AU2020328185A1

AU2020328185A1 - Connecting element and tube connection comprising same

Info

Publication number: AU2020328185A1
Application number: AU2020328185A
Authority: AU
Inventors: Hansi Homburg; Andreas Kirchberger; Thomas Schaaf; Oliver Vocks
Original assignee: Rehau Industries SE and Co KG
Current assignee: Rehau Industries SE and Co KG
Priority date: 2019-08-15
Filing date: 2020-08-13
Publication date: 2022-04-07
Also published as: DE202019104494U1; WO2021028537A1; CN114222879A; EP4013985A1; CN114222879B

Abstract

The invention relates to a connecting element (1) for establishing a tube connection between the connecting element (1) and a plastic tube or a metal-plastic composite tube. The connecting element (1) comprises at least one support body (2, 2a) for sliding a tube end (14) onto said support body, said support body being provided with a plurality of peripherally extending outer ribs (3, 3a, 3b, 3c). The at least one support body (2, 2a) has a central axis (4) and an open end (8). At least two peripherally extending outer ribs (3, 3a, 3b, 3c) are inclined at an acute angle (9, 9a, 9b, 9c) with respect to the central axis (4), the acute angle (9, 9a, 9b) at which the peripherally extending outer rib (3, 3a, 3b) is inclined with respect to the central axis (4) being different from the acute angle (9a, 9b, 9c) at which at least one of the peripherally extending outer ribs (3a, 3b, 3c) that is further away from the open end (8) than the peripherally extending rib (3, 3a, 3b) is inclined with respect to the central axis (4).

Description

Connecting element and pipe connection comprising it

The present invention relates to a connecting element for producing a pipe connection between the connecting element and a plastics pipe or a metal-plastics composite pipe, wherein the connecting element has at least one support body provided with a plurality of circumferential outer ribs onto which a pipe end is pushed, wherein the at least one support body has a central axis and an open end and at least two circumferential outer ribs are inclined at an acute angle with respect to the central axis. The present invention relates additionally to a pipe connection between an end of a pure plastics pipe or of a plastics composite pipe and a connecting element, wherein the pipe connection comprises an end of a pure plastics pipe or of a plastics composite pipe and such a connecting element.

Such connecting elements and pipe connections comprising them are known from the prior art. Fixing of the pipe end to the connecting element takes place via a fixing sleeve which is arranged over the pipe end and by which the pipe end is pressed against the outer contour of the support body provided with circumferential outer ribs. A distinction is made between different types of connection technique according to the way in which the fixing sleeve used is applied. In sliding sleeve connections, which are also referred to as axial press connections, the support body of the connecting element is inserted into an expanded or non-expanded pipe end and a sliding sleeve fitted externally to the pipe end is pushed by means of a special sliding tool in the axial direction onto the pipe end with the inserted support body of the connecting element. Such an axial press system with a sliding sleeve is described, for example, in DE 101 30 858 Al. In radial press connections, the press sleeve is first pushed onto the plastics pipe to be connected. Then the support body, which can be made of metal or a plastics material, is pushed into the pipe end of the plastics pipe. The press sleeve is positioned over the support sleeve on the pipe end and finally pressed radially onto the pipe end by means of corresponding pressing tools and thereby irreversibly mechanically deformed. In this case, the support body can consist of metal, for example dezincification-resistant brass or stainless steel, or of a hydrolysis-resistant polymer material, such as polysulfone (PSU), polyethersulfone (PES) or polyphenylsulfone

(PPSU).

In particular in the case of mechanical pipe connections in which the pipe end to be applied to the support body is not expanded, it is necessary to match the dimensions of the individual components to one another, wherein in particular the outside diameter of the connecting element and the inside diameter of the pipe are so chosen that the connecting element on the one hand can easily be inserted into the pipe end but does not fall out of the pipe under its own weight. In addition, when metal-plastics composite pipes in particular are cut, a burr can form which further impedes the insertion of a connecting element into the cut pipe end. Furthermore, the insertability of the connecting element into the pipe end can also be adversely affected by cutting, because the ovality of the pipe can be further increased by the influence of pipe shears. For these reasons, it is generally necessary to calibrate the pipe with a special tool before the connecting element is inserted or the pipe is pushed onto the support body of the connecting element, so that the ovality of the pipe is reduced and, in addition, any burr present is removed by trimming of the pipe end.

