METHOD FOR REPAIRING AND/OR REINFORCING A PIPE SYSTEM,AND A DEVICE FOR UTILIZATION OF THE METHOD

Abstract: A method for repairing and/or reinforcing a pipe system, according to which a tubular member (2) is inserted into a pipe (1) forming a part of the pipe system, having sealed end portions and longitudinally extending impressions, deformations or similar (3, 3'), arranged to reduce the diameter of the tubular member (2) with regard to a circle enclosing the tubular member (2), said reduced diameter being arranged to be smaller than the internal diameter of the pipe (1), an explosive charge (4) with associated igniting device being arranged embraced by the tubular member (2), whereby detonation of said explosive charge (4) is arranged to cause expansion of the tubular member (2) to a surrounding contact position against the internal wall surface of the pipe (1). Advantageously the sealed end portions, or at least one of same, when the explosive charge (4) is detonated and following establishment of a surrounding contact position against the pipe (1), are arranged to be opened and pressed into a sealing contact position against the surrounding pipe (1).

Description: Method for repairing and/or reinforcing a pipe system, and a device for utilization of the method The present invention relates to a method for repairing and/or reinfor- cing a pipe system, and a device for utilization of the method. With regard to pipe systems, e.g. located below the ground plane, formation of cracks or fractures can occur, caused by variations in te peratur, movement in surrounding material, pressure changes and similar causes. When such pipe systems are located in a position diffi¬ cult to access, repairs cause obvious problems, e.g. due to the fact that the pipe system must be freed from surrounding material, in order to facilitate repair/exchange of a damaged part. With reference to US Patent No. 2 977 994, a method is disclosed for repair of a pipe system, in which a flexible and tubular hose is inserted into a pipe system in a deformed or compressed cross-sectional condition, joined in said deformed condition by means of releasable members, whereby the hose after insertion into the pipe system can be arranged to take up a mainly circular cross-sectional position, extending in contact with the internal wall surface of the pipe system. The above disscussed method of repairs makes it thus possible to arrange a flexible hose as an internal restricting surface in an existing pipe system, but for many applications it is desirable to accomplish an internal metallic surface, in order to obtain resistance against exis¬ ting variations in temperature and pressure, as well as certain types of liquid and gaseous mediums, which are transported in the pipe system. For certain applications, repair can be performed with a pipe having a smaller diameter than the pipe to be repaired, and by insertion of same into an embraced relationship to the damaged pipe, but to facilitate this operation, the inserted pipe must have a considerably smaller cross-sectional area than the outer pipe, in order to facil tate inser¬ tion, and seals must be arranged at the outer end portions of the inserted pipe in contact with the surrounding outer pipe. Said reduction in area is an obvious disadvantage, and it is also extremely difficult to accomplish seals betweeen the end portions of the inserted pipe and the surrounding pipe, whereby the method only occasionally can be used. The object of the present invention is to disclose a method for repairing and/or reinforcing a pipe system, and a device for utilization of the method, which facilitates a sealing/reinforcing operation in an existing pipe system, and which accomplishes a metallic internal wall surface in the pipe system in an extremely fast and simple fashion, completely without the sealing problems related to the repair method discussed on basis of a pipe, insertable into an existing pipe system. An embodiment of a device for utilization of the method according to the present invention is more fully described below, intended to simplify the understanding of the method, but it should be emphasized, that the embodiment shown should only be regarded as an example of an embodiment within the scope of the invention. The enclosed drawing shows in:- Fig. 1 a longitudinal section of a pipe to be repaired, having a device according to the present invention inserted into same. Fig. 2 a cross-sectional view of the pipe shown in fig. 1 with the inserted device, before repair and/or reinforcement has been performed with regard to the surrounding pipe. Fig. 3 a view corresponding to fig. 2, when repair and/or reinforcement has been accomplished. For example, when a pipe breakage has occured below a road surface, the damaged pipe can often not be accessed, without causing great difficu¬ lties for passing vehicles, and the work also involves risk for the workers. According to the present invention, a smaller portion of the pipe is made accessable at a suitable point, e.g. when a pipe extends below a road surface in a perpendicular relationship to same, access is advantageously obtained at one side of the road surface. The pipe made accessable is thereafter opened, e.g. in location to an existing joint, in order to facilitate insertion of a device according to the present invention in direction towards, and past, the point where leakage or breakage has occurred, or to the point whereto the pipe is intended to be reinforced. With reference to fig. 1, a pipe 1 is shown, intended to be repaired or j S.£-A reinforced. Into said pipe 1, a longitudinally extending tubular member 2 has been inserted in previously described fashion, comprising of a tubular member originally having a preferably circular cross-section, arranged with longitudinally extending impressions or deformations 3, 3' directed towards the centre axis of the tubular member 2. An example of such a cross-sectional configuration is shown in fig. 2. The end portions of the tubular member 2 are arranged sealed, and said seal is preferably arranged by compression of the end portions in direction towards the centre axis, thereby forming pointed portions. Embraced by the tubular member 2, an exposive charge 4 is arranged with associated igniting member, which igniting member facilitates detonation of the explosive charge 4 in a previously known manner, e.g. by electrical, mechanical or any other type of influence. When the tubular member 2 has been located in a position surrounded by the pipe 1, the igniting member is influenced, whereby the explosive charge 4 is detonated. Due to the pressure influence from the explosion, the tubular member 2 is first expanded, whereby complete contact is established against the internal wall surface of the surrounding pipe 1, and as a second step, the end portions of the tubular member 2 are also pressed against the surrounding pipe 1, whereby the inserted tubular member 2 is arranged to communicate with the remaining part of the pipe 1. Said expanded position is shown in fig. 3. Since the end portion of the tubular member 2 preferably comprise of pointed portions before expansion, formed by means of a compression or press operation, said end portion form a part in close contact with the pipe 1 after expansion, which prevents a gas or liquid flow between the tubular member 2 and the surrounding pipe 1. Furthermore, said tubular member 2 has a circumference mainly corresponding to the internal circumference of the pipe 1 in an unexpanded position, whereby said tubular member 2 mainly completely takes up a sealing contact position against the internal wall surface of the surrounding pipe 1 when expanded. With reference to the above embodiment, the end portions of the tubular member 2 are arranged to be expanded and opened when the explosive charge 4 is detonated. However, it should be mentioned, that obviously only one end portion can be arranged in the described fashion, having a different type of sealing member located at the opposed end portion. The latter sealing member can advantageously be arranged attachable together with the explosive charge 4 and associated igniting means, and for example manually removed, when the tubular member 2 has been expanded by means of the detonated explosive charge 4. Obviously, also other types of sealing end members can be used, e,g, manually removable end seals at both end portions, with regard to applications where both end portions are accessable after insertion and expansion of the tubular member 2. In the shown embodiment, the tubular member 2 comprises of a tubular part, having longitudinally extending and towards the centre axis directed deformations or impressions 3, 3', arranged in a mainly cross- shaped configuration, and arranged to reduce the diameter of an enclosing circle. It should be e phazised, that also other cross-sectional confi- gurations obviously can be used, including deformations, impressions or grooves 3, 3', extending in longitudinal direction of the tubular member 2, and arranged to reduce the diameter of an enclosing circle. Provided that the tubular member 2 is arranged with such a cross- sectional configuration, that when expanded by means of explosive force from the explosive charge 4 it takes up a cross-sectional configuration having a larger diameter than the diameter for a circle enclosing the tubular member 2 before said ' expansion, the cross-sectional configura¬ tion is suited for utilization according to the method. The embodiment shown and described is thus only intended to serve as an example of a basic embodiment within the scope of the method according to the present invention, and can thus be varied in a number of diffe¬ rent ways with regard to the cross-sectional configuration, of the tubular member 2, the method in which the end portions are sealed, as well as the method in which the explosive charge 4 is located in a position embraced by the tubular member 2. _ O PI

