Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
  • F16L55/16—Devices for covering leaks in pipes or hoses, e.g. hose-menders
  • F16L55/162—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe
  • F16L55/165—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe a pipe or flexible liner being inserted in the damaged section
• • 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
  • F16L23/00—Flanged joints
  • F16L23/02—Flanged joints the flanges being connected by members tensioned axially
  • F16L23/024—Flanged joints the flanges being connected by members tensioned axially characterised by how the flanges are joined to, or form an extension of, the pipes
• • 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
  • F16L23/00—Flanged joints
  • F16L23/12—Flanged joints specially adapted for particular pipes
  • F16L23/125—Flanged joints specially adapted for particular pipes with an internal or external coating
• • 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
  • F16L58/18—Protection of pipes or pipe fittings against corrosion or incrustation specially adapted for pipe fittings
  • F16L58/187—Protection of pipes or pipe fittings against corrosion or incrustation specially adapted for pipe fittings for flanged joints

Definitions

• the present invention relates to a method for the formation of a terminal section of an inner lining sheath applicable to a pipeline section during an inner lining (or relining) operation.
• the terminal section acts as a gasket, for example between two flanges that join the pipeline section, subjected to the lining operation, to an adjacent pipe section, or to a valve or other structure, or between the end of the pipeline section and an external joint (elbow couplings, for example with Straub joint or similar).
• Relining procedures are commonly used for the maintenance or repair of pipeline sections, in particular of sections which are difficult to replace.
• the lining is usually made up of a sheath of duly woven material impregnated with glue, resin, tar or other appropriate binder, usually hardening resin; the sheet is applied to the internal surface of the pipeline, usually with the edges positioned side by side along a generating line and duly impregnated to provide continuity.
• the fabric could be for example a matt, for example made of polyester, and the sheath may include different layers of different materials according to the requirements; for example other fabrics or matts of different fibres, such as glass fibres or other fibres.
• a layer of appropriate lining material is also foreseen, such as polyethylene or polyurethane, which is attached internally to the sheath and is in contact with the fluid that flows through the pipe.
• the resin can be hardened using different methods depending on the type of resin; it can be cold or hot hardened, for example using steam circulation or hot air, or by means of light or ultraviolet radiation using appropriate lamps.
• Continuous lining can be applied to very long pipeline sections that also feature different pipes connected by joints such as flanges or other joining elements.
• the simplest solution is to cut the lining flush to the end of the pipeline section concerned.
• This solution is only possible if there is an adequate adhesion and hold between pipe and resin along the entire pipeline section concerned; this usually depends if the pipeline surface can be processed and on its conditions of deterioration. In the case of old pipes, or non metal ones, these requisites are rarely met.
• the terminal part of the lining can be covered with adequate products such as polymers, tar, suitable types of cement, or even better with hardening resins.
• the sheath however is not always adequately protected against structural stress and the lining can often become detached, even during the assembly of the connection. Furthermore, hardening products require a long setting time.
• Good stress resistance can be obtained by means of internal ribbing, usually made of stainless steel, with the ribs separated and blocked by suitable lock plates.
• a sleeve made of elastomeric material, for example, can be applied inside the lining and blocked at the ends by at least two ribs. This system takes a long time and reduces the internal diameter of the pipes, making it irregular with consequent losses in pipe flow rate when operational.
• stainless steel sheet terminal parts are sometimes applied, separated by screw supports, wedges or other systems and then fixed with locking wedges or by welding.
• the said terminal parts require the lining to be spread on the application area using sealants such as silicone; they are not very stable and resistance to mechanical stress is poor. This solution, like the previous one, is difficult to apply in the case of small pipeline diameters.
• sealants do not adhere well to certain types of resin, such as polyethylene, used in composite type linings for the side facing the fluid.
• a suitable resin preferably a hardening resin
• the application of the sheath and the application of the mould can be executed in any order.
• the pipe can be part of a pipeline or part of a section of a pipeline, which may include a number of pipes, to which the sheath is applied.
• the said sheath juts out of the pipe for a suitable length and the said chamber is delimited by the external surface of the lining, in the said section.
• the external surface is, in particular, the surface of the sheath which, inside the pipe, is in contact with the pipe's internal wall.
• the end of the pipe includes a connection element (for example a flange or collar) to connect the pipe to another pipeline component such as a pipe, fitting, valve, cover or rupture disc, meter or other suitable component, fitted with a corresponding connection element.
• a connection element for example a flange or collar
• the chamber is delimited by a front surface of the said flange that faces the corresponding front surface of the flange of another component. The terminal section formed, thus juts out and comes in contact with the said front surface and can act as gasket between the flange and the flange of the component to be connected to the pipe.
• the chamber is delimited on one side by a part of the external wall of the pipe so that the section formed can line a part of the external surface of the said pipe and be connected to the sheath at the edge of the pipe.
• the part of the external wall of the pipe can be duly covered by an elbow coupling joint (for example a Straub joint).
• the injected resin is the same resin as, or is compatible with, the resin that impregnates the sheath, so that the section formed is an integral part of the actual sheath, creating a chemical bond between the resins or in any case providing adequate adhesion.
• the resin that impregnates the sheath can be of the epoxy type and the one injected in the chamber can be of the polyurethane type.
• FIGS. 3a, 3b and 3c represent, schematically, the stages of a method according to this invention, applied to a pipe to be connected to another pipe with an elbow coupling and execution of the said coupling;
• figure 4 represents, schematically, a coupling formed between the pipe treated with the method described in figures la-le and another pipeline component.
• the sheath of a known type, is applied to the pipe using known methods.
• the sheath may include one or more layers of fabric impregnated with resin, preferably of a suitable hardening type, for example polyurethane or preferably epoxy resin.
• the term fabric is understood to also include matts, for example polyester fibre matts.
• the sheath can also include a layer of surface lining, which will cover the surface that faces the fluid.
• the application of the sheath includes the hardening of the resin, in an adequate manner, according to the type of resin; the resins can be hardened using steam circulation or hot air, or light or ultraviolet radiation or simply, for these types of resins, by mixing several components, or in any other known manner.
• sheath 2 is applied to pipe 1.
• the pipe can feature a flange 4 at the end.
• a mould 3 of the appropriate shape, suitable for the end of the pipe, is applied to the end of the pipe.
• the mould can create, as shown in figure lc, a chamber 5 delimited by the front surface 7 of the flange, by the mould and by the external surface 6 of the sheath, which, according to a possible aspect of the invention, inside the pipe adheres to the pipe's internal wall.
• the sheath is made to preferably jut out for an appropriate section from the pipe, so it adheres to the mould.
• the mould features an opening 8 of a shape that corresponds to the sheath, so it can be fitted to the said section.
• the mould features an internal surface 10 that adheres to the outer edge 9 of the sheath.
• the mould can feature breather holes 20, duly arranged, to allow the chamber 5 to be filled; for example the breather holes can be positioned so that they are on the top when the mould is being used.
• a duly positioned resin input hole 21 can also be foreseen, which can alternatively be used for a supply line.
• the figures illustrate the case in which the mould is applied before the sheath, but the sheath can be applied before the mould, which can be fitted, in a similar case to that of the figures concerned, on the section of the sheath jutting out of the pipe.
• Figures Id and le show the injection stage of a resin, preferably of the hardening type, in the said chamber until it is full.
• the mould can be removed.
• the part of the said section of the sheath jutting out of the pipe can be preferably removed, for example cut, as shown in figure le. If considered appropriate and acceptable, it can be left. It shall extend into a pipeline component to be joined to pipe 1.
• the section 11, formed with the process according to this invention is an integral part of the sheath, partially represented with section view in figure le, and radically juts out of the sheath; it is retained by the end of the positioned pipe, preventing the detachment of the sheath when the pipe is in use and when subjected to mechanical or fluid dynamic stress.
• the section 11 can also act as gasket between the flange 4 of the pipe 1 and the corresponding flange 12 of a pipeline component 13 connected to the former pipe.
• the mould used can be shaped so that the surface of the section 1 1 , that faces the component to be joined, is suitable for the flange of the said component; for example, if foreseen, it can feature ring projections or grooves that correspond to grooves and projections on the flange. It is clear that the section will adhere and adapt perfectly to the flange 4 of pipe 1. As shown in figures la- Id, the mould can have projections 14 to close the holes of the flange 4 and create corresponding holes in section 1 1 for the connection screws. Other solutions are possible, and the holes in the flange can for example be closed in another way or they can be used as breather holes, if deemed suitable.
• the holes on section 11 can also be made after the hardening stage.
• the mould features an opening to house the section of sheath 2 jutting out from the pipe, as shown by way of example in figure 4, means can be foreseen to improve adhesion and to mutually hold the mould and sheath in position, such as an elastic lip 15 incorporated in the mould.
• Figures 3a- 3c show the case of a pipe without flange, intended to be connected to another component 13' by means of an elbow coupling.
• the mould 3' can form a chamber 5' delimited by the sheath, by the edge 16 of the end of the pipe and by part of the external wall 17 of the pipe, so that the section 1 1 ' formed covers the said part of the external wall and connects onto the edge 16 of the sheath 2'.
• the section 11 ' can be held in place by the joint 18 and in turn the said section 11 ' holds in place the sheath, so that the latter is resistant to mechanical and fluid dynamic stress.
• the section 1 1 ' can cooperate with a gasket 19 of the coupling to act as seal.
• the section 11 ' can also replace the coupling gasket, and if required it can be made of an appropriate shape, for example with ring projections or other elements in order to cooperate directly with the joint 18 to act as seal.
• the coupling can be created and applied according to known methods.
• sheath section jutting out of the pipe which is housed in a special opening in the mould.
• Other solutions are possible, such as a mould made to adhere to the internal surface of the sheath.
• the sheath can be cut flush before the application of the mould and the sheath will delimit the chamber with the cut outer edge.
• hardening resin is injected in the chamber when the resin that impregnates the sheath has almost completely, but not completely, hardened, so that the section formed is an integral part of the rest of the sheath once both resins have hardened.
• the said embodiment allows the formation of a strong bond between the sheath and the formed section.
• Resins can be of a known type, adequately selected.
• a preferred resin to be injected can be a polyurethane resin. It can harden in the mould after its components have been mixed, without the need to apply heat, and it is compatible with epoxy resins commonly used to impregnate the sheath. If the section formed must act as gasket for the coupling, this will be taken into consideration when selecting the resin to be injected, so that it will have suitable characteristics.
• the hardness of the hardened resin can be, by way of a non-limiting example, between 60 and 97 Shore A.
• the thickness of the section formed must also be suitable; by way of a non-limiting example it can be between 1 and 10 mm or more, also depending on the size of the coupling.
• the injected resin may include reinforcement fibres, such as glass fibres, polyester fibres or other types.
• reinforcement fibres such as glass fibres, polyester fibres or other types.
• the mould can be made of any suitable material.
• it should be a material that does not stick to the resin, thus avoiding the use of release agents.
• the material is adequately flexible to favour the removal of the mould if made of one single piece, even if small undercuts are present.
• a preferred material is silicone plastic.
• Other solutions are however possible, also with moulds made up of different parts for more complex shapes of the section or with moulds made of other materials such as aluminium, with the use of release agents.
• the method according to the present invention makes it possible to create a single internal lining sheath, with a section that extends radically outwards from the sheath, to act as seal in a connection coupling with another pipeline component connected to the lined pipe.
• a section formed is also retained by the coupling which is formed, thus stopping the sheath from slipping, also in case of thermal expansion of the pipe.
• the resistance of the sheath and the lack of additional structures inside the pipe allows the use of cleaning devices such as pigs.
• section formed in this way adapts perfectly to the surface of the end of a pipe, better than any available preformed gasket, also in the case of defects or irregularities on the surface.
• This aspect can be of particular interest, given that the pipelines that require relining are often old or deteriorated pipelines which it is not possible to, or it is not convenient to, replace.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=43976069

Family Applications (1)

Country Status (2)

Cited By (3)

Citations (4)

• 2011
  • 2011-02-04 IT ITMI2011A000162A patent/IT1403913B1/it active
• 2012
  • 2012-02-01 WO PCT/IB2012/050472 patent/WO2012104801A1/en active Application Filing

Patent Citations (4)

Also Published As

Similar Documents

Legal Events