Fitting with an axial contour for orbital welding and orbital-welding device therefor

Abstract

The invention relates to a fitting (152, 702, 802), in particular a plug-on fitting, for non-detachable connection to a pipe end (154, 704, 804, 904, 1004) of a pipeline by means of orbital welding, comprising a fitting body (706), which has a tubular joining region (708, 709) with a fitting opening (710, 711) for the insertion of a pipe end (154, 704, 804, 904, 1004), wherein the fitting body (706) has an outer contour (714) extending from the fitting opening (710, 711), and wherein the outer contour (714) has an axial contour (724), which is spaced apart from the fitting opening (710, 711) and is intended for fixing the fitting body (706) in a form-fitting manner in the longitudinal direction. The invention relates to a further fitting (902, 1002), in particular a plug-in fitting, for non-detachable connection to a pipe end (154, 704, 804, 904, 1004) of a pipeline by means of orbital welding. The invention further relates to an orbital-welding device (100, 101, 801, 901, 1001), to a system (700, 800, 900, 1000) having such an orbital-welding device, and to uses of the fittings.

Description

[0001] Fitting with axial contour for orbital welding and orbital welding device for it

[0002] The present invention relates to a fitting, in particular a push-on fitting, for permanently connecting to a pipe end of a pipeline by means of orbital welding, comprising a fitting body having a tubular joining area with a fitting opening for inserting a pipe end, wherein the fitting body has an outer contour extending from the fitting opening. The present invention further relates to a fitting, in particular a push-in fitting, for permanently connecting to a pipe end of a pipeline by means of orbital welding, comprising a fitting body having a tubular joining area, wherein the tubular joining area has an insertion section extending from a fitting opening for insertion into a pipe end and a joining section adjoining thereto, wherein the fitting body has an outer contour extending from the fitting opening.

[0003] The present invention further relates to an orbital welding device with a welding head having a receptacle for positioning a joining area of ​​two joining partners that are at least tubular in the joining area, preferably a fitting, in particular one of the fittings described above or an embodiment thereof, and a pipe end. The present invention further relates to a system. The present invention further relates to an orbital welding process. The present invention further relates to the use of one of the fittings described above or an embodiment thereof.

[0004] In the prior art, arc-based orbital welding processes, in particular tungsten inert gas (TIG) welding processes, are used, for example, for the metallurgical joining of pipes. In this process, the pipe ends to be joined are typically arranged side by side in a butt joint and welded together by moving the welding tool circumferentially (orbitally) around the joint. The welding torch can be guided manually or automatically.

[0005] On the outside of the pipes, discoloration can be largely suppressed by the shielding gas used in TIG welding; however, residual heat in the workpiece can still cause oxidation after the welding process. To protect the inner surface of the pipes from oxidation, additional measures are necessary, such as purging the pipes with forming gas.

[0006] Orbital welding of copper pipes has proven particularly challenging in this respect. Due to copper's high thermal conductivity, the heat introduced into the material from the outside during the welding process is quickly dissipated, requiring higher energy levels to reach the necessary temperatures at the weld point. This results in increased energy consumption, making the use of battery-powered welding equipment difficult. Furthermore, copper's high thermal conductivity leads to significant heating of the pipe's inner surface, making it particularly susceptible to discoloration and oxidation.

[0007] It has been found that the orbital welding process can be optimized to reduce the heating of the inner pipe surface, even when welding copper, and thus to minimize susceptibility to discoloration and oxidation on the pipe's interior. It has been shown that precise alignment of the electrode and the components being joined, as well as precise electrode guidance during the welding process, are particularly advantageous for such process optimization. However, existing orbital welding devices are in need of improvement in terms of precision and / or are quite large or complex, making them unsuitable, especially for handheld applications.Against this background, the present invention is based on the objective of providing a fitting, an orbital welding device, a system with such a fitting and such an orbital welding device, and an orbital welding process with which at least some of the aforementioned problems can be reduced or avoided.

[0008] The aforementioned problem is solved according to the invention by a fitting, in particular a push-on fitting, for permanently connecting to a pipe end of a pipeline by means of orbital welding, with a fitting body which has a tubular joining area with a fitting opening for inserting a pipe end, wherein the fitting body has an outer contour extending from the fitting opening and wherein the outer contour has an axial contour spaced from the fitting opening for positive locking fixation of the fitting body in the longitudinal direction.

[0009] The axial contour provided on the fitting allows the welding head of an orbital welding device used for the orbital welding process to positively lock the fitting in a defined axial position. This enables, in particular, a predetermined positioning of the fitting opening relative to the welding electrode, allowing for precise orbital welding, especially with a very small distance between the welding electrode and the fitting. This positive axial locking allows for precise alignment of the welding electrode and the fitting opening, thus optimizing the orbital welding process to reduce energy consumption and the heating of the inner surface of the pipe end being joined with the fitting. This, in turn, reduces the susceptibility to discoloration and oxidation on the pipe's interior.

[0010] The fitting opening of the fitting body is preferably circular for the insertion of a pipe section with a circular cross-section. The fitting body has, in particular, an inner contour extending from the fitting opening. This contour is preferably essentially, and especially at least partially, cylindrical to allow the pipe end to be inserted into the fitting opening. The fitting body is preferably made of metal, for example, copper or a copper alloy.

[0011] The joining area includes in particular the area of ​​the fitting body in which the joining points (weld points) are to be created during the orbital welding process, especially the area directly at the fitting opening.

[0012] The outer contour is the contour extending from the fitting opening on the outside of the fitting body. The axial contour is for the positive locking of the fitting body in the longitudinal direction. The longitudinal direction corresponds to the direction in which the tubular fitting body extends towards the fitting opening, i.e., the direction in which the pipe end can be inserted into or removed from the fitting body.

[0013] The above-mentioned problem is further solved according to the invention by a fitting, in particular a push-in fitting, for permanently connecting to a pipe end of a pipeline by means of orbital welding, with a fitting body having a tubular joining area, wherein the tubular joining area has an insertion section extending from a fitting opening for insertion into a pipe end and a joining section adjoining it, wherein the fitting body has an outer contour extending from the fitting opening and wherein the outer contour has an axial contour spaced apart from the insertion section for positive locking fixation of the fitting body in the longitudinal direction.

[0014] As with the fitting described above, in particular the push-on fitting, the axial contour of the fitting described above, in particular the push-in fitting, allows for a predetermined positioning of the fitting opening relative to the welding electrode of a welding head of an orbital welding device in order to carry out the orbital welding process precisely, especially with a very small distance between the welding electrode and the fitting. This enables, in particular, an optimization of the orbital welding process in order to reduce energy consumption and to reduce the heating of the inner surface of a pipe end to be joined with the fitting, and thus the susceptibility to discoloration and oxidation on the inside of the pipe.

[0015] The fitting opening of the fitting body is preferably circular for inserting the insertion section of the fitting into a pipe section with a circular cross-section. The outer contour of the insertion section is preferably essentially, and in particular at least partially, cylindrical to allow the insertion section to be inserted into a pipe end. The fitting body is preferably made of metal, for example copper or a copper alloy.

[0016] The fitting body has, in particular, an inner contour extending from the fitting opening. This is preferably, and especially preferably, completely cylindrical in order to prevent pressure losses of a medium flowing through the fitting.

[0017] The fitting body has an insertion section and a joining section. The joining section preferably connects directly to the insertion section. The joining area particularly comprises the area of ​​the fitting body where the joining points are to be created during the orbital welding process, especially the area of ​​the transition from the insertion section to the joining section.

[0018] In one embodiment of the fitting, particularly a push-fit fitting, the outer contour at the transition from the insertion section to the joining section has a widening with a stop edge directed towards the insertion section to abut a pipe end. In particular, the insertion section can have a smaller outer diameter than the joining section, with a stop edge formed at the transition between the insertion and joining sections. The stop edge defines the insertion depth of the fitting into the pipe end. Simultaneously, the stop edge defines the joining area in which the fitting is welded to the pipe end.

[0019] In the area of ​​the stop edge, a step with a wall thickness greater than that of the adjacent area of ​​the fitting body can be provided. This allows for a material reservoir for the molten metal (also known as the weld pool) during the welding process.

[0020] The above-mentioned problem is further solved according to the invention by an orbital welding device with a welding head which has a receptacle for positioning a joining area of ​​two joining partners that are at least tubular in the joining area, preferably a fitting, in particular one of the fittings described above or an embodiment thereof, and a pipe end, wherein the welding head is adjustable between an open position and a closed position and wherein the welding head has a fitting fixing contour which is designed to come into contact with an axial contour of the fitting and optionally with an optional azimuthal contour of the fitting in the closed position of the welding head and with a joining area of ​​a fitting arranged in a predetermined fitting position in the receptacle, such that the joining area of ​​the fitting is positively locked in the predetermined fitting position.preferably held in the specified fitting position by a form-fit and force-fit connection.

[0021] Such an adjustable welding head makes it easier for the operator, in the open position, to position the orbital welding device against the components to be joined, in particular the fitting and a pipe end, or to arrange the joining area of ​​the components in the fixture. Furthermore, by adjusting it to the closed position, the fitting's fixing contour and its associated axial contour, and optionally the optionally provided azimuthal contour of the fitting inserted into the fixture, can be positively engaged and / or held in place, so that the fitting is positioned in the predetermined fitting position in the welding head, in particular that the fitting opening or the stop edge is positioned at a predetermined distance from the welding electrode. In this way, an orbital welding process with precise alignment of the welding electrode to the fitting is possible, thus enabling the previously described optimization of the orbital welding process.

[0022] The welding head of the orbital welding device is designed to position a joining area between two components that are at least tubular in shape. Each component has a joining area where it is to be welded together. In the case of a push-on fitting, the joining area of ​​the fitting can, for example, include an area at the fitting opening, and the joining area of ​​the pipe end to be welded to it can include the area of ​​the pipe end that is located at the fitting opening when the fitting is pushed on. In the case of a push-in fitting, the joining area of ​​the fitting can, for example, include an area at a stop edge for a pipe end, and the joining area of ​​the pipe end to be welded to it can include the area of ​​the pipe opening that abuts the stop edge when the fitting is inserted.The joining area of ​​the fitting and the joining area of ​​the pipe end, more generally the respective joining areas of the two joining partners, together form the joining area of ​​the two joining partners.

[0023] The specified fitting position is, in particular, a specified axial fitting position. Furthermore, the specified fitting position can also be a specified axial and azimuthal fitting position. An azimuthal fitting position refers to the orientation of the fitting in the circumferential direction.

[0024] The fitting fixing contour can, in particular, comprise an axial fixing contour for positive and optionally force-fit interaction with the axial contour of a fitting, as well as optionally an azimuthal fixing contour for positive and / or force-fit interaction with the optional azimuthal contour of the fitting. The axial fixing contour preferably has one or more counter surfaces oriented obliquely or perpendicularly, preferably perpendicularly, to the longitudinal extent for abutting one or more corresponding surfaces of the axial contour of a fitting. The fixing in the axial direction can preferably be on both sides, i.e., with respect to both opposite directions of displacement in the longitudinal direction. For this purpose, the axial fixing contour preferably comprises at least two counter surfaces oriented oppositely with respect to the longitudinal extent.

[0025] The azimuthal fixing contour preferably has a contour that deviates from a circular shape in the circumferential direction, for example a polygonal contour, for interaction with an optional corresponding azimuthal contour of the fitting. The optional fixing in the azimuthal direction can preferably be on both sides, i.e., with respect to both opposite directions of rotation in the circumferential direction, so that the fitting remains in the predetermined azimuthal fitting position.

[0026] The azimuth fixing contour can also have a knurled surface, for example with RAA knurling or a plurality of small grooves, for force-fit and / or form-fit interaction with an optional corresponding azimuth contour of the fitting. The corresponding azimuth contour of the fitting can, for example, also have a knurled surface.

[0027] The above-mentioned problem is further solved according to the invention by a system with the previously described orbital welding device or an embodiment thereof and with a fitting, in particular one of the previously described fittings or an embodiment thereof.

