FI67442C - FOERFARANDE FOER REHABILITERING AV ETT OTAETT ROER SAMT FODERROER FOER UTFOERANDE AV FOERFARANDET - Google Patents

Description

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Patent and register held · (44) NthcMIoipwKMi) · kMtL | uac »iMn date. -

Patent · och regfotarttyralsan '' Amglm «hr * odi mUkratu pwbWcfd 30.11.84 (J ^ (33) (J1)« KUtoM-e ^ irt frioriut 08.12.77

Norway-Norway (NO) 774210 (70 (72) Sven B. Sverdrup, Jac. Neumannsv. 20, N-1364 Hvalstad, Norway-Norway (NO) (74) Berggren Oy Ab (54) Method for rehabilitating a leaking pipe and sealing pipe method The present invention relates to a method for rehabilitating or repairing an existing leaking pipe, e.g. for water or sewer purposes, in which the pipe along its entire length is connected to two accessible points, e.g. The invention is also directed to a sealing tube for carrying out the method, in which case a flexible sealing tube is inserted and / or pulled between them, after which its ends are most preferably sealed to the tube.

Sewer pipes, for example for waste and excess water, have largely been made of short concrete pipe elements connected to each other by sleeve joints.

It has been found that these joints tend to leak over time, causing various problems, depending on the location of the lead relative to the groundwater level. If the pipeline is located below the groundwater level, then wastewater or sewage will seep out through leaking joints and contaminate nature. If, on the other hand, the groundwater level is above the level of the pipeline, then the groundwater leaks into the pipeline and increases the overload of it and its potential treatment plant, to which it flows. In addition, such a leak may have an adverse effect due to the lower groundwater level.

Various ways of sealing such pipes are known.

One such method is based, for example, on pressing the sealing compound into the joints from inside the line. However, this requires precise placement of complex equipment in the pipe, and moreover, the sealing compound is quite dependent on moisture to maintain its sealing composition and strength, a need which is irrationally not always met in the required amount.

In addition, it is known to use sealing pipes which are inserted into the cable in shorter pieces and cast there, e.g. with epoxy or the like. This involves great difficulties and costs, especially where it is difficult to get inside the cable, e.g. when the pool is a long distance away.

U.S. Pat. No. 3,123,101 discloses a liner tube having an outer diameter slightly smaller than the inner diameter of the damaged tube to be patched, and a constant size along the entire length of the tube. The liner is in a flattened form before use and is pressurized to be rounded prior to use.

The disadvantage of this known liner pipe is that it is difficult to pass it through a bended pipe, or the diameter of the liner pipe must be considerably smaller than that of the pipe to be lined.

The object of the present invention is to eliminate the above-mentioned disadvantages of known liner pipes and to provide a liner pipe which is very flexible and easy to place also inside a pipe provided with bends. To achieve this, the invention is characterized in that a pipe with a periodically varying outer diameter having a maximum value greater than or equal to the inner diameter of the pipeline in the unloaded, free space of the sealing tube but smaller than the inner diameter of the pipeline when the sealing tube is

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Due to the bellows structure of the pipe according to the invention, the diameter of the pipe decreases when a longitudinal stretch or internal pressure is applied to the pipe. This in turn facilitates the passage of the pipe through the pipe to be refurbished. When the tension or pressure is released, the liner pipe will rest firmly on the wall of the surrounding pipe.

In order that the invention may be better understood, it will be explained in more detail with reference to an application example shown in the drawing. Here, the existing wire is usually marked with 1. The line comprises concrete elements 2, which are connected to each other by means of sleeve joints 3. Line 1 extends from basin 4 to basin 5.

The conduit 1 schematically shows a sealing pipe 6, which is just being inserted between the basins 4 and 5. The sealing tube 6 is corrugated because it is formed in pairs by mutually pivoting parts, the shape of which is approximately like the surface of a truncated cone.

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The ends of the sealing tube have sealed covers 7 and 8. The second, 7 has a fastening device 9 for fastening a traction member 10 which is used to pull the sealing tube 6 to the line 1. The second cover 8 has a valve device 11 which can apply internal overpressure to the sealing tube 6, e.g. compressed air. The sealing tube is mainly made of plastic, e.g. polyethylene. Its wall thickness t with respect to the largest outer diameter depends on several factors, e.g. flexibility, strength, resistance to internal and external pressure, and economy of the material.

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However, it has been found that for current materials and applications, the average thickness t of the wall gives a good result if it is 1-3% of the largest outer diameter. In addition, it may be appropriate to slightly reduce the thickness of the wall portions with the largest diameter to increase the flexibility of the pipe, especially when the wall thickness of the pipe is relatively large.

It should be noted that the corrugation of the tube has a double function. First, it helps to make the pipe flexible so that it can be drawn into the line, e.g. through an existing pool, and can be used in curved lines. Second, the corrugation allows the pipe to assume a smaller maximum diameter when the pipe is subjected to tension and / or internal pressure during insertion. Thus, any waveform that satisfies these requirements can be used.

When implementing the embodiment according to the invention, it is first done so that the long sealing pipe 6 is brought to a length which roughly corresponds to the length of the line 1 at access points, e.g. between basins 4 and 5, taking into account possible line bends. This can be done by cutting a suitable piece from the screw of the sealing tube or by joining, for example, welding together shorter pieces.

A sealed lid 7 or 8 is then placed at each end of the pipe piece 6 thus arranged, at least one of which has an attachment point 9 for the traction member and the other a valve 11. A rope 10 or the like previously inserted between the basins 4 and 5 is secured to the attachment point 9. with gas at the pressure coming through the valve 11. In this case, the pipe whose largest outer diameter when unloaded is slightly larger and the smallest inner diameter slightly smaller than the inner diameter of the conduit 1 is somewhat elongated and at the same time its largest outer diameter is shortened. The internal gas pressure as well as the geometry and dimensions of the pipe must be matched to each other and to the internal diameter of the line so that the latter exceeds the maximum diameter of the pipe in the presence of internal overpressure. By pulling the rope 10 from the basin 4 and at the same time pushing and guiding the tube 6, the rope is introduced into the line 1. Once the pipe is in place, i.e. when it protrudes approximately equal amounts from both ends of the line 1, the compressed gas is released. Then · the pipe retracts slightly π; 67442 and its largest parts are pressed outwards against the inner surface of the cable.

Finally, the protruding end portions of the tube are cut off and its end edges are tightly and firmly connected to the conduit in a suitable manner. It will be apparent from the foregoing that the present invention provides a method and apparatus which, in a rapid, simple and reasonable manner, is capable of rehabilitating existing lines which may be both irregular and large in length.

Claims (7)

1. Method of rehabilitating or etherizing an existing sealed tube, e.g. for water and wastewater purposes, whereby in the pipe along its entire length there are between two accessible points, e.g. wells are inserted and / or drawn into a flexible feed tube, after which its ends are preferably connected tightly to the tube, characterized in that as a feed tube is used a tube with periodically varying outer diameter, which has a maximum value greater than or equal to the inner tube length. diameter in the unloaded, free state of the casing, but less than the inner diameter of the casing when the casing is extended by stretching or internal overpressure. 2. A method according to claim 1, characterized in that the feed tube is closed at both ends before insertion and put under internal overpressure, and that the overpressure is removed and the ends of the pipe are opened before being connected to the pipe. Feed tube for carrying out the method according to claim 1 or 2, which feed tube (6) is flexible for insertion into an existing pipe (2) along its entire length between two extensible points, for example wells (4, 5), and is arranged to be able to be tightly connected to the pipe at its ends after insertion, characterized in that the casing is made of corrugated plastic pipe (6) or hose, the largest outer diameter of which is greater or equal to and the minimum outer diameter respectively. smaller than the inner diameter of the existing pipe (2) and that the largest outer diameter of the plastic pipe (6) or tube is arranged to be smaller than the inner diameter of the existing pipe (2) when the plastic pipe (6) or hose is extended by stretching or internal overpressure . Feed tube according to claim 3, characterized in that it consists of a corrugated, flexible plastic tube (6) or hose, the largest and smallest outer diameter of which is larger and smaller. less than the internal diameter of the existing pipeline (2).