeline from outside (c~, for example, U~SR Inventor's Certi-~icate No. 1 018 729, IPC F16 L 5~/009 198~ ~n~ u.S.
Patent 4,135,958 issued January 23, 1979 to Insitu~orm International Inc.).
s~rious disadva~kage o~ ~his method consi6ta in that it cannot be uaed for coatin~ activ~ pipeli~es, This method can only be uaed by the.~acturer when the heater is mov~d alon~ ~he external su~face of the pipe.
.~
~ 2 It is an object of the invention to improve the quality of protective coatin~s in actin~ pipe-lines.
Another object o~ the invention is to ma~e the service life of acting pipelines lo~ger~
- One more object of this invention is to make the section of the active pipeline coated at one setting much lon~er~
Still another object of this invention is to make the pipeline more reliable.
And, finally, a further obaect of thi~ invention is to cut the cost of the protective coating applied on ac~ive pipelines.
q'hese and other objects of` the invention are ~chieved in ~hat in a method of internal anticorrosi~e protection of` pipelines, comprisin~ the steps of feedin~ a ~lexible hose into the pipeline, securin~
the end of said hose, whic~ is turned inside out~ to the internal wall of the pipeline, moving the hose along the pipeline, pressin~ said hose against the intern~l surface of the pipeline by producin~ an excessive pressure in the spac~ de~ined by the hose and the pipe, and heati~g the pipe, according to the inv~ntion, the pipe is heated ~rom inside and the hose is silnultaneously presse~ a~airlst th~ lnt~rnal surface of the pip~, the pressure differential on 3~
both si~es of the hose fed into the pipeline being suitably adjusted.
~ rlhis method provides a protective coating of active pipelines and those under construction. This is ~chiev-ed in that the pipeline is heated ~rom in~ide~ Simul-taneous pressin~ of the hose to the pipe wall and its heati~ produce a reliable bonding of the hose and pipe. The guali~y of the coatlng thus made is extremely high, which makes the service life of' the pipeline much longer.
This method can be used to provide a protective coatin~ o~ active pipelines and t~lose still being laidg both on the sur~ace and buried ones.
Since the pressure dif`ferenc~ o~ both sides of the hose fed into the pipeline can be adjusted, the feeding speed can be controlle~, and the ~orce with which the hos~ is pres~ed against the wall of the pipe can be regulated~ This rules out ruptures of the hose and adds to the better qual~ty of the pipe coat-ing~
In the pre~erred embodiment o~ the i~ventio~
the pipeline is heated simultarleously with the hose being fed lnto the pipe. The guality of the coating this formed i~ much better because the temperature in the zone where the hose i8 pr~ssed against the internal sur~ace o~ thc pipe is constant.
It is advis~ble that the pxessure dif~erential is re~ulated by re~ulatin~ the pressure ol' the working medium in the pipeline before the hose fed into the pipe.
~ his permits prevention o~ hydraulic and pheumatic shocks on the hose in the pipeline~
ln one o~ the embodiments of the invention the pressure differential is regulated by lowering the pressure in the pipeline be~ore the moving hose and simultaneous communication of the space between the hose and pipe with atmosphere. In thiS manrler ruptures of the hose can be prevented, if they are due to irregular movement of the hose. Ilhe vacuum produced in the pipeline in front of the hose provides better conditions for ~rying the walls of the pipe, th~ ad-hesion of the hose to the wall of the pipe is substan-tially improved. ~ower is also sa~ed since the pressure crop is localized ~ithin the pipeline.
~ hîs protects the hose against ruptures and improves the quality of th~ protective coati~g.
It is ad~isable that protectors made of a material capable of prod~cing9 in combination with the pipe metal, an electrochemical potential are installed into the annular gap between the hose and p~pe ~imultaneously with the feddin~ o~ the hose into this pipe.
~3 This makes the pipelin~ more reliable since the mechanical protection of the pipeline is supplemented by the additional electrochemical protection ~hich can ward off corrosion ~ven wh~n the hose is not tight.
In one OI` the embodiments of the invention, after the polymer hose is introduced into thc ~ipe-line, anotner hose made of a no~-ther~oplastic material is introduced in this pipeli~e. ~hen the pipe is heated, the polymer ho.se melts.
'l'his produces a durable and corrosion-proof`
protective coating made o~, for example a carbon-filled plastic or glass ~iber.
In another embodiment oY this invention, blip is applied on ~he internal su~face of the pipe before the hose is fed into it, and, after the glass cloth hose has been placed into the pipe, it is heated until the slip ~elts.
This embodiment provides a stronger and more reliable coating ~or protection of the pipeline agains t corrosi on in ~;re ss ive me di a .