[0028] The fitting of the system comprises, in particular, a tubular fitting body with a fitting opening from which an outer contour extends that is adapted to the fitting fixing contour of the orbital welding device. In particular, the outer contour can have an axial contour and / or azimuthal contour adapted to the fixing contour of the orbital welding device.The above-mentioned problem is further solved according to the invention by an orbital welding process, in particular carried out with the previously described orbital welding device or an embodiment thereof or with the previously described system or an embodiment thereof, in which two joining partners, in particular a fitting and a pipe end, which are at least in one joining area are tubular, are arranged to each other, in particular in an overlap joint, and in which one or more joining points are created in the joining area which connect the joining partners in a material-locking manner, preferably a chain of joining points extending in the circumferential direction of the joining partners is created which connects the joining partners in a material-locking manner.

[0029] A chain of joining points can connect the joining partners in a particularly fluid-tight manner. In this case, the chain of joining points serves both to firmly connect the joining partners and to create a fluid-tight seal of the connection.

[0030] If only one or more individual joining points are provided, the fitting preferably has an additional sealing element that ensures a fluid-tight seal between the fitting and the pipe end. In this case, the one or more joining points serve to firmly connect the joining partners.

[0031] The aforementioned problem is further solved according to the invention by using one of the fittings described above or an embodiment thereof for permanently connecting to a pipe end of a pipeline by means of orbital welding, in particular with the orbital welding device described above or an embodiment thereof.

[0032] The following describes various embodiments of the fittings, the orbital welding device, the system, the orbital welding process, and the use, with each embodiment applying independently to the fittings, the orbital welding device, the system, the orbital welding process, and the use. Furthermore, the individual embodiments can be combined with one another as desired.

[0033] In one embodiment, particularly of the push-fit fitting, the fitting body forms a weld edge in the area of ​​the fitting opening. This allows the orbital welding process to be carried out more precisely, especially with a smaller distance between the fitting, particularly the weld edge, and the welding electrode. The weld edge preferably has a shoulder with a reduced wall thickness compared to the wall thickness of an adjacent area of ​​the fitting body. The material of the shoulder with reduced wall thickness requires less heat input for melting and can provide material for the weld pool.

[0034] The weld edge can be formed by the outer contour and / or the inner contour of the fitting. In particular, a reduction in wall thickness can be provided on the outer contour and / or the inner contour. The weld edge can be oriented essentially perpendicular to the longitudinal direction of the fitting. However, it is also conceivable that the weld edge is oriented at an angle to the longitudinal direction of the fitting.

[0035] In one embodiment, particularly of the push-fit fitting, the fitting body has an inner contour extending from the fitting opening, wherein the inner contour includes an inwardly projecting insertion limiting element for limiting the insertion depth of a pipe end through the fitting opening into the fitting. In this way, the insertion of the pipe end into the fitting can be limited. Furthermore, the user receives haptic feedback through the stop against the insertion limiting element when the pipe end has been inserted sufficiently far into the fitting. The insertion limiting element preferably has a stop surface that extends substantially transversely to the longitudinal extent of the fitting. The insertion limiting element can, for example, be designed as an inwardly projecting circumferential bead or as one or more circumferentially arranged and inwardly projecting protrusions.

[0036] The distance between the insertion limiting element and the fitting opening is preferably at least 0.8 times the inner diameter of the fitting opening, more preferably at least 1.3 times the inner diameter of the fitting opening.

[0037] In one embodiment, particularly of the push-fit fitting, the fitting body has an inner contour extending from the fitting opening. A clamping element for axially fixing and / or centering a pipe end is provided on this inner contour, preferably in a groove within the fitting body. The clamping element is preferably in the form of a clamping ring. The clamping element can, in particular, have several circumferentially distributed spring elements that can elastically spring outwards when a pipe end is inserted through the fitting opening. In this way, the spring elements can exert an elastic force on the inserted pipe end, thereby securing it against being pulled out with a certain force and thus fixing it in place, as well as centering it in the fitting opening.Preferably, the spring elements are directed inwards and away from the fitting opening, which can strengthen the force-fit locking mechanism against the pipe end being pulled out.

[0038] The groove can be formed in particular by a groove provided in the fitting body, which forms the axial contour on the outer contour.

[0039] The clamping element is preferably made of metal, a heat-resistant plastic, a mineral material (e.g., mineral fiber or ceramic), or a combination thereof. It is also conceivable that the clamping element is at least partially made of plastic, particularly an elastomer. Instead of a clamping element, especially a clamping ring, with spring elements, or in addition to one, a sealing element such as an O-ring can also be provided. Such a sealing element, for example an O-ring, can also provide a degree of centering and / or frictional locking of the inserted pipe end. Furthermore, a sealing element can also seal the connection, for example, if, instead of a chain of joining points, only one or more individual joining points are created that connect the joining partners by a material bond.

[0040] The distance between the fitting opening or welding edge and the axial contour is preferably at least 3 mm, more preferably at least 4 mm. This ensures that the space in the welding head of the orbital welding device used to weld the fitting is sufficient for the axial fixing contour to be applied to the axial contour and for the welding electrode and / or electrode circulation mechanism to be positioned in the area of ​​the fitting opening or welding edge.

[0041] The distance between the fitting opening or weld edge and the clamping element is preferably a maximum of 8 mm, more preferably a maximum of 7 mm. This ensures that the clamping element is positioned as close as possible to the weld edge to achieve good centering of the pipe section in the fitting opening.

[0042] The distance between the fitting opening or weld edge and the axial contour is preferably a maximum of 7 mm, more preferably a maximum of 6 mm. This allows for a more compact design of the fitting and weld head. Furthermore, if a groove for the clamping element is provided in the area of ​​the axial contour, this achieves a favorable distance between the fitting opening or weld edge and the clamping element.

[0043] In a corresponding embodiment of the fitting, particularly a push-on fitting, the distance between the fitting opening and the axial contour is in the range of 3–7 mm, preferably 4–6 mm, and / or the distance between the fitting opening and the clamping element is 8 mm or less, preferably 7 mm or less. When the pipe end is inserted into the fitting opening, a gap preferably remains in the circumferential direction between the fitting and the pipe end, with a gap width of no more than 0.3 mm, more preferably no more than 0.2 mm. The gap can also have a negligible width. Furthermore, the gap can, for example, have a gap width in the range of 0.05–0.3 mm, particularly in the range of 0.1–0.2 mm. The specified maximum gap widths, or the gap widths in the specified ranges, allow the distance between the welding electrode and the pipe end to be reliably set within the desired range.

[0044] For this purpose, the fitting opening preferably has an inner diameter in the range of dA + 0.14 mm to dA + 0.21 mm if the fitting is intended for a pipe from the metric series with a nominal outside diameter dA of 6 mm, 8 mm, 10 mm, 12 mm, 15 mm or 18 mm or from the inch series with a nominal outside diameter dA of 6.35 mm (1 / 4"), 7.94 mm (5 / 16"), 9.52 mm (3 / 8"), 12.7 mm (1 / 2") or 15.87 mm (5 / 8"), and / or an inner diameter in the range of dA + 0.14 mm to dA + 0.20 mm if the fitting is intended for a pipe from the metric series with a nominal outside diameter dA of 22 mm or 28 mm or from the inch series with a nominal outside diameter OE of 19.05 (3 / 4"), 22.22 (7 / 8") or 25.4 mm (1"), and / or an inner diameter in the range dA + 0.14 mm to dA + 0.19 mm, if the fitting is for a pipe from the metric series with a nominal outside diameter dA of 35 mm,42 mm or 54 mm or from the inch series with a nominal outside diameter dA of 28.57 mm (1 1 / 8"), 34.92 mm (1 3 / 8"), 41.27 mm (1 5 / 8") or 53.97 mm (2 1 / 8").

[0045] In this way, a circumferential gap with the desired gap width within the permissible tolerance range of the pipes can be achieved. For example, in a fitting for a pipe from the metric series with a nominal outside diameter dA of 18 mm, the fitting opening preferably has an inside diameter in the range of 18 mm + 0.14 mm - 18.14 mm to 18 mm + 0.21 mm - 18.21 mm.

[0046] In one embodiment, particularly of the push-in fitting, a clamping element for axially fixing and / or centering the fitting in a pipe end is provided on the outer contour of the fitting body, preferably in a groove provided in the fitting body. The clamping element and / or the groove are preferably arranged in the insertion section. The clamping element is preferably designed in the form of a clamping ring. The clamping element can, in particular, have several circumferentially distributed spring elements that can elastically spring inwards when the fitting is inserted into a pipe end. In this way, the spring elements can exert an elastic force on the inserted pipe end and thereby fix the fitting with a certain force against being pulled out of the pipe end and center the fitting in the pipe end.Preferably, the spring elements are directed outwards and away from the fitting opening, which can strengthen the force-fit locking mechanism against the fitting being pulled out of the pipe end.

[0047] The clamping element is preferably made of metal or a heat-resistant plastic.

[0048] Instead of a clamping element, in particular a clamping ring, with spring elements, or in addition to one, a sealing element such as an O-ring can also be provided. Such a sealing element, for example an O-ring, can also provide a certain degree of centering and / or force-fit securing of the fitting inserted into the pipe end. Furthermore, a sealing element can also seal the connection, for example, if instead of a chain of joining points, only one or more individual joining points are created that connect the joining partners materially. The distance of the stop edge to the axial contour is preferably at least 3 mm, more preferably at least 4 mm.In this way, it is ensured that the space in the welding head of the orbital welding device, with which the fitting is to be welded, is sufficient for the axial fixing contour to be applied to the axial contour and for the welding electrode and / or electrode circulation mechanism to be positioned in the area of ​​the stop edge.

[0049] The distance between the stop edge and the axial contour is preferably a maximum of 7 mm, more preferably a maximum of 6 mm. This allows the fitting and welding head to be designed more compactly.

[0050] The distance between the stop edge and the clamping element is preferably a maximum of 8 mm, more preferably a maximum of 7 mm. This ensures that the clamping element is positioned as close as possible to the stop edge to achieve good centering of the fitting in the pipe section at the stop edge.

[0051] In a corresponding embodiment of the fitting, in particular push-in fittings, the distance of the stop edge to the axial contour is in the range of 3 - 7 mm, preferably 4 - 6 mm and / or the distance of the stop edge to the clamping element is 8 mm or less, preferably 7 mm or less.

[0052] The height of the stop edge can, if the fitting is intended for a pipe from the metric series with a nominal outside diameter dA,m according to column dA,m of the following table or for a pipe from the inch series with a nominal outside diameter dA,z according to column dA,z of the following table, lie in particular within the range specified in the column "Height range" of the relevant row of the following table:

[0053] In this way, with typical pipe thicknesses for the relevant nominal outside diameters, a butt joint geometry can essentially be achieved between the pipe end and the stop edge. For example, with a fitting for a metric pipe with a nominal outside diameter of 10 mm, the height of the stop edge can be in the range of 0.72 mm - 0.88 mm or 0.9 mm - 1.1 mm.

[0054] Furthermore, the height of the stop edge, if the fitting is intended for a pipe from the metric series with a nominal outside diameter dA,m according to column dA,m of the following table or for a pipe from the inch series with a nominal outside diameter dA,z according to column dA,z of the following table, may lie in particular within the range specified in the column "Height range" of the relevant row of the following table: In this way, with typical pipe thicknesses for the relevant nominal outside diameters, an essentially overlapping joint geometry can be achieved between the pipe end and the stop edge.

[0055] If the stop edge has a height corresponding to the wall thickness of the pipe end intended for the fitting, a butt joint geometry results when the pipe end is pushed onto the fitting. In this case, the welding electrode is preferably oriented substantially perpendicular to the surface of the fitting or pipe end with respect to the longitudinal direction of the mounting. If the stop edge has a height less than the wall thickness of the pipe end intended for the fitting, a lap joint geometry results when the pipe end is pushed onto the fitting. In this case, the welding electrode is preferably oriented at an angle, particularly at an angle of 45°, towards the pipe end and the lap joint with respect to the longitudinal direction of the mounting.

[0056] If the stop edge has a height greater than the wall thickness of the pipe end intended for the fitting, a lap joint-like geometry also results when the pipe end is pushed onto the fitting. In this case, the welding electrode is preferably also oriented at an angle, particularly at an angle of 45°, towards the joining area of ​​the lap joint with respect to the longitudinal direction of the holder.

[0057] The fitting body may have an external chamfer at the insertion opening. This facilitates the insertion of the fitting into a pipe end.

