WO2006006865A2

WO2006006865A2 - Method for laying fabric in water pipes and a fabric pack for carrying out the method

Info

Publication number: WO2006006865A2
Application number: PCT/NO2005/000227
Authority: WO
Inventors: Viggo Amundsen
Original assignee: World Water Ways As
Priority date: 2004-06-25
Filing date: 2005-06-24
Publication date: 2006-01-19
Also published as: NO20042670D0; NO20042670A; WO2006006865A3; NO320167B1

Abstract

The present invention relates to a method for laying a fabric (1) in a water pipe (3, 3'), which fabric (1) constitutes a fabric pack (10), characterised by the steps of placing the fabric pack (10) on a transport device (2), fastening one end of the fabric (1) to a first end of the pipe (3, 3') or to a second length of fabric (1), moving the transport device (2) in the pipe (3) in the longitudinal direction of the pipe (3, 3') whilst fabric (1) is discharged from the fabric pack (10), fastening a second end of the fabric (1) to a second end of the pipe (3, 3') or to one end of a second length of fabric (1) so that the fabric (1) is extended in the pipe, and allowing water to flow through the pipe and fill it, so that the water pressure presses the fabric (1) into contact with the internal surface of the pipe (3, 3'). The invention also relates to a fabric pack (10) for carrying out the method.

Description

Method for laying fabric in water pipes and a fabric pack for carrying out the method

The present invention relates to a method for laying fabric in a water pipe, and a fabric pack for carrying out the method.

In the case of hydroelectric power stations, it is previously known to line water-carrying tunnels blasted out of rock with a fabric material in order to reduce the hydrodynamic flow losses, i.e., loss of velocity of the flowing water masses as a result of the irregular blasted surface in the tunnel.

Moreover, in water distribution systems, so-called "pipes-in-pipes" are known, where a polyethylene pipe is passed into another larger pipe with a water leak as a lining in order to reduce or eliminate leakage losses. This solution has been developed based on the fact that in normal water distribution systems about 25-40% of the water leaks out into the ground en route to the user. This is because the concrete or steel pipes normally used decay or rust with time, and/or that leaks occur in the joints between the pipes. However, the installation of such polyethylene pipes in originally laid concrete or steel pipes is costly and difficult, and in practice it is virtually impossible to line large extents of pipe in this way.

It is also previously known to coat the inside of steel water pipes with cement to reduce the leakage losses, but rust will then form on the back of the cement coating which results in this coating gradually coming off the pipe surface.

In countries like Norway, where there is more than enough accessible fresh water/drinking water, the aforementioned normal leakage loss is by no means dramatic, even though it is of course undesirable. However, in other, more southerly countries with little precipitation and fresh water reserve, a leakage loss of such magnitude has fairly dramatic consequences, both in terms of costs and from a social point of view.

According to the invention, the aforementioned problems are sought to be solved by means of a fabric pack for laying fabric in a water pipe, wherein the fabric is formed into a cylindrical stocking having a circumference adapted to the internal diameter of the pipe and a length adapted to the length of the pipe, and wherein the fabric, when flat, is folded in such a way about the transverse centre thereof that it can be unfolded instantly and without hindrance upon later application of water pressure inside the fabric, and wherein the fabric in its longitudinal direction is also folded or rolled into a plurality of layers which form the fabric pack, so that fabric can be discharged from the fabric pack in order to be laid in the longitudinal direction of the pipe.

According to the invention, the aforementioned problems are further sought to be solved by means of a method for laying a fabric inside a water pipe, which fabric constitutes a fabric pack as disclosed above, comprising the steps of placing the fabric pack on a transport device; peripherally fastening one end of the fabric to the a first end of the pipe or to a second length of fabric; moving the transport device in the pipe in the longitudinal direction of the pipe whilst fabric is discharged from the fabric pack; fastening a second end of the fabric to a second end of the pipe or to one end of a second length of fabric, so that the fabric is extended in the pipe; and allowing water to flow through the pipe and fill it, so that the water pressure presses the fabric against the internal surface of the pipe.

Advantageous embodiments of the invention are set forth in the dependent claims.

The invention is described in more detail below with reference to the attached drawings, wherein:

Figure 1 is a sectional view of a flat, unfolded fabric, with the direction of folding indicated by arrows;

Figure 2 shows the fabric of Figure 1 with the sides folded towards the centre thereof;

Figure 3a is a sectional view of an alternative folding of the fabric;

Figure 3b is a sectional view of another alternative folding of the fabric;

Figures 4a and 4b are, respectively, a basic longitudinal section and sectional view of the fabric in Figure 2 or 3, packed into a fabric pack according to the invention and placed on a carriage in a pipe, an arrow indicating the direction of travel of the carriage in the pipe in Figure 4a; Figure 5 is a top view of a section of the fabric in Figure 2 or 3 with broken folding lines for packing an alternative fabric pack according to the invention;

Figure 6 is a perspective partial view of a pipe with a pipe flange mounted thereon; and

Figure 7 is a basic longitudinal sectional view of a water pipe with a pipe section removed, and with a flange mounted on each end of the pipe and with a fabric pack according to the invention installed in each pipe section.

In the following description all directional designations are related to the longitudinal direction of the pipe, unless otherwise specified.

In Figure 1 a fabric 1 is shown in cross-section. The fabric 1 is formed into a cylindrical stocking which, in the figure, is shown in a flat and unfolded state, and where the direction of folding is indicated by arrows. An obvious requirement as regards the fabric material is that it is essentially water-proof at the pressures that prevail in the water pipe, and that the tearing strength and durability of the material are adequate. The fabric 1 is preferably made of PVC, and with a currently preferred fabric thickness of 1 mm. The circumference of the fabric is adapted to the diameter of the pipe in which it is to be installed as a lining, preferably having a slightly smaller circumference than the pipe diameter as it advantageously slightly elastic diametrically. However, the fabric is preferably not elastic in its longitudinal direction, parallel to the longitudinal direction of the pipe.

In Figure 2, the fabric 1 is shown with its sides folded in towards the centre thereof.

Figure 3a shows an alternative folding of the fabric 1 towards the centre thereof, and Figure 3b shows another alternative folding of the fabric 1 towards the centre thereof. As can be seen from Figures 3a and 3b, the fabric 1 is preferably folded into a plurality of layers and folds about the centre thereof.

With reference to Figures 2 and 3, it is crucial when folding the fabric 1 that it must be capable of being unfolded instantly when pressure is applied therein in such a way that the fabric 1 is lifted into contact with the pipe wall without getting caught up in itself. Thus, the skilled person will easily find alternative ways of folding that give this result, and the invention is therefore not intended to be limited to the illustrated embodiments. Figure 4 is a basic longitudinal view of the fabric in Figs. 2 or 3 packed into a fabric pack 10 according to the invention and placed on a transport device, preferably a self- propelling carriage 2, in a pipe 3, an arrow indicating the direction of travel of the carriage 2 in the pipe 3. The fabric pack 10 is preferably provided in that the fabric 1 is folded into a plurality of layers on top of each other transverse to the longitudinal direction of the fabric 1. Alternatively, as the skilled person will appreciate, the plurality of layers of the fabric 1 which constitute the fabric pack 10 may also be provided in that the fabric 1 is folded alternately in either direction at an angle of 45° relative to the longitudinal direction of the fabric 1, as is indicated by the broken fold lines on the fabric 1 shown in the top view in Fig. 5. However, such an embodiment of the fabric pack 10 is less preferable as the folding is more complex and the discharging of the fabric 1 from the fabric pack 10 does not take place in the longitudinal direction of the pipe 3 on the advance of the carriage 2 in the pipe 3. On the other hand, the fabric pack 10 according to this embodiment could be packed as compactly as the fabric pack 10 according to the embodiment first described which has folds transverse to the longitudinal direction of the pipe 3. As a third (non-illustrated) embodiment, the fabric pack can be provided by rolling up the fabric 1 shown in Figs. 1-3 on a drum fastened to, or which is later fastened to the carriage 2.

The fabric 1 is fastened to one end of the pipe 3, as will be described in more detail below, so that the fabric 1 is discharged from the fabric pack 10 as the carriage 2 moves forwards through the pipe 3. The carriage 2 is preferably equipped with a known (non- illustrated) pendulum control to keep the carriage 2 horizontal in the pipe 3, since the carriage 3 otherwise has a tendency to crawl on the pipe wall at points where the pipe 3 bends. The dimensions of the carriage 2 are preferably adapted to the dimensions of the pipe 3, and first and foremost to the internal diameter of the pipe 3.

Fig. 6 shows a section of the pipe 3, to which a flange 4 has been mounted, preferably by welding. The flange 4 comprises a plurality of bolt holes 5 for fastening two flanges 4 to each other using (non-illustrated) bolts through the bolt holes 5.

Figure 7 is a basic longitudinal sectional view of a water pipe 3 with a pipe section 3' removed, and with a flange 4 mounted on each pipe end and with a length of fabric 1 installed in each pipe section. One end of the fabric 1 is fastened to each flange 4 and extended between two flanges, as shown in the pipe section 3'. In the remaining sections of the pipe 3 shown in Figure 7, the fabric 1 has not yet been stretched out, but is fastened to its respective flange 4. As an example, it may be mentioned that for laying fabric 1 in a water pipe 3 having an internal diameter of 1.57 metres, it is advantageous to remove a pipe section 3' having a length of about 6 metres for every five kilometres of pipe 3, after which flanges 4 are mounted to the pipe ends and the fabric 1 is laid in the pipe sections 3 and 3' using the carriage 2.

Advantageously, the fabric is first fastened to the contact face of each flange 4, which later will constitute a pipe joint, by gluing (glue of the type Locktite 411 has been found to be very suitable), after which holes are made in the fabric in alignment with the bolt holes 5. The flanges 4 which will form a pipe joint are then brought into contact with each other, after which bolts are passed through the bolt holes 5 and then tightened. The fabric 1 glued to the contact face of each flange 4, and which is clamped between two pipe flanges 4, will then advantageously form the packing material between the pipe flanges 4 in a joint, without any additional packing being required. When the fabric 1 has been installed and extended in the pipe sections 3, 3' and these have been joined together again, water is allowed to flow into the pipe sections 3, 3' with the result that the water pressure presses the fabric into contact with the internal surface of the pipe 3 as a lining, and seals against leaks. In the case of extreme water pressures, for example, when the water comes from damns, the use of pressure reduction valves may be necessary.

It is also possible to join two lengths of fabric 1 inside the pipe 3 by using a mobile (non-illustrated) welding unit to weld the fabric material, which preferably consists of PVC. A welding unit of this kind is known per se, and will not be described in more detail here beyond mentioning the fact that high-frequency current is applied to two bars laid on each side of the fabric 1, and with a sheet of insulating material in between. This sheet will remain inside the fabric 1 after the welding operation, and is removed by the water, hi the exemplary embodiment described above, an overlap of 3 to 5 cm in the joint between the two lengths of fabric 1 is advantageous.

Claims

P a t e n t c l a i m s

1.

A fabric pack (10) for laying fabric (1) in a water pipe (3, 3'), characterised in that the fabric (1) is formed into a cylindrical stocking with a circumference adapted to the internal diameter of the pipe (3, 3') and a length adapted to the length of the pipe (3, 3'), and wherein the fabric (1), when flat, is folded in such a way about the transverse centre thereof that it can be unfolded instantly and without hindrance upon later application of water pressure inside the fabric (1), and wherein the fabric (1) in its longitudinal direction is further folded or rolled into a plurality of layers which form the fabric pack (10), so that fabric (1) can be discharged from the fabric pack (10) in order to be laid in the longitudinal direction of the pipe (3).

2.

A fabric pack according to claim 1, characterised in that the circumference of the fabric (1) is slightly smaller than the pipe diameter, as the fabric (1) is slightly elastic diametrically, and that the fabric (1) is inelastic in its longitudinal direction.

3.

A fabric pack according to one of the preceding claims, characterised in that the fabric

(1) is folded into a plurality of layers or folds about the centre thereof.

4.

A fabric pack according to any one of the preceding claims, characterised in that the fabric (1) is folded into a plurality of layers on top of each other transverse to the longitudinal direction of the fabric (1).

5.

A fabric pack according to any one of claims 1 to 3, characterised in that the fabric (1) is alternately folded in either direction at an angle of 45° relative to the longitudinal direction of the fabric (1).

6.

A fabric pack according to any one of claims 1 to 3, characterised in that the fabric (1) is rolled up on a drum. A method for laying fabric (1) in a water pipe (3, 3'), which fabric (1) constitutes a fabric pack (10) according to any one of the preceding claims, characterised in that it comprises the steps of: placing the fabric pack (10) on a transport device (2); peripherally fastening one end of the fabric (1) to a first end of the pipe (3, 3') or to a second length of fabric (1); moving the transport device (2) in the pipe (3) in the longitudinal direction of the pipe (3, 3') whilst fabric (1) is discharged from the fabric pack (10); fastening a second end of the fabric (1) to a second end of the pipe (3, 3') or to one end of a second length of fabric (1) so that the fabric (1) is extended in the pipe; and allowing water to flow through the pipe and fill it, so that the water pressure presses the fabric (1) into contact with the internal surface of the pipe (3, 3').

8.

A method according to claim 7, characterised by the additional step of welding a pipe flange (4) to one end of the pipe (3, 3') for joining two pipes (3, 3') and fastening the fabric (1) to the contact face of the pipe flange (4).

9.

A method according to claim 8, characterised in that the fabric (1) is fastened to the contact face of the flange (4) by gluing.

10.

A method according to claim 8 or 9, characterised in that the fabric (1) constitutes the only packing material between the pipe flanges (4) in a joint.

11.

A method according to claim 7, characterised in that the end of the fabric (1) is fastened to the end of a second length of fabric (1) by means of welding.

12.

A method for lining a water pipe (3), characterised in that it comprises the features of: laying a number of lengths of fabric (1) formed into a cylindrical stocking, and having a circumference that essentially corresponds to the internal circumference of the pipe (3), in the pipe along the longitudinal length of the pipe (3); joining together the number of lengths of fabric (1) into one cylindrical stocking, if the number is more than one; peripherally fastening the remaining ends of the number of lengths of fabric (1) to the pipe (3) so that the number of lengths of fabric (1) is extended between the fastenings; and allowing water to flow through and fill the pipe (3) so that the water pressure presses the number of lengths of fabric (1) into contact with the internal surface of the pipe (3).