WO2012020171A2

WO2012020171A2 - Renovation module

Info

Publication number: WO2012020171A2
Application number: PCT/FI2011/050709
Authority: WO
Inventors: Magnus Nordström
Original assignee: Oy Kwh Pipe Ab
Priority date: 2010-08-13
Filing date: 2011-08-11
Publication date: 2012-02-16
Also published as: FIU20100350U0; FI9463U1; WO2012020171A3

Abstract

The present invention relates to a renovation module for renewing pipelines. The module comprises a cylindrical tubular shell (1) having fastening means (3-6, 2, 9) at both ends thereof for attaching to a corresponding module. According to the invention ribs (10,11) extending from the shell (1) of the module are formed to the outer surface of the shell to between the fastening means (3-6, 2, 9), at least two of the ribs crossing each other so that at least one rib (10) runs more parallel with the longitudinal direction of the module than the other and at least one rib (11) runs more parallel with the perpendicular direction of the module than the other with the at least one longitudinal rib (10) being higher than the perpendicular rib (11). The invention provides advantages in regard to e.g. material consumption and installability.

Description

Renovation module

The present invention relates to a renovation module according to the preamble of the independent claim for renovating sewer pipe lines and other corresponding pipelines .

Many pipelines are subject to wear and they are damaged in the course of time due to environmental effects and stresses caused by usage. These include subterranean sewer pipelines, especially pipelines made of concrete. Due to wear the pipes have to be repaired at some point of time. For subterranean pipes this can only be made by digging the pipes up and replacing the pipes. Structures might have to be dismantled for renovating pipes located in buildings. Such work is time-consuming and expensive, especially when operating in densely populated areas. In order to avoid complete replacement of pipes they can be repaired with relining pipes inserted into the pipe from the end of the pipe portion to be fixed. Relining pipes are usually made of plastic and they are used for forming a lining inside the pipes. Thus the structural strength of the existing pipe can be utilized.

There are numerous types of relining pipes. One solution is to use a flexible plastic pipe, such as a segmented corrugated plastic pipe, the parts of which are attached to each other above ground by welding and the pipe is pushed in one piece to its place via e.g. a sewer well into the pipe section to be renovated. Such a pipe is inexpensive, but as it is only. possible to use as relatively small diameters, as a corrugated pipe of a large diameter has no room to bend in a sewer well due to lack of room. Additionally it is difficult to arrange a branching system into structure without having to dig the branching location open . Another possibility is to use pipe elements having a length of the diameter of the sewer well or the free length of another working space. In this case the pipe elements can be inserted as extensions of the pipe element line already in the sewer portion. Thus the pipe is continued an element at a time until the end of the sewer portion.

The pipe elements can be cast or otherwise formed as tubular pieces. The actual pipe part comprises female muffs and the pipe is connected by placing a connecting piece having a length of two muff parts into the connection, the connecting piece having means for grabbing the female muff. Thus the actual pipes are supported by each other only by their ends. In this construction the pipe becomes thicker at the muff parts, whereby the middle part is not supported by the inside of the old pipe. Thus the wall thickness of the pipe must be sufficient to carry the internal and external stresses of the pipe. As only the ends of the pipes form the longitudinal mating surfaces, the internal connecting pipe can slip inside the actual relining pipe. The connecting surfaces do not comprise a locking structure counteracting pulling forces, so that if the pipe must for some reason be pulled back, the connection can break. Due to this there is a risk of broken connections in unknown places when using the above-described pipes and the

relining work can fail.

One relining pipe construction comprises elements formed from extruded pipe by cutting the pipe into pieces having a suitable length and by turning a female muff part into one end of the elements produced thus, with a male locking part being turned in the other end. The outer edge of the male locking portion and the bottom of the muff part comprise snap-locking mating parts preventing the pipe elements from detaching from each other when pulled. Additionally, it is easy to provide the design with two mating surfaces counteracting the pressing forces, whereby the joints of the pipe element are relatively resistant to pushing. The design is, however, rather expensive, as the pipe must be extruded so as to have very thick walls in order to be able to machine sufficiently robust end structures for the joint. Thus the material costs will be high. Additionally the production of the muff part and the locking part by machining increases the cost. During machining there can occur dimensional errors that make the installation difficult or even impossible. In this structure the outer surface of the pipe is smooth.

Finnish patent 91992 describes a pipe element for forming a relining pipe. Here the wall thickness of the pipe elements is relatively thin for saving material and it has been possible to dimension the wall thickness of the pipe to meet the operation conditions of the relining pipe. The dimensioning of these pipes is controlled by the directives and standards of the field and the pipes must withstand certain stresses during use and installation. On the other hand the elements must have sufficient mating surfaces for receiving the longitudinal push and pull loads especially during installation. The largest stresses are created during installation, which is due to the fact that the pipe portion to be relined can be several hundreds of meters in length and installation lengths of tens of meters are commonplace. The portions can also comprise curves

increasing the. resistance. Thus, the whole resistance between whole relining pipe portion and the wall of the sewer is exerted on the joint of e.g. an element pushed from the sewer well. Finnish utility model 7657 describes a joint for pipe modules having mating surfaces described as oblique in relation to each other. The aim of this is to provide a more reliable joint. The aim of the present invention is to produce a renovation module by means of which the material costs of the module can be reduced.

Another aim of the invention is to produce a module that is easier to install.

A further aim of the invention is to produce a module that can be produced in a single operation. The . invention is based on forming ribs to the outer surface of the module, between the female muff part and the male locking part, the ribs extending from the shell of the module, at least two of the ribs crossing each other. According to an embodiment of the invention the ribs running more parallel with the longitudinal axis of the module are higher.

According to one embodiment the higher ribs run parallel with the longitudinal axis of the module and the lower . ribs run perpendicularly in relation to them parallel with the circumference of the shell of the module, whereby the ribs are at right angles in relation to each other. According to one embodiment of the invention the lower ribs have a taper for facilitating the removal of the module from the mould. According to one embodiment the module comprises at least one perpendicular grabbing groove breaking the ribbing.

More specifically, the renovating module according to the invention is characterized by what is disclosed in the characterizing part of the independent claim.

Considerable advantages are achieved by means of the invention. The invention allows producing a renovating module

fulfilling the regulations and standards for each diameter with as low a material usage as possible. Its

installability is better than that of a pipe with a smooth surface as the mating surface against the old pipe is smaller. The ring stiffness of the pipe is very good, but the perpendicular flex grooves allow providing the pipe with a sufficient perpendicular flexibility for

installation into a curved pipe as well. This is important as especially subterranean pipes can move during their lifecycle, whereby an originally direct pipeline can form considerable curves when there is a need for renovation. Due to the external ribbing the renovation pipe is solidly installed in its place when the space between the old pipe and the new pipe is filled with a filler material, such as aircrete. This will also improve the strength of the structure. An important advantage is that the module can be produced of plastic by form extrusion, whereby the module is produced in a single production step and the joint pieces will be accurate. In the following, the invention is disclosed in more detail by means of reference to the appended drawings. Figure 1 illustrates a renovating module according to the invention as a perspective view.

Figure 2 is a schematic illustration of the joint between the modules.

The renovation module according to the invention comprises a cylindrical tubular shell 1 the ends of which are provided with means for attaching the modules to each other. The female muff part 2 remains as the outermost in the joint and it is shown only as a ring in the end of the shell in figure 1. The fastening means are outside the ring. The male fastening part comprises a locking part 3 and the sealing part 4. The sealing part 4 includes grooves for installing a sealing member and the locking part comprises a locking ring 5 provided at the end of the shell 1 of the pipe and extending radially therefrom as well as a locking groove 6 located behind it' when seen from the end of the pipe. The main features of the structure of the locking means are shown in figure 2. As can be seen in figure 2, in the installed module pair the end of the female muff part 2 is located against the extension 7 formed in the male

fastening part and, correspondingly, there is a

perpendicular extension inside the female muff part 2 against which the end of the male locking part, formed by the locking ring 5, is located. Thus the joint will be able to bear large loads. The locking in the pull direction is provided by means of a locking extension 9 angled towards the end of the muff part 2 and radial in the direction of the locking ring. Thus the muff part with its locking extension 9 can easily be pushed over the locking ring, but the resistance is larger in the return direction, thus preventing inadvertent release of the modules. The locking ring 5 and the locking extension 9 are preferably

dimensioned so that disassembling the structure requires a sufficient force but is, however, possible without breaking the modules.

As the interlocking between the modules is not as such a part of the invention, the locking can be carried out in other ways as well and it is not described in more detail herein. It should, however, be mentioned that the locking of e.g. Finnish patent 91992 can be preferably used and a more detailed description of it is in the disclosure of the said patent.

The invention itself relates to the structure between the locking parts of the shell 1 of the renovation module.

Therein the shell 1 is provided with longitudinal and perpendicular ribs 10, 11 providing stiffness to the structure. In the embodiment of figure 1 the longitudinal grooves 10 run parallel with the longitudinal axis of the module and the perpendicular ones^ 11 run radially so that the ribs are at right angles in relation to each other. The longitudinal ribs 10 are higher than the perpendicular ribs 11, whereby the perpendicular ribs 11 do not touch the walls of the old pipe during installation and the force needed for the installation is reduced. The perpendicular ribs 11 have tapers by means of which the piece produced by extrusion or injection moulding can easily be removed.

One feature of the invention are grabbing grooves 12, this example comprising two grooves. The longitudinal ribs 10 break at the location of the grooves 12 and a ribless portion is formed in the shell 1, wherein the material thickness and bending flexibility correspond to the

material of the shell. At this location the module bends more easily, thus helping installation in curved pipelines. The number of grabbing grooves 12 can be any as desired or it can be zero. The largest amount is limited by the strength and stiffness values required of the pipe. The actual meaning of the grabbing grooves is, however, to facilitate the attaching of the modules to each other. When the module is inserted into its place in the pipe to be renovated, a fork-like clamp can be arranged into the grabbing groove, the clamp being supported along the edges of the opening to be renovated. Now the module is supported in place and the next module can be inserted against the support to the end of the previous module. This facilitates installation .

In addition to the above disclosure the present invention has other embodiments as well. The number of the ribs can also vary fully as desired and they can also be directed obliquely or curvedly. The essential feature is that the structure comprises at least two ribs, one of which runs more parallel with the longitudinal axis of the module while the other runs crosswise in relation thereto, more perpendicularly in relation to the longitudinal axis. The ribs running parallel with the longitudinal axis must be. higher.

Claims

We claim:

1. A renovation module for renewing pipelines, the module comprising a cylindrical tubular shell (1) having- fastening means (3-6, 2, 9) in both ends thereof for connecting to a corresponding module, characterized in that ribs extending from the shell (1) of the module are formed to the outer surface of the shell between the fastening means (3-6, 2, 9) , at least two of the ribs crossing each other so that at least one rib (10) runs more parallel with the longitudinal direction of the module than the other and at least one rib (11) runs more parallel with the perpendicular direction of the module than the other with the at least one

longitudinal rib (10) being higher than the perpendicular rib (11) .

2. A renovation module according to claim 1, characterized in that the higher ribs (10) run parallel with the

longitudinal axis of the module and the lower ribs (11) run perpendicularly in relation to them parallel with the circumference of the shell (1) of the module, whereby the ribs (11, 12) are at straight angles in relation to each other.

3. A renovation module according to claim 1 or 2,

characterized in that the lower ribs (11) have a taper for facilitating the removal of the module from the mould.

4. A renovation module according any of the above claims, characterized in that the module comprises at least one perpendicular grabbing groove (12) breaking the ribbing.