Against this background, the object of the present invention is to provide a connecting element and a pipe connection comprising it which overcome the disadvantages of the prior art. In particular, the connecting element according to the invention is to be capable of being inserted more easily into a pipe end, wherein the step of pipe calibration is optionally no longer required.

These and other objects are achieved according to the present invention by a connecting element having the features of claim 1 and a pipe connection having the features of claim 12. Preferred embodiments of the connecting element according to the invention and of the pipe connection according to the invention are described in the dependent claims.

According to the present invention, it has been recognized that circumferential outer ribs that are inclined at an acute angle with respect to the central axis of the support body have a positive impact on the insertability of the support body into a pipe end.

This effect is very pronounced in particular in the case of very shallow inclination angles. However, owing to the length of the circumferential outer ribs that results from the very shallow inclination angles, the radial force transmitted by the fixing sleeve is distributed over a larger surface area, which can adversely affect the stability of the resulting pipe connection. This can be counteracted in that the support body of the connecting element comprises at least one further circumferential outer rib with a larger inclination angle. In the case of such circumferential outer ribs with a larger inclination angle, the radial force transmitted by the fixing sleeve acts on a smaller surface area, whereby the stability of the pipe connection is improved. In addition, the ovality of the pipe end produced, for example, by cutting the pipe to length can be reduced by circumferential outer ribs with inclination angles of different sizes on pushing onto the support body of the connecting element. A burr which may be present at the pipe end, which can be caused by the cutting tool during cutting of the pipe, also has scarcely no impact on the insertability of the support body having such circumferential outer ribs into the pipe end. Therefore, the additional step of pipe calibration is unnecessary when such a connecting element is used.

Accordingly, the present invention lies in the provision of a connecting element for producing a pipe connection between the connecting element and a plastics pipe or a metal-plastics composite pipe, wherein the connecting element has at least one support body provided with a plurality of circumferential outer ribs onto which a pipe end is pushed, wherein the at least one support body has a central axis and an open end and at least two circumferential outer ribs are inclined at an acute angle with respect to the central axis, wherein the connecting element is distinguished according to the invention in that the acute angle at which the circumferential outer rib is inclined with respect to the central axis differs from the acute angle at which at least one of the circumferential outer ribs that is spaced further apart from the open end than the first mentioned circumferential outer rib is inclined with respect to the central axis. The present invention relates additionally to a pipe connection between an end of a pure plastics pipe or of a plastics composite pipe and a connecting element, which pipe connection comprises a pipe end of a pure plastics pipe or of a plastics composite pipe and a connecting element according to the invention.

With regard to the connecting element according to the invention, it can be of use if the acute angle at which the circumferential outer rib is inclined with respect to the central axis is smaller than the acute angle at which the at least one of the circumferential outer ribs that is spaced further apart from the open end than the first-mentioned circumferential outer rib is inclined with respect to the central axis. This contributes towards a greater reduction in the ovality of the cut pipe end. For this purpose, it is particularly preferred if the inclination angles of the circumferential outer ribs increase starting from the open end of the pipe body.

It can also be found to be expedient if the difference between the acute angle at which the circumferential outer rib is inclined with respect to the central axis and the acute angle at which at least one of the circumferential outer ribs that is spaced further apart from the open end than the circumferential outer rib is inclined with respect to the central axis lies in a range of from 30 to 200, preferably in a range of from 50 to 150 and particularly preferably in a range of from 80 to 120. With inclination angles in these ranges, a balanced relationship between the easy insertability of the support body of the connecting element according to the invention and the stability of the pipe connection is obtained.

It can also be advantageous if the support body comprises at least one circumferential outer rib with a substantially rectangular cross section. Such circumferential outer ribs with a substantially rectangular cross section are less susceptible to fall impact defects. Since such rectangular ribs can have a negative impact on the ability of the pipe end to be pushed on, it is preferred if at least one circumferential outer rib that is inclined at an acute angle with respect to the central axis is arranged on the side of the at least one circumferential outer rib with a substantially rectangular cross section that faces the open end of the support body and/or on the side of the at least one circumferential outer rib having a substantially rectangular cross section that is remote from the open end of the support body. It is particularly preferred in this context if the circumferential outer ribs with a substantially rectangular cross section have a smaller outside diameter than the outer ribs that are inclined at an acute angle with respect to the central axis. This ensures that the pipe can easily be pushed onto the support body of the connecting element according to the invention, wherein the reduced diameter of the circumferential outer ribs with a substantially rectangular cross section ensures the sealing action in the pressed state on all the circumferential outer ribs. It is particularly preferred for this purpose if the inclined circumferential outer ribs have a steep inclination angle, preferably in a range of from 150 to 500. Thus, the inclined circumferential outer ribs can engage deep into the pipe material and ensure high tightness of the resulting pipe connection. In further preferred embodiments, a circumferential outer rib with a substantially rectangular cross section represents the outer rib that is furthest away from the open end of the support body. In particularly preferred embodiments, the circumferential outer ribs with a substantially rectangular cross section can also be the circumferential outer ribs that are furthest away from the open end of the support body. In this case, the circumferential outer ribs can also have an equally large outside diameter as the inclined circumferential outer ribs. On introduction of the support body into the pipe end, the burr which may form is in such a case already levelled by the inclined circumferential outer ribs, so that the introduction of the support body into the pipe end is no longer impeded.