When the ~lip melts, pores are f ormed i~ the coatin~, But the pressure buil~ up in the glass cloth hose in the process of heating the slip comple-tely prevents ~ormation oY pores in the coatin~ andt consequently 7 improves the reliability of the pipeline .
It is advi~able that the pipeline is h~ated from inside by purnpin~ heated gas thro~h the internal hose made from a non-thermoplastic rnateri~l.
In this manner the processes of drying and heating the internal surface o~ the pipellne can be combined and made simplier.
It is also advisable that the heated gas should be fed in the pipeline to meet the hose introduced into the pipe and released throu~h the pipe into atmosphere. This embodiment of the invention makes drying of the pipe and regulation of the pressure di~ferential on both sides of the hose a much ~implier task.
In accordance with another embodiment of the invention, the pipe is heated simultaneously with the introductio~ of the hose into it by ~eedi~g a co~bu~-tible mixture into the pipe and igniting it khereafter.
I'his method pxovi~es a built-up o~ pressure inside the pipeline. '~his ma~es the device realizing the method much simplier.
The hose i5 heated and pressed against the pipe wall at the same ti~e. '~he guality of the coating becomes better since the ho~e fills all pores and pits in the pipe wall. The wall of the pipeline cools o~ practically simultaneously throughout the leng~h o~ the pipeline. Relaxation stresses in the coating are reduced and its guality becomes better. In this way the cost of the coatin~ is cut down and the coat-in~ application process becomes mole e~fective sinc~
the hose is pushed forward and pressed against the pipeline walls by the force o~ the combustible mixture~
In accordance with one of the embodiments of the invention a protective alloy is applied onto the internal surface o~ the pipeline before the hose is pressed thereto, This provides an a~ditional electrochemical protection of the pipeline in case the hos~ is ruptur -ed. Besides, t~he dissolution products of the prot~ctive alloy, for example~ an ~l~minum-Gallium allo~, are deposited on the wall o~ the pipeline and form an oxide film which protects the pipeline a~ainst corrosi-on for many years-to come.
Other objects and advanta~es of the invention will become apparent from the following description of preferred embodiments theresf, ta~en in conju~ction with the accompanying drawings.
A method of internal anticorrosion protection of pipelines consists in introducing a flexible hose into the pipeline, securing the forward end o~ the hose, which is turned inside ou~, on the internal surface o~ the pipeline, and then moving the hose and pressing it against this internal surface of the pipeline. The hose is pushed along the pipeline and ~ 3~
pressed against its walls by the excess pressure built up i~ the space between the turncd out end o~
the hose and the pipe. ~lhe pipeline is heated at the same time as the hose is presse~ against the wall thereo~`~
~xample 1 A polyethylene hose i5 introduced into a pipeline~
the leadin~ end of the hose being tur~ed inside out and secured to the internal surface of the pipeline.
Air compres~ed to 0.3 ~a is pumped into the space between the hose and the pipe. A heater is installed into the pipe in front of the hose which pushes it alon~ the pipe. In this way the hose and the heater are moving simultaneously in the pipe.
The internal surface o-~ the pipeline is heated to 150C. Compressed air presses the hose to the wall o~ the pipe and welds it reliably to this wall. As the hose is pushed along the pipeline, a pressure of 0.15 MPa is produced in the space before the hoso.
This pressure is produced by compressed air fed into the pipe space be~ore the hose end. '~he air is re-leased to atmosphere through an opening made in the pipe at the end of the coated se~tion. '~he pressure can be built up by pumpin~ the air out of the pipe space i~ ~ront of the hose. Prior to installation?
the hose is rein~orced with wire made of an alumi~um 30~3 alloy. The pip~line is hr~ated by supplying a not ~as through the hose a~d, consequently, the pipeline. The hot gas can be either supplied at the end of the pipe-line in the direction opposite to the movement of the hose or at the beginnirlg o~` the pipeline in the same direction. In botr. cases the hot gas is released to atmosphere throu~h the hose.
Example 2.
A polyethylene hose is introduced into a pipeline, a carbon-~illed plastic hose bein~ inserted inside the ~irst hose. The leadin~ ends of both hoses are turned inside out and secured to the internal surface of the pipeline. After that, air heated to 150C at a pressure o~ 0.2 MPa is pumped into the hose and it starts moving along the pipeline drying and heating the walls. The polyethylene hose melts as it is heated further o~ and, ~hen cooling, it welds tlle internal hose to the wall of the pipeline.
~ ot air can also be pumped into the pipeline in the opposite directio~ to tne movement of the hose and released throu~h the internal hose.
