SYSTEM FOR CONNECTING RIGID PIPES AND FOR CONNECTING FLEXIBLE PIPES

Description

[0001] The invention relates to a system for connecting rigid pipes and for connecting flexible pipes, wherein the pipes have mutually corresponding outer diameters. The invention also relates to a plurality of fittings suitable for use in such a system, as well as to a system of fittings.

[0002] The technical field relevant to the present invention is the on-site installation of piping systems, in which a piping system consisting of pipe sections and fittings is generally installed to conduct and transport a fluid, i.e. a liquid or a gas. A fitting is basically understood to be a connecting piece for a pipeline, and a fitting is most frequently used to connect two or more pipe sections. Accordingly, the fitting preferably has two or more press sections, for example in the form of press sleeves. The most common fittings include straight connections, changes of direction in the form of pipe bends, reducers, branches such as T-pieces or intersections. However, a fitting can also be understood to be a pipe connection of a valve or other component. For example, thermometers or pressure gauges, as fittings, only have one connection for one pipe section.Thus, the fitting of a valve has only one press section to connect a pipe section to the valve.

[0003] Press connections are used to connect pipe sections to fittings and other components. A press section of a fitting is radially deformed inward using a press jaw when the pipe section is inserted, creating a permanent, tight, and possibly even permanent connection. The fittings can be provided with a sealant, such as an O-ring, to ensure the tightness of the connection, or they can be sealed by direct contact between the materials of the pipe section and the fitting, for example, a metallic seal.

[0004] The pressing technology used for radial forming of the pressing section primarily includes radially acting pressing systems as well as pressing systems that use radial-axial pressing, whereby a part of the fitting is displaced axially during the pressing process in order to effect radial forming.

[0005] The pipeline systems described above are primarily used to transport drinking or heating water, gas for operating a heating system, or industrial gases. In principle, any fluid medium can be transported in the pipelines.

[0006] For the purposes of this application, a rigid pipe is defined as a pipe connected to an externally sealed fitting. The strength of the pipe material is sufficient that the external forces acting through the fitting enable a permanent seal, but do not deform the rigid pipe, or only slightly, so that the connection remains stable and tight.

[0007] In addition, applications are also known, such as for PE pipes or thin-walled copper pipes, which are sealed externally and additionally incorporate an internal support sleeve. This is because the strength of the material is not entirely sufficient for external sealing without the risk of deforming the pipe. The inserted support sleeve serves only a supporting function and not a sealing function. Such pipes are also considered rigid pipes for the purposes of this application, as they can be connected with an externally sealing fitting.

[0008] In the context of this application, a flexible pipe is understood to be a pipe which is provided with an internally sealing fitting with a

[0009] The low strength of the pipe material requires that the forces acting through the fitting from the inside and outside ensure a permanent seal without excessive deformation. The flexible pipe is subjected to a force from the inside and outside, ensuring that the connection remains stable and tight.

[0010] Rigid pipes are made of solid materials, particularly metallic ones. Rigid plastics are also suitable as solid materials. Rigid pipes are preferred for installations with larger straight sections along walls or ceilings, or within wall or ceiling structures.

[0011] On the other hand, flexible pipes are used in installations, particularly plastic pipes, so-called all-plastic pipes, or pipes made of composite materials, so-called multi-layer composite pipes, consisting of one or more layers of plastic and one or more thin layers of metal. Flexible pipes are used in particular for the installation of pre-wall technology such as retrofitted plumbing systems, where the flexible pipes are often bent on-site in tight spaces and installed in a curved state.

[0012] Furthermore, rigid and flexible pipes are available in various outer diameters. Metal pipes are typically available in outer diameters ranging from 6 mm to 108 mm and up to 6 inches. Plastic pipes typically have outer diameters in the range of 6 mm to 63 mm, although significantly larger outer diameters are also used here.

[0013] When installing a piping system that uses both rigid and flexible pipes, matching pipe dimensions are selected for the inner and outer diameters. The exact values may then only match by chance, so matching dimensions are selected with the best possible match. In combination with the specific fittings for rigid and flexible pipes, specific fitting geometries and die geometries generally exist for each system or dimension.

[0014] Therefore, different press jaws must be kept on site for different pipes and fittings. This requires considerable effort on site, as a large number of press jaws and possibly even different pressing tools must be kept on hand. This creates a very complex product diversity and the associated production, storage, and logistics. For the customer, especially the tradesman, this complexity of pipes, fittings, and press jaws is further amplified by the numerous systems from different manufacturers available on the market.

[0015] The following solutions are known from the state of the art.

[0016] US 2020 / 378530 A1 describes a fitting for connecting flexible, internally sealed pipes to a support body with a sealing function.

[0017] US 2019 / 024827 A1 discloses a fitting for connecting rigid, externally sealing pipes with a chamber, a sealing element, a clamping element with protruding ends and a separating element between the sealing element and the clamping element.

[0018] DE 10 2015 109 268 A1 describes a fitting with a compression sleeve having a chamber open at the distal end, in which a sealing element, cutting elements, and a retaining element are arranged. The retaining element partially protrudes axially from the chamber. The cutting elements are held on the annular retaining element by being pushed onto, inserted into, clamped into, or materially connected to the retaining element.

[0019] GB 687 497 A discloses a fitting for connecting to a flexible pipe in the form of a hose coupling with a base body including a support body connected to a sleeve. A multi-layer hose is connected to the fitting. Before inserting the hose into the fitting, a portion of the outer layer is removed at the end, a ring is placed on top, and the fabric of the remaining reinforcement layer is wrapped around the ring. Thus, before and after pressing the fitting, the reinforcement layer material lies between the open end of the compression sleeve.

[0020] Therefore, the present invention is based on the technical problem of simplifying the on-site effort required for installing piping systems. The technical problem consists, in particular, in providing suitable combinations of fittings for rigid and flexible pipes and the corresponding pressing tools. A further technical problem consists in providing fittings for use in the aforementioned systems, particularly with regard to improving their manufacturing costs.

[0021] The above-mentioned technical problem is solved according to the invention by a system for connecting rigid pipes and for connecting flexible pipes, in which the pipes have mutually corresponding outer diameters, with a pressing jaw having a pressing contour, with at least one first fitting for press-connecting to a rigid pipe, wherein the at least one first fitting is designed as an externally sealing fitting and seals a rigid pipe to be connected from the outside and wherein the at least one first fitting has a first press sleeve with a first outer contour, with at least one second fitting for press-connecting to a flexible pipe, wherein the at least one second fitting is designed as an internally sealing fitting and seals a flexible pipe to be connected from the inside and wherein the at least one second fitting has a second press sleeve with a second outer contour,and wherein the outer contour of the first pressing sleeve and the outer contour of the second pressing sleeve are each adapted at least in sections to the pressing contour of the pressing jaw and can be pressed by the pressing jaw.,

[0022] According to the invention, it has been recognized that the effort required on site is reduced if fittings for rigid pipes and fittings for flexible pipes each have a press sleeve whose outer contours are at least identical, preferably even identical, so that they can be pressed using the same pressing tool and the same associated pressing jaw with the corresponding pressing contour. Thus, piping systems with rigid pipes and piping systems with flexible pipes can be installed using the same pressing tool and the same pressing jaw. Therefore, fewer tools and pressing jaws need to be kept on site, and the time required for setting up the tools is reduced. Fewer jaw changes and less tool complexity on site lead to simpler tool management.

[0023] A pressing jaw is considered a component of the overall pressing tool system. In its most common application, the pressing jaw consists of two halves of the pressing jaw, which are attached to a pressing tool. These halves have an inlet contour that is operatively connected to a piston. These halves are rotated from an open position to a closed position by a linearly driven motorized piston. This rotational movement presses a fitting arranged in the pressing jaw.

[0024] The pressing jaw can also consist of two pressing jaw halves, which are connected to each other via a joint and have coupling means at the open end. A pressing tong, which in turn is part of a pressing tool and is operatively connected to a piston via an inlet contour, engages the two coupling means of the pressing jaw. The linear advance of the piston of the pressing tool compresses the pressing tongs at the front end, and the engagement with the coupling means also compresses the pressing jaw. In addition to a two-part pressing jaw, multi-part pressing jaws are also known as pressing collars.

[0025] Metals are particularly used as materials for rigid pipes, for example, stainless steels such as ferritic steels such as 1.4521, austenitic steels such as 1.4404, duplex steels such as 1.4462, gunmetal, SiBr, copper, but also rigid plastics such as cross-linked polyethylene (PE-X), polyethylene with increased temperature resistance (PE-RT), polyvinyl chloride (PVC), and polypropylene (PP) with appropriate wall thicknesses. Furthermore, multi-layer composite pipes can be rigid, for example, with a thicker aluminum layer; fiber-reinforced pipes can also be used. Flexible pipes can be made of the same plastics or of a composite of plastic and metal layers, but with a thinner wall thickness, so that flexibility is ensured by the geometric design.

[0026] Rigid pipes and flexible pipes differ, regardless of the material properties and dimensions of the pipe, in that a rigid pipe can be connected using an externally sealing fitting, whereas a flexible pipe can only be connected using an internally sealing fitting. Due to its rigid nature, the dimensional stability of the rigid pipe is sufficiently great to absorb the forces generated during radial pressing and to ensure the sealing, holding, or fixing function together with the pressed fitting. Flexible pipes, on the other hand, are supported from the inside by a support sleeve and are formed onto the support sleeve when the fitting is pressed. Fittings for rigid pipes are therefore externally sealing fittings, while fittings for flexible pipes are internally sealing fittings.

[0027] Since rigid pipes are often made of a material with a higher strength, they generally have a thinner wall thickness than flexible pipes made of a material with a lower strength. Therefore, the fittings of the described system are preferably used for pairs of rigid pipes with the same outer diameters as possible.

[0028] Pipes and flexible pipes are used, although the exact external dimensions may vary. The internal dimensions may differ more than the external dimensions. For example, an existing system of metal and plastic pipes may contain rigid pipes with an external diameter of 16 mm and flexible pipes with an external diameter of 15 mm.

[0029] This results in the outer diameters of the rigid pipes and the flexible pipes being the same or similar. If the rigid pipes and the flexible pipes are installed in a common piping system, only minimal flow losses occur due to the equally slightly different internal cross-sections. Therefore, the approach is always to combine a pair of adjacent outer diameters in a system with a single pressing jaw with a single pressing contour, for example, pairs of pipe outer diameters 16 mm / 15 mm or 54 mm / 50 mm.

[0030] As already explained in the introduction, a fitting is located on each side of a connector or fitting. Depending on the function of the connector or fitting, one fitting is usually provided for a fitting, or up to four fittings are provided for a crossover.

[0031] The described fittings and their components are preferably made of a metal to ensure formability with sufficient hardness and dimensional stability after forming. Suitable metals include the metals already mentioned for the rigid pipes, for example, stainless steels such as ferritic steels such as 1.4521, austenitic steels such as 1.4404, duplex steels such as 1.4462, gunmetal, SiBr, and copper.

[0032] However, the described fittings and their components can also be made of a non-metallic material or plastic if the non-metallic material has sufficient properties for pressing and permanently connecting to pipes. Examples of suitable materials include the following: cross-linked polyethylene (PE-X), silane-cross-linked polyethylene (PE-Xb) or physically cross-linked polyethylene (PE-Xc), polyethylene with increased temperature resistance (PE-RT), polyvinyl chloride (PVC), polypropylene (PP) with appropriate wall thicknesses, polyphenyl sulfone (PPSU), polyetheretherketone (PEEK) or polyaryletherketone (PAEK), aliphatic bio-based polyamide (PA410, PA12, PA12-GF30) or polypropylene random copolymer with modified crystal structure and increased temperature resistance (PP-RCT).

[0033] In the system according to the invention, the outer contours of the first compression sleeve and the second compression sleeve are preferably each adapted, at least in sections, to the pressing contour of the pressing jaw. The characteristic "adapted" means that the outer contours of the respective compression sleeves preferably lie flat against each other at least in sections on the pressing contour. During pressing, the compression forces, preferably directed radially inward, are transferred to the compression sleeve at the section-by-section contact surfaces by the pressing jaw. This reshapes the compression sleeve in such a way that the holding and sealing effect against the pipe to be connected is permanently established.

[0034] The press sleeves can generally have different geometries, as long as they have sections in the outer contour that become effective when the fitting is pressed with the press jaw. Preferably, the press sleeves form a chamber facing inwards towards the pipe to be accommodated, and at least one clamping element, sealing element and / or force transmission element is accommodated in each chamber. The design of the chambers allows the aforementioned elements to be pre-installed to create a pull-out-proof and tight connection between the rigid or flexible pipe and the fitting. The chamber can be enclosed on three sides by the press sleeve, but the chamber can also be at least partially open towards the distal end of the press sleeve.