It can also be advantageous if the connecting element further comprises at least one circumferential flange. Such a circumferential flange serves as an application point for a pressing tool during production of the pipe connection according to the invention.

It can also be of use if the connecting element is in the form of a polymer component or in the form of a metal component. In this case, it has been found to be particularly advantageous if the polymer material of the connecting element is selected from the group consisting of polypropylene (PP), polyamides, polyvinylidene fluoride (PVDF), polyethersulfone (PES), polysulfone (PSU), polyphenylsulfone (PPSU), polyphenylene sulfide (PPS), polyvinyl chloride (PVC), polyoxymethylene (POM), acrylonitrile butadiene-styrene copolymer (ABS) and polyester carbonate (PESC) as well as copolymers and blends of these polymers, in each case also in fibre-reinforced form. Alternatively, metal materials such as, for example, brass, in particular Ecobrass@, red brass and stainless steel, can also be used.

In relation to the pipe connection according to the invention, it can be preferred if the pipe connection is in the form of an axial press connection with a sliding sleeve. The high stability of the connecting element according to the invention is particularly suitable for such an axial press connection in the production of which high axial forces act in particular on the circumferential flange. The fact that a burr which may have formed during cutting of the pipe is levelled again by the circumferential outer ribs having different inclination angles has a particularly advantageous effect in the case of axial press systems in which the pipe end is not expanded before the support body is introduced.

According to the present invention, there are used as plastics pipes pure plastics pipes, preferably of polyethylene (PE, in particular PE 100 and PE-RT), crosslinked polyethylene (PE-X, in particular PE-Xa, PE-Xb and PE-Xc), polypropylene (in particular polypropylene random copolymer PP-R) and polybutylene (PB); and also plastics composite pipes, preferably with layers of polyethylene (PE, in particular PE 100 and PE-RT), crosslinked polyethylene (PE-X, in particular PE-Xa, PE-Xb and PE Xc), polypropylene (in particular polypropylene random copolymer PP-R) and/or polybutylene (PB). A layer of ethylene-vinyl alcohol copolymer (EVOH) can additionally be present as an oxygen barrier layer. Metal-plastics composite pipes (MPC pipes) preferably comprise according to the present invention layers of polyethylene (PE, in particular PE 100 and PE-RT), crosslinked polyethylene (PE-X, in particular PE-Xa, PE-Xb and PE-Xc), polypropylene (in particular polypropylene random copolymer PP R) and/or polybutylene (PB) and at least one layer of metals, preferably aluminium. The metal layer is preferably butt-welded. In the case of plastics composite pipes and MPC pipes, adhesion promoter layers can be introduced between individual layers. According to the present invention, all the pipes of a pipe connection according to the invention can be of identical construction or one or more of the pipes can have different pipe structures. In addition, the pipes according to the present invention can also be fibre-reinforced. Fibre reinforcement of the line pipes can be present in individual or in all pipes, over the entire pipe length or also only in sections. With regard to the plastics pipe or the metal-plastics composite pipe of the pipe connection according to the invention, it is particularly preferred that at least one layer of the respective pipe comprises crosslinked polyethylene (in particular PE-Xa, PE-Xb and PE-Xc). The material "crosslinked polyethylene" is a material which has shape memory or a so called "memory effect". This memory effect is due to the fact that crosslinked polyethylene, after a change in its outer geometry, tries to return to its original shape again. When pipes are expanded, this has the result that, after expansion, a pipe comprising PE-X tries to achieve the pipe inside diameter prior to expansion again. Since a support body of a connecting element is inserted into the expanded pipe end after expansion, the memory effect results in particularly high tightness of the pipe connection according to the invention when a pipe that comprises at least one layer comprising crosslinked polyethylene is used.