E~ample 3 Initially, slip is pumped through the pipeline.
~fter that~ using the method described in EXample 2 9 two hose~ are introduced into the pip~line. 'I`he external hose is made o~ polyethylene, the intcrnal one of glass cloth.
v~hen two hoses are introduced into the pipeline, the i~ternal ~Jall thereof is heated to 500C.
Tne heat- melts the .51ip and welds both hoses to the wall of the pipe.
~ xample 4, lnitially, slip is pulQped throu~h the pipeline.
'l`herl, t~o hoses are introduced into the pipeline es described in Example 3. 'l'he workin~ medium pumped into the pipeline i~ a mixture of oxygen and propane taken in ~ proportion 1 to 4 by wei~ht. After tne hoses are in the pipeline, the mixture is ignited.
`The heat produced by the burnin~ mixture heats the internal ~all of the ~ipeline ~nd the hoses are welded thereto.
Example 5 A polyethylene hose is introduced into the pipe~
line as in Example 1.
Prior to introducing the polymer hose into the pipeline, a layer of a protective alloy is sprayed over the internal su~face of the pipe~ 'l'he protective alloy comprises the ~olloY/in~, parts bg weight:
Magnesium 1 ;
Gallium - 0,5 ;
The balance - Aluminum~
This alloy is preheated to a temperature of 950C.
~hen the melt i~ sprayed over the wall of thc p~peline ' .
3~8 1~ --usin~ approximately 80 ~ o~ the melt for one syuare meter o~ the internal surface. 'llnen a polyethylene hose is introduced into the pipelin~. The ho~e is melte~
and a protective coating i9 formed through the heat of ~he wall o~ the pipeline.
~xample 6 A polyethylene hose is introduced into the pipe-line as described in Exampl~ 1~
i~hen the hose is manuf~ctux~d~ it is rein~orced with wire made of a protective alloy, Al-Ga alloy, for example, as described in Example 5.
ln case the hose is ruptured, an electrochemical potential is produced between the metal of the pipe wall and the wires. ~his potential protects the pipe-line against corrosio~
The wire in the place of rupture is dissol~ed and the dissolution products are deposited on the pipe wall as an oxide ~ilm which protects the pipeline against corrosion.
Claims (4)
1. A method of internal anticorrosive protection of a pipeline, comprising the steps of:
introducing a flexible hose into said pipeline;
building up an excess pressure in the space between said pipeline and said hose whose end is turned inside out and secured to an internal surface of said pipeline;
pushing forward and pressing said hose to said internal surface of said pipeline by said excess pressure;
heating said pipeline from inside;
said build-up of excess pressure, pressing said hose to said heated internal surface of said pipeline and fusing said hose onto the internal surface of said pipeline being performed simultaneously.
introducing a flexible hose into said pipeline;
building up an excess pressure in the space between said pipeline and said hose whose end is turned inside out and secured to an internal surface of said pipeline;
pushing forward and pressing said hose to said internal surface of said pipeline by said excess pressure;
heating said pipeline from inside;
said build-up of excess pressure, pressing said hose to said heated internal surface of said pipeline and fusing said hose onto the internal surface of said pipeline being performed simultaneously.
2. A method as claimed in claim 1, wherein the pipeline is heated simultaneously with the introduction of the hose therein.
3. A method as claimed in Claim 2, wherein the pressure differential is regulated by adjusting the pressure of a working medium in the pipeline before the hose being introduced therein.
4. A method as claimed in Claim 1, wherein a pressure differential on both sides of the hose is regulated by lowering the pressure in the pipeline before the moving hose and, simultaneously, providing communication of the space between the hose and the pipe wall with atmosphere.