[0058] In one embodiment, in particular the push-on fitting or the push-in fitting, the outer contour has an azimuthal contour spaced from the fitting opening or from the insertion section for positive locking and / or force locking fixation of the fitting body in the circumferential direction.

[0059] The azimuthal contour allows the fitting to be fixed in a predetermined azimuthal position in the circumferential direction. This reliably prevents azimuthal rotation of the fitting in the circumferential direction during the welding process, enabling the welding electrode to reliably reach the individual positions for the joint points to be created in the circumferential direction.

[0060] The azimuth contour is preferably designed for a form-fit fixation of the fitting body in the circumferential direction. This enables a particularly reliable azimuth fixation. Alternatively or additionally, the azimuth contour can be designed for a force-fit fixation.

[0061] The azimuthal contour preferably exhibits discrete rotational symmetry in the circumferential direction. For example, the azimuthal contour can be designed in the form of a polygonal contour. In this way, various predetermined azimuthal fitting positions are possible within the weld head receptacle, allowing the weld head to be attached to the fitting in different positions.

[0062] In one embodiment, particularly of the push-fit or push-in fitting, one or more contour elements are provided on the outer contour, each forming both the axial and azimuthal contours. This allows the fitting to be designed more compactly. Furthermore, a welding head corresponding to the fitting can also be designed more compactly.

[0063] In one embodiment, particularly of the push-on or push-in fitting, one or more first contour elements are provided on the outer contour, forming the axial contour, and one or more second contour elements are provided on the outer contour, forming the azimuthal contour. The one or more first contour elements are, in particular, designed separately from the one or more second contour elements. The one or more first contour elements and the one or more second contour elements can, in particular, have different distances from the fitting opening. The spatial separation of the axial and azimuthal contours allows for greater design flexibility for the axial and azimuthal contours. Furthermore, the first and second contour elements can be designed with simpler geometry, which simplifies manufacturing.

[0064] In one embodiment, particularly of the push-on or push-in fitting, the one or more contour elements, or the one or more first and / or second contour elements, are designed to project outwards and / or be recessed inwards relative to an adjacent area of ​​the outer contour. In particular, the one or more contour elements can be bead-shaped and / or groove-shaped.

[0065] An outwardly projecting contour element, particularly for the axial and / or azimuthal contour, preferably has chamfered edges. This facilitates the insertion of the contour element into the corresponding counter contour of the fitting's fixing contour on the welding head. The outwardly projecting contour element can, for example, be designed in the form of an outwardly projecting bead.

[0066] In particular, an outwardly projecting contour element can have a corresponding inclined side surface on its side facing the fitting opening and / or on its side facing away from the fitting opening. The respective inclined side surface thus forms a chamfer of the contour element. In a cross-sectional plane defined by the longitudinal and radial directions of the fitting, the respective inclined side surface runs inclined, in particular, to the radial direction. A respective inclined side surface can, for example, lie on an imaginary conical surface. The fitting fixing contour of the welding head preferably has a corresponding inclined side surface for each inclined side surface of the contour element, in particular at a groove of the fitting fixing contour corresponding to the contour element.

[0067] A contour element forming the axial contour preferably has a surface oriented substantially perpendicular to the longitudinal direction. This provides a defined stop for a counter surface on the welding head for precise axial alignment. For this purpose, a surface oriented perpendicular to the longitudinal direction, for example in the form of an edge, can be provided, particularly at the transition of the contour element to a longitudinally adjacent part of the outer contour, i.e., at the base of the contour element. A preferably inclined side surface begins in this case preferably radially spaced from the base of the contour element, for example adjacent to the surface oriented perpendicular to the longitudinal direction, especially the edge. This allows the distance between the fitting opening and the base of the contour element to be defined more precisely, so that the fitting opening in the welding head can be aligned even more accurately with the welding electrode.

[0068] At the transition of the contour element to a longitudinally adjacent part of the outer contour, i.e., at the base of the contour element, the radius of curvature of the contour element is preferably less than 0.5 mm, more preferably less than 0.3 mm, and particularly less than 0.2 mm. This achieves a sharp transition between the contour element and the adjacent outer contour, allowing the distance between the fitting opening and the base of the contour element to be defined more precisely, thus enabling the fitting opening in the welding head to be aligned even more accurately with the welding electrode. This is particularly preferably achieved in combination with the previously described surface of the contour element oriented perpendicular to the longitudinal direction. However, it is also conceivable that the preferably provided inclined side surface begins directly at the base of the contour element.

[0069] Such a small radius of curvature of less than 0.5 mm, preferably less than 0.3 mm, and particularly less than 0.2 mm, can be produced, for example, by rolling using a rolling tool or alternatively by machining using a machining tool. Accordingly, the contour element preferably has a rolled and / or machined area at the transition to a longitudinally adjacent part of the outer contour.

[0070] In one embodiment, particularly of the push-on or push-in fitting, the azimuthal contour has several, preferably at least ten, recessed areas, in particular surfaces, distributed circumferentially around the circumference of the outer contour. For example, the azimuthal contour can be designed as a recessed polygonal contour. The at least ten surfaces, in particular their design as at least a decagon, allow the depth of the recessed areas to be less than with a smaller number of surfaces, for example, a square. In this way, a reduction in the cross-sectional area of ​​the inner contour of the fitting can be reduced or completely avoided, for example, to reduce pressure losses of a medium flowing through the fitting.

[0071] In one embodiment, particularly of the push-on or push-in fitting, the azimuthal contour has several, preferably at least three, protruding areas, in particular surfaces, distributed in an azimuthal direction around the circumference of the outer contour. The azimuthal contour can be designed, in particular, as a protruding polygonal contour or as a plurality of separate protruding elements, in particular bulges, arranged around the circumference.

[0072] The number of protruding areas is preferably three or more, in particular five or more, to allow the welding head to be attached to the fitting at different angles.

[0073] In one embodiment, particularly of the push-on or push-in fitting, the outer contour has a clamping area whose outer cross-section is adapted to the inner cross-section of the fitting opening. Preferably, the outer diameter of the clamping area is adapted to the inner diameter of the fitting opening in at least one direction, or more preferably differs from it by less than 1 mm. This enables symmetrical clamping of the pipe end and fitting in the welding head.

[0074] The clamping area can be located, for example, in the region of the axial contour and / or azimuthal contour, particularly a recessed axial contour and / or azimuthal contour. This allows for a more compact design of the fitting and the welding head. The clamping area can also be located on the side of the axial contour and / or the azimuthal contour facing away from the fitting opening.

[0075] In one embodiment, particularly the push-on or push-in fitting, the fitting is designed as a double fitting (also called a socket), a tee, or an elbow. The double fitting can be mirror-symmetrical or asymmetrical, for example, as a reducing fitting for connecting pipe ends of different nominal diameters. The fitting can also be part of a component, such as a plant part.

[0076] In one embodiment, in particular the push-on fitting or push-in fitting, the fitting body is made of copper or a copper alloy, steel or aluminum or an aluminum alloy.

[0077] The fitting body is preferably a formed part. This reduces manufacturing costs. However, it is also conceivable that the fitting is at least partially machined, for example, for some features of the inner or outer contour.

[0078] In one embodiment, in particular the orbital welding device, the welding head has a pipe fixing contour which is designed to come into contact with an outer contour of the pipe end in the closed position of the welding head and with a joining area of ​​a pipe end arranged in a predetermined pipe position in the receptacle, so that the joining area of ​​the pipe end is held in the pipe position by positive and / or force locking.

[0079] The pipe fixing contour can, in particular, have one or more curved surfaces adapted to the curvature of a pipe with a predetermined outer diameter. Furthermore, the pipe fixing contour can have multiple surfaces arranged at various circumferentially distributed positions to contact the pipe end. This allows for a radial, positive-locking fixation of the pipe to prevent tilting of the pipe end against the fitting.

[0080] The pipe end or joining area can be fixed by the pipe fixing contour, particularly by means of a force-fit connection. In this way, the axial position of the pipe end can be fixed.

[0081] In one embodiment, particularly the orbital welding device, at least part of the fitting fixing contour is formed by a movable fixing element. In the open position of the welding head, this element is positioned in an open position, exposing the joining area of ​​the fitting. In the closed position of the welding head, the fixing element is positioned in a closed position, holding the joining area of ​​the fitting in the predetermined fitting position. The movable fixing element is therefore, in particular, part of the movable section of the welding head. The movable fixing element preferably has a fitting contact surface for bearing against the fitting, which is part of the fitting fixing contour.

[0082] In this way, the fitting can be easily inserted into the receptacle in the open position of the welding head, especially through the insertion opening, and fixed in the receptacle in the closed position of the welding head.

[0083] The fitting fixing contour preferably further comprises a fixed part of the fitting fixing contour, which is formed by a fixing element on the fixed part of the welding head. For example, the axial fixing contour and / or the azimuthal fixing contour can be formed by one or more fixing elements on the fixed part of the welding head.

[0084] The one or more movable fixing elements can, for example, form a counter bearing for contact with the fitting, which engages an axial contour of the fitting with the axial fixing contour on the fixed part of the welding head and / or an azimuthal contour of the fitting with the azimuthal fixing contour on the fixed part of the welding head.

[0085] In one embodiment, at least part of the pipe fixing contour is formed by a movable fixing element. In the open position of the welding head, this element is positioned in an open position, exposing the joining area of ​​the pipe end. In the closed position of the welding head, the fixing element is positioned in a closed position, holding the joining area of ​​the pipe in place. The movable fixing element is therefore, in particular, part of the movable section of the welding head. The movable fixing element preferably has a pipe contact surface for bearing against the pipe end, which is part of the pipe fixing contour.

[0086] In this way, the pipe end can be easily inserted into the holder in the open position of the welding head, especially through the insertion opening, and fixed in the holder in the closed position of the welding head.

[0087] The pipe fixing contour preferably further comprises a fixed part of the pipe fixing contour, which is formed by a fixing element on the fixed part of the welding head.

[0088] The one or more movable fixing elements can, for example, form a counter bearing for the attachment at the pipe end, which holds the pipe end in contact with the fixed fixing element on the fixed part of the welding head.

[0089] The movable part of the fitting fixing contour and the movable part of the pipe fixing contour are preferably coupled, particularly mechanically, such that they can move synchronously. This achieves synchronous fixing of the pipe end and fitting. In one embodiment, particularly the orbital welding device, the welding head has a first opening and a second opening opposite the first, between which the receptacle extends longitudinally. This allows two joining partners, particularly a fitting and a pipe end, to be positioned within the receptacle with their joining area facing the first and second openings, respectively.

[0090] The welding head surrounds the receiver, particularly at least partially, in an azimuthal direction.

[0091] The first and second openings can be connected to each other. In particular, the welding head can be adjustable between an open position and a closed position, wherein in the open position the welding head has an insertion opening connecting the first and second openings for inserting a joining area of ​​two joining partners, at least tubular in the joining area, in particular a fitting and a pipe end, into the receptacle, and wherein the insertion opening is at least partially closed in the closed position.

[0092] The insertion opening forms, in particular, an azimuthal insertion area. This allows the two joining partners, with their joining area in the open position, to be inserted through the insertion opening into the receptacle. This means the welding head can be placed laterally onto the joining partners, especially the fitting and the pipe end, particularly if they are already arranged relative to each other, for example, nested together. In the closed position, the two joining partners, with their joining area, can be fixed in the receptacle. Preferably, the insertion opening is completely closed in the closed position. This provides better protection for the user against UV radiation and welding fumes. Furthermore, this design helps to retain the shielding gas within the welding head, particularly in the area of ​​the welding electrode.In one embodiment, the orbital welding device comprises an adjustment mechanism and a locking mechanism for actuating the adjustment mechanism, wherein the adjustment mechanism is configured to move the welding head between the open and closed positions. The locking mechanism is preferably mechanically operable. The adjustment mechanism can, in particular, comprise one or more locking ring segments, preferably driven in opposite directions.

[0093] In one embodiment, the orbital welding device comprises an electrode recirculation mechanism and an electrode drive, in particular a motor, for driving the electrode recirculation mechanism, wherein the electrode recirculation mechanism is configured to move the electrode holder or welding electrode circumferentially around the holder. In this way, the welding electrode can be moved automatically and in a controlled manner circumferentially around the joining area of ​​the joining partners arranged in the holder during the orbital welding process in order to weld them together, in particular by means of a chain of joining points.

[0094] In one embodiment, particularly the orbital welding device, the welding head has one or more closure ring segments, each of which has a circumferential opening and is arranged circumferentially around the receptacle and mounted such that the respective closure ring segment is rotatable about an imaginary longitudinal axis of the receptacle. Preferably, each closure ring segment is positioned in an open rotational position in which the opening forms part of the insertion opening, and in a closed rotational position in which the closure ring segment at least partially closes the insertion opening. This mechanism allows the welding head to be adjusted between open and closed positions in a simple, reliable, and, in particular, space-saving manner.This allows the welding head to be designed compactly, which is particularly advantageous in difficult assembly situations and when the welding head is part of a handheld device.

[0095] One or more of the closure ring segments can, in particular, represent movable fixing elements that form part of the fitting fixing contour and / or part of the pipe fixing contour.

[0096] In one embodiment, particularly the orbital welding device, the welding head has several locking ring segments, and the direction of rotation from the open to the closed position of at least two of the multiple locking ring segments, especially two locking ring segments arranged longitudinally side by side, is opposite. In this way, the ends of these locking ring segments move towards each other at their respective ring segment openings when moving from the open to the closed position. This allows for a more compact design, since the individual locking ring segments only need to move approximately to the middle of the insertion opening to close it. Furthermore, such a counter-rotating movement enables symmetrical fixation and, in particular, centering of the joining partners in the fixture.

[0097] In one embodiment, one or more of the first of the one or more closure ring segments are arranged in the area of ​​the first opening and / or one or more of the second of the one or more closure ring segments are arranged in the area of ​​the second opening. This achieves a symmetrical closure of the insertion opening with respect to the longitudinal axis of the receptacle. Preferably, both joining partners, in particular the fitting and the pipe end, can be fixed by the closure ring segments in this way.

[0098] The locking ring segments at the first opening can, in particular, form part of the fitting's fixing contour. The locking ring segments at the second opening can, in particular, form part of the pipe's fixing contour. Preferably, a first locking ring segment with a first direction of rotation and a further locking ring segment with an opposite direction of rotation are arranged in the area of ​​the first and / or second opening. In this way, symmetrical, bilateral fixing of the joining partners at the first and second openings is possible.

[0099] In one embodiment, the fitting fixing contour comprises a fitting clamping contour, and the pipe fixing contour comprises a pipe clamping contour. In the closed position of the welding head, the inner cross-section of the fitting clamping contour is adapted to the inner cross-section of the pipe clamping contour, and in particular, the inner diameter of the inner cross-section of the fitting clamping contour differs from the inner diameter of the inner cross-section of the pipe clamping contour by less than 1 mm. This ensures uniform fixing of the fitting and pipe end, especially without displacement of the fitting and pipe end relative to each other due to transverse forces. Furthermore, the adjustment mechanism, in particular the locking ring segments, can be designed identically on both sides of the welding head, thereby reducing manufacturing costs.

[0100] In one embodiment, particularly the orbital welding device, the device comprises a handheld unit that includes the welding head and preferably a handle connected to the welding head. Preferably, a welding power source and a control unit can also be housed in the handheld unit. Furthermore, the handheld unit can have a battery or accumulator, a receptacle, or a connection for one, particularly for a replaceable accumulator. For example, a connection for plugging in a replaceable accumulator can be provided. This enables flexible and easy operation of the orbital welding device, even under confined working conditions. Preferably, the orbital welding device is designed entirely as a handheld unit, particularly with an integrated or pluggable accumulator, especially a replaceable accumulator. This allows for particularly flexible and easy use of the orbital welding device.

[0101] It is also conceivable that the orbital welding device, in addition to the handheld unit, includes at least one case or backpack, connected to the handheld unit, for example, via a hose package, in which components of the orbital welding device, such as the welding power source and / or a battery or accumulator, or a holder for one, are located. In this way, the handheld unit can be designed to be more compact and lighter, thus simplifying its operation. At the same time, the orbital welding device remains portable.

[0102] In one embodiment, particularly the orbital welding device, a control unit is provided which is configured to control the orbital welding device such that a weld seam is produced by means of the welding electrode on two joining partners arranged in the receptacle, consisting of a circumferentially extending chain of joining points. For this purpose, the control unit preferably comprises at least one processor and at least one memory containing instructions, the execution of which on the at least one processor results in corresponding control of the orbital welding device. The memory can, for example, be a ROM memory or a RAM memory. In particular, the control unit of the orbital welding device can control the welding power source and / or the welding electrode drive.

[0103] In one embodiment, particularly of the system, the fitting opening or the joining section of the fitting is arranged in the predetermined fitting position in the area of ​​the welding electrode. This ensures a predetermined alignment of the fitting with respect to the welding electrode, enabling the orbital welding process to be carried out reliably.

[0104] In one embodiment, particularly the system with a push-on fitting, the axial contour with respect to the welding edge and the fitting fixing contour with respect to the welding electrode are adapted such that, with the fitting inserted into the receptacle, the tip of the welding electrode maintains a radial distance to the outer surface of the pipe end in the range of 0.3–1.5 mm, preferably 0.4–1.4 mm, more preferably 0.5–1.3 mm, particularly 0.60–0.80 mm, and / or an axial distance to the welding edge in the range of 0.15–1.2 mm, preferably 0.25–1.1 mm, more preferably 0.35–1.0 mm, particularly 0.40–0.70 mm, in every rotational position of the electrode ring segment. Preferably, the predetermined fitting position is such that the radial distance of the tip of the welding electrode to the outer surface of the pipe end or to the welding edge lies within one of the aforementioned ranges.In this embodiment, the welding electrode is oriented obliquely inwards towards the receiver in relation to the longitudinal direction.

[0105] In one embodiment, particularly the orbital welding device, the welding electrode is inclined relative to its circumferential movement, specifically inclined inwards in the direction of movement. This enables penetrating welding. Additionally, the welding electrode can also be inclined inwards in the longitudinal direction relative to the receiving electrode. In this case, the welding electrode is doubly inclined, namely inclined towards the weld edge and in the welding direction.

[0106] In one embodiment, particularly the system with a push-in fitting, the axial contour with respect to the stop edge and the fitting fixing contour with respect to the welding electrode are adapted such that, with the fitting inserted into the receptacle, the tip of the welding electrode maintains a radial distance to the outer surface of the pipe end and / or to the outer surface of the fitting in the range of 0.3 - 1.5 mm, preferably 0.4 - 1.4 mm, more preferably 0.5 - 1.3 mm, in particular 0.60 - 0.80 mm, and an axial distance to the welding edge or stop edge in the range of 0.15 - 1.2 mm, preferably 0.25 - 1.1 mm, more preferably 0.35 - 1.0 mm, in particular 0.40 - 0.70 mm, in every rotational position of the electrode ring segment. Preferably, the specified fitting position is such that the radial distance of the tip of the welding electrode to the outer surface of the pipe end and / or to the outer surface of the fitting lies in one of the aforementioned areas.In this embodiment, the welding electrode is oriented obliquely inwards towards the receiver in relation to the longitudinal direction.

[0107] In one embodiment, particularly the system with a push-fit fitting, the axial contour with respect to the stop edge and the fitting fixing contour with respect to the welding electrode are adapted such that, with the fitting inserted into the receptacle, the tip of the welding electrode maintains a radial distance from the outer surface of the pipe end in the range of 0.3–1.5 mm, preferably 0.4–1.4 mm, and particularly 0.40–0.80 mm, in every rotational position of the electrode ring segment. In this embodiment, the welding electrode is oriented radially inwards towards the receptacle with respect to the longitudinal direction.

[0108] In this way, very precise electrode guidance is possible in the orbital welding process, whereby the small distance tolerance between electrode tip and fitting enables a stable welding process with particularly low heat inputs into the fitting or pipe end, so that the susceptibility to discoloration and oxidation on the inside of the pipe is greatly reduced and a process with low energy consumption is allowed.

[0109] Further features and advantages of the fittings, the orbital welding device, the system, the orbital welding process, and its use will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawing. The drawing shows...

[0110] Fig. 1 shows a first embodiment of the orbital welding device,

[0111] Fig. 2a-d shows the welding head of the orbital welding device from Fig. 1,

[0112] Fig. 3 shows a schematic block representation of the functional components of the orbital welding device from Fig. 1.

[0113] Fig. 4 shows a schematic block representation of the welding power source of the orbital welding device from Fig. 1.

[0114] Fig. 5a-b shows a schematic representation of the creation of a joining point in the orbital welding process.

[0115] Fig. 6a-c shows an embodiment of the orbital welding process on a fitting and a pipe end,

[0116] Fig. 7 shows another embodiment of the orbital welding device,

[0117] Figs. 8a-e show more detailed views of the welding head of the orbital welding device from Fig. 1.

[0118] Fig. 9a-b shows an embodiment of the fitting and the system,

[0119] Figs. 10a-b show a further embodiment of the fitting, a further embodiment of the orbital welding device, and a further embodiment of the system.

[0120] Fig. 12a-b shows a further embodiment of the fitting, a further embodiment of the orbital welding device, and a further embodiment of the system and

[0121] Fig. 13a-b Sectional views of contour elements.

[0122] Fig. 1 shows a schematic representation of an embodiment of the orbital welding device.

[0123] The orbital welding device 100 is designed as a mobile welding device in the form of a handheld unit 102. In the present embodiment, the handheld unit 102 comprises all components of the orbital welding device 100, making the orbital welding device 100 very flexible to handle, even under difficult installation conditions.

[0124] The hand-held device 102 initially comprises a welding head 104, which has a receptacle 106 in which a joining area of ​​two joining partners, for example a pipe end and a fitting, can be arranged.

[0125] The handheld device 102 further comprises a handle 108 with a shaft 110 on which the welding head 104 is arranged, and a grip 112 for holding and operating the handheld device 102. The grip 112 has a connection 114 at its end opposite the shaft 110 for an interchangeable accumulator unit 116. The shaft 110 also has a connection 115 for an interchangeable shielding gas magazine 120.The handle 108 houses various components for operating the orbital welding device 100, namely, in particular, an adjustment mechanism 122 for adjusting the welding head 104 between an open and a closed position, an electrode drive 124 for driving a welding electrode 126 in the welding head 104, a welding power source 128 for providing the ignition voltage and welding current for the orbital welding process, a control unit 130 for controlling the orbital welding device 100, a valve 132 for controlling the shielding gas supply, and a user interface 134 comprising display and operating elements 136 for configuring the orbital welding device 100, as well as a torch trigger 138 for starting an orbital welding process. Furthermore, the accumulator unit 116 includes an accumulator 140, for example, a lithium-ion accumulator, and the shielding gas magazine 120 includes a shielding gas container 142.

[0126] Figures 2a-d show the welding head 104 of the orbital welding device 100 in a schematic, perspective view, in the open position (Fig. 2a), in the open position after arranging a joining area 150 of two joining partners, namely a fitting 152 and a pipe end 154, in the receptacle 106 (Fig. 2b), as well as in the closed position before (Fig. 2c) and during the execution of an orbital welding process (Fig. 2d).

[0127] The welding head 104 has a fixed part 160, which circumferentially surrounds the receptacle 106, and a movable part 162. In the open position, the movable part 162 is at least partially retracted into the fixed part 160, exposing an insertion opening 164 in the circumferential direction. In the closed position, the movable part 162 closes the insertion opening 164, so that the receptacle 106 is essentially completely closed in the circumferential direction. In the axial direction (longitudinal direction), the receptacle 106 extends between a first opening 166 and a second opening 168. An adjustment mechanism 170 is provided on the welding head 104 for adjusting it between the open and closed positions.Furthermore, an electrode circulation mechanism 172 is provided on the welding head 104, with which the welding electrode 126 can be moved circumferentially around the receptacle 106 in the closed position of the welding head 104 for the performance of an orbital welding process.

[0128] Fig. 3 shows a schematic block diagram of the functional components of the orbital welding device 100 from Fig. 1. The accumulator 140 supplies all electrical components of the orbital welding device 100 with electrical energy. In particular, the accumulator 140 supplies the welding power source 128, the control unit 130 and the electrode drive 124.

[0129] The welding power source 128 provides the ignition voltage for arc ignition and the welding current for the orbital welding process. For this purpose, the welding power source 128 has two outputs 174, 176, one of which is electrically conductively connected to the welding electrode 126 during an orbital welding process, and the other is electrically conductively connected to one or more contacting elements 178 for contacting a joining partner arranged in the receptacle 106.

[0130] The electrode drive 124 preferably has an electric motor and is connected, for example via an axis 180, to the electrode recirculation mechanism 172 in order to transmit the movement, for example a rotary movement, from the electric motor to the electrode recirculation mechanism 172, so that the electrode recirculation mechanism 172 moves the welding electrode around the receptacle 106.

[0131] The control device 130 is designed to control the orbital welding device 100 and for this purpose may in particular have at least one microprocessor 182 and a memory 184 with instructions, the execution of which on the at least one microprocessor 182 effects the control of the orbital welding device 100.

[0132] Furthermore, the control unit 130 is connected to the user interface 134 to output user output, for example via a screen included by the display and control elements 136, and to receive user input, for example via buttons or touchscreen included by the display and control elements 136 or from the burner button 138.

[0133] The control unit 130 is specifically designed to control an orbital welding process. For this purpose, the control unit 130 is connected to the electrode drive 124, the valve 132 for controlling the shielding gas flow to the welding head 104, and the welding power source 128.

[0134] In the present embodiment, the adjustment mechanism 122 is mechanically designed, so that a user can manually actuate the adjustment mechanism 170 to move the welding head 104 between the closed and open positions. Alternatively, or additionally, the adjustment mechanism 122 could be motorized, for example, by having an electric motor controllable via the control unit 130, so that the welding head 104 can be automatically adjusted between the closed and open positions.

[0135] The shielding gas cylinder 142, which contains a shielding gas, in particular an inert gas, and is preferably replaceable, is connected to the welding head 104 via the valve 132. The welding head 104 preferably has a shielding gas guide to deliver the shielding gas for the orbital welding process to the area of ​​the welding electrode 126. Fig. 4 shows a schematic block diagram of the functional components and connections of the welding power source 128. The welding power source 128 has two inputs 186, 188 for connecting the two poles of the accumulator 140 and two outputs 174, 176 for providing the ignition voltage and the welding current and for electrically conductive connection with the contacting element 178 and the welding electrode 126.

[0136] The welding power source 128 has an electronic circuit 190 which is supplied by the voltage, in particular DC voltage, applied to the inputs 186, 188 and can provide an ignition voltage for igniting an arc and a welding current for supplying an arc welding process via the outputs 174, 176. The electronic circuit 190 can, for example, comprise one or more electronic switches, in particular a half-bridge circuit, and preferably at least one coil.

[0137] The electronic circuit 190 can further include its own control device, for example a microprocessor, which controls the operation of the welding power source 128, in particular by controlling one or more switches of the electronic circuit 190.

[0138] The electronic circuit 190 is functionally configured to provide a high-voltage pulse at outputs 174 and 176 for igniting the welding arc. This is illustrated in Fig. 4 by the functional module HV ignition 194. Furthermore, the electronic circuit 190 is configured to provide welding current control, allowing the current intensity of a welding current flowing through outputs 174 and 176, i.e., the welding current intensity, to be regulated, particularly according to a predefined current characteristic. This is illustrated in Fig. 4 by the functional module welding current control 192.

[0139] Accordingly, the control unit of the welding power source 128 can be configured, in particular, to generate a high-voltage pulse to ignite a welding arc and subsequently to provide a welding current for an orbital welding process, and in particular to regulate the welding current. The control unit of the welding power source 128 is preferably configured to regulate the welding current according to a predetermined or predefinable welding current characteristic curve when the arc is burning.

[0140] The welding power source 128 can be connected to, or is connected to, the control unit 130 and can thus be controlled by the control unit 130. In particular, the control unit 130 can control the control unit of the welding power source 128 in order to initiate and / or configure the control of the operation of the welding power source 128 by the control unit of the welding power source 128.

[0141] Instead of two separate control units, it is also conceivable that the control unit 130 and the control unit of the welding power source 128 are designed as a common control unit, for example as a microprocessor.

[0142] The following explains the execution of an orbital welding process with the orbital welding device 100, namely the execution of an orbital welding process on a pipe end 154 and a fitting 152.

[0143] Figures 5a and 5b each show a schematic cross-sectional view of the joining area 150 of fitting 152 and pipe end 154 arranged in the welding head 104, with the figures showing only the upper half. Some of the components of the welding head 104 are shown with dashed lines.

[0144] The fitting 152 is pushed onto the pipe end 154 as shown in Fig. 5a.

[0145] For this purpose, the inner cross-section of the fitting 152 is preferably adapted to the outer cross-section of the pipe end 154 in such a way that only a small gap remains between the outer wall of the pipe end 154 and the inner wall of the fitting 152.

[0146] The overlap joint formed in this way between pipe end 154 and fitting 152 forms the joining area 150, in which fitting 152 and pipe end 154 are to be welded together.

[0147] To perform the orbital welding process, the welding head 104 is first moved to the open position via the adjustment mechanism 122, so that the movable part 162 of the welding head 104 exposes the insertion opening 164 (Fig. 2a). The hand-held device 102 with the welding head 104 can then be placed laterally with the insertion opening 164 onto the joining area 150 of the pipe end 154 and the fitting 152 pushed onto it, so that the joining area 150 is arranged in the receptacle 106 (Fig. 2b), while the remaining part of the fitting 152 and the remaining part of the pipe end 154 extend out of the receptacle 106 through the openings 166, 168.

[0148] The welding head 104 is then moved into the closed position via the adjustment actuator 122 (Fig. 2c). In the closed position, the joining area 150 of the pipe end 154 and the fitting 152 is preferably fixed in the receptacle 106 by the stationary part 160 and the movable part 162 of the welding head 104 by means of a positive and / or non-positive locking mechanism, particularly in the axial direction and more preferably also in the azimuthal direction. Furthermore, this fixing preferably also aligns the pipe end 154 and the fitting 152, and most preferably centers the pipe end 154 in the fitting 152.

[0149] In Fig. 5a, the contours 200, 202 that fix the fitting 152 and the pipe end 154 are shown schematically with dashed lines. The fixing is achieved, in particular, such that the joining area 150 is located in the area of ​​the welding electrode 126. The welding electrode 126 is directed obliquely inwards, in particular at an angle to the radial direction in the range of 5–45°, for example 45°, and can also be directed obliquely in the circumferential direction, i.e., in the welding direction, for example at an angle in the range of 0–15° to the radial direction. In the arrangement shown in Fig. 5a, the tip of the welding electrode 126 points towards the overlap joint. The contours 200, 202 can, in particular, at least partially form one or more contacting elements 178 to electrically connect the fitting 152 and the pipe end 154 to an output of the welding power source 128.

[0150] The contours 200 are specifically adapted to the outer contour of the fitting. The contours 200, 202 that fix the fitting 152 and the pipe end 154 can be designed, in particular, to clamp the fitting 152 and the pipe end 154, especially to hold them in a force-fit position. Such fixation of the fitting 152 and / or the pipe end 154 ensures reliable electrical contact between the fitting 152 and the pipe end 154.

[0151] The orbital welding device 100 with the welding head 104 and the fitting 152 form a system 700.

[0152] In the closed position of the welding head 104, the joining area 150 is preferably completely enclosed in the circumferential direction, so that the shielding gas supplied during the orbital welding process is kept in the joining area 150 and the environment, in particular the user, is protected from welding fumes and UV light generated during the orbital welding process.

[0153] After adjusting the welding head 104 to the closed position, the user can trigger the start of the orbital welding process, for example, by pressing the torch trigger 138. The control unit 130 controls the electrode drive 124 and the welding power source 128 such that the welding electrode 126 creates a chain of weld points 210 in the circumferential direction, which connect the fitting 152 and the pipe end 154 by means of a material bond. Figures 5a-b schematically show the creation of a weld point 210. To create a first weld point 210, the welding power source 118 first generates a high-voltage pulse, which causes a contactless ignition of an arc between the welding electrode 126 and the fitting 152 or pipe end 154. The welding power source 118 then regulates the welding current according to a welding current characteristic curve, which in particular includes a sequence of high current phases and low current phases.During the high-current phases, the heat input caused by the arc leads to the formation of a molten pool (also called a weld pool) at the overlap joint of fitting 152 and pipe end 154. This pool solidifies at least partially during the low-current phase, forming a joining point 210. To ensure that the next joining point is offset circumferentially from the previous joining point, the control unit 130 activates the electrode drive 124, which moves the welding electrode 126 circumferentially. During the next high-current phase, the welding power source 118 melts a new weld pool for the adjacent joining point, which preferably overlaps the first joining point. A new ignition is not required for the second and subsequent joining points, as the arc preferably burns continuously until the last joining point.

[0154] In this way, the chain of joining points 210 is gradually created, by which fitting 152 and pipe end 154 are preferably fluid-tightly connected to each other at the overlap joint. Figures 6a-b show the creation of the joining points 210 in schematic sectional views corresponding to the section plane labeled "Via" in Figure 5a, where Figure 6a shows a point in time during the ongoing orbital welding process and Figure 6b shows a point in time after completion of the orbital welding process. Figure 6c shows a perspective view of the finished joint (weld) of fitting 152 and pipe end 154.

[0155] After the weld has been completed, the welding power source 128 reduces the welding current to zero, extinguishing the arc. By actuating the adjustment mechanism 122, the user can then return the welding head 104 to the open position and remove the welding head 104 laterally from the now materially bonded fitting 152 and pipe end 154.

[0156] Fig. 7 shows another embodiment of the orbital welding device. The orbital welding device 101 has a similar structure and function to the orbital welding device 100. Functionally corresponding components are therefore provided with the same reference numerals, even if they may be arranged or designed differently in some respects, and reference is made to the above description of Figs. 1-6c and the following description of Figs. 8a-e.

[0157] The orbital welding device 101 differs from the orbital welding device 100 in that some components, namely the shielding gas cylinder 142 and the accumulator 140 in Fig. 7, are designed separately from the handheld device and connected to it by corresponding gas and electrical lines. This allows the handheld device to be designed more compactly and lighter.

[0158] Furthermore, larger inert gas cylinders 142 and accumulators 140 can be used in this way. The inert gas cylinder 142 and the accumulator 140 can, for example, be arranged in a separate case or backpack.

[0159] Instead of a battery, a mains connection can also be provided to supply power to the handheld device 102 and the welding power source 128. This allows for longer operation, albeit with less flexibility in handling.

[0160] Figures 8a-e show more detailed views of the welding head 104 of the orbital welding device 100 from Fig. 1 and of the orbital welding device 101 from Fig. 7, respectively. Fig. 8a shows the welding head 104 in perspective view, with the outer components partially transparent and indicated by dashed lines. Figures 8b-d show perspective views of the electrode circulation mechanism 172 and the adjustment mechanism 170, specifically in the open (Fig. 8b) and closed positions of the welding head (Figs. 8c-d), as well as in the starting position (Figs. 8b-c) and the rotated position of the electrode circulation mechanism 172 (Fig. 8d). In Figures 8c-d, the joining area 150 of the fitting 152 and the pipe end 154 is also shown inserted into the receptacle 106. Fig. 8e shows the welding head 104 with the joining area 150 of fitting 152 and pipe end 154 arranged in the receptacle 106 in a sectional view.

[0161] The welding head 104 has the receptacle 106 for positioning a joining area 150 of two joining partners that are at least tubular in the joining area 150, namely the fitting 152 and a pipe end 154.

[0162] The electrode recirculation mechanism 172 of the welding head 104 comprises a C-shaped electrode ring segment 302, which is arranged circumferentially around the receptacle 106 and is mounted in the welding head 104 such that it can be rotated endlessly about an imaginary longitudinal axis A of the receptacle 106, i.e., through any angle. The electrode ring segment 302 has a circumferential ring segment opening 304, the size of which is adapted to the insertion opening 164 and which, in the open position (see Fig. 8a&b), is arranged such that it forms part of the insertion opening 164.

[0163] The electrode ring segment 302 has an electrode holder 306 for the welding electrode 126, which can be inserted into or is inserted into the electrode holder 306. When the welding electrode 126 is worn, it can be removed from the electrode holder 306 and a new welding electrode can be inserted.

[0164] The electrode ring segment 302 is designed as a bevel gear segment and accordingly has a bevel gear toothing 308 on one side. The electrode recirculation mechanism 172 further comprises several, in this case two, drive gears 310, 312 in the form of drive bevel gears arranged circumferentially around the receptacle and driven by the electrode drive 124. These drive gears engage with the bevel gear toothing 308 of the electrode ring segment 302, enabling the electrode ring segment 302 to move the welding electrode 126 circumferentially around the receptacle 106. The electrode ring segment 302 is also electrically connected, or connectable, to the welding power source 128.

[0165] The welding head 104 further comprises several C-shaped closure ring segments 402, 403, 404, 405, each of which is arranged circumferentially around the receptacle 106 and is mounted in the welding head 104 in such a way that it is rotatable about the longitudinal axis A of the receptacle (see Fig. 8c&d).

[0166] The locking ring segments 402, 403, 404, 405 are arranged in pairs next to each other, namely two locking ring segments 402, 403 in the area of ​​the first opening 166 and two locking ring segments 404, 405 in the area of ​​the second opening 168.

[0167] The closure ring segments 402, 403, 404, 405 each have a ring segment opening 406 in the circumferential direction, the size of which is adapted to the insertion opening 164.

[0168] The locking ring segments 402 - 405 can each be adjusted between an open rotation position (see Fig. 8b) and a closed rotation position (see Fig. 8c&d), whereby the direction of rotation from the open rotation position to the closed rotation position of the locking ring segments 402 and 403 or 404 and 405 arranged directly next to each other is opposite.

[0169] To adjust the locking ring segments 402-405 from the open rotary position to the closed rotary position, the orbital welding device 100 has an actuating element 410 in the form of a handle sleeve, with which the locking ring segments 402-405 can be adjusted synchronously from the open rotary position to the closed rotary position and vice versa. Instead of a handle sleeve, a lever, for example, can also be used as the actuating element 410.

[0170] In the open position (see Fig. 8a&b) the locking ring segments 402 - 405 are positioned in the respective open rotational position, in which the respective ring segment opening 406 of the locking ring segments 402 - 405 is positioned such that it forms part of the insertion opening 164.

[0171] In the closed position (see Fig. 8c&d) the locking ring segments 402 - 405 are positioned in their respective closed rotational positions, in which the locking ring segments 402 - 405 are each positioned such that they partially close the insertion opening 164.

[0172] In order to close the insertion opening 164 as completely as possible in the closed position, the welding head 104 has an upper cover 440 and a lower cover 442, each of which is connected in a rotationally fixed manner to two locking ring segments 402 and 405 (upper locking ring segments) and 403 and 404 (lower locking ring segments) rotating in the same direction, so that the covers 440, 442 release the insertion opening 164 in the open position of the welding head 104 and close it in the closed position of the welding head 104.

[0173] Fig. 8e shows the welding head 104 with the joining area 150 of the pipe end 154 arranged in the receptacle 106 and the fitting 152 pushed on, in a sectional view. Fitting 152 has an outer contour 714 and welding head 104 has a corresponding fitting fixing contour 750 to fix fitting 152 in a predetermined fitting position when welding head 104 is closed, so that fitting opening 710 assumes a predetermined position relative to welding electrode 126, in particular a predetermined distance from the tip of welding electrode 126. The fitting fixing contour 750 corresponds to contour 202 schematically indicated in Fig. 5a. Preferably, the welding electrode 126 maintains the predetermined distance or distance range to fitting opening 710 in every rotational position of the welding electrode 126, so that the orbital welding process can be carried out with a very small distance between welding electrode 126 and fitting opening 710.

[0174] The locking ring segments 402-405 are preferably designed to clamp the fitting 152 and the pipe end 154 in the specified position. For this purpose, the locking ring segments 402-405 can, for example, be slightly spring-loaded, for instance by being made of a spring-loaded material and / or by being spring-mounted. In this way, reliable electrical contact between the fitting 152 and the pipe end 154 is also achieved by the locking ring segments 402-405.

[0175] Figures 9a-b show an embodiment of the fitting and an embodiment of the system. Figure 9a shows a perspective view of the fitting 702 and a pipe end 704 inserted into the fitting 702. The fitting 702 is accordingly a push-fit fitting. The fitting 702 is identical to the fitting 152 from Figures 5a and 8e. Figure 9b shows a sectional view of the joining area of ​​the fitting 702 and the pipe end 704 arranged in the receptacle 106 of the welding head 104, with the contours of components of the welding head 104 shown as dashed lines in Figure 9b. Figure 9b is a schematic representation of Figure 8e, where the fitting 702 corresponds to the fitting 152 and the pipe end 704 to the pipe end 154.

[0176] The fitting 702 has a fitting body 706 which has a tubular joining area 708 with a fitting opening 710 for inserting the pipe end 704.

[0177] In the present embodiment, the fitting 702 is designed as a double fitting, also referred to as a socket, and the fitting body 706 accordingly has a further tubular joining area 709 with a further fitting opening 711 for inserting another pipe end. In the present embodiment, the fitting 702 has a mirror-symmetrical design.

[0178] Alternatively, fitting 702 could also be designed as a tee, elbow, or as part of another component, for example, a system part to be connected to pipe end 704. Furthermore, fitting 702 could also be designed as a double fitting without a mirror-symmetrical design, for example, as a reducing fitting for coupling pipe ends of different nominal diameters.

[0179] The fitting body 706 has an outer contour 714, which extends on the outside of the fitting 702 from the fitting opening 710. Furthermore, the fitting body 706 has an inner contour 715, which extends on the inside of the fitting 702 from the fitting opening 710.

[0180] On the outer contour 714 of the fitting body 706, a first contour element 720 in the form of a radially outwardly projecting bead and a second contour element 722 in the form of a radially inwardly recessed groove are arranged. The first contour element 720 forms an axial contour 724 for the positive locking of the fitting body 706 in the longitudinal direction. The second contour element 722 forms an azimuthal contour 726 for the positive locking of the fitting body 706 in the circumferential direction. The groove base 728 of the azimuthal contour 726 has a polygonal contour with a plurality, in this embodiment ten, of surfaces 730 distributed in the circumferential direction.

[0181] The azimuthal contour 726 is dimensioned such that the outer diameter DA on two opposing surfaces 730 corresponds to the inner diameter Di of the fitting opening. In this way, the azimuthal contour 726 simultaneously forms a clamping area 727 of the fitting 702.

[0182] At the fitting opening 710, the fitting body 706 forms a weld edge 732 with a shoulder 734, which has a reduced wall thickness compared to the wall thickness of the adjacent area of ​​the fitting body 706. The shoulder 734 is formed by a step 735 on the outer contour 714.

[0183] The distance d s The distance from the fitting opening 710 or welding edge 732 to the axial contour 724 is in the range of 4 - 6 mm.

[0184] The inner contour 715 comprises an inwardly projecting insertion limiting element 740 formed by the fitting body 706, with a stop edge 742 for limiting the insertion depth d e of the pipe end 704 into the pipe. The insertion depth d e preferably at least 0.8 • Di, preferably at least 1.3 • Di.

[0185] Furthermore, the inner contour 715 includes a groove 744 in which a clamping element 746 in the form of a clamping ring is arranged for axially fixing and centering the tube end 704. The groove 744 is formed in this case by the outwardly projecting first contour element 720.

[0186] The clamping ring 746 is C-shaped in the circumferential direction for easier installation in the groove 744 and has a plurality of elastic spring elements 747 arranged circumferentially, directed inwards and away from the fitting opening 710. When the pipe end 704 is inserted, the spring elements 747 are slightly pressed outwards, thereby centering the pipe end 704 in the fitting opening 710 and providing a certain degree of force-fit axial fixation of the pipe end 704 against being pulled out of the fitting opening 710.

[0187] The distance dk from the fitting opening 710 or welding edge 732 to the clamping ring 746 is in the range of 4 - 7 mm.

[0188] Fig. 9b shows the fitting 702 pushed onto the pipe end 704 in the receptacle 106 of the welding head 104, with the contours of the welding head 104 indicated by dashed lines. The area of ​​the pipe end 704 at the fitting opening 710 represents the joining area 705 of the pipe end 704. The joining area 708 of the fitting 702 and the joining area 705 of the pipe end 704 together form the joining area 707 of the two joining partners, fitting 702 and pipe end 704.

[0189] The welding head 104 has a fitting fixing contour 750 corresponding to the outer contour 714 of the fitting 702. The fitting fixing contour 750 is formed by the fixed part 160 of the welding head 104 and partly also by the movable part 162 of the welding head 104, in particular by the locking ring segments 402, 403.

[0190] The fitting fixing contour 750 comprises on the fixed part 160 of the welding head 104 a groove-shaped axial fixing contour 752 corresponding to the axial contour 724 for receiving the first bead-shaped contour element 720 and a bead-shaped azimuthal fixing contour 754 corresponding to the azimuthal contour 726 for engaging in the groove-shaped second contour element 722 and with internally multi-edged fixing surfaces 756 for contact with the externally multi-edged surfaces 730.

[0191] Furthermore, the fitting fixing contour 750 on the movable part 162 of the welding head for receiving 106 includes fitting contact surfaces 758 on the closure ring segments 402 and 403. The closure ring segments 402, 403 thus represent movable fixing elements that form part of the fitting fixing contour 750.

[0192] The welding head 104 also has a pipe fixing contour 760, which is formed by the stationary part 160 of the welding head 104 and partially by the movable part 162 of the welding head 104, in particular by the locking ring segments 404, 405. The pipe fixing contour 760 comprises, on the stationary part 160 of the welding head 104, a first pipe contact contour 762 adapted to the outer diameter of the pipe end 704, and, on the movable part 162 of the welding head, pipe contact surfaces 764 on the locking ring segments 404 and 405 directed towards receiving 106. The locking ring segments 404, 405 thus constitute movable fixing elements that form part of the pipe fixing contour 760. The pipe installation contour 762 and pipe installation surfaces 764 form a pipe clamping contour 765.

[0193] The azimuthal fixing contour 754 with the associated fitting contact surface 758 of the opposing closure ring segments 402 and 403 constitute a fitting clamping contour 755 that interacts with the clamping area 727 of the fitting 702. Since the outer cross-sections of the clamping area 727 and the pipe end 704, and correspondingly the inner cross-sections of the fitting clamping contour 755 and the pipe clamping contour 765, are essentially identical in the closed position, the fitting 702 and the pipe end 704 can be fixed essentially symmetrically and without significant lateral forces when adjusted to the closed position.

[0194] To carry out a welding process in the joining area 707 of fitting 702 and pipe end 704, the pipe end 704 with the attached fitting 702 is arranged in the open position of the welding head 104 through the insertion opening in the receptacle 106, such that the axial contour 724 is arranged substantially in the area of ​​the axial fixing contour 752 and the azimuthal contour 726 is substantially aligned with the azimuthal fixing contour 754.

[0195] The welding head 104 is then moved from the open position to the closed position, whereby the locking ring segments 402-405 with the fitting contact surfaces 758 and the pipe contact surfaces 764, when moved from the open to the closed rotary position, further shift the fitting 702 and the pipe end 704 towards the fitting fixing contour 750 and pipe fixing contour 760, respectively, so that the axial contour 724 is in contact with the axial fixing contour 752 and the azimuthal fixing contour 754 is in contact with the azimuthal contour 726 such that the fitting 702 is held in the axial and azimuthal fitting position defined by the axial fixing contour 752 and the azimuthal fixing contour 754, with the fitting contact surfaces 758 acting as counter bearings to hold the fitting 702 in its defined fitting position relative to the axial fixing contour. Hold 752 and azimuthal fixation contour 754.Furthermore, the pipe end 704 is held in a form-fitting manner in a centered orientation to the fitting 702 by the simultaneous application of pipe fixing contour 760 and pipe contact surfaces 764 to the outer contour 703 of the pipe end 704, and optionally held in a force-fit manner in an axial pipe position to the fitting 702.