The connecting element according to the invention can be a threaded shaped part or a threadless shaped part, that is to say a connecting element which does not have a thread. This includes in particular connection pieces, connection angles, manifolds, T pieces, wall T-pieces, wall angles, system transitions, transition pieces, angled transition pieces each of which does not have a thread. Accordingly, the term "threaded shaped part" refers to a connecting element which has at least one threaded shaped part. This includes in particular connection pieces, connection angles, manifolds, T pieces, wall T-pieces, wall angles, system transitions, transition pieces and angled transition pieces each of which have at least one internal and/or external thread.

According to the invention, materials which are suitable for the sliding sleeve are preferably polymeric materials such as, for example, polypropylene and glass-fibre reinforced polypropylene, polyamides and glass-fibre-reinforced polyamides, temperature-resistant thermoplastics such as polyphenylsulfone (PPSU), polyvinylidene fluoride (PVDF), polyethersulfone (PES), polysulfone (PSU), polyphenylene sulfide (PPS), acrylonitrile-butadiene-styrene copolymer (ABS) and polyester carbonate (PESC) as well as copolymers and blends of these polymers, wherein these polymer materials can also be used in fibre-reinforced form, in particular glass-fibre-reinforced form, and also metal materials such as, for example, brass, in particular Ecobrass@, red brass and stainless steel. Temperature-resistant plastics and in particular polyphenylsulfone and polyvinylidene fluoride are particularly preferred as materials for the sliding sleeve. Crosslinked polyethylene (in particular PE-Xa, PE-Xb and PE-Xc) is likewise particularly preferred as the material for the sliding sleeve.

The pipe connection according to the present invention is used in particular in piping and connection systems in drinking water installations, in sprinkler systems, in heating element connections, in concrete core tempering and in surface heating and/or surface cooling systems.

The pipe connection according to the invention and individual parts thereof, in particular the connecting element according to the invention, can be produced, for example, line-by-line or layer-by-layer using a line-building or layer-building manufacturing process (e.g. 3D printing). Preferably, however, the connecting element according to the invention is produced by an injection moulding process.

The invention will be explained in detail hereinbelow with reference to the embodiments shown in the figures, in which:

Fig. 1 shows a cross-sectional view of a connecting element according to an embodiment of the present invention;

Fig. 2 shows a cross-sectional view of a connecting element according to a further embodiment of the present invention; and

Fig. 3 shows a cross-sectional view of a pipe connection according to an embodiment of the present invention.

Fig. 1 shows in a cross-sectional view a connecting element 1 according to the invention for producing a pipe connection between the connecting element 1 and a plastics pipe or a metal-plastics composite pipe according to an embodiment of the present invention. The connecting element 1 according to the invention is a connecting piece having two support bodies 2, 2a. In the embodiment shown in Fig. 1, the connecting element 1 is in the form of a one-piece plastics component of glass-fibre reinforced polyphenylsulfone (PPSU). The construction of the connecting element 1 according to the invention is described in detail hereinbelow with reference to the support body 2 on the left in Fig. 1, it being appreciated that these remarks apply correspondingly to the support body 2a on the right in Fig. 1 and to further support bodies which may be present in other embodiments. In the embodiment shown in Fig. 1, the support body 2 has four circumferential outer ribs 3, 3a, 3b, 3c. On its inner side, the support body 2 has in each case a substantially cylindrical inner surface with a common central axis 4. A circumferential flange 5 forms the termination of the support body 2. The two support bodies 2, 2a are connected together via a connecting region 6. In addition, the two support bodies 2, 2a together with the connecting region 6 form a connector channel 7 through which a medium is able to flow during operation of the connecting element 1 according to the invention.

The four circumferential outer ribs 3, 3a, 3b, 3c are sawtooth-shaped in cross section. The side of the circumferential outer ribs 3, 3a, 3b, 3c that faces the open end 8 is in each case inclined at an acute angle 9, 9a, 9b, 9c with respect to the central axis 4. The side of the circumferential outer ribs 3, 3a, 3b, 3c that is remote from the open end 8 encloses a right angle with the central axis 4, wherein the transitions to the side that faces the open end 8 and to the base region of the support body 2, 2a are rounded in each case. In this case, the acute angle 9 of the circumferential outer rib 3 is 70, the acute angle 9a of the circumferential outer rib 3a is 150, the acute angle 9b of the circumferential outer rib 3b is 200 and the acute angle 9c of the circumferential outer rib 3a is 300. The acute angle 9, 9a, 9b, 9c at which the respective outer rib 3, 3a, 3b, 3c is inclined with respect to the central axis 4 thus increases constantly starting from the open end 5. The ovality which occurs when the pipe is cut to length is thus greatly reduced when the pipe end is pushed onto the support body 2, 2a of the connecting element 1 according to the invention. The additional step of pipe calibration can thus be omitted when a connecting element 1 according to the invention is used.

In a pipe connection according to the invention, the ends of identical or different plastics pipes or metal-plastics composite pipes can be connected to the two support bodies 2, 2a.

Fig. 2 shows a further embodiment of the connecting element 1 according to the invention. In order to avoid repetition, only differences with respect to the embodiment of the connecting element 1 shown in Fig. 1 will therefore be described hereinbelow. The remarks made in relation to Fig. 1 also apply correspondingly to the embodiment of Figure 2. The same elements are identified in the figures by identical reference numerals.

Fig. 2 shows a further embodiment of the connecting element 1 according to the invention, again in a cross-sectional view. The connecting element 1 according to the invention shown in Fig. 2 differs from the embodiment shown in Fig. 1 only in terms of the configuration of the circumferential outer ribs. In the connecting element 1 according to the invention according to Fig. 2, the circumferential outer rib 3 adjacent to the open end 4 is in the form of a sawtooth-shaped outer rib, wherein the acute angle 9 at which the circumferential outer rib 3 is inclined with respect to the central axis 4 is in this case 150. This is followed by two circumferential outer ribs 10, 1Oa with a substantially rectangular cross section. Between the circumferential outer rib 1Oa and the circumferential flange 5 there is arranged a further circumferential outer rib 3a, wherein the acute angle 9a at which the circumferential outer rib 3a is inclined with respect to the central axis 4 is 200 in the embodiment according to Fig. 2. The pronounced inclination of the circumferential outer ribs 3, 3a effects deep engagement of the circumferential outer ribs into the pipe material and thus high tightness of the resulting pipe connection. The circumferential outer ribs 10, 1Oa have a smaller outside diameter than the circumferential outer ribs 3, 3a that are inclined at an acute angle with respect to the central axis 4. This ensures that the pipe can easily be pushed onto the support body 2, 2a of the connecting element 1 according to the invention. The circumferential outer ribs 10, 10a with a substantially rectangular cross section also make the connecting element 1 according to the invention less susceptible to fall impact defects. In addition, the connecting element 1 in the embodiment shown in Fig. 2 is in the form of a one-piece plastics component of glass-fibre-reinforced polyphenylsulfone (PPSU).

Finally, Fig. 3 shows in a cross-sectional view a pipe connection 11 which comprises the connecting element 1 according to the invention according to Fig. 1 and in the embodiment shown is in the form of a sliding sleeve connection, wherein a pipe 12 has been connected only to the support body 2a. A sliding sleeve 13 has thereby been pressed in the axial direction over the expanded end 14, which has been pushed onto the support body 2a, of a plastics pipe 12 which has been pushed close to the circumferential flange 5a of the support body 2a of the connecting element 1 according to the invention.

To produce the pipe connection 11 according to the invention, the sliding sleeve 13 is first pushed over the end 14 of the plastics pipe 12. Then an expander tool is inserted into the end 14 of the plastics pipe 12 and the plastics pipe 12 is expanded at the end by means of an expander tool. The support body 2a of the connecting element 1 according to the invention is subsequently inserted into the expanded end 14 of the plastics pipe 12 until the expanded end 14 of the plastics pipe 12 approximately abuts the circumferential collar 5a. Finally, the sliding sleeve 13 is pushed in the axial direction by means of a suitable pushing tool onto the expanded end 14 of the plastics pipe 12 with the inserted support body 2a. The plastics material of the plastics pipe 12 is thereby pressed into the outer contour of the support body 2a of the connecting element 1 according to the invention.

In alternative embodiments, the pipe connection 1 according to the invention can also be an axial press connection having a sliding sleeve 13 in which the end 14 of the plastics pipe 12 is not expanded. The step of expanding the pipe end 12 is then absent from the production of the pipe connection 1 according to the invention.

The present invention has been described in detail with reference to the embodiments of the present invention shown in the figures. It will be appreciated that the present invention is not limited to the embodiments shown but rather the scope of the present invention follows from the accompanying claims.

Claims

1. Connecting element (1) for producing a pipe connection (11) between the connecting element (1) and a plastics pipe (12) or a metal-plastics composite pipe (12), wherein the connecting element (1) has at least one support body (2, 2a) provided with a plurality of circumferential outer ribs (3, 3a, 3b, 3c) onto which a pipe end (14) is pushed, wherein the at least one support body (2, 2a) has a central axis (4) and an open end (8) and at least two circumferential outer ribs (3, 3a, 3b, 3c) are inclined at an acute angle (9, 9a, 9b, 9c) with respect to the central axis (4),

characterised in that

the acute angle (9, 9a, 9b, 9c) at which the circumferential outer rib (3, 3a, 3b) is inclined with respect to the central axis (4) differs from the acute angle (9a, 9b, 9c) at which at least one of the circumferential outer ribs (3a, 3b, 3c) that is spaced further apart from the open end (8) than the circumferential outer rib (3, 3a, 3b) is inclined with respect to the central axis (4).

2. Connecting element (1) according to claim 1, characterised in that the acute angle (9, 9a, 9b) at which the circumferential outer rib (3, 3a, 3b) is inclined with respect to the central axis (4) is smaller than the acute angle (9a, 9b, 9c) at which at least one of the circumferential outer ribs (3a, 3b, 3c) that is spaced further apart from the open end (8) than the circumferential outer rib (3, 3a, 3b) is inclined with respect to the central axis (4).

3. Connecting element (1) according to claim 1 or claim 2, characterised in that the difference between the acute angle (9, 9a, 9b) at which the circumferential outer rib (3, 3a, 3b) is inclined with respect to the central axis (4) and the acute angle (9a, 9b, 9c) at which at least one of the circumferential outer ribs (3a, 3b, 3c) that is spaced further apart from the open end (8) than the circumferential outer rib (3, 3a, 3b) is inclined with respect to the central axis (4) lies in a range from 30 to

200.

4. Connecting element (1) according to any one of the preceding claims, characterised in that the sides of the circumferential outer ribs (3, 3a, 3b, 3c) facing the open end (8) of the support body (2, 2a) are inclined at an acute angle (9, 9a, 9b, 9c) with respect to the central axis (4).

5. Connecting element (1) according to any one of the preceding claims, characterised in that the support body (2, 2a) comprises at least one circumferential outer rib with a substantially rectangular cross section.

6. Connecting element (1) according to claim 5, characterised in that at least one circumferential outer rib (3, 3a, 3b, 3c) that is inclined at an acute angle (9, 9a, 9b, 9c) with respect to the central axis (4) is arranged both on the side of the at least one circumferential outer rib with a substantially rectangular cross section that faces the open end (8) of the support body (2, 2a) and on the side of the at least one circumferential outer rib with a substantially rectangular cross section that is remote from the open end (8) of the support body (2, 2a).

7. Connecting element (1) according to claim 5 or claim 6, characterised in that a circumferential outer rib with a substantially rectangular cross section represents the outer rib that is furthest away from the open end (8) of the support body.

8. Connecting element (1) according to any one of claims 5 to 7, characterised in that the circumferential outer ribs with a substantially rectangular cross section have a smaller outside diameter than the outer ribs (3, 3a, 3b, 3c) that are inclined at an acute angle (9, 9a, 9b, 9c) with respect to the central axis (4).

9. Connecting element (1) according to any one of the preceding claims, characterised in that it further comprises at least one circumferential flange (4, 4a) which forms the termination of the support body (2, 2a).

10. Connecting element (1) according to any one of the preceding claims, characterised in that the connecting element (1) is in the form of a polymer component.

11. Connecting element (1) according to any one of the preceding claims, characterised in that the polymer material of the connecting element (1) is selected from the group consisting of polypropylene (PP), polyamides, polyvinylidene fluoride (PVDF), polyethersulfone (PES), polysulfone (PSU), polyphenylsulfone (PPSU), polyphenylene sulfide (PPS), polyvinyl chloride (PVC), polyoxymethylene (POM), acrylonitrile-butadiene-styrene copolymer (ABS) and polyester carbonate (PESC) as well as copolymers and blends of these polymers, in each case also in fibre-reinforced form.

12. Pipe connection (11) between an end (14) of a plastics pipe (12) or of a metal plastics composite pipe (12) and a connecting element (1), comprising: an end (14) of the plastics pipe (12) or of the metal-plastics composite pipe (12); and a connecting element (1) according to any one of claims 1 to 11.

13. Pipe connection (12) according to claim 12, characterised in that the pipe connection (12) is in the form of an axial press connection having a sliding sleeve (13).