Claims: Claims 1. Method for repairing and/or reinforcing a pipe system by insertion of a tubular member (2) into a pipe (1), said tubular member (2) arranged enclosing an explosive charge (4), arranged to expand the inserted tubular member (2) by means of explosive force when detonated into a contact position against surrounding pipe (1), characterised in that the tubular member (2) before insertion into the pipe (1) is arranged with longitudinally extending deformations, impressions or similar, thereby giving the tubular member (2) a diameter restricted by an enclosing circle being smaller than the internal diameter of the • pipe (1) to be repaired or reinforced, arranged to take up a contact position against surrounding pipe (1) by means of explosive force when the explosive charge (4) is detonated. 2. Method according to claim 1, characterised in that at least one of the end portions of the tubular member (2) is sealed before detonation of the explosive . charge (4) in such a manner, that it manually must be opened when the tubular member (2) has been expanded to a contact position against the surrounding pipe (1) by means of detonation of the explosive charge (4). 3. Device for utilization of the method according to any of claims 1 and 2, including a tubular member (2), arranged enclosing an explosive charge (4), which when detonated is arranged to expand the tubular member (2) by means of explosive force to a contact position against a surrounding pipe (1), characterised in that the tubular member (2) is arranged with at least one longitudinally extending deformation, impres¬ sion or similar (3, 3'), arranged to give the tubular member (2) a cross-sectional area with the diameter of an enclosing circle smaller than the internal diameter of a pipe (1) intended to be repaired or reinforced, and arranged to be expanded diametrically by means of explosive force when the explosive charge (4) is detonated to a mainly complete contact position against the surrounding and internal wall surface of the pipe (1). 4. Device according to claim 3, characterised in that the external circumference of the tubular member (2) is arranged mainly corresponding to the internal circumference of the pipe (1). 5. Device according to any of claims 3 and 4, characterised in that at least one end portion of the tubular member (2) is arranged sealed by means of a sealing member attached against the tubular member (2). 6. Device according to any of claims 3 - 5, characterised in that the tubular member (2) has such a wall thickness in relation to the force from the explosive charge (4), that the circumference in non-expanded condition is slightly increased by plastical deformation, when the explosive charge is detonated. 7. Device according to any of claims 3 - 6, characterised in that at least the end portion of the tubular member (2) intended to be a first insertable portion in relation to the pipe (1) to be repaired or rein¬ forced, has a mainly pointed or convex outer surface, arranged to serve as a guiding means when the tubular member (2) is axially moved in relation to the surrounding pipe. CMPI

Inventors: GEBELIUS SVEN R
Applicants: GEBELIUS SVEN R
Application year: 1981
Main classification: B21D39
IPC codes: B21D39, B23K20, F16L55