[0035] Advantageously, the chamber of the first compression sleeve and the chamber of the second compression sleeve can accommodate different clamping elements, sealing elements, and / or force transmission elements. Thus, with the same compression geometry of the compression jaw and the first and second compression sleeves, differently adapted compression elements can be used for sealing, holding, and fixing the rigid pipe or flexible pipe within the first and second fittings. The flexibility of the design of the fittings and the elements they contain ensures that the fittings are well adapted to rigid and flexible pipes alike, while the same compression contour can be used. Within the described system, an optimal connection technology for rigid and flexible pipes alike is achieved.

[0036] If, as described, the outer contours of the first compression sleeve and the second compression sleeve match at least in sections, identical sections of the compression sleeves for both pipe types are pressed equally. The compression sleeves are thus formed in the same way in the matching sections when the compression jaw closes. Further preferably, the compression sleeves for the rigid pipes and the compression sleeves for the flexible pipes have identical outer contours and are therefore formed by the same compression jaw, possibly with different compression forces.

[0037] Furthermore, it can be provided that the first compression sleeve has a first additional compression section, and that the second compression sleeve has a second additional compression section, wherein the first additional compression section and the second additional compression section have different outer contours and can each be formed in sections by the compression jaw. Thus, different functionalities can be formed into the fittings for rigid pipes and the fittings for flexible pipes. Nevertheless, both fittings are pressed with the same compression jaw and the same compression contour.

[0038] The basic design of fittings consists of a base body and the compression sleeves, which are either integrally formed with the base body or connected to the base body by a material or force fit. Fittings for flexible pipes also feature a support sleeve to support and seal an inserted pipe from the inside, and to absorb compression forces.

[0039] The following describes embodiments of fittings for rigid pipes and fittings for flexible pipes. On the one hand, these embodiments represent preferred embodiments of the described system. On the other hand, the embodiments also represent independent solutions to the above-mentioned technical problems, either individually or in combination.

[0040] In the following, the dimensions and ratios of the fittings are calculated and compared. The calculations characterize the fittings of the described system in a preferred manner.

[0041] In a preferred embodiment of the system, the ratio of the volume V(rigid) of the chamber of the compression sleeve of the first fitting to the volume V(flex) of the chamber of the compression sleeve of the second fitting is given by δ = V starr V flex , where the volume V(rigid) is given by V starr = π ⋅ LK starr 4 ⋅ DK starr 2 − DR starr 2 , with LK(rigid) length of the chamber, with DK(rigid) the inner diameter of the chamber and with DR(rigid) the outer diameter of the rigid pipe to be accommodated, where the volume V(flex) is given by Vflex=π⋅LKflex4⋅DKflex2−DRflex2, where LK(flex) is the length of the chamber, DK(flex) is the inner diameter of the chamber and DR(flex) is the outer diameter of the flexible pipe to be accommodated, that the ratio is given by δ=VrigidVflex=LKrigidLKflex⋅DKrigid2−DRrigid2DKflex2−DRflex2, and wherein δ takes values from a range of values [0.50; 3.00], preferably [0.50; 1.50], particularly preferably [0.75; 1.25].

[0042] The length of the chamber, also called the chamber length, is preferably determined by the length of the section of the same diameter that forms the chamber, i.e., by the length of the cylindrical section that forms the chamber. Rounded areas on one or both sides of the cylindrical section are not taken into account when determining the chamber length.

[0043] The ratio δ of the described embodiment thus indicates the ratio of the volume of the chamber surrounding an inserted pipe of the compression sleeve of a fitting for pressing a rigid pipe and the volume of the chamber surrounding an inserted pipe of the compression sleeve of a fitting for pressing a flexible pipe. Similar chamber volumes and thus a ratio δ as close as possible to 1 facilitate the pressing of rigid and flexible pipes with the same pressing contour.

[0044] However, if the chamber volumes are significantly unequal, pressing of rigid and flexible pipes with one pressing contour cannot be fully guaranteed.

[0045] For example, with a chamber volume ratio of δ<0.5, where the chamber volume of the compression sleeve of the fitting for flexible pipes is at least twice as large as the chamber volume of the compression sleeve of the fitting for rigid pipes, the chamber length of the compression sleeve of the fitting for rigid pipes may be too short to accommodate the elements provided in the chamber. Secondly, for such a ratio, the chamber of the compression sleeve of the fitting for rigid pipes may have an insufficient height and thus an insufficient degree of compression. It is also possible that for a ratio of δ<0.5, the chamber of the compression sleeve of the fitting for flexible pipes may require an excessively large height and thus an excessively high degree of compression.

[0046] However, with a ratio of the chamber volumes δ>1.5, in particular δ>3.0, in which the chamber volume of the press sleeve of the fitting for rigid pipes is therefore larger by a factor of at least 1.5, in particular at least 3.0, than the chamber volume of the press sleeve of the fitting for flexible pipes, the chamber length of the press sleeve of the press sleeve of the fitting for flexible pipes may be too short to accommodate elements provided in the chamber, such as a force transmission ring. On the other hand, for such a ratio, the chamber of the press sleeve of the fitting for flexible pipes may have an insufficient height and thus an insufficient degree of compression. It is also possible that for a ratio δ>1.5, in particular δ>3.0, the chamber of the press sleeve of the fitting for rigid pipes may have an excessively large height and thus an insufficient degree of compression.

[0047] However, if, as stated in the preferred embodiment of the system, chamber volumes as similar as possible are selected, the ratio δ=1. Thus, both the chamber height and the chamber length of the compression sleeves of the fittings for rigid and flexible pipes can be selected such that a uniform degree of compression is achieved with one compression contour for pressing rigid and flexible pipes. In this way, a sealing compression of rigid and flexible pipes can be ensured with one compression contour.

[0048] Alternatively, a system with deliberately different chamber volumes can be selected. In this case, the ratio of the chamber volumes within the specified limits is not equal to 0, i.e., δ<>1. Thus, both the chamber height and the chamber length of the press sleeves of the fittings for rigid and flexible pipes can be selected so that an optimal arrangement of various functional elements within the chamber of the first fitting for rigid pipes and the second fitting for flexible pipes can be achieved through different chamber volumes. In this way, a single press contour can ensure a tight pressing of rigid and flexible pipes while simultaneously ensuring optimal adaptation of the functional elements.

[0049] In a further preferred embodiment of the system, the ratio of the difference between the inner diameter DK(rigid) of the chamber of the compression sleeve of the first fitting and the outer diameter DR(rigid) of the rigid pipe to be accommodated to twice the length LK(rigid) of the chamber is given by ε starr = DK starr − DR starr 2 ⋅ LK starr and ε(rigid) takes values from a range of values [0.10; 0.50], preferably [0.2; 0.4], particularly preferably [0.25; 0.35].

[0050] The parameter ε(rigid) of the described embodiment thus specifies the ratio of the chamber height to the chamber length of the compression sleeve of a fitting for pressing a rigid pipe. It has been shown that a ratio in which the value ε(rigid) ideally assumes the value 0.3 or deviates as little as possible from this value, i.e., the chamber height corresponds to approximately one-third of the chamber length, achieves a sufficient degree of compression for the reliable pressing of rigid pipes using the compression sleeve of the fitting for pressing rigid pipes.

[0051] For values of ε(rigid) that deviate significantly from the target value ε(rigid)=0.3, it has been shown that a significantly shorter or significantly longer chamber length compared to the chamber height results in various disadvantages.

[0052] For example, a value of ε(rigid)<0.1, where the chamber length is more than 10 times the chamber height, may result in chamber lengths that are too long for the achieved installation space. On the other hand, for such a value of ε(rigid), even with a reasonably selected chamber length, the chamber height may be too small to provide sufficient space for the elements to be accommodated.

[0053] It is also possible that for ε(rigid)<0.1 a compression ratio that is too high is achieved.

[0054] For example, with a value of ε(rigid)>0.5, where the chamber length is less than twice the chamber height, the chamber length may be too short to provide sufficient space for the elements to be accommodated, even if the chamber height is chosen sensibly. It is also possible that for ε(rigid)>0.5, the compression ratio may be too high.

[0055] If, however, as indicated in the preferred embodiment of the system, an ε(rigid) is selected as close as possible to the target value of ε(rigid)=0.3, such a selected ratio of chamber length to chamber height can ensure sufficient space for accommodating elements inside the chamber as well as an optimally selected degree of compression for safe pressing of rigid pipes.

[0056] In a further preferred embodiment of the system, the ratio of the difference between the inner diameter DK(flex) of the chamber of the compression sleeve of the second fitting and the outer diameter DR(flex) of the flexible pipe to be accommodated to twice the length LK(flex) of the chamber is given by ε flex = DK flex − DR flex 2 ⋅ LK flex and ε(flex) takes values from a value range [0.10; 0.70], in particular [0.10; 0.50], preferably [0.20; 0.60], in particular [0.2; 0.4], particularly preferably [0.25; 0.50], in particular [0.25; 0.35].

[0057] The parameter ε(flex) of the described embodiment thus specifies the ratio of the chamber height to the chamber length of the compression sleeve of a fitting for pressing a flexible pipe. The advantages and disadvantages resulting from the selection of the value of the parameter ε(flex) correspond to the previously described advantages and disadvantages of the parameter ε(rigid), so that a target value of ε(flex)=0.3 is also aimed for the chamber geometry of the compression sleeve of a fitting for pressing a flexible pipe, with a sufficient degree of compression and sufficient space to accommodate elements inside the chamber.

[0058] In a further preferred embodiment of the system, in which ε(rigid) is given by ε starr = DK starr − DR starr 2 ⋅ LK starr , with the inner diameter DK(rigid) of the chamber of the compression sleeve of the first fitting, with the outer diameter DR(rigid) of the rigid pipe to be accommodated and with the length LK(rigid) of the chamber, where ε(flex) is given by ε flex = DK flex − DR flex 2 ⋅ LK flex , with the inner diameter DK(flex) of the chamber of the compression sleeve of the second fitting, with the outer diameter DR(flex) of the flexible pipe to be accommodated and with the length LK(flex) of the chamber, the ratio α is given by α = ε starr ε flex = LK flex LK starr ⋅ DK starr − DR starr DK flex − DR flex and α takes values from a range of values [0.50; 3.00], preferably [0.50; 1.50], particularly preferably [0.75; 1.25].

[0059] The ratio α of the described embodiment thus indicates the ratio of the chamber height and length of the compression sleeve of a fitting for pressing rigid pipes and the ratio of the chamber height and length of the compression sleeve of a fitting for pressing flexible pipes. Similar ratios of the chamber height and length of the compression sleeves and thus a ratio δ as close as possible to 1 improve the pressing of rigid and flexible pipes with the same pressing contour.

[0060] The results from the choice of the value of the ratio α = ε starr ε flex The resulting advantages and disadvantages correspond to the previously described advantages and disadvantages for the value of the ratio δ of the volume of the chamber of the press sleeve of a fitting for pressing a rigid pipe and the volume of the chamber of the press sleeve of a fitting for pressing a flexible pipe, wherein a value α<0.5 corresponds to an at least 2-fold greater ratio of the chamber height and length of the press sleeve of a fitting for connecting a flexible pipe compared to the corresponding ratio of the press sleeve of a fitting for connecting a rigid pipe and wherein a value α>1.5 corresponds to an at least 1.5-fold greater ratio of the chamber height and length of the press sleeve of a fitting for connecting a rigid pipe compared to the corresponding ratio of the press sleeve of a fitting for connecting a flexible pipe.

[0061] In a further preferred embodiment of the system, the degree of compression β(rigid) when pressing the first fitting to a rigid pipe is given by β starr = DK starr + 2 s starr − DPK starr DR starr , with the inner diameter DK(rigid) of the chamber of the press sleeve of the first fitting before pressing, with the wall thickness s(rigid) of the press sleeve in the area of the first fitting to be pressed before pressing, with the outer diameter DR(rigid) of the rigid pipe to be accommodated before pressing and with the inner diameter DPK(rigid) of the pressing contour of the pressing jaw in the area of the first fitting to be pressed DR(rigid), where β(rigid) assumes values of β(rigid)<0.15, preferably β(rigid)<0.12, particularly preferably β(rigid)<0.10.

[0062] In this way, a tight connection with high pull-out strength is achieved during pressing, and wrinkling of the pipe to be connected and the fitting can be minimized. The degree of pressing indicates the change in the chamber diameter of the compression sleeve during pressing, taking the wall thickness of the compression sleeve into account, and relates this change to the diameter of the pipe to be pressed. This change is achieved by compressing the compression jaw during pressing, with the inner diameter of the compression jaw after pressing determining the diameter of the chamber of the compression sleeve in the pressed state.

[0063] A compression ratio of approximately 0, corresponding to a compression ratio of approximately 0%, means that the chamber has not been compressed and thus has not experienced any change in diameter. However, for large pipe diameters, the compression ratio indicated by β(rigid) can easily reach values in the low percentage range, approximately 1% corresponding to β(rigid)=0.01, even with a satisfactory sealing compression. However, if the compression ratio is too high, for example, a compression ratio of 0.15 or greater, corresponding to a compression ratio greater than 15%, this can lead to excessive deformation and ultimately to the deformation of the fitting to be compressed and / or the pipe.

[0064] In a further preferred embodiment of the system, the degree of compression β(flex) when pressing the second fitting to a flexible pipe is given by β flex = DK flex + 2 s flex − DPK flex DR flex , with the inner diameter DK(flex) of the chamber of the press sleeve of the second fitting before pressing, with the wall thickness s(flex) of the press sleeve in the area of the second fitting to be pressed before pressing, with the outer diameter DR(flex) of the flexible pipe to be accommodated before pressing and with the inner diameter DPK(flex) of the pressing contour of the pressing jaw in the area of the second fitting to be pressed after pressing, where β(flex) assumes values of β(flex)<0.15, preferably β(flex)<0.12, particularly preferably β(flex)<0.10.

[0065] In this way, a tight connection with high pull-out strength can be achieved and the wrinkling of the pipe to be connected and the fitting during pressing can be minimized.

[0066] In contrast, a compression ratio β(flex) of approximately 0, corresponding to a compression ratio of approximately 0%, means that the fitting has not been tightly pressed into the pipe to be connected and the chamber diameter of the compression sleeve has not changed. For large pipe diameters, however, the compression ratio indicated by β(flex) can easily reach values in the low percentage range, approximately 1% corresponding to β(flex)=0.01, even with a satisfactory compression ratio. If the compression ratio β(flex) is too high, for example, with a compression ratio of 0.15 or greater, corresponding to a compression ratio of 15% or greater, the fitting or pipe to be pressed can be deformed too much, resulting in wrinkling and the excessive pressing forces leading to deformation of the fitting and / or pipe to be pressed.

[0067] In a further preferred embodiment of the system, the degree of compression β(rigid) when pressing the first fitting to a rigid pipe is given by β starr = DK starr + 2 s starr − DPK starr DR starr , with the inner diameter DK(rigid) of the chamber of the press sleeve of the first fitting before pressing, with the wall thickness s(rigid) of the press sleeve in the area to be pressed of the first fitting before pressing, with the outer diameter DR(rigid) of the rigid pipe to be accommodated before pressing and with the inner diameter DPK(rigid) of the pressing contour of the pressing jaw in the area to be pressed of the first fitting after pressing, and the degree of pressing β(flex) when pressing the second fitting with a flexible pipe is given by β flex = DK flex + 2 s flex − DPK flex DR flex , with the inner diameter DK(flex) of the chamber of the press sleeve of the second fitting before pressing, with the wall thickness s(flex) of the press sleeve in the area of the second fitting to be pressed before pressing, with the outer diameter DR(flex) of the flexible pipe to be accommodated before pressing and with the inner diameter DPK(flex) of the pressing contour of the pressing jaw in the area of the second fitting to be pressed after pressing, so that the ratio τ is given by τ = β starr β flex = DK starr + 2 s starr − DPK starr DK flex + 2 s flex − DPK flex DR flex DR starr , where τ takes values from a range of values [0.50; 1.50], preferably [0.75; 1.5], particularly preferably [0.80; 1.20].

[0068] The ratio τ thus indicates the ratio of the degree of compression of the press connection of a fitting for a rigid pipe to the degree of compression of the press connection of a fitting for a flexible pipe with the same pressing tool, i.e. the same pressing jaw, and provides information about whether the press connections are pressed with approximately the same force.

[0069] By a suitable choice of the ratio τ, an optimal degree of compression can be achieved both for pressing a fitting with a rigid pipe and for pressing a fitting with a flexible pipe with the same

[0070] Pressing tool can be achieved. For example, if a fitting is optimally pressed onto a rigid pipe, it is also possible to optimally press a fitting onto a flexible pipe using the same pressing tool, so that collapse or insufficient compression of a fitting onto a flexible pipe can be prevented when pressed using the same pressing tool without having to change the pressing tool for the pressing processes. At the same time, if a fitting is optimally pressed onto a flexible pipe, it is possible to prevent collapse or insufficient compression of a fitting onto a rigid pipe when pressed using the same pressing tool.

[0071] If, on the other hand, a ratio τ that is too small or too large is selected, for example τ<0.5 or τ>1.5, the fitting for connecting to a rigid pipe may be pressed optimally but the fitting for connecting to a flexible pipe may be pressed too strongly when pressed with the same pressing tool, causing it to collapse, or may be pressed too weakly, preventing a tight connection.

[0072] However, with optimal pressing of the fitting for connection to a flexible pipe, if the ratio τ is selected to be too small or too large, for example τ<0.5 or τ>1.5, the fitting for connection to a rigid pipe may either be pressed too little, causing the connection to leak and have too low a pull-out strength, or it may be pressed too much, causing damage to the rigid pipe and / or the elements in the chamber of the press sleeve, for example the sealing element.

[0073] Alternatively, the system can be selected with deliberately different compression ratios. In this case, the ratio of the compression ratios within the specified limits is not equal to 0, i.e., τ <> 1. Thus, the compression ratios of the press sleeves of the fittings for rigid and flexible pipes can be selected such that an optimal arrangement of various functional elements within the chamber of the first fitting for rigid pipes and the second fitting for flexible pipes can be achieved through different fitting designs. In this way, a single compression contour can ensure a tight pressing of rigid and flexible pipes while simultaneously ensuring optimal adaptation of the functional elements.

[0074] An embodiment of a fitting for connecting to a rigid pipe for a previously described system, which solves the technical problem outlined above, has a structure with a base body, with a stop element formed circumferentially in the base body and projecting inwards, with a compression sleeve connected to the base body and forming an outer contour, wherein the compression sleeve has a chamber directed inwards towards the pipe to be received, with a clamping ring arranged in the chamber, wherein the clamping ring consists of a plastic and has a plurality of clamping elements oriented opposite to the pull-out direction of the pipe to be inserted, and wherein the clamping elements are integrated in the clamping ring, are supported on the wall in a distal outer corner region of the compression sleeve and project inwards, and with a sealing element arranged in the chamber adjacent to the stop element, wherein the compression sleeve together with the clamping ring,the clamping elements and the sealing element seal the rigid pipe to be connected from the outside,

[0075] The compression sleeve is preferably formed integrally and in one piece with the base body. When pressed, the sealing element rests seamlessly against the compression sleeve and the pipe being inserted, as it is located in the area of the stop element, i.e., where the inserted pipe rests and ends. This gap-free design improves hygiene by avoiding dead spaces and areas prone to stagnation.

[0076] The pipe is secured against pullout and / or excessive internal pressure by the clamping ring, which accommodates or holds the clamping elements. The clamping elements absorb the pullout force by deforming the pipe at specific points and bracing themselves against the wall of the compression sleeve. This ensures a direct flow of force from the pipe via the compression sleeve into the fitting. After pressing, the clamping ring itself merely serves a supporting function and contributes little or nothing to the pullout protection.

[0077] The clamping ring of the fitting described here is designed as a plastic clamping ring with metal cutting edges mounted as clamping elements. The plastic ring also features axial slots that make the clamping ring flexible and thus facilitate installation in the fitting within the compression sleeve.

[0078] The clamping elements or cutting edges can be designed as wire elements arranged in recesses provided for them. An alternative embodiment of the clamping ring is a two-component clamping ring, in which the cutting edges are placed in the injection mold and then overmolded.

[0079] The clamping elements can be fixed in the plastic of the clamping ring using force-fitting, form-fitting, or material-fitting methods, for example, using an adhesive. The clamping elements can be manufactured in various ways, for example, as cast or stamped parts. The number of clamping elements can be determined depending on the requirements or dimensions; at least three clamping elements are preferred. The same clamping elements can also be used for fittings for different pipe dimensions.

[0080] Furthermore, it is preferred that the clamping elements integrated into the clamping ring are arranged in the distal region of the chamber, opposite the stop elements. When the compression sleeve is pressed, the clamping elements are clamped diagonally and counter to the pipe's extension direction between the deformed compression sleeve and the pipe wall, generating a counterforce counter to the extension direction. This arrangement enables effective fixation of the pipe in the pressed fitting.

[0081] Furthermore, the clamping ring can have inward-facing webs spaced apart from the clamping elements, whereby the webs define an azimuthal inner cross-section in sections that is the same size as or slightly smaller than the outer diameter of the pipe. The clamping ring performs a pipe-holding function thanks to the webs. The webs hold the inserted pipe when the fitting is not pressed, so that the pipe cannot slip out of the fitting without considerable tensile force. The webs also guide the pipe when inserted into the fitting. If the inner cross-section is slightly smaller than the outer diameter of the pipe, the pipe is also offered slight resistance when inserted. This gives the user haptic feedback when inserting the pipe that the pipe is inserted deep enough into the fitting.

[0082] In principle, the clamping ring can also be designed as a classic metallic cutting ring or circumferential wire ring, as is known from the state of the art.

[0083] The described embodiment allows the rigid pipe to be inserted up to the stop element, signaling to the user that the pipe to be connected has been pushed sufficiently deep into the fitting. Preferably, the stop element consists of at least two inward-facing recesses, such as punch marks, preferably three punch marks. In contrast to a completely circumferential recess, individual recesses create fewer dead spaces and thus improve hygiene conditions.

[0084] Furthermore, it is preferred that the seal is designed, at least in sections, as a lip seal and, after compression, seals the gap between the pipe and the compression sleeve up to the end of the inserted pipe. This ensures a high degree of hygiene and prevents crevice corrosion.

[0085] Because the seal is geometrically designed as a lip seal, at least in sections, the gap between the pipe and the fitting is completely sealed by the sealing element all the way to the end of the pipe after the fitting is pressed together. This, especially in conjunction with the described point-type pipe stop, prevents dead spaces where media can collect. The lip seal therefore ensures the required system tightness. Alternatively, the sealing element can also be designed as a classic O-ring.

[0086] A further advantage is that the force transmission ring guides and holds the pipe flat. This reduces the pipe's skewing when the fitting is pressed.

[0087] An embodiment of a fitting for connecting to a flexible pipe for a previously described system, which solves the technical problem outlined above, has a structure with a base body, with a compression sleeve connected to the base body and forming an outer contour, wherein the compression sleeve has a chamber directed inwards towards the pipe to be received, with a force transmission ring arranged in the chamber and with a support body connected to the base body and provided with a sealing contour directed outwards towards the pipe to be inserted, wherein the force transmission ring is mounted in the compression sleeve, wherein the compression sleeve including the force transmission ring and the support body are arranged at a distance from one another and define an annular space for inserting and receiving the pipe to be received,wherein a portion of the force transmission ring protrudes axially from the compression sleeve and forms a portion of the outer contour to be pressed, wherein the compression sleeve, together with the force transmission ring and the support body, seals the flexible pipe to be connected from the inside,

[0088] The compression sleeve, including the force transmission ring, and the support body are arranged at a distance from one another and define an annular space for inserting and receiving the flexible pipe. During pressing, the force transmission ring arranged in the chamber transfers the pressing force generated by the pressing jaw via the compression sleeve to the flexible pipe and presses the pipe radially inward onto the support body. The sealing contour arranged on the outside of the support body is pressed into the material of the flexible pipe, thereby fixing and sealing the flexible pipe against the fitting. The sealing of the fitting against the pipe is preferably ensured without an additional soft seal via the sealing contour, and the force is transmitted by the force transmission ring, which can be designed as a plastic ring.

[0089] Additionally or alternatively, an additional soft seal, such as an O-ring or a flat gasket made of ethylene propylene diene (monomer) rubber (EPDM), fluorocarbon rubber (FKM), or polytetrafluoroethylene (PTFE), can be provided. In both cases, the seal is preferably provided at the outer end of the support body facing the pipe, so that no or only minimal dead spaces are created.

[0090] The compression sleeve or support body is formed as a single piece with the base body. However, they can also be connected to the base body either by a material bond, for example, by welding or gluing, or by a force-fit connection, for example, by pressing or sliding on.

[0091] The support body is required to seal the flexible pipe, especially a multi-layer composite pipe, against the fitting. The support body is preferably made of metal and offers significantly improved chemical resistance and robustness compared to support bodies made of a rigid plastic such as polyphenylene sulfone (PPSU).

[0092] The section of the force transmission ring that protrudes axially from the compression sleeve forms a section of the outer contour to be pressed. In this case, the chamber formed by the compression sleeve is axially open at the sides and is closed laterally by the force transmission ring. The protruding section of the force transmission ring not only improves force transmission to the flexible pipe, but also visually distinguishes it from a fitting for rigid pipes with the same outer contour of a system described above. This is because a fitting for rigid pipes has a compression sleeve made entirely of metal. Furthermore, this design of the force transmission ring is easier to install in the compression sleeve.

[0093] Furthermore, the sleeve section and / or the force transmission ring can have inwardly projecting cams for guiding and holding the tube. This provides support for the tube, haptic feedback when overcoming the cams during insertion of the tube, and also guides the tube during insertion.

[0094] Furthermore, the compression sleeve can have inwardly directed recesses, for example formed as punch marks or undercuts in the wall, for an internally arranged locking of the force transmission ring with the compression sleeve.

[0095] Furthermore, the force transmission ring can have a cylindrical portion and / or a toothed portion for engagement with the pipe to be inserted in order to create the fixation.

[0096] The pipe can be secured against pulling out, for example, by means of corresponding retaining ribs on the sealing contour of the support body.

[0097] The force transmission ring can also have inwardly projecting webs that define an inner cross-section that is equal to or slightly smaller than the outer diameter of the pipe. Thus, the circumferentially distributed webs provide guidance and support for the pipe.

[0098] A further embodiment of a fitting for connecting to a rigid pipe for a previously described system, which solves the technical problem outlined above, has a structure with a base body, with a compression sleeve connected to the base body and forming an outer contour, wherein the compression sleeve has a chamber directed inwards towards the pipe to be received, with a sleeve section formed at the distal end of the compression sleeve and extending beyond the chamber, wherein the sleeve section forms a section of the outer contour to be formed, and with a sealing element arranged in the chamber, wherein an inner section of the base body extends radially within the chamber in the direction of the pipe to be inserted, wherein a section of the sealing element is arranged between the compression sleeve and the inner section of the base body, and wherein a section of the sealing element is arranged between the compression sleeve and the pipe to be inserted,whereby the compression sleeve, together with the sealing element, seals the rigid pipe to be connected from the outside.

[0099] The sealing element therefore preferably fills a significant portion of the chamber or the entire chamber. The sealing element seals both on the side of the base body and on the rigid tube, which is inserted at the front up to the base body. The axially extending sealing element also allows for a high tolerance for the correct insertion depth of the tube and ensures a virtually gap-free connection.

[0100] This ensures reliable sealing and a division into a wetted area with the inner section of the base body and the end of the inserted pipe, and a non-wet area of the compression sleeve. Furthermore, the inner section of the base body and the end of the inserted pipe can be in contact with each other at the end. This creates a particularly good connection without restricting the open cross-section within the pipe and within the base body of the fitting.

[0101] In this embodiment, the fixing and sealing functions are also realized by two separate elements. Preferably, the compression sleeve is molded onto the base body in a form-fitting manner or is integrally bonded to the base body.

[0102] Preferably, the sleeve portion and / or the sealing element has inwardly projecting cams for guiding and holding the tube. This provides support for the tube, haptic feedback when overcoming the cams during insertion of the tube, and also guides the tube during insertion.

[0103] Furthermore, cams can be factory-imprinted into the front distal section of the compression sleeve, which serve to locally deform the rigid tube during compression. Therefore, a clamping ring with a holding function is not necessary with this design. Furthermore, the cams ensure torsional rigidity after compression. The cams can also serve to guide and hold the tube.

[0104] Alternatively, a design of the described fitting with a cutting ring inserted into the chamber is also possible. In this case, the sealing element can be shorter in the axial direction than in the previously described embodiment.

[0105] An embodiment of a fitting for connecting to a flexible pipe for a system as described above, which solves the technical problem outlined above, has a structure with a base body, with a compression sleeve connected to the base body and forming an outer contour, wherein the compression sleeve has a chamber directed inwards towards the pipe to be received, with a force transmission ring arranged in the chamber and with a support body connected to the base body and provided with a sealing contour directed outwards towards the pipe to be inserted, wherein the compression sleeve and the force transmission ring have mutually corresponding viewing windows, wherein the compression sleeve, together with the force transmission ring and the support body, seals the flexible pipe to be connected from the inside.

[0106] The viewing windows provide a visual insertion check to ensure that the pipe to be connected has been pushed far enough into the fitting.

[0107] The compression sleeve, including the force transmission ring, and the support body are arranged at a distance from each other and define a space for inserting and receiving the flexible pipe. The force transmission ring located in the chamber transfers the pressing force generated by the pressing jaw to the flexible pipe during pressing and presses the pipe radially inward onto the support body. The sealing contour located on the outside of the support body is pressed into the material of the flexible pipe, thereby securing and sealing the flexible pipe against the fitting.

[0108] Preferably, the compression sleeve and the support body are formed as separate elements and connected to the base body. Alternatively, the compression sleeve or the support body can be formed as a single piece with the base body. They can be connected to the base body either by a material fit, for example, by welding or gluing, or by a force fit, for example, by pressing or sliding on.

[0109] The support body is required to seal the flexible pipe, especially a multi-layer composite pipe, against the fitting. The support body is preferably made of metal and offers significantly improved chemical resistance and robustness compared to support bodies made of a rigid plastic such as polyphenylene sulfone (PPSU).

[0110] Furthermore, the sleeve section and / or the force transmission ring can have inwardly projecting cams for guiding and holding the tube. This provides support for the tube, haptic feedback when overcoming the cams during insertion of the tube, and also guides the tube during insertion.

[0111] Furthermore, the force transmission ring can have a cylindrical section and / or a toothed section for engagement with the pipe being inserted to create the fixation. The geometric difference between the outer diameters of the flexible pipes can be compensated for by adjusting the wall thickness.

[0112] The sealing of the fitting against the pipe is preferably ensured without an additional soft seal via the sealing contour, and the force transmission is ensured by the force transmission ring, which can be designed as a plastic ring. By deforming the compression sleeve during pressing, the flexible pipe is pressed onto the sealing contour, thereby achieving a sealing effect.

[0113] Additionally or alternatively, an additional soft seal, such as an O-ring or a flat gasket made of ethylene propylene diene (monomer) rubber (EPDM), fluorocarbon rubber (FKM), or polytetrafluoroethylene (PTFE), can be provided. In both cases, the seal is preferably provided at the outer end of the support body facing the pipe, so that no or only minimal dead spaces are created.

[0114] The pipe can be secured against pulling out, for example, by means of corresponding retaining ribs on the sealing contour of the support body.

[0115] In a preferred embodiment, the compression sleeve has a sleeve portion extending beyond the chamber, wherein the sleeve portion forms a portion of the outer contour to be formed by a compression jaw. The sleeve portion serves to deform in the direction of the pipe in order to achieve axial fixation and, if necessary, also to prevent rotation of the pipe relative to the fitting. Thus, the force transmission ring can also indirectly assume the sealing function, and the described sleeve portion serves to secure the pipe.

[0116] The force transmission ring can also have inwardly projecting webs that define an inner cross-section that is equal to or slightly smaller than the outer diameter of the pipe. Thus, the circumferentially distributed webs provide guidance and support for the pipe.

[0117] The technical problem identified above is also solved by a system for connecting rigid pipes and for connecting flexible pipes, comprising a plurality of first fittings for connecting to a rigid pipe, wherein the first fittings are designed as externally sealing fittings and seal the rigid pipes to be connected from the outside, and a plurality of second fittings for connecting to a flexible pipe, wherein the second fittings are designed as internally sealing fittings and seal the flexible pipes to be connected from the inside, wherein the first fittings for connecting to a rigid pipe have a base body and a compression sleeve connected to the base body, wherein the second fittings for connecting to a flexible pipe have a base body, a compression sleeve connected to the base body and a support body connected to the base body,wherein the base body of the first fitting for connecting to a rigid pipe and the base body of the second fitting for connecting to a flexible pipe have the same structure.

[0118] A similar structure is assumed if the base bodies have the same dimensions and geometry, but differ in the magnitude of manufacturing tolerances. The goal is to produce the base bodies in large quantities, which can then be used for both rigid pipe fittings and flexible pipe fittings.

[0119] Preferably, the fittings correspond to the previously described fittings for connecting to a rigid pipe and the previously described fittings for connecting to a flexible pipe.

[0120] The previously described fittings for the system for connecting rigid pipes and for connecting flexible pipes therefore have the same base body and an associated, adapted compression sleeve. For flexible pipes, a support body is also required. The base bodies can therefore have only small forming angles and can therefore also be made from materials that are difficult to form, for example, ferritic steels such as 1.4521 or duplex steels such as 1.4462. The same base body can therefore be used in the fitting for both rigid pipes and flexible pipes, thus enabling a modular design of the fittings for the described system. This design has production-related advantages, as the same component is used as the basis for all fittings in the system.

[0121] However, the press sleeve differs depending on the application for rigid pipes and flexible pipes and is, for example, mounted force-fittingly onto the base body by factory pressing. One advantage of the two-part design of base body and press sleeve is that the fitting is divided into a media-contacting base body and a non-media-contacting press sleeve. This makes it possible, for example, to manufacture the base body from a very high-quality, corrosion-resistant material, while using a cost-effective material for the sleeve. In principle, the material selection can be made specifically with regard to the respective requirements, i.e., the medium to be conveyed via the rigid pipe and / or the flexible pipe.

[0122] Furthermore, all of the fittings described above should be geometrically designed with a flat chamber and the smoothest possible transitions, thus facilitating subsequent insulation. This is because the flat chamber and smooth transitions make it easier to slide a thermal insulation pipe onto the pipe and fitting without jamming on protrusions or edges. Preferably, the ratio of chamber height to chamber length should be small, large radii should be used, no beads or sharp edges should be formed, and / or the transition between the various steps should be designed as a slope, preferably with a small angle.

[0123] The previously described fittings also have the advantage of a robust construction compared to plastic fittings. Many robust metal components are integrated into the fittings, so that, for example, little or no damage to the support body occurs when the pipe is bent. The use of cutting elements in fittings for rigid pipes also increases robustness, as the fixation is achieved through a positive fit rather than a friction fit.

[0124] In the following, the invention is explained using exemplary embodiments with reference to the drawing. Fig. 1a-fine first system for connecting rigid pipes and for connecting flexible pipes with information on determining the formulas, Fig. 2a-fine second system for connecting rigid pipes and for connecting flexible pipes with information on determining the formulas, Fig. 3a-rExemplary embodiments of the system according to Fig. 1a-d and the system according to Fig. 2 a-d with information on the determination of the formulas, Fig. 4a-ea fitting for connecting to a rigid pipe, in particular for a system according to Fig. 1a bis 1f , Fig. 5a-e a fitting for connecting to a flexible pipe, in particular for a system according to Fig. 1a bis 1f , Fig. 6a-c alternative embodiments of the Fig. 5a bis 5e shown fittings, Fig. 7a-the fitting for connecting to a rigid pipe, especially for a system according to Fig. 2a bis 2f and Fig. 8a-e a fitting for connecting to a flexible pipe, in particular for a system according to Fig. 2a bis 2f .

[0125] In the following description of the various embodiments according to the invention, components and elements with the same function and the same mode of operation are provided with the same reference numerals, even if the components and elements in the various embodiments may have differences in their dimensions or shape.

[0126] In the following, exemplary embodiments of systems according to the invention for connecting rigid pipes and for connecting flexible pipes are first explained. The details of the individual fittings according to the invention are then discussed.

[0127] Fig. 1a und 1b show a first system 2 according to the invention for connecting rigid pipes 4 and for connecting flexible pipes 6, wherein the pipes 4 and 6 have mutually corresponding outer diameters. The system 2 has a pressing jaw 10 having a pressing contour 8 with an upper pressing jaw half 10a and a lower pressing jaw half 10b, which, as explained below, is suitable for pressing different fittings 20 and 40.

[0128] System 2 has, according to Fig. 1a further comprises at least one first fitting 20 for press-connecting to the rigid pipe 4, wherein the at least one first fitting 20 has a first press sleeve 21 which is provided with a first outer contour 22.

[0129] System 2 also has, according to Fig. 1b at least one second fitting 40 for press-connecting to a flexible pipe 6, wherein the at least one second fitting 40 has a second press sleeve 41 with a second outer contour 42.

[0130] According to the invention, the outer contour 22 of the first pressing sleeve 21 and the outer contour 42 of the second pressing sleeve 41 are each adapted at least in sections to the pressing contour 8 of the pressing jaw 10 and can be pressed by the pressing jaw 10.

[0131] In the Fig. 1a und 1b The aforementioned components are shown in a sectional view, with an upper pressing jaw half 10a and a lower pressing jaw half 10b being shown in contact with the fittings 20 and 40 prior to pressing. Further details of the pressing jaw 10 and the two fittings 20 and 40 are explained in connection with the other figures.

[0132] Thus, according to the invention, the same pressing jaw 10 with the same pressing contour 8 can be used to press and permanently seal both the first fitting 20 for connecting to a rigid pipe 4 and the second fitting 40 for connecting to a flexible pipe 6. This property applies in particular to rigid pipes 4 and flexible pipes 6 with the same or at least matched outer diameters.

[0133] This reduces the effort required on a construction site, since the same pressing jaw 10 with the same pressing contour 8 and the same pressing tool (not shown) is used to generate the necessary pressing force for connecting rigid pipes 4 and flexible pipes 6 of the same dimensions. While the pressing tool preferably generates a linear movement of a ram or piston, the two pressing jaws 10 are moved toward each other into a closed position by means of an inlet contour, so that the pressing sleeves 21 and 41, respectively, are deformed radially inward.

[0134] In addition, the pressing jaws can also be designed as parts of a pressing loop, the protruding ends of which are pressed together by means of a pressing device in order to cause the radially inward-acting deformation.

[0135] As explained in detail in the introduction, a 20 or 40 fitting is primarily understood to be a straight connection. Changes in direction are also possible in the form of pipe bends, reducers, branches such as T-pieces, or intersections with two or more compression sections. Furthermore, a fitting or pipe connection can be a valve with only one compression section.

[0136] Because the outer contour 22 of the first compression sleeve 21 and the outer contour 42 of the second compression sleeve 41 are each adapted, at least in sections, to the pressing contour 8 of the pressing jaw 10, when the pressing jaws 10 move together, there is increasing, at least in sections, surface contact between the pressing contour 8 on the one hand and at least a section of the outer contour 22 of the first compression sleeve 21 or the outer contour 42 of the second compression sleeve 41 on the other. By moving the pressing jaws 10 together to a predetermined end position, the pressing sleeves 21 and 41 are completely pressed and deformed. In the process, the pressing sleeves 21 and 41 are deformed in the same way by the pressing jaw 10 in the geometrically corresponding sections. The effect according to the invention that one pressing jaw 10 is suitable for two different pressing sleeves 21 and 41 of two fittings 20 and 40 is thus achieved.In particular, the compression sleeves 21 and 41 can be largely identical.

[0137] From the Fig. 1a und 1b In addition, the dimensions of various sizes characterizing the geometries of the fittings 20, 40 for rigid pipes 4 and for flexible pipes 6 in conjunction with the geometry of the pressing jaw 10 before pressing are shown.

[0138] Fig. 1c und 1d show that in the Fig. 1a and 1d System 2 for connecting rigid pipes 4 and for connecting flexible pipes 6 is shown in a pressed state. The dimensions of various sizes characterizing the geometries of the fittings 20, 40 for rigid pipes 4 and for flexible pipes 6 in conjunction with the geometry of the pressing jaw 10 are shown after pressing.

[0139] The Fig. 1a shows, in a state before pressing, the inner diameter DK(rigid) of the chamber 23 of the press sleeve 21, the wall thickness s(rigid) of the press sleeve 21 in the area of the fitting 20 to be pressed and the outer diameter DR(rigid) of the rigid pipe 4 to be accommodated.

[0140] In the Fig. 1c the inner diameter DPK(rigid) of the pressing contour 8 of the pressing jaw 10 is shown in the area to be pressed of the first fitting 20 after pressing.

[0141] From the Fig. 1a and 1c The dimensions shown result in the degree of compression β(rigid), which is given by β starr = DK starr + 2 s starr − DPK starr DR starr .

[0142] The compression ratio β(rigid) preferably assumes values of β(rigid)<1.5. This compression ratio ensures that a tight connection with high pull-out strength is achieved and that wrinkling of the pipe to be connected and the fitting during compression is minimized. For a tight connection with high pull-out strength, a compression ratio β(rigid) that assumes values of β(rigid)<0.12 is preferred, and β(rigid)<0.10 is particularly preferred.

[0143] With a compression ratio β(rigid) of 0, corresponding to a compression ratio of 0%, the fitting is not tightly pressed into the pipe to be connected. With a compression ratio of 0.15 or greater, corresponding to a compression ratio of 15% or more, the fitting or pipe to be pressed is deformed too much, resulting in wrinkling of the material to be pressed, and the excessive pressing forces lead to deformation of the fitting and the pipe to be pressed.

[0144] The Fig. 1b shows, in a state before pressing, the inner diameter DK(flex) of the chamber 43 of the press sleeve 41, the wall thickness s(flex) of the press sleeve 41 in the area of the fitting 40 to be pressed and the outer diameter DR(flex) of the flexible pipe 6 to be accommodated.

[0145] In the Fig. 1d the inner diameter DPK(flex) of the pressing contour 8 of the pressing jaw 10 in the area to be pressed of the second fitting 40 after pressing is specified.

[0146] From the Fig. 1b and Fig. 1d The dimensions shown result in the degree of compression β(flex), which is given by β flex = DK flex + 2 s flex − DPK flex DR flex .

[0147] The compression ratio β(flex) preferably assumes values of β(flex)<0.15. This compression ratio ensures a tight connection with high pull-out strength and minimizes wrinkling of the pipe to be connected and the fitting during compression. A compression ratio β(flex) with values of β(flex)<0.12, particularly preferably β(flex)<0.10, is preferred for a tight connection with high pull-out strength.

[0148] With a compression ratio β(flex) of 0, corresponding to a compression ratio of 0%, the fitting is not tightly pressed into the pipe to be connected. Furthermore, it has been shown that with a compression ratio of 0.15 or higher, corresponding to a compression ratio of 15% or more, the fitting or pipe to be pressed is deformed too much, resulting in wrinkling of the material to be pressed, and the excessive pressing forces lead to deformation of the fitting and the pipe to be pressed.

[0149] In summary, the Fig. 1a, 1b , 1c und 1d The ratio τ of the compression ratios β(rigid) and β(flexible) results from the dimensions, where τ is given by τ = β starr β flex = DK starr + 2 s starr − DPK starr DK flex + 2 s flex − DPK flex DR flex DR starr .

[0150] The ratio τ preferably assumes values from a range of [0.50; 1.50]. For such a ratio τ, a degree of compression that is as similar as possible can be ensured for the compression of the fitting for connecting a rigid pipe 4 and the compression of the fitting for connecting a flexible pipe 6, so that in both compression processes, a tight connection between the fitting and the pipe to be connected can be achieved with the same compression tool.

[0151] In this way, with optimal pressing of a fitting with a rigid pipe 4, collapse or insufficient pressing of a fitting with a flexible pipe 6 can be prevented when pressed with the same pressing tool, the pressing jaw 10. At the same time, with optimal pressing of a fitting with a flexible pipe 6, collapse or insufficient pressing of a fitting with a rigid pipe 4 can be prevented when pressed with the same pressing tool. For optimal pressing, both for connecting a rigid and a flexible pipe, a ratio τ that assumes values from the range [0.75; 1.25], particularly preferably [0.80; 1.20], is preferred.

[0152] It has been shown that with a ratio τ of t<0.5, optimal compression of a fitting with a rigid pipe 4 results in the fitting connecting to a flexible pipe 6 being overcompressed when pressed with the same compression tool, resulting in wrinkling and collapse of the flexible pipe 6. In contrast, with a ratio τ>1.5, optimal compression of a fitting with a rigid pipe 4 results in insufficient compression of the fitting with a flexible pipe 6 when pressed with the same compression tool. Such insufficient compression regularly results in a leak in the connection of the fitting with a flexible pipe 6 and in insufficient pull-out strength.

[0153] Furthermore, with a ratio τ of τ>1.5, with optimal pressing of a fitting with a flexible pipe 6, the fitting for connection to a rigid pipe 4 is pressed too strongly when pressed with the same pressing tool, resulting in wrinkling and collapse of the rigid pipe 4. Furthermore, over-pressing of the fitting for connection to a rigid pipe 4 can cause damage to the sealing element and / or other elements within the chamber 23 of the press sleeve 21. In contrast, a ratio τ<0.5 with optimal pressing of a fitting with a flexible pipe 6 leads to insufficient pressing of the fitting with a rigid pipe 4 when pressed with the same pressing tool. Such insufficient pressing regularly results in a leak in the connection of the fitting with a rigid pipe 4 and in insufficient pull-out strength.

[0154] Fig. 2a und 2b show a second system 102 according to the invention for connecting rigid pipes 4 and for connecting flexible pipes 6, wherein the pipes 4 and 6 have mutually corresponding outer diameters. The system 102 has a pressing jaw half 110a of a pressing jaw 110 having a pressing contour 108, which, as explained below, is suitable for pressing different fittings 120 and 140.

[0155] The system 102 has at least one first fitting 120 for press-connecting to the rigid pipe 4, wherein the at least one first fitting 120 has a first press sleeve 121 provided with a first outer contour 122.

[0156] The system 102 further comprises at least one second fitting 140 for press-connecting to a flexible pipe 6, wherein the at least one second fitting 140 comprises a second press sleeve 141 with a second outer contour 142.

[0157] According to the invention, the outer contour 122 of the first pressing sleeve 121 and the outer contour 142 of the second pressing sleeve 141 are each adapted at least in sections to the pressing contour 108 of the pressing jaw 110 and can be pressed by the pressing jaw 110.

[0158] In contrast to the first system 2, in the system 102, the first compression sleeve 121 has a first additional compression section 121a and the second compression sleeve 141 has a second additional compression section 141b. As in Fig. 2 As can be seen, the first additional pressing section 121a and the second additional pressing section 141b have different outer contours, each of which can be deformed in sections by the pressing jaw 110 and its pressing contour 108 with corresponding sections 108a and 108b. Thus, it is possible to form different functionalities into the pressing sleeves 121 and 141 using the same pressing jaw 110 for rigid pipes 4 and flexible pipes 6. Furthermore, since the pressing sleeves 121 and 141 have matching pressing sections 121c and 141c, they are deformed in the same way by the same section 108c of the pressing contour 108 of the pressing jaw 110 during pressing.

[0159] The Fig. 1e und 1f show both fittings 20 and 40 in a side view. The outer contours 22 and 42 of the two press sleeves 21 and 41 match, so that the same press jaw 10 can be used for pressing the press sleeves 21 and 41. The identical correspondences of the press sleeves 121 and 141 show the corresponding Fig. 2e und 2f for fittings 120 and 140.

[0160] As in the Fig. 1a bis 2f As shown, the compression sleeves 22, 122 and 42, 142 each have a chamber 23, 123 and 43, 143 directed inward toward the pipe 4 or 6 to be received, for accommodating additional functional elements required for pressing and sealing the connection, the different shapes and functions of which are explained in connection with the other figures. The essentially identical or similarly designed chambers 23, 123 and 42, 142 therefore each accommodate different functional elements.

[0161] In analogy to the Fig. 1a und 1b are in the Figuren 2a und 2b the dimensions of various sizes characterizing the geometries of the fittings 120, 140 for rigid pipes 4 and for flexible pipes 6 in conjunction with the geometry of the pressing jaw 10 before pressing are shown.

[0162] Show more Fig. 2c und 2d in analogy to the Fig. 1c und 1d that in the Fig. 2a and 2d The system 102 shown for connecting rigid pipes 4 and for connecting flexible pipes 6 in a pressed state. The dimensions of various sizes characterizing the geometries of the fittings 120, 140 for rigid pipes 4 and for flexible pipes 6 in conjunction with the geometry of the pressing jaw 110 are shown after pressing.

[0163] The Fig. 2a shows, in a state before pressing, the inner diameter DK(rigid) of the chamber 123 of the press sleeve 121, the wall thickness s(rigid) of the press sleeve 121 in the area of the fitting 120 to be pressed and the diameter DR(rigid) of the rigid pipe 4 to be accommodated.

[0164] In the Fig. 2c the inner diameter DPK(rigid) of the pressing contour 108 of the pressing jaw 110 in the area to be pressed of the first fitting 120 is specified after pressing.

[0165] From the Fig. 2a and 2c The dimensions given above are based on the dimensions already Fig. 1 The compression ratio β(rigid) is given by β starr = DK starr + 2 s starr − DPK starr DR starr .

[0166] The Fig. 2b shows, in a state before pressing, the inner diameter DK(flex) of the chamber 143 of the press sleeve 141, the wall thickness s(flex) of the press sleeve 141 in the area of the fitting 140 to be pressed and the diameter DR(flex) of the flexible pipe 6 to be accommodated.

[0167] In the Fig. 2d the inner diameter DPK(flex) of the pressing contour 108 of the pressing jaw 110 in the area to be pressed of the second fitting 140 is specified after pressing.

[0168] From the Fig. 2b and Fig. 2d The dimensions shown are based on the dimensions already mentioned in relation to Fig. 1 The compression ratio β(flex) is given by β flex = DK flex + 2 s flex − DPK flex DR flex .

[0169] The Fig. 3a bis 3i show embodiments of the first inventive system 2 according to the Fig. 1 For determining various sizes to characterize the geometries of fittings for rigid and flexible pipes. The fittings are shown only with the compression sleeve 21 or 41 and the inserted pipe 4 or 6, but without the elements required for pressing within the fitting. In the following, the sizes are determined based on the dimensions of the chambers 23 or 43, such as height, length, and volume.

[0170] In Fig. 3a First, a first fitting 20 for pressing a rigid pipe 4 with a compression sleeve 21 having an inwardly directed chamber 23 is shown. As in Fig. 3a As can be seen, the chamber length LK(rigid) is defined as the length of the section of the chamber 23 in which the outer contour 22 of the chamber 23 runs essentially plane-parallel to the outer shell of the rigid pipe 4 surrounded by the fitting 20. Consequently, LK(rigid) is defined as the length of the section that lies between the sections of the outer contour 22 of the chamber 23 that are curved towards the pipe 4.

[0171] Furthermore, it can be seen that the inner diameter DK(rigid) of the chamber 23 is defined without taking into account the wall thickness of the chamber 23, whereas the outer diameter DR(rigid) of the rigid pipe 4 to be accommodated is defined by taking into account the wall thickness of the pipe 4. Thus, the height of the chamber 23 is given by the difference DK(rigid)-DR(rigid). This results in a chamber volume V starr = π ⋅ LK starr 4 ⋅ DK starr 2 − DR starr 2 .

[0172] In Fig. 3b a second fitting 40 for pressing a flexible pipe 6 with a compression sleeve 41 having an inwardly directed chamber 43 is shown. Analogous to Fig. 3a , is in Fig. 3b It can be seen that the chamber length LK(flex) is defined as the length of the section of the chamber 43 in which the outer contour 42 of the chamber 43 runs essentially plane-parallel to the outer shell of the flexible pipe 6 surrounded by the fitting 40. Consequently, LK(flex) is defined as the length of the section that lies between the sections of the outer contour 42 of the chamber 43 that are curved towards the pipe 6.

[0173] Furthermore, it can be seen that the inner diameter DK(flex) of the chamber 43 is defined without taking into account the wall thickness of the chamber 43, whereas the outer diameter DR(flex) of the flexible pipe 6 to be accommodated is defined by taking into account the wall thickness s(flex) of the pipe 6. Thus, the height of the chamber 43 is given by the difference DK(flex)-DR(flex). This results in a chamber volume V flex = π ⋅ LK flex 4 ⋅ DK flex 2 − DR flex 2 .

[0174] From these chamber volumes, the ratio δ = V starr V flex be formed.

[0175] From the dimensions mentioned in accordance with the Fig. 3a und 3b the ratios ε(rigid) and ε(flex) of the chamber height and chamber length can also be formed. ε(rigid) is defined by ε starr = DK starr − DR starr 2 ⋅ LK starr . ε(flex) is defined by ε flex = DK flex − DR flex 2 ⋅ LK flex .

[0176] In addition, the ratio α can also be calculated by α = ε starr ε flex = LK flex LK starr ⋅ DK starr − DR starr DK flex − DR flex . where α takes values from a range of values [0.50; 3.00], preferably [0.50; 1.50], particularly preferably [0.75; 1.25].

[0177] Thus, α indicates the ratio of the ratio of chamber height ((DK(rigid)-DR(flex) / 2)) and chamber length DK(rigid) of the press sleeve 21 of a fitting 20 for pressing rigid pipes 4 and of the chamber height ((DK(rigid)-DR(flex) / 2)) and length DK(rigid) of the press sleeve 41 of a fitting 40 for pressing flexible pipes 6.

[0178] Fig. 3c bis 3i now show a pair each formed from a Fig. 3a shown first fitting 20 and one in Fig. 3b shown second fitting 40, whereby the varying dimensions of the fittings 20 and 40 result in different values for the ratio of the chamber volumes or for the ratio of the ratios of chamber height to chamber length of the chambers 23 and 43, whereby both ratios are determined by δ be specified.

[0179] For a ratio of δ=1 or α=1 according to Fig. 3c The interior of the chambers 23, 43 provides sufficient space for the elements to be accommodated by the chambers 23, 43, such as an O-ring or a claw ring. Furthermore, this ensures an optimal degree of compression for both the first fitting 20 and the second fitting 40.

[0180] In Fig. 3d bis Fig. 3f Examples of dimensions resulting in a ratio of δ<0.5 or α<0.5 are shown. Such selected dimensions result in either a too short chamber length of the chamber 23 of the first fitting 20, as in Fig. 3d shown, or too low a chamber height of the chamber 23, as in Fig. 3f shown, so that no space remains for elements to be accommodated by the chamber 23, or too high a chamber height of the chamber 43 of the second fitting 40 resulting in too high a degree of compression, as in Fig. 3e shown.

[0181] In Fig. 3g bis Fig. 3i Examples of dimensions resulting in a ratio of δ>1.5 or α>1.5 are shown. Such selected dimensions result in either a too short chamber length of the chamber 43 of the second fitting 40, as in Fig. 3g shown, or too low a chamber height of the chamber 43 of the second fitting 40, as in Fig. 3h shown, so that no space remains for elements to be accommodated by the chamber 43, or too high a chamber height of the chamber 23 of the first fitting 20 resulting in too high a degree of compression, as in Fig. 3i shown.

[0182] For other fitting designs, the limit values 0.5<=δ<=3.00 or 0.5<=α<=3.00 may also apply.

[0183] The Fig. 3j und 3k show embodiments of the second system 102 according to the invention with the fittings 120 and 140.

[0184] In Fig. 3j First, a first fitting 120 for pressing a rigid pipe 4 with a compression sleeve 121 having an inwardly directed chamber 123 is shown. As in Fig. 3j As can be seen, the chamber length LK(rigid) is defined as the length of the section of the chamber 123 in which the outer contour 122 of the chamber 123 runs essentially plane-parallel to the outer shell of the rigid pipe 4 surrounded by the fitting 120. Consequently, LK(rigid) is defined as the length of the section that lies between the sections of the outer contour 122 of the chamber 123 that are curved towards the pipe 4. It can also be seen that the chamber diameter DK(rigid) is defined without taking into account the wall thickness of the chamber 123, whereas DR(rigid), the diameter of the rigid pipe 4 to be accommodated, is defined with the wall thickness of the pipe 4. Thus, the height of the chamber 123 is given by the difference DK(rigid)-DR(rigid).

[0185] In Fig. 3k a second fitting 140 for pressing a flexible pipe 6 with a compression sleeve 141 having an inwardly directed chamber 143 is shown. Analogous to Fig. 3j , is in Fig. 3k It can be seen that the chamber length LK(flex) is defined as the length of the section of the chamber 143 in which the outer contour 142 of the chamber 143 runs essentially plane-parallel to the outer shell of the flexible pipe 6 surrounded by the fitting 140. Consequently, LK(flex) is defined as the length of the section that lies between the sections of the outer contour 142 of the chamber 143 that are curved towards the pipe 6. It can also be seen that the chamber diameter DK(flex) is defined without taking into account the wall thickness of the chamber 143, whereas DR(flex), the diameter of the flexible pipe 6 to be accommodated, is defined with the addition of the wall thickness s(flex) of the pipe 6. The height of the chamber 143 is thus given by the difference DK(flex)-DK(flex).

[0186] For fittings 120 and 140, these definitions result in the chamber volumes V starr = π ⋅ LK starr 4 ⋅ DK starr 2 − DR starr 2 . and V flex = π ⋅ LK flex 4 ⋅ DK flex 2 − DR flex 2 , and their relationship δ = V starr V flex .

[0187] Likewise, α is given by α = ε starr ε flex and indicates the ratio of the ratio of chamber height ((DK(rigid)-DR(flex) / 2) and chamber length DK(rigid) of the press sleeve 121 of a fitting 120 for pressing rigid pipes 4 and of the chamber height ((DK(rigid)-DR(flex) / 2) and length DK(rigid) of the press sleeve 141 of a fitting 140 for pressing flexible pipes 6.

[0188] Fig. 3l bis Fig.3r now show a pair each formed from a Fig. 3j shown first fitting 120 and one in Fig. 3k shown second fitting 140, wherein the varying dimensions result in different values for the ratio of the chamber volumes or for the ratio of the ratios of chamber height to chamber length, both ratios being indicated by δ and α respectively.

[0189] For a ratio of δ=1 or α=1 as in Fig. 3l As shown, the interior of the chambers 123, 143 provides sufficient space for the elements to be accommodated by the chambers 123, 143, for example, a sealing element. Furthermore, this ensures an optimal degree of compression for both the first fitting 120 and the second fitting 140.

[0190] In Fig. 3m bis Fig. 3o Examples of dimensions resulting in a ratio of δ<0.5 or α<0.5 are shown. Such selected dimensions result in either a too short chamber length of the chamber 123 of the first fitting 120, as in Fig. 3m shown, or too low a chamber height of the chamber 123, as in Fig. 3o shown, so that no space remains for elements to be accommodated by the chamber 123, or too high a chamber height of the chamber 143 of the second fitting 140 resulting in too high a degree of compression, as in Fig. 3n shown.

[0191] In Fig. 3p bis Fig. 3r Examples of dimensions resulting in a ratio of δ>1.5 or α>1.5 are shown. Such selected dimensions result in either a too short chamber length of the chamber 143 of the second fitting 140, as in Fig. 3p shown, or too low a chamber height of the chamber 143 of the second fitting 140, as in Fig. 3q shown, so that no space remains for elements to be accommodated by the chamber 143, or too high a chamber height of the chamber 123 of the first fitting 120 resulting in too high a degree of compression, as in Fig. 3r shown.

[0192] For other fitting designs, the limit values 0.5<=δ<=3.00 or 0.5<=α<=3.00 may also apply.

[0193] The individual embodiments of fittings 20, 120 and 40, 140 are explained in detail below using further figures.

[0194] The Fig. 4a bis 4e show a first embodiment of a fitting 20 for connecting to a rigid pipe 4 for a previously described Fig. 1a bis 1f explained system 2. The fitting has a base body 24 and a stop element 25 formed circumferentially in the base body 24 and projecting inwards. Furthermore, a press sleeve 21 is provided which is connected to the base body 24 and forms an outer contour 22 and has a chamber 23 directed inwards towards the pipe 4 to be received. In the chamber 23, a clamping ring 26 consisting of a plastic with a plurality of clamping elements 27 oriented opposite to the pull-out direction of the pipe 4 to be inserted is arranged. In addition, a sealing element 28 is arranged in the chamber 23 adjacent to the stop element 25 and has a round section 28a and a flat section 28b forming a lip seal.

[0195] The press sleeve 21 is integrally connected to the base body 24, so that the press section in the form of the press sleeve 21 and the base body 24 can advantageously be manufactured in one piece.

[0196] The stop element 25 consists of two inwardly directed and radially opposite recesses 25a, which are designed, for example, as punch marks. The pipe stop is thus made at specific points and not circumferentially, thereby avoiding dead spaces, even when a pipe 4 is inserted and the seal 28 seals in the area of the stop element 25. Fig. 4 b For both sides of the fitting 20, a pair of radially opposite punch marks is shown, one pair for each fitting side.

[0197] The pipe 4 is secured against pullout and / or excessive internal pressure by the clamping ring 26, which is designed as a plastic clamping ring and in which metallic cutting edges are arranged as clamping elements 27. The plastic clamping ring 26 also has circumferential slots 26a and 26b, which make the clamping ring 26 flexible overall and thus facilitate installation in the fitting 20 within the press sleeve 21. Furthermore, the clamping ring 26 can thus be designed as a circumferentially closed ring and can be more easily reduced in radius during pressing.

[0198] The clamping elements 27 are designed as cutting edges in the form of wire elements that are inserted into designated recesses. The clamping elements 27 are thus fixed in the plastic of the clamping ring 26 with a positive fit. The clamping elements 27 can be manufactured in various ways, for example, as cast parts or as stamped parts. The number of clamping elements 27 is six in this case, but can be determined depending on the requirements or dimensions of the clamping ring 27.

[0199] The clamping elements 27 are further arranged in the distal area of the chamber 23 opposite the stop elements 25 and absorb the pull-out force by the clamping elements 27 selectively deforming the tube 4, see Fig. 4e , and are supported on the wall in a distal outer corner region 21a of the press sleeve 21. This ensures a direct flow of force from the pipe 4 via the press sleeve 21 into the fitting 4. After pressing, the clamping ring 26 merely has a supporting function and contributes only slightly or not at all to the pull-out protection.

[0200] Furthermore, the clamping ring 26 has inwardly directed webs 26c spaced from the clamping elements 27, wherein the webs 26c define an inner cross-section that is equal to or slightly smaller than the outer diameter of the pipe 4. The webs 26c hold the pipe 4 in the unpressed state of the fitting 20 accordingly Fig. 4d , so that the pipe 4 cannot slip out of the fitting 20. In addition, inwardly directed webs 26d are also formed, which guide a pipe 4 to be inserted during insertion.

[0201] In addition, the webs 26c guide the pipe 4 as it is inserted into the fitting 20. If the inner cross-section of the inner surfaces of the webs 26c is slightly smaller than the outer diameter of the pipe 4, the pipe 4 is subjected to slight resistance as it is inserted. Thus, the user receives haptic feedback when inserting the pipe 4 that the pipe 4 is inserted into the fitting.

[0202] The seal 28 is designed as a lip seal with sections 28a and 28b and, after pressing, seals the gap 29 between the pipe 4 and the compression sleeve 21 up to the end 4a of the inserted pipe 4. For this purpose, the seal 28 rests with the round section 28a on an inclined section within the chamber 23 and is thereby positioned. The flat section 28b is arranged between the compression sleeve 21 and the pipe 4 to be inserted, which is particularly noticeable in the pressed state. Fig. 4e After pressing, the gap 29 is filled.

[0203] The pressing process is carried out by comparing the Fig. 4d und 4e clearly. The two pressing jaw halves 10a and 10b are moved radially inward, and due to the contact of the pressing contour 8 of the two pressing jaw halves 10a and 10b, the pressing sleeve 21 is deformed radially inward. This deforms, on the one hand, the clamping ring 26 such that the clamping elements 27 press inward into the material of the pipe 4, thus securing the pipe 4 to the fitting 20. On the other hand, when the pressing sleeve 21 is deformed, the seal 28, and in particular the section 28b as a lip seal, is also deformed radially inward, and the seal 28 seals the gap 29.

[0204] The sealing element 28 thus ensures a high level of hygiene and prevents crevice corrosion. In conjunction with the point-type pipe stop 25, this prevents dead spaces where media can collect. The lip seal also ensures the system's tightness.

[0205] The Fig. 5a bis 5e show a fitting 40 for connecting to a flexible pipe 6 for a system 2 according to the Fig. 1a bis 1f The fitting 40 comprises a base body 44 and a compression sleeve 41 connected thereto, forming an outer contour 42. The compression sleeve 41 forms a chamber 43 directed inward toward the pipe 6 to be received, in which a force transmission ring 46 is arranged. Furthermore, a support body 50 is connected to the base body 44 and provided with a sealing contour 48 directed outward toward the pipe 6 to be inserted.

[0206] The compression sleeve 41 and the support body 50 are arranged at a distance from each other and define a space for inserting and receiving the pipe 6, as can be seen in particular from Fig. 5d results.

[0207] The compression sleeve 41 and the support body 50 are integrally connected by welding to the base body 44. The support body 50 is required for sealing the flexible pipe 6, in particular a multi-layer composite pipe, against the fitting 40. The support body 50 is preferably made of metal and enables significantly improved chemical resistance and robustness compared to support bodies made of a solid plastic.

[0208] Furthermore, the compression sleeve 41 has recesses 41a in the wall in the form of punch marks for an internal locking of the force transmission ring 46 with the compression sleeve 41. The force transmission ring 46 is thus positioned and fixed in the compression sleeve 41.

[0209] The force transmission ring 46 has cylindrical sections 46a and 46b and an inwardly projecting rib 46c for engagement with the pipe 6 to be inserted.

[0210] The sealing of the fitting 40 with respect to the pipe 6 is preferably ensured without additional soft sealing via the sealing contour 48 of the support body 50 and the force transmission by the force transmission ring 46.

[0211] The pressing of the fitting 40 is carried out by a comparison between the Fig. 5d und 5e clearly. The two pressing jaw halves 10a and 10b are moved radially inward, and due to the contact of the pressing contour 8 of the two pressing jaw halves 10a and 10b, the pressing sleeve 41 is deformed radially inward. This, on the one hand, deforms the force transmission ring 46 such that the force is transmitted to the material of the pipe 6. The pipe 6 is thereby deformed radially inward and is thereby pressed sealingly onto the sealing contour 48 of the support body 50. The sealing takes place at the outer end 50a of the support body 50 facing the pipe 6, so that no dead spaces arise in this area.

[0212] The pipe 6 is secured against pulling out, for example, by the retaining ribs 48a of the sealing contour 48.

[0213] Furthermore, the Fig. 5a bis 5e that a section 46d of the force transmission ring 46 protrudes axially from the press sleeve 41 and forms a section of the outer contour 42 to be pressed. This configuration achieves an external appearance that differs from the fitting 20, which facilitates the differentiation between the fittings 20 and 40 of a system.

[0214] The compression sleeve 41 also has a viewing window 51, allowing for the insertion of the tube 6. If the tube 6 has a particular color, this can be clearly visible as a signal color through the viewing window 51 in the compression sleeve 41.

[0215] Fig. 6a shows a first alternative embodiment of the fitting 40, in which the press sleeve 41 is connected as a separate part to the base body 44 by a weld seam 44a, while the support body 50 is formed integrally with the base body 44.

[0216] From the description of fittings 20 and 40, the outer contours 22 and 42 for the press sleeves 21 and 41 are largely identical. Thus, fittings 20 and 40 are suitable for a system as described in the Fig. 1a bis 1f is shown. Fittings 20 and 40 can be pressed by the same pressing jaw 10 without requiring a change of the pressing tool when a user switches between pressing fittings 20 and pressing fittings 40.

[0217] Fig. 6b shows a further alternative embodiment of an unpressed fitting 40, wherein like reference numerals identify like or similar elements, each having like functions.

[0218] In the embodiment according to Fig. 6b An axial extension 46e of section 46d of force transmission ring 46 is provided, which facilitates and thus improves the application of a pressing tool. Furthermore, rib 46c is axially offset inward, whereby the friction to be overcome and the associated haptic signal during connection occur at an axial position closer to the maximum insertion depth when inserting a pipe.

[0219] Furthermore, the fitting 40 Fig. 6b a support body 50, on the outside of which a circumferential and radially inwardly extending recess in the form of a bead 50b is formed. In the bead 50b, a seal in the form of an O-ring 53 is arranged, which when a pipe is pushed on with its

[0220] The inner diameter is pressed against the inside and creates an additional sealing effect during compression. This design is more aerodynamic than a continuous, small inner diameter.

[0221] A further change of the fitting 40 compared to the design according to Fig. 6a consists in the fact that the viewing window 51 is arranged axially offset in the direction of the base body 44 and is no longer arranged in the area of the pressing contour 8. An advantage of this design is that the viewing windows are also visible during the pressing process and are not covered by the pressing profile.

[0222] Fig. 6c shows a further embodiment which is essentially the same as the embodiment according to Fig. 6b is the same, although different dimensions have been chosen.

[0223] A difference to Fig. 6a and 6c is in Fig. 6b the base body 44 is designed as a solid turned part, while in the Fig. 6a and 6c the base body 46 is designed as a formed part.

[0224] Fig. 7a bis 7d show a fitting 120 for connecting to a rigid pipe 4 for a system according to the Fig. 2a bis 2f The fitting 120 has a base body 124 and a compression sleeve 121 connected thereto and forming an outer contour 122, wherein the compression sleeve 121 has a chamber 123 directed inward toward the pipe 4 to be received. At the distal end of the compression sleeve 121, a sleeve portion 121a is formed, which extends beyond the chamber 123. The sleeve portion 121a forms a portion of the outer contour 122 to be formed. Furthermore, a sealing element 128 is arranged in the chamber 123.

[0225] The compression sleeve 121 is molded onto the base body 124 in a form-fitting manner with a section 121b, resulting in a tapered diameter of the base body 124 in a section 124a. The compression sleeve 121 is therefore firmly connected to the base body 124.

[0226] Furthermore, an inner section 124b of the base body 124 extends radially inside the chamber 123 in the direction of the pipe 4 to be inserted. A section 128a of the sealing element 128 is arranged between the press sleeve 121 and the inner section 124b of the base body 124 and a further section 128b of the sealing element 128 is arranged between the press sleeve 121 and the pipe 4 to be inserted, as can be seen in particular from the Fig. 7c und 7d results.

[0227] The sealing element 128 fills a significant portion of the chamber 123 and thus seals both on the side of the base body 124 and on the rigid pipe 4, which is inserted at the front end up to the base body 4. This enables the separation into the media-contacting area of the base body 124 and the non-media-contacting area of the compression sleeve 121. The long sealing element 128 also allows a high tolerance for the correct insertion depth of the pipe 4 and overall ensures a virtually gap-free connection between the fitting 102 and the pipe 4.

[0228] Furthermore, the sleeve portion 121a and the sealing element 128 have inwardly projecting cams 121c as well as cams 128c distributed around the circumference for guiding and holding the tube 4. This provides support for the tube 4, haptic feedback when overcoming the cams 121c and the cams 128c during insertion of the tube to control the insertion depth, and also guides the tube during insertion. Cams 128d of the sealing element 128, which are also arranged circumferentially, rest against the outside of the inner portion 124b even in the unpressed state.

[0229] The cams 121c, which are factory-stamped in the front section of the compression sleeve 121, also serve to locally deform the rigid pipe 4 during compression. Therefore, a clamping ring with a holding function is not necessary in this design. Furthermore, the cams 121c ensure torsional rigidity after compression.

[0230] The pressing process is carried out by a comparison between the Fig. 7c und 7d clarified. The two pressing jaw halves 110a and 110b are moved radially inward, and the contact of the pressing contour 108 of the two pressing jaw halves 110a and 110b deforms the pressing sleeve 121 radially inward. The sections 108a and 108c of the pressing contour 108 rest against the sections 121a and 121c of the pressing sleeve 121 and deform the pressing sleeve 121 radially inward in these two sections. On the one hand, this forms the section 121a onto the pipe 4, whereby the section 121a can be formed circumferentially in its entirety or only in sections. On the other hand, the deformation of the section 121c leads to a deformation of the sealing element 128, so that the pipe 4 is sealed against the pressing sleeve 121. In this case, the section 128a and the cams 128d of the sealing element 128 are pressed against the outside of the inner section 124a of the base body 124. Likewise, the section 128b and the ring 128c are pressed against the outside of the tube 4.As a result, both the base body 124 of the fitting 120 and the pipe 4 are sealed against the external press sleeve 121.

[0231] As can be seen from the Fig. 7c und 7d further, the inserted pipe 4 abuts the end face of the section 124b of the base body 124. This avoids a change in cross-section at the transition between the pipe 4 and the fitting 120.

[0232] Fig. 7e shows the annular sealing element in a perspective view, while the Fig. 7f und 7g show the sealing element 128 in two views sectioned at different azimuth angles. The circumferential and inwardly directed bead-like sections 128a and 128b additionally have inwardly directed cams 128c and 128d, which perform the functions described above.

[0233] The Fig. 8a bis 8d show a fitting 140 for connecting to a flexible pipe 6 for a system 102 according to the Fig. 2a bis 2f The fitting 140 has a base body 144, to which a compression sleeve 141 forming an outer contour 142 is integrally connected. The compression sleeve 141 further has a chamber 143 directed inwards towards the pipe 6 to be received, in which a force transmission ring 146 is arranged. A support body 150 is also integrally connected to the base body 144 and has a sealing contour 148 directed outwards towards the pipe 6 to be inserted. Alternatively, the support body 150 can also be formed integrally with the base body 144. The fitting 140 thus has a three-part structure on each of the sides to be pressed, comprising the base body 144 and the compression sleeve 141 and support body 150 connected thereto.

[0234] The compression sleeve 141 and the support body 150 are arranged at a distance from each other and define an annular space for inserting and receiving the pipe 6.

[0235] The support body 150 is required to seal the flexible pipe 6, in particular a multi-layer composite pipe, against the fitting 140. The support body 150 is preferably made of metal and enables significantly improved chemical resistance and robustness compared to support bodies made of a solid plastic such as polyphenylene sulfone (PPSU).

[0236] The force transmission ring 146 has a toothed section 146a for engagement with the pipe 6 to be inserted. This enables guidance and holding of the pipe 6, ensuring a secure position of the pipe 4 relative to the fitting 140 prior to pressing. Recesses 146c are provided circumferentially between the toothed sections 146a for improved flexibility of the force transmission ring 146. Furthermore, the force transmission ring 146 is designed as a C-ring to facilitate insertion into the compression sleeve 141.

[0237] The sealing of the fitting 140 against the pipe 6 is ensured without an additional soft seal via the sealing contour 148 and the force transmission through the force transmission ring 146. By deforming the press sleeve 141 during pressing, the flexible pipe 6 is pressed onto the sealing contour 148, thereby achieving a sealing effect.

[0238] In the illustrated embodiment, the sealing takes place at the outer end 150a of the support body 150 facing the pipe 6, so that no dead spaces arise here after pressing.

[0239] The retaining ribs 148a of the sealing contour 148 also provide protection against the pipe 6 being pulled out.

[0240] Furthermore, the compression sleeve 141 has a sleeve portion 141b extending beyond the chamber 143, which forms a portion of the outer contour 142 of the compression sleeve 141 to be formed by a compression jaw 110. For this purpose, the compression jaw 110 has a corresponding portion 108b of the compression contour 108.

[0241] The pressing process is determined by comparing the Fig. 8d und 8e The two pressing jaw halves 110a and 110b are moved radially inward, and the contact of the pressing contour 108 of the two pressing jaw halves 110a and 110b deforms the pressing sleeve 121 radially inward. Sections 108b and 108c of the pressing contour 108 rest against sections 141b and 141c of the pressing sleeve 141 and deform the pressing sleeve 141 radially inward in these two sections. As a result, on the one hand, section 141b is formed onto the pipe 4, whereby section 141b can be formed circumferentially in its entirety or only in sections. On the other hand, the deformation of section 141c leads to the pipe 6 being formed onto the sealing contour 148 of the support body 150.

[0242] The force transmission ring 146 also has inwardly projecting webs 146b that define an inner cross-section that is equal to or slightly smaller than the outer diameter of the tube 6. Thus, the circumferentially distributed webs 146b form a guide and support for the tube 6.

[0243] Furthermore, the compression sleeve 141 and the force transmission ring 146 have corresponding viewing windows 151 and 152. Thus, when installing the pipe 6 in the fitting 140, the insertion depth of the pipe 6 can be checked, since the pipe 6 is sealed internally via the support body 150.

[0244] The Fig. 8b The viewing windows 151 and 152 shown are in the Fig. 8d und 8e cannot be seen because a different section through the fitting was chosen to show the inwardly projecting webs 146b.

[0245] The Fig. 7a bis 7d and 8a bis 8d also show a system for connecting rigid pipes 4 and for connecting flexible pipes 6. On the one hand, the system has a plurality of fittings 120 for connecting to a rigid pipe 4 according to the Fig. 7a bis 7d and secondly a plurality of fittings 140 for connecting to a flexible pipe 6 according to the Fig. 8a bis 8d The base body 124 of the fitting 120 and the base body 144 of the fitting 140 for connecting to a rigid pipe 6 are of identical design.

[0246] The press sleeves 121 and 141 are connected to the base bodies 124 and 144, respectively. For flexible pipes 6, the support body 150 is also included. The base body 124 and 144 also exhibit only a small deformation curve and can therefore also be made from difficult-to-form materials such as duplex steel or one of the ferritic steels mentioned above. The same base body 124 and 144 can be used in both the fitting 120 for rigid pipes 4 and the fitting 140 for flexible pipes 6, thus enabling a modular design of the fittings of the described system.

[0247] The system for connecting rigid pipes 4 and for connecting flexible pipes 6 according to the Fig. 7a bis 7d and 8a bis 8d is also for an inventive system 102 according to the Fig. 2a bis 2f suitable.

[0248] However, the press sleeves 121 and 141 differ in their respective applications for rigid pipes 4 and for flexible pipes 6 and are, for example, mounted force-fittingly by factory pressing onto the base body 124 or 144. A further advantage of the two-part design consisting of the base body 124 or 144 and the press sleeve 121 or 141 is that the fitting 120 or 140 is divided into a media-contacting base body 124 or 144 and a non-media-contacting press sleeve 121 or 141. This makes it possible, for example, to manufacture the base body 124 or 144 and, if applicable, the support body 150 from a very high-quality, corrosion-resistant material, while using a cost-effective material for the press sleeve 121 or 141. In principle, the material selection can be made specifically with regard to the respective requirement, i.e. the medium to be conveyed with the rigid pipe 4 and / or with the flexible pipe 6.

[0249] From the description of the fittings 120 and 140, the outer contours 122 and 142 for the press sleeves 121 and 141 are largely identical. Thus, the fittings 120 and 140 are suitable for a system as described in the Fig. 2a bis 2f is shown. Fittings 120 and 140 can be crimped by the same crimping jaw 110 without requiring a change in the crimping tool when a user switches between crimping fittings 120 and crimping fittings 140.

Claims

1. System (2; 102) for connecting rigid pipes (4) and for connecting flexible pipes (6), wherein the pipes (4, 6) have corresponding outer diameters, - with a press jaw (10; 110) having a press contour (8; 108), - with at least one first fitting (20; 120) for press-fitting to a rigid pipe (4), -- wherein the at least one first fitting (20; 120) is formed as an externally sealing fitting and externally seals a rigid pipe (4) to be connected, and -- wherein the at least one first fitting (20; 120) comprises a first press sleeve (21; 121) having a first outer contour (22; 122), - with at least one second fitting (40; 140) for press-fitting to a flexible pipe (6), -- wherein the at least one second fitting (40; 140) is formed as an internally sealing fitting and seals a flexible pipe (6) to be connected from the inside, and -- wherein the at least one second fitting (40; 140) comprises a second press sleeve (41; 141) having a second outer contour (42; 142), - wherein the outer contour (22; 122) of the first press sleeve (21; 121) and the outer contour (42; 142) of the second press sleeve (41; 141) are each adapted at least in sections to the press contour (8; 108) of the press jaw (10; 110) and can be pressed by the press jaw (10; 110).

2. System (2; 102) according to claim 1, characterised in that the outer contours (22; 122; 42; 142) of the first press sleeve (21; 121) and of the second press sleeve (41; 141) match at least in sections.

3. System (2; 102) according to claim 1 or 2, characterised - in that the press sleeves (21; 121; 41; 141) form a chamber (23; 123; 43; 143) directed inwards towards the pipe (4, 6) to be received, and - in that at least one clamp element, sealing element and / or force transmission element is accommodated in the chamber (23; 123; 43; 143).

4. System (2; 102) according to claim 3, characterised in that the chamber (23; 123) of the first press sleeve (21; 121) and the chamber (43; 143) of the second press sleeve (41; 141) accommodate different clamp elements, sealing elements and / or force transmission elements.

5. System (2; 102) according to any one of claims 1 to 4, characterized - in that the first press sleeve (121) has a first additional press section (121a), - in that the second press sleeve (141) has a second additional press section (141b), - wherein the first additional press section (121a) and the second additional press section (141b) have outer contours (108a; 108b) differing from each other and can each be formed in sections by the press jaw (110).

6. System (2; 102) according to any one of claims 1 to 5, characterized in that the first fitting (20; 120) and / or the second fitting (40; 140) are formed according to one of the claims 6 to 21.

7. System (2; 102) according to any one of claims 3 to 6, characterised - in that the ratio of the volume V(starr) of the chamber (23, 123) of the press sleeve (21, 121) of the first fitting (20, 120) to the volume V(flex) of the chamber (43, 143) of the press sleeve (41, 141) of the second fitting (40, 143) is given by δ = V starr V flex , - in that the volume V(starr) is given by V starr = π ⋅ LK starr 4 ⋅ DK starr 2 − DR starr 2 , with LK(starr) being the length of the chamber (23, 123), with DK(starr) being the inner diameter of the chamber (23, 123) and with DR(starr) being the outer diameter of the rigid pipe (4) to be accommodated, - in that the volume V(flex) is given by V flex = π ⋅ LK flex 4 ⋅ DK flex 2 − DR flex 2 , with LK(flex) being the length of the chamber (43, 143), with DK(flex) being the inner diameter of the chamber (43, 143) and with DR(flex) being the diameter of the flexible pipe (6) to be accommodated, - in that the ratio is given by δ = V starr V flex = LK starr LK flex ⋅ DK starr 2 − DR starr 2 DK flex 2 − DR flex 2 , and - in that δ takes values from a value range [0.50; 3.00], preferably [0.50; 1.50], particularly preferably [0.75; 1.25].

8. System (2; 102) according to any one of claims 3 to 7, characterised - in that the ratio of the difference between the inside diameter DK(starr) of the chamber (23, 123) of the press sleeve (21, 121) of the first fitting (20, 120) and the outside diameter DR(starr) of the rigid pipe (4) to be accommodated to twice the length LK(starr) of the chamber (23, 123) is given by ε starr = DK starr − DR starr 2 ⋅ LK starr and - in that ε(starr) takes values from a value range [0.10; 0.50], preferably [0.2; 0.4], particularly preferably [0.25; 0.35].

9. System (2; 102) according to any one of claims 3 to 8, characterised - in that the ratio of the difference between the inner diameter DK(flex) of the chamber (43, 143) of the press sleeve (41, 141) of the second fitting (40, 140) and the external diameter DR(flex) of the flexible pipe (6) to be accommodated to twice the length LK(flex) of the chamber (43, 143) is given by ε flex = DK flex − DR flex 2 ⋅ LK flex and - in that ε(starr) takes values from a value range [0.10; 0.70], in particular [0.10; 0.50], preferably [0.20; 0.60], in particular [0.2; 0.4], particularly preferably [0.25; 0.50], in particular [0.25; 0.35].

10. System (2; 102) according to any one of claims 3 to 9, characterised - in that ε(starr) is given by ε starr = DK starr − DR starr 2 ⋅ LK starr , with the inner diameter DK(starr) of the chamber (23, 123) of the press sleeve (21, 121) of the first fitting (20, 120) and with the outer diameter DR(starr) of the rigid pipe (4) to be accommodated and with the length LK(starr) of the chamber (23, 123), - in that ε(flex) is given by ε flex = DK flex − DR flex 2 ⋅ LK flex , with the inner diameter DK(flex) of the chamber (43, 143) of the press sleeve (41, 141) of the second fitting (40, 140) and with the outer diameter DR(flex) of the flexible pipe (6) to be accommodated and with the length LK(flex) of the chamber (23, 123), - in that the ratio α is given by α = ε starr ε flex = LK flex LK starr ⋅ DK starr − DR starr DK flex − DR flex and - in that α takes values from a value range [0.50; 3.00], preferably [0.50; 1.50], particularly preferably [0.75; 1.25].

11. System (2; 102) according to any one of claims 3 to 10, characterised - in that the degree of compression β(starr) when the first fitting (20, 120) is press-fitted to a rigid pipe (4) is given by β starr = DK starr + 2 s starr − DPK starr DR starr , with the inner diameter DK(starr) of the chamber (23, 123) of the press sleeve (21, 121) of the first fitting (20, 120) before pressing, with the wall thickness s(starr) of the press sleeve (21, 121) in the area of the first fitting (20, 120) to be pressed before pressing, with the outer diameter DR(starr) of the rigid pipe (4) to be accommodated before pressing and with the inner diameter DPK(starr) of the press contour (8, 108) of the press jaw (10, 110) in the region of the first fitting (20, 120) to be pressed after pressing, and - in that β(starr) takes values with β(starr)<0.15, preferably β(starr)<0.12, particularly preferably β(starr)<0.10.

12. System (2; 102) according to any one of claims 3 to 11, characterised - in that the degree of compression β(flex) when the second fitting (40, 140) is press-fitted to a flexible pipe (6) is given by β flex = DK flex + 2 s flex − DPK flex DR flex , with the inner diameter DK(flex) of the chamber (43, 143) of the press sleeve (41, 141) of the second fitting (40, 140) before pressing, with the wall thickness s(flex) of the press sleeve (41, 141) in the area of the second fitting (40, 140) to be pressed before pressing, with the outer diameter DR(flex) of the flexible pipe (6) to be accommodated before pressing and with the inner diameter DPK(flex) of the press contour (8, 108) of the press jaw (10, 110) in the region of the second fitting (40, 140) to be pressed after pressing, and - in that β(flex) takes values with β(flex)<0.15, preferably β(flex)<0.12, particularly preferably β(flex) <0.10.

13. System (2; 102) according to any one of claims 3 to 12, characterised - in that the degree of compression β(starr) when the first fitting (20, 120) is press-fitted to a rigid pipe (4) is given by β starr = DK starr + 2 s starr − DPK starr DR starr , with the inner diameter DK(starr) of the chamber (23) of the press sleeve (21, 121) of the first fitting (20, 120) before pressing, with the wall thickness s(starr) of the press sleeve (21, 121) in the area of the first fitting (20, 120) to be pressed before pressing, with the outer diameter DR(starr) of the rigid pipe (4) to be accommodated before pressing and with the inner diameter DKP(starr) of the press jaw (10, 110) in the region of the first fitting (20, 120) to be pressed after pressing, - in that the degree of compression β(flex) when the second fitting (40, 140) is press-fitted to a flexible pipe (6) is given by β flex = DK flex + 2 s flex − DPK flex DR flex , with the inner diameter DK(flex) of the chamber (43, 143) of the press sleeve (41, 141) of the second fitting (40, 140) before pressing, with the wall thickness s(flex) of the press sleeve (41, 141) in the area of the second fitting (40, 140) to be pressed before pressing, with the outer diameter DR(flex) of the flexible pipe (6) to be accommodated before pressing and with the inner diameter DPK(flex) of the press contour (8, 108) of the press jaw (10, 110) in the region of the second fitting (40, 140) to be pressed after pressing, - in that the ratio τ is given by τ = β starr β flex = DK starr + 2 s starr − DPK starr DK flex + 2 s flex − DPK flex DR flex DR starr , and - in that τ takes values from a value range [0.50; 1.50], preferably [0.75; 1.25], particularly preferably [0.80; 1.20].