Applications Claiming Priority (22)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SU3797662 | 1984-10-17 | ||
| SU3797913 | 1984-10-17 | ||
| SU843797420A SU1404750A1 (en) | 1984-10-17 | 1984-10-17 | Method of applying protective coating on internal surface of pipe-line |
| SU3797913 | 1984-10-17 | ||
| SU3797653 | 1984-10-17 | ||
| SU3797421 | 1984-10-17 | ||
| SU3797424 | 1984-10-17 | ||
| SU843797653A SU1395524A1 (en) | 1984-10-17 | 1984-10-17 | Method of lining internal surfaces of pipes with polymeric film material |
| SU3797915 | 1984-10-17 | ||
| SU3797417 | 1984-10-17 | ||
| SU3797417 | 1984-10-17 | ||
| SU3797658 | 1984-10-17 | ||
| SU3797915 | 1984-10-17 | ||
| SU3797406 | 1984-10-17 | ||
| SU3797662 | 1984-10-17 | ||
| SU3797421 | 1984-10-17 | ||
| SU3797658 | 1984-10-17 | ||
| SU843797652A SU1399160A1 (en) | 1984-10-17 | 1984-10-17 | Device for lining inner surface of pipes |
| SU3797406 | 1984-10-17 | ||
| SU3797652 | 1984-10-17 | ||
| SU3797424 | 1984-10-17 | ||
| SU3797420 | 1984-10-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1282308C true CA1282308C (en) | 1991-04-02 |
Family
ID=27582370
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000493130A Expired - Lifetime CA1282308C (en) | 1984-10-17 | 1985-10-16 | Method of internal anticorrosive protection of pipelines |
Country Status (6)
| Country | Link |
|---|---|
| AU (1) | AU5195086A (en) |
| CA (1) | CA1282308C (en) |
| DE (2) | DE3590521C2 (en) |
| FR (1) | FR2571822B1 (en) |
| GB (1) | GB2176263A (en) |
| WO (1) | WO1986002429A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2200712A (en) * | 1986-04-30 | 1988-08-10 | Trest Juzhvodoprovod | Method of protecting internal surface of pipeline against corrison |
| ES2026254T3 (en) * | 1987-04-27 | 1992-04-16 | Angus Fire Armour Limited | PIPE RENOVATION SYSTEM. |
| GB2213230B (en) * | 1987-12-28 | 1992-05-06 | Osaka Bosui Kensetsusha Kk | Method of lining branch pipe portion of underground main pipe with rigid plastics tube |
| BE1007792A6 (en) * | 1993-12-21 | 1995-10-24 | Capelle Robert | Filling process pipe tube by survivors. |
| GB9526062D0 (en) * | 1995-12-20 | 1996-02-21 | Wood John | Pipes |
| UA59354C2 (en) * | 1996-09-18 | 2003-09-15 | Московскоє Государствєнноє Прєдпріятіє "Мосводоканал" | coating applied on to the inner surface of a pipe, method for applying it on the inner surface of the pipeline, two-layer blank part for the coating and method for making it |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1221431B (en) * | 1958-09-22 | 1966-07-21 | Du Pont | Process for applying a thermoplastic coating to the inner surface of an essentially tubular structure |
| SU542890A1 (en) * | 1972-12-11 | 1977-01-15 | Всесоюзный научно-исследовательский институт разработки и эксплуатации нефтепромысловых труб | The method of applying a protective coating of polymeric material |
| GB1533233A (en) * | 1974-11-21 | 1978-11-22 | English Clays Lovering Pochin | Method of lining pipes |
| GB2021728A (en) * | 1978-05-26 | 1979-12-05 | Insituform Ltd | Improvements relating to the lining of passageways |
| SU916861A1 (en) * | 1980-07-28 | 1982-03-30 | Уфимский Нефтяной Институт | Method of constructing metallic hot-product pipeline |
| SU1024653A1 (en) * | 1980-12-26 | 1983-06-23 | Всесоюзный Научно-Исследовательский И Экспериментально-Конструкторский Институт Торгового Машиностроения | Method and device for coating internal surface of pipeline |
| US4456401A (en) * | 1981-11-09 | 1984-06-26 | Finic, B.V. | Method and apparatus for relining underground passageway |
| DE3173936D1 (en) * | 1981-12-21 | 1986-04-03 | Insituform Int Inc | Method for sealing pipes |
| JPS59193284A (en) * | 1983-04-15 | 1984-11-01 | Hitachi Ltd | Corrosion preventive tape |
-
1985
- 1985-10-14 FR FR8515212A patent/FR2571822B1/en not_active Expired
- 1985-10-16 CA CA000493130A patent/CA1282308C/en not_active Expired - Lifetime
- 1985-10-16 WO PCT/SU1985/000086 patent/WO1986002429A1/en active Application Filing
- 1985-10-16 DE DE19853590521 patent/DE3590521C2/de not_active Expired - Fee Related
- 1985-10-16 DE DE19853590521 patent/DE3590521T/en active Pending
- 1985-10-16 GB GB08613639A patent/GB2176263A/en not_active Withdrawn
- 1985-10-16 AU AU51950/86A patent/AU5195086A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| WO1986002429A1 (en) | 1986-04-24 |
| FR2571822A1 (en) | 1986-04-18 |
| GB8613639D0 (en) | 1986-07-09 |
| DE3590521T (en) | 1986-09-18 |
| DE3590521C2 (en) | 1990-02-08 |
| GB2176263A (en) | 1986-12-17 |
| AU5195086A (en) | 1986-05-02 |
| FR2571822B1 (en) | 1989-05-19 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |