Double pipe system

Abstract

To achieve high flexibility in assembling and to secure connection technology of high accessibility to an inner pipe and high reliability, by improving a method of assembling a double pipe system.SOLUTION: A double pipe system 1 including a primary pipeline 2 conducting a medium and a secondary pipeline 3 arranged around the primary pipeline for protection, includes pipes 4 and fittings 5 of the primary pipeline, and pipes and fittings of the secondary pipeline surrounding the primary pipeline, the pipes and the fittings of the primary pipeline are connected to each other, the pipes of the secondary pipeline are configured as an integrated plastic pipe, and the fittings are configured as half-shells 8, the half-shells of the fittings of the secondary pipeline and the pipes adjoining to the fittings are connected together by means of electric welding sleeves 9, or the half-shells of the fittings and the fittings adjoining to the fittings and consisting of half-shells are connected together by means of electric welding sleeves.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a double - pipe system comprising a primary pipeline for guiding a medium and a secondary pipeline arranged around the primary pipeline for protection, including the pipes and fittings of the primary pipeline and the pipes and fittings of the secondary pipeline surrounding it, where the pipes and fittings of the primary pipeline are coupled to each other, the pipe of the secondary pipeline is formed as an integral plastic pipe, and the fittings are formed as half - shells, and to a method of installing this double - pipe system.

Background Art

[0002] Double - pipe systems are legally defined or installed by end - users to prevent the unexpected outflow of harmful chemicals into the environment or to prevent human harm. Further, double - pipe systems are used especially to protect particularly expensive equipment (machinery, IT infrastructure). The secondary pipeline has a protective pipe that surrounds the inner pipe or primary pipe that guides the fluid. The secondary containment system can be buried underground or configured above ground, and can be pressurized or configured as a drainage system, and usually has a kind of detection system for detecting leaks. The systems existing today are joined to each other by simultaneous or staged welding. The joining techniques vary greatly from continent to continent. However, especially in Europe, this joining is increasingly being realized by heat welding (in the case of polyolefins).

[0003] Prior art has shown that prefabricated joints with inner and outer fittings are manufactured, with the inner and outer fittings being connected to the inner and outer pipes, respectively. A large inventory is required based on the numerous different diameters of the inner and outer pipes and the various fittings, such as T-junctions and angle members, that need to be assembled, which is no longer desirable today. Similarly, secondary containment pipes are manufactured by inserting a thinner inner / actual pipe into a thicker outer / containment pipe and providing a centering member. In this case, connecting the pipes to the molded member is the most difficult task. Existing systems require a significant number of simultaneous connections for installation. Typical adhesive bonding involves first applying a primer to both surfaces to be butted, then applying cementite to both surfaces, then quickly joining the parts by rotating them a quarter turn, and holding them for 30 seconds to 1 minute until the cementite hardens. Naturally, this method can become even more difficult when attempting to manufacture the inner and outer joints simultaneously. The surface that needs to be prepared is twice as large, and the inner tube must be attached to the protective tube to ensure the full use of the sleeve. Furthermore, when simultaneous coupling is performed, the inner coupling is done "without seeing". Another drawback of the existing system is that the inner coupling cannot be inspected during pressure testing, making it difficult to pinpoint and repair the location of the defective coupling if a leak occurs. [Overview of the project] [Problems that the invention aims to solve]

[0004] The object of the present invention is to improve the double-tube system and the method for assembling the double-tube system, thereby enabling high flexibility in the assembly of the double-tube system without requiring a large number of different components, and ensuring good access to the inner tube and reliable coupling technology. [Means for solving the problem]

[0005] This problem is solved, according to the present invention, by having the half-shell of a secondary conduit joint and the pipe following the joint joined to each other by an electric welding sleeve, wherein the electric welding sleeve, which is temporarily positioned on the outer diameter of the pipe of the secondary conduit, is partially fitted over and welded onto the joint consisting of both half-shells, or by having the half-shell of the joint and the subsequent joint consisting of half-shells joined to each other using an electric welding sleeve.

[0006] A double-pipe system according to the present invention comprises a primary conduit for guiding a medium and a secondary conduit arranged around the primary conduit for protection, the primary conduit includes pipes and fittings, which are preferably joined to each other by welding or adhesive. The primary conduit pipes and fittings are preferably made of plastic, but a primary conduit made of metal is also possible, surrounded by a secondary conduit made of plastic. Furthermore, the double-pipe system according to the present invention has surrounding secondary conduit pipes and fittings, which are formed as a single, i.e., one-piece plastic pipe, and the fittings are formed as half-shells. The half-shells of the secondary conduit fittings and the pipes following these fittings are joined to each other using electric welding sleeves. Similarly, the fittings following these fittings are also joined to each other by electric welding sleeves.

[0007] It has been found to be advantageous for the electric welding sleeve to be formed as a single, hollow cylindrical sleeve. This allows the use of a standard electric welding sleeve, which is temporarily fitted over the pipe of the secondary conduit during assembly, preferably fitted halfway over the fitting before welding, and then welded to the pipe and fitting. The electric welding sleeve preferably has two heating elements, preferably heating coils, which are positioned on both sides of the sleeve and welded to the fitting and pipe of the secondary conduit, respectively.

[0008] Preferably, the half-shell is formed by a separating plane that extends from the axial line through the joint to the center. In other words, the two half-shells are preferably formed symmetrically.

[0009] It is advantageous if the secondary pipeline joints do not have a heating element, that is, if the half-shell does not have a heating element.

[0010] Another advantageous embodiment is shown where at least one half-shell of the secondary conduit fitting has a seal extending along a separation plane, the seal materially bonding to the half-shell of the fitting in the region of the electric welding sleeve or in the connecting pipe piece after the electric welding sleeve has been fixedly installed and welded to the secondary conduit. The seal extends along the edge or wall of the half-shell in the separation plane. The separation plane extends along the axis of the fitting and divides the fitting into two symmetrical half-shells. The seal preferably extends to the center of the edge. It has been found advantageous that the seal is positioned on the edge outside the edge in the region of the connecting pipe piece of the half-shell, so that the seal makes direct contact with the electric welding sleeve and materially bonds to this electric welding sleeve upon heating.

[0011] It is advantageous if the pipes and fittings of the primary conduit are joined to each other by electric welding. This allows the same welding method to be used for both the primary and secondary conduits. For the primary conduit, other joining methods such as adhesive or butt welding can also be considered.

[0012] Preferably, the joints of the primary pipeline system are formed as electric welded joints.

[0013] The joints are preferably formed as T-shaped members, branch members and / or curved members. That is, the T-shaped members, branch members and / or curved members of the secondary conduit are formed as half-shells and welded using electric welding sleeves during assembly.

[0014] The half-shells of the joint each have connecting pipe pieces on the connecting side, and it is advantageous that the outer diameter of the connecting pipe pieces preferably matches the outer diameter of the pipe. The connecting pipe pieces of the joint have an outer diameter smaller than the central region of the joint. This means that the joint or half-shell has a stepped portion against which the electric welding sleeve abuts during assembly, thereby pre-defining the precise position of the electric welding sleeve, or allowing the installer to determine how far the electric welding sleeve must be pushed onto the joint in order to properly install it. In variations where two joints are welded to each other, it is advantageous that the joint has markings on its connecting pipe pieces, which indicate to the installer whether the electric welding sleeve is in the correct position.

[0015] It was found to be advantageous that a spacer element is placed within the joint, ensuring that the primary and secondary pipelines are concentrically positioned relative to each other. The spacer element ensures that the primary and secondary pipelines are concentrically spaced apart from each other. Furthermore, the spacer element helps in the axial positioning of the joint relative to the primary pipeline.

[0016] Preferably, spacer elements are also provided inside the pipe, but in that case, these spacer elements do not need to be the same as the spacer elements in the joint.

[0017] In a preferred embodiment, the secondary conduit fitting has at least one clip, which serves to temporarily secure the half-shell to the primary conduit. This makes it easier to fit the electric welding sleeve over the secondary conduit fitting. The clip can be attached to the half-shell later as a separate component or molded together during injection molding.

[0018] Another preferred possibility is that the spacer element provides a degree of self-locking effect in the primary conduit, thereby achieving the effect of temporarily fixing the joint in place in the primary conduit, which already has the advantage that the installer does not yet need to fix the electric welding sleeve, and can therefore more easily install the electric welding sleeve.

[0019] The method according to the present invention for installing a double conduit system includes the following steps: The step involves welding a section of the primary pipeline to at least one fitting and pipe, in which case electric welding is preferably used for welding the fitting and pipe of the primary pipeline. The welding is performed in the section to inspect the weld on the one hand and to partially attach or connect the pipe of the secondary pipeline on the other hand. The welding of the section of the primary pipeline divides it so that the pipe of the secondary pipeline can be fitted over at least one side of the primary pipeline.

[0020] Furthermore, the electric welding sleeve is provisionally positioned on the outer diameter of the pipe of the secondary conduit that is to be fitted over the primary conduit. Then, the pipe of the secondary conduit with the provisionally positioned electric welding sleeve is fitted over the pipe of the primary conduit that has already been welded to a joint to form a sub-section. After the primary conduit or sub-section is installed, the primary conduit can be pressurized to detect any potential leaks.

[0021] Next, the secondary pipeline joint is preferably attached by fitting or joining two half-shells around the primary pipeline joint. Of course, it is also possible to attach the joint consisting of two half-shells of the secondary pipeline around the pipe of the primary pipeline. This is generally carried out at the supporting points where the pipeline is fixed in position. To weld the secondary pipeline, an electric welding sleeve temporarily arranged on the outer diameter of the pipe of the secondary pipeline is partially fitted over and welded to the joint of the secondary pipeline consisting of two half-shells. The electric welding sleeve has approximately half of it arranged on the pipe outer diameter and the remaining half arranged on the joint for welding.

[0022] Preferably, the electric welding sleeve is fitted over the joint of the secondary pipeline or the connecting pipe pieces of the two half-shells until it abuts. In this case, the stopper is preferably formed by a larger cross-section in the central region of the joint.

[0023] Embodiments of the present invention will be described based on the drawings, but the present invention is not limited to this embodiment.

Brief Description of the Drawings

[0024] [Figure 1] It is a view showing a part of the double-pipe system according to the present invention together with one half-shell. [Figure 2] It is a view showing a half-shell of the double-pipe system according to the present invention. [Figure 2a] It is a view showing a half-shell of the double-pipe system according to the present invention where a seal is arranged on the outside in the region of the connecting pipe piece. [Figure 3] It is a view showing a part of the double-pipe system according to the present invention. [Figure 4] It is a view showing step by step the method according to the present invention for installing a double-pipeline system. [Figure 5] It is a view showing step by step the method according to the present invention for installing a double-pipeline system. [Figure 6]This diagram shows a step-by-step method according to the present invention for installing a double-pipe system. [Figure 7] This figure shows a portion of the double-tube system according to the present invention, along with a single half-shell equipped with a verifiable clip. [Figure 8] This figure shows two joints connected to each other by an electric welding sleeve. [Modes for carrying out the invention]

[0025] The diagram in Figure 1 shows a three-dimensional representation of a partially welded joint 7 of a secondary conduit 3, with the upper half-shell omitted in Figure 1. The electric welding sleeve 9 shown on the right has already been correctly positioned and welded to the joint 7. In contrast, the electric welding sleeves 9 on the left and lower sides still need to be fitted over the connecting pipe piece 13 of the joint 7. The double-pipe system 1 according to the present invention has a primary conduit 2 through which a medium circulates. The primary conduit 2 has a pipe 4 and a joint 5, which are preferably welded to each other by an electric welding sleeve 16, but other types of joining, such as adhesive or butt welding, are also possible. The primary conduit 2 is preferably made of plastic, but a metal conduit is also quite possible as a primary conduit.

[0026] Furthermore, the double-pipe system 1 according to the present invention includes a secondary conduit 3. The secondary conduit 3 is positioned around the primary conduit system 2. The secondary conduit 3 serves to protect the environment from spilled media or prevent personal injury in the event of a leak from the primary conduit system 2. The secondary conduit 3 includes a pipe 6 and fittings 7, the fittings 7 being formed as half-shells 8. The pipe 6 is formed as a single piece of plastic and is usually manufactured by extrusion molding. The pipe 6 is fitted over the pipe 4 of the primary conduit 2, in which case only a portion of the primary conduit 2 is installed at any given time, thereby allowing for the subsequent installation of the secondary conduit 3. Both half-shells 8 of the fittings 7 of the secondary conduit 3 are fitted around the corresponding locations of the primary conduit 2. In most cases, these locations are the fittings 5 ​​of the primary conduit 2, as shown in Figure 1. The half-shells 8 of the joint 7 can also be attached to other locations that function as support points 18 to which the double-pipe system 1 is attached, as can be seen, for example, in Figure 3. For the concentric arrangement of both pipes 2 and 3, the half-shells 8 have spacer elements 17. These spacer elements 17 space the joints 5 and 7 concentrically apart from each other. Furthermore, the spacer elements 17 serve to position the half-shells 8 in the axial direction. In Figure 1, the shape of the seal 10 extending along the edge or wall portion 12 of the half-shell 8 is clearly visible. During welding using the electric welding sleeve 9 positioned in the joint 7 of the secondary pipe 3, the seal 10 materially bonds to the half-shell 8 in the area of ​​the electric welding sleeve 9. Figure 2 shows the half-shell 8 of the joint 7 of the secondary pipe 3. The connecting pipe piece 13 into which the electric welding sleeve 9 is fitted for welding the half-shell 8 or the joint 7 is clearly visible. A stopper for the electric welding sleeve 9 is formed by a stepped portion 15, which is created based on the fact that the diameter of the connecting pipe piece 13 is smaller than the central region 14 of the half shell 8 or the joint 7, thereby correctly positioning the sleeve accordingly. Furthermore, in Figure 2, the shape of the seal 10 along the edge 12 of the half shell 8 can again be clearly seen.The seal 10 extends within the separating plane 11 of the two half-shells 8 that form the joint 7. Figure 2 shows an embodiment in which the seal 10 extends centrally across the entire edge of the half-shell 8. Figure 2a shows an embodiment in which the seal 10 is positioned on the outside of the region of the connecting pipe piece 13, on the outer diameter portion of the connecting pipe piece 13, for material bonding directly to the electric welding sleeve 9 during welding with the electric welding sleeve 9. Figure 3 shows various joints 7 formed as half-shells 8. T-shaped members and 90° angled members are shown as examples, but other joints such as half-shells for mounting points formed as branch members, curved members or support points 18 are also conceivable.

[0027] Figures 4 to 6 illustrate step-by-step the method according to the present invention for installing the double-pipe system 1. Figure 4 shows a portion of the primary conduit 2 that is already installed, preferably by welding the pipe 4 to the fitting 5, and thus the pipe 6 of the secondary conduit 3 can be fitted over it. However, this portion of the primary conduit 2 is welded only to the extent that at least one side of the primary conduit 2 remains accessible for the secondary conduit 3 to be fitted over it. Furthermore, Figure 4 shows the preparation of the pipe 6 of the secondary conduit 3 by provisionally positioning an electric welding sleeve 9 on the outer diameter of the pipe 6, and then fitting the pipe 6 and the electric welding sleeves 9 positioned on both sides of this pipe over the portion of the primary conduit 2. Figure 5 shows the method of fitting the pipe 6 onto the primary conduit 2 together with the electric welding sleeves 9 positioned on this pipe 6. Figure 6 shows the pipe 6 of the secondary conduit 2, moved to approach the fitting 7. Next, the electric welding sleeve 9 is fitted over the connecting pipe piece 13 of the fitting 7 up to the stepped portion 15. Then, the electric welding sleeve 9 is welded. This results in a double-pipe system 1 as illustrated in Figure 3. Figure 7 shows an open fitting 7 or half-shell 8 of a secondary conduit 3 with a primary conduit 2 extending inside. A clip 18 installed inside the secondary conduit 3 is clearly visible, and this clip 18 lightly attaches the half-shell 8 to the primary conduit 3 for assembly. This has the advantage of easily and temporarily positioning the half-shell 8 in the primary conduit 2, thereby facilitating the installation of the second half-shell and the fitting of the electric welding sleeve 9 for the installer.

[0028] Figure 8 shows a case where two joints 7 of a secondary conduit 3 are welded directly to each other without any pipe members in between. An electric welding sleeve 9 is positioned in the center of both connecting pipe pieces 13 of the joint, and in this case the axial positioning of the electric welding sleeve 9 is preferably predetermined by an index on the joint. [Explanation of Symbols]

[0029] 1. Double-tube system 2 Primary conduit 3. Secondary pipelines 4. Primary pipeline pipes 5. Primary pipeline joints 6. Secondary pipelines 7. Secondary pipeline joints 8 Half Shell 9 Electric welding sleeve 10 stickers 11 Separation plane 12 Edge / Wall Half Shell 13 connecting pipe pieces 14 Central area 15 Step section 16 Electric welding sleeves, primary conduits 17 Spacer element 18 clips

Claims

1. A double-pipe system (1) comprising a primary pipe (2) for guiding a medium and a secondary pipe (3) arranged around the primary pipe (2) for protection, the system comprising pipes (4) and fittings (5) of the primary pipe (2) and surrounding pipes (6) and fittings (7) of the secondary pipe (3), the pipes (4) and fittings (5) of the primary pipe (2) being connected to each other, the pipes (6) of the secondary pipe (3) being formed as a one-piece plastic pipe, and the fittings (7) being formed as a half-shell (8). The double pipe system (1) is characterized in that the half shell (8) of the joint (7) of the secondary pipeline (3) and the pipe (6) following the joint (7) are connected to each other using an electric welding sleeve (9), or the half shell (8) of the joint (7) and the joint (7) consisting of a half shell (8) following the joint (7) are connected to each other using an electric welding sleeve (9).

2. 2. The double pipe system (1) according to claim 1, wherein the electric welding sleeve (9) is formed as a one-piece hollow cylindrical sleeve.

3. 2. The double pipe system (1) according to claim 1, wherein the half shell (7) is formed by a separation plane extending centrally through the joint (7) along its axis.

4. 2. The double-pipe system according to claim 1, wherein at least one half shell (8) of the joint (7) has a seal (10) extending along a parting plane (11) extending parallel to the axis, and the seal (10) is connected in a material-bonded manner to the half shell (8) of the joint (7) or to the half shell (7) and the electric welding sleeve (9) in the region of the electric welding sleeve (9).

5. 2. The double pipe system (1) according to claim 1, wherein the pipe (4) and the fitting (5) of the primary pipe line (2) are connected to each other by electric welding.

6. 2. The double pipe system (1) according to claim 1, wherein the joint (5) of the primary pipe is formed as an electrically welded sleeve (16).

7. 2. The double pipe system (1) according to claim 1, wherein the joints (5, 7) are configured as T-sections, branches and / or bends.

8. 2. The double pipe system according to claim 1, wherein the half shells (8) of the joint each have a connecting pipe piece (13) on the connecting side, the outer diameter of which preferably corresponds to the outer diameter of the pipe (6).

9. 2. The double pipe system (1) according to claim 1, wherein a spacer element (17) is arranged in the joint (7), and the spacer element (17) ensures a concentric arrangement of the primary pipe and the secondary pipe relative to each other.

10. 2. The double pipe system (1) according to claim 1, wherein at least one clip (18) is arranged in the joint (7) for temporarily fixing the half shell (8) in position in the primary pipe (2).

11. A method for installing a double pipe system according to any one of claims 1 to 10, comprising: welding a section of the primary pipeline (2) to at least one fitting (5) and to at least one pipe (4); provisionally placing an electric welding sleeve (9) on the outer diameter of the pipe (6) of the secondary pipeline (3) to be fitted onto the primary pipeline (2); - fitting the pipe (6) of the secondary pipeline (3) with the temporarily placed electric welding sleeve (9) onto the pipeline section of the partial section welded to the fitting (5) of the primary pipeline (2); Attaching the fitting (7) of the secondary line (3), preferably by fitting two half shells (8) around the fitting (5) of the primary line (2); In a method comprising:

1. A method according to claim 1, characterized in that an electric welding joint (9) temporarily placed on the outer diameter of the pipe (6) of the secondary pipeline (3) is partially slipped onto the joint (7) consisting of two half shells (8) and welded.

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