[0196] In this way, fitting 702 and pipe end 704 can be fixed in a predetermined fitting and pipe position in the welding head 104, thus enabling a precise orbital welding process. The fitting fixing contour 750 of the welding head 104 is therefore designed to engage with the axial contour 724 and the azimuthal contour 726 of the fitting 702 when the welding head 104 is in the closed position and the joining area 708 of the fitting 702 is arranged in a predetermined fitting position in the receptacle 106, such that the joining area 708 of the fitting 702 is positively locked in the predetermined fitting position.

[0197] In particular, the axial contour 724 with respect to the welding edge 732 and the fitting fixing contour 750 with respect to the welding electrode 126 are adapted such that the tip of the welding electrode 126 maintains a radial distance Sr to the outer surface of the pipe end 704 in the range of 0.3 - 1.5 mm, preferably 0.4 - 1.4 mm, more preferably 0.5 - 1.3 mm, in particular 0.60 - 0.80 mm, and an axial distance Sa to the welding edge 732 in the range of 0.15 - 1.2 mm, preferably 0.25 - 1.1 mm, more preferably 0.35 - 1.0 mm, in particular 0.40 - 0.70 mm, in every rotational position of the electrode ring segment 302.

[0198] In this way, precise electrode guidance is possible during the welding process, which allows for better optimization of the welding process in order to reduce the heating of the inner surface of a pipe end to be joined and thus the susceptibility to discoloration and oxidation on the inside of the pipe.

[0199] The orbital welding device 100 and the fitting 702 (or the identical fitting 152) form a system 700.

[0200] Figures 10a-b show a further embodiment of the fitting, the orbital welding device, and the system. Figure 10a shows a perspective view of the fitting 802 and a pipe end 804 inserted into the fitting 802. Like the fitting 702, the fitting 802 is a push-fit fitting. Figure 10b shows a sectional view of the joining area of ​​the fitting 802 and the pipe end 804, arranged in the receptacle 106 of the welding head 806. The contours of components of the welding head 806 are shown as dashed lines in Figure 10b.

[0201] The orbital welding device 801 has essentially the same design and function as the orbital welding device 100, so reference is made to the description of the orbital welding device 100 above. The orbital welding device 801 differs from the orbital welding device 100 only in that the geometry of some components of the welding head 806 is adapted to the fitting 802. Where no separate reference numerals are given for the components of the welding head 806 in Fig. 10b, these are provided with the reference numerals of the corresponding components of the orbital welding device 100.

[0202] The orbital welding device 801 and the fitting 802 thus form a system 800.

[0203] Fitting 802 has a similar structure to fitting 702. Corresponding components are provided with the same reference numerals, and reference is made to the description in Figs. 9a-b. Fitting 802 differs from fitting 702 in that, instead of a first contour element 720 for the axial contour 724 and a separate second contour element 722 for the azimuthal contour 726, a contour element 810 is provided, which forms both the axial contour 724 and the azimuthal contour 726. The contour element 810 is formed in the form of an outwardly projecting bead with inclined side surfaces 812, 813 and several surfaces 814, in this embodiment ten, distributed circumferentially, which form a polygonal contour 815.

[0204] Accordingly, the fitting fixing contour 750 of the welding head 806 has a groove 820 corresponding to the contour element 810, which forms both the axial fixing contour 752 and the azimuthal fixing contour 754. In particular, the axial fixing contour 752 comprises side surfaces 822, 823 of the groove 820 corresponding to the side surfaces 812, 813; and the azimuthal fixing contour 754 comprises counter surfaces 824 corresponding to the surfaces 814, which form the (internally) multi-sided groove base 826 of the groove 820.

[0205] By forming the axial contour 724 and azimuthal contour 726 with a contour element 810, the welding head 806 can be designed to be more compact in the longitudinal direction than the welding head 104.

[0206] Figures 11a-b show a further embodiment of the fitting, the orbital welding device, and the system. Figure 11a shows a perspective view of the fitting 902 and a pipe end 904 pushed onto the fitting 902. The fitting 902 is accordingly a push-fit fitting. Figure 11b shows a sectional view of the joining area of ​​the fitting 902 and the pipe end 904 arranged in the receptacle 106 of the welding head 906, with the contours of components of the welding head 906 shown as dashed lines in Figure 11b. The orbital welding device 901 has essentially the same structure and function as the orbital welding device 100, so reference is made to the above description of the orbital welding device 100 in this regard.The orbital welding device 901 differs from the orbital welding device 100 only in that the geometry of some components of the welding head 906 is adapted to the fitting 902. Where no separate reference numerals are given for the components of the welding head 906 in Fig. 11b, these are provided with the reference numerals of the corresponding components of the orbital welding device 100.

[0207] The orbital welding device 901 and the fitting 902 thus form a system 900.

[0208] Fitting 902 has a fitting body 903 with a tubular joining area 908 and an insertion section 912 extending from a fitting opening 910 for insertion into a pipe end, such as the pipe end 904, and a connecting section 914 adjoining the insertion section. Fitting 902 is designed as a double fitting with a mirror-symmetrical structure. Alternatively, fitting 902 could also be designed, for example, as a tee, elbow, part of another component, or reducing fitting.

[0209] The fitting body 903 has an outer contour 916 extending from the fitting opening 910. Furthermore, the fitting body 903 has an inner contour 918 extending from the fitting opening 910. The inner contour 918 is cylindrical.

[0210] In the area of ​​the insertion section 912, a groove 920 is provided on the outer contour 916 of the fitting body 903, in which a clamping element 922 in the form of a clamping ring is provided for axially fixing and / or centering a pipe end, such as the pipe end 904, to the fitting 902. For easier assembly in the groove 920, the clamping ring 922 is C-shaped and has a plurality of elastic spring elements 923 arranged circumferentially and directed outwards and away from the fitting opening 910. The spring elements 923 are pressed slightly inwards when the insertion section 912 is inserted into the pipe end 904, thereby centering the insertion section 912 in the pipe end 904 and providing a certain force-fit axial fixation of the fitting 902 in the pipe end 904 against the fitting 902 being pulled out of the pipe end 904.

[0211] At the transition from the insertion section 912 to the joining section 914, the outer contour 916 has a radial widening 930 with a stop edge 932 directed towards the insertion section 912 to stop a pipe end, such as the pipe end 904. The distance dk between the clamping element 922 and the stop edge 932 is preferably in the range of 4–7 mm.

[0212] A contour element 934 is further arranged on the outer contour 916, spaced apart from the insertion section 912 or the stop edge 932. The contour element 934 is designed in the form of a radially outwardly projecting bead with two side surfaces 936, 937, which form an axial contour 938, and a plurality, in the present embodiment ten, of circumferentially polygonal surfaces 940, which form an azimuthal contour 942. The distance d s The distance between stop edge 932 and contour element 934 or axial contour 938 is preferably in the range of 4 - 6 mm.

[0213] Fig. 11b shows a cross-sectional view of the fitting 902 inserted into the pipe end 904. The area of ​​the pipe end 904 at the pipe opening 909, which is in contact with the stop edge 932, represents the joining area 905 of the pipe end 904. The joining area 908 of the fitting 902 and the joining area 905 of the pipe end 904 together form the joining area 907 of the two joining partners, fitting 902 and pipe end 904.

[0214] The fitting fixing contour 750 of the welding head 906 has a

[0215] Contour element 934 corresponding groove 944, the side surfaces 946, 947 of which form the axial fixing contour 752 and the groove base 950 of which is formed by several polygonal opposite surfaces 948, forms the azimuthal fixing contour 754.

[0216] The radial expansion 930 is adapted to a predetermined wall thickness of a pipe end with a corresponding outer diameter, such as the wall thickness of the pipe end 904, so that the joining section 914 and the outer surface of the pipe end 904, which is pushed up to the stop edge 932, lie against each other in a substantially stepless manner. This results in a butt-joint geometry. The welding electrode 126 is accordingly directed radially inwards with respect to the longitudinal axis into the receptacle 106 and thus substantially perpendicular to the butt joint of the pipe end 904 and the joining section 914.

[0217] The axial contour 938 is adapted with respect to the stop edge 932 and the fitting fixing contour 750 is adapted with respect to the welding electrode 126 such that the tip of the welding electrode 126 maintains a radial distance Sr to the pipe end 904 or to the joining section 914 in the range of 0.3 - 1.5 mm, preferably 0.4 - 1.4 mm, in particular 0.40 - 0.80 mm, in every rotational position of the electrode ring segment 302.

[0218] Before inserting the fitting 902, the pipe end 904 was expanded with a tool so that the inner diameter of the pipe end 904 corresponds to the inner diameter of the fitting 902. In this way, pressure losses or turbulence of a medium flowing through the pipe end 904 and fitting 902 due to a reduction in cross-section are avoided.

[0219] To facilitate the insertion of the fitting 902 into the pipe end 904, the fitting body 903 has an inclined external chamfer 952 at the fitting opening 910.

[0220] Figures 12a-b show a further embodiment of the fitting, the orbital welding device, and the system. Figure 12a shows a perspective view of the fitting 1002 and a pipe end 1004 pushed onto the fitting 1002. Like the fitting 902, the fitting 1002 is a push-fit fitting. Figure 12b shows a sectional view of the joining area of ​​the fitting 1002 and the pipe end 1004, arranged in the receptacle 106 of the welding head 1006. The contours of components of the welding head 1006 are shown as dashed lines in Figure 12b.

[0221] The orbital welding device 1001 has essentially the same design and function as the orbital welding device 100, so reference is made to the description of the orbital welding device 100 above. The orbital welding device 1001 differs from the orbital welding device 100 only in that the geometry of some components of the welding head 1006 is adapted to the fitting 1002. Where no separate reference numerals are given for the components of the welding head 1006 in Fig. 12b, these are provided with the reference numerals of the corresponding components of the orbital welding device 100.

[0222] The orbital welding device 1001 and the fitting 1002 thus form a system 1000.

[0223] Fitting 1002 has a similar structure to fitting 902. Corresponding components are provided with the same reference numerals, and reference is made to the description in Fig. 11a-b.

[0224] Fitting 1002 differs from fitting 902 in that the contour element 934 forms only an axial contour 938. An azimuthal fixation of fitting 1002 in the welding head 1006 can be achieved, for example, by means of a force-fit connection between the opposing parts of the fitting fixation contour 750 on the fixed part 160 and the movable part 162 of the welding head 1006, by means of which these, in particular the locking ring segments 402, 403, exert a radial force on fitting 1002 in the closed position of the welding head 1006. Furthermore, fitting 1002 differs from fitting 902 in that the radial expansion 930 is less than a predetermined wall thickness of a pipe end with a corresponding outer diameter, such as the wall thickness of the pipe end 1004, resulting in a lap joint-like geometry.The welding electrode 126 is accordingly oriented obliquely inwards with respect to the longitudinal direction towards the pipe end towards the lap joint, so that when the fitting 1002 is inserted into the receptacle 106 with the pipe end 1004 pushed onto it, the welding electrode 126 points towards the lap joint, in particular essentially towards the base of the lap joint.

[0225] In particular, the axial contour 938 with respect to the stop edge 932 and the fitting fixing contour 750 with respect to the welding electrode 126 are adapted such that the tip of the welding electrode 126 maintains a radial distance Sr to the outer surface of the pipe end 1004 in the range of 0.3 - 1.5 mm, preferably 0.4 - 1.4 mm, more preferably 0.5 - 1.3 mm, in particular 0.60 - 0.80 mm, and an axial distance Sa to the stop edge 932 in the range of 0.15 - 1.2 mm, preferably 0.25 - 1.1 mm, more preferably 0.35 - 1.0 mm, in particular 0.40 - 0.70 mm, in every rotational position of the electrode ring segment 302.

[0226] Figures 13a-b show cross-sections of outwardly projecting contour elements 1102, 1202 on the outer contour 1110, 1210 of a fitting in a section plane corresponding to Figure 9b or 10b. For example, the contour element 720 from Figure 9b, the contour element 810 from Figure 10a, or the contour element 934 from Figure 11a or Figure 12a could be designed with a cross-section like the contour element 1102 or 1202.

[0227] The contour elements 1102 and 1202 have slanted side surfaces 1104, 1106 and 1204, 1206 respectively on both sides.

[0228] The contour element 1102 further points to the respective transition to the one in

[0229] Adjacent to the longitudinally oriented part 1111 of the outer contour, i.e., at the base 1108 of the contour element, a surface 1109 in the form of an edge is formed, oriented perpendicular to the longitudinal direction. The surface 1109 serves as a stop for a corresponding counter-surface of the fitting fixing contour, in order to align the fitting fixing contour and the contour element 1102 very precisely with each other.

[0230] The radius of curvature Ri at the transition from part 1111 to surface 1109 and the radius of curvature R2 at the transition from part 1211 to the inclined side surface 1204 are preferably each less than 0.3 mm, and more preferably less than 0.2 mm. In this way, the respective distance between the fitting opening and the base 1108 or 1208 of the contour element 1102 or 1202 can be defined more precisely, so that the fitting opening in the welding head can be aligned even more accurately with the welding electrode.

[0231] The respective radius of curvature Ri, R2 can be made correspondingly small on the side of the contour element 1102, 1202 facing the fitting opening and / or on the side of the contour element 1102, 1202 facing away from the fitting opening.

[0232] The small radii of curvature Ri and R2 can be produced in particular by one- or two-sided post-processing of the contour elements 1102, 1202 in the area of ​​their base 1108, 1208, in particular by rolling using a rolling tool 1302 or by machining using a machining tool 1304, as indicated in Fig. 13a-b with dashed contours.

[0233] Reference symbol list:

[0234] 100, 101, 801, 901, 1001 Orbital welding device

[0235] 102 Handheld device

[0236] 104, 806, 906, 1006 Welding head

[0237] 106 recording

[0238] 108 Handle part

[0239] 110 Shaft 112 Handle

[0240] 114 Connection for a battery unit

[0241] 115 Connection for a shielding gas magazine

[0242] 116 Accumulator unit

[0243] 118 Welding power source

[0244] 120 shielding gas magazine

[0245] 122 Adjustment actuation

[0246] 124 Electrode drive

[0247] 126 Welding electrode

[0248] 128 Welding power source

[0249] 130 Control unit

[0250] 132 Valve

[0251] 134 User interface

[0252] 136 Display and Control Elements

[0253] 138 burner buttons

[0254] 140 accumulator

[0255] 142 protective gas cylinders

[0256] 150 joining area

[0257] 152, 702, 802, 902, 1002 fitting

[0258] 154, 704, 804, 904, 1004 Pipe end

[0259] 160 fixed part of the welding head

[0260] 162 moving part of the welding head

[0261] 164 Insertion opening

[0262] 166 first opening

[0263] 168 second opening

[0264] 170 Adjustment mechanism

[0265] 172 Electrode circulation mechanism

[0266] 174, 176 outputs of the welding power source

[0267] 178 contact elements

[0268] 180 axis

[0269] 182 Microprocessor 184 Memory

[0270] 186 entrances

[0271] 190 electronic circuit

[0272] 192 Welding current control

[0273] 194 HV ignition

[0274] 200, 202 contours

[0275] 210 Joining point

[0276] 302 Electrode ring segment

[0277] 304 Ring segment opening

[0278] 306 bracket

[0279] 308 Bevel gear teeth

[0280] 310, 312 Drive wheel 2, 403, 404, 405 Locking ring segments

[0281] 406 Ring segment opening

[0282] 410 Actuating element

[0283] 440 top cover

[0284] 442 lower cover, 800, 900, 1000 system

[0285] 703 Outer contour of the pipe end

[0286] 705 Joining area of ​​the pipe end

[0287] 706 Fitting bodies

[0288] 707 Joining area of ​​the joining partners

[0289] 708, 709 Fitting joint area

[0290] 710, 711 Fitting opening

[0291] 714 Outer contour

[0292] 715 Inner contour

[0293] 720 first contour element

[0294] 722 second contour element

[0295] 724 Axial contour

[0296] 726 Azimuthal contour

[0297] 727 Clamping area 728 Groove base

[0298] 730 areas

[0299] 732 Weld edge

[0300] Paragraph 734

[0301] 735 level

[0302] 740 Insertion limiting element

[0303] 742 Stop edge

[0304] 744 Groove for the clamping element

[0305] 746 clamping element

[0306] 747 spring elements

[0307] 750 Fitting fixing contour

[0308] 752 Axial fixation contour

[0309] 754 Azimuthal fixation contour

[0310] 755 Fitting clamping contour

[0311] 756 fixing surfaces

[0312] 758 fitting system surfaces

[0313] 760 Pipe fixing contour

[0314] 762 Pipe system contour

[0315] 764 pipe installation areas

[0316] 765 Pipe clamping contour

[0317] 810 Contour element, 813 Side surfaces

[0318] 814 areas

[0319] 815 Polygonal contour

[0320] 820 Nut

[0321] 822 side surfaces

[0322] 824 opposite surfaces

[0323] 826 Groove

[0324] 903 Fitting body

[0325] 905 Joining area of ​​the pipe end

[0326] 907 Joining area of ​​the joining partners 909 Pipe opening

[0327] 908 Joining area

[0328] 910 Fitting opening

[0329] 912 Introductory section

[0330] 914 Joining section

[0331] 916 Outer contour

[0332] 918 Inner contour

[0333] 920 groove for the clamping element

[0334] 922 clamping element

[0335] 923 Spring element

[0336] 930 widening

[0337] 932 Stop edge

[0338] 934 Contour element

[0339] 936, 937 side surfaces

[0340] 938 Axial contour

[0341] 940 areas

[0342] 942 Azimuthal contour

[0343] 944 Nut

[0344] 946 side surfaces

[0345] 948 opposite surfaces

[0346] 950 Groove

[0347] 952 Outer chamfer

[0348] 1102, 1202 Contour elements

[0349] 1104, 1106, 1204, 1206 sloping side surfaces

[0350] 1108, 1208 feet of the contour element

[0351] 1109 vertical surface

[0352] 1110. 1210 Outer contour

[0353] 1111. 1211 adjacent part of the outer contour

[0354] 1302 Rolling tool

[0355] 1304 Cutting tool

Claims

Patent claims 1. Fitting (152, 702, 802), in particular a push-on fitting, for permanently connecting to a pipe end (154, 704, 804, 904, 1004) of a pipeline by means of orbital welding, with a fitting body (706) which has a tubular joining area (708, 709) with a fitting opening (710, 711) for inserting a pipe end (154, 704, 804, 904, 1004), wherein the fitting body (706) has an outer contour (714) extending from the fitting opening (710, 711), characterized in that the outer contour (714) has an axial contour (724) spaced apart from the fitting opening (710, 711) for positive locking fixation of the fitting body (706) in the longitudinal direction.

2. Fitting according to claim 1, characterized in that the fitting body (706) forms a weld edge (732) in the area of ​​the fitting opening (710, 711), wherein the weld edge (732) preferably has a shoulder (734) with a wall thickness reduced compared to the wall thickness of an adjacent area of ​​the fitting body (706).

3. Fitting according to claim 1 or 2, characterized in that the fitting body (706) has an inner contour (715) extending from the fitting opening (710, 711) and that the inner contour (715) comprises an inwardly projecting insertion limiting element (740) for limiting the insertion depth of a pipe end (154, 704, 804, 904, 1004) through the fitting opening (710, 711) into the fitting (152, 702, 802).

4. Fitting according to one of claims 1 to 3, characterized in that the fitting body (706) has an inner contour (715) extending from the fitting opening (710, 711) and that a clamping element (746) for axially fixing and / or centering a pipe end (154, 704, 804, 904, 1004) is provided on the inner contour (715) of the fitting body (706), preferably in a groove (744) provided in the fitting body (706).

5. Fitting according to one of claims 1 to 4, characterized in that the distance (d s ) the distance (dk) of the fitting opening (710, 711) to the axial contour (724) is in the range of 3 - 7 mm, preferably 4 - 6 mm, and / or that the distance (dk) of the fitting opening (710, 711) to the clamping element (746) is 8 mm or less, preferably 7 mm or less.

6. Fitting (902, 1002), in particular a push-fit fitting, for permanently connecting to a pipe end (154, 704, 804, 904, 1004) of a pipeline by means of orbital welding, with a fitting body (903) having a tubular joining area (908), wherein the tubular joining area (908) has an insertion section (912) extending from a fitting opening (910) for insertion into a pipe end (154, 704, 804, 904, 1004) and an adjoining joining section (914), wherein the fitting body (903) has an outer contour (916) extending from the fitting opening (910), characterized in that the outer contour (916) has an axial contour (938) spaced apart from the insertion section (912). for the form-fitting fixation of the fitting body (903) in the longitudinal direction.

7. Fitting according to claim 6, characterized in that the outer contour (916) at the transition from the insertion section (912) to the joining section (914) has a widening (930) with a stop edge (932) directed towards the insertion section (912) for stopping a pipe end (154, 704, 804, 904, 1004), wherein in the area of ​​the stop edge (932) a step with a wall thickness increased compared to the wall thickness of the adjacent area of ​​the fitting body is preferably provided.

8. Fitting according to claim 6 or 7, characterized in that a clamping element (922) for axially fixing and / or centering the fitting (902, 1002) in a pipe end (154, 704, 804, 904, 1004) is provided on the outer contour (916) of the fitting body (903), preferably in a groove (910) provided in the fitting body (903).

9. Fitting according to one of claims 6 to 8, characterized in that the distance (d s) the stop edge (932) to the axial contour (938) is in the range of 3 - 7 mm, preferably 4 - 6 mm and / or that the distance (dk) of the stop edge (932) to the clamping element (922) is 8 mm or less, preferably 7 mm or less.

10. Fitting according to one of claims 1 to 9, characterized in that the outer contour (714, 916) has an azimuthal contour (942) spaced apart from the fitting opening (710, 711) or from the insertion section (912) for positive locking and / or force locking fixation of the fitting body (706, 903) in the circumferential direction.

11. Fitting according to one of claims 1 to 10, characterized in that one or more contour elements (810, 934) are provided on the outer contour (714, 916), each of which defines both the axial contour (724, 938) and the form the azimuthal contour (726, 942), and / or that one or more first contour elements (720) are provided on the outer contour (714) which form the axial contour (724), and one or more second contour elements (722) are provided on the outer contour (714) which form the azimuthal contour (726).

12. Fitting according to one of claims 1 to 11, characterized in that the azimuthal contour (726) has several, preferably at least ten, recessed areas, in particular surfaces (730), distributed circumferentially over the circumference of the outer contour (714).

13. Fitting according to one of claims 1 to 12, characterized in that the azimuthal contour (916) has several, preferably at least three, protruding areas, in particular surfaces (940), distributed in an azimuthal direction over the circumference of the outer contour (916).

14. Fitting according to one of claims 1 to 13, characterized in that the outer contour (714) has a clamping area (727) whose outer cross-section is adapted to the inner cross-section of the fitting opening (710, 711), preferably whose outer diameter (DA) differs from the inner diameter (Di) of the fitting opening (710, 711) by less than 1 mm.

15. Orbital welding device (100, 101, 801, 901, 1001), comprising a welding head (104, 806, 906, 1006) which has a receptacle (106) for positioning a joining area (150, 707, 907) of two joining partners that are at least tubular in the joining area, preferably a fitting (152, 702, 802, 902, 1002), in particular a fitting according to one of claims 1 to 14, and a pipe end (154, 704, 804, 904, 1004), characterized in that the welding head (104, 806, 906, 1006) is adjustable between an open position and a closed position, and that the welding head (104, 806, 906, 1006) has a fitting fixing contour (750) which is designed to engage, in the closed position of the welding head (104, 806, 906, 1006) and with a joining area (708, 709, 908) of a fitting (152, 702, 802, 902, 1002) arranged in a predetermined fitting position in the receptacle (106), with an axial contour (724, 938) of the fitting (152, 702, 802, 902, 1002) and optionally with an optional azimuthal contour (726, 942) of the fitting (152, 702, 802, 902, 1002) in connection, so that the joining area of ​​the fitting (152, 702, 802, 902, 1002) is held in a form-fitting manner in the specified fitting position.

16. Orbital welding device according to one of claim 15, characterized in that the welding head (104, 806, 906, 1006) has a pipe fixing contour (760) which is designed to come into contact with an outer contour (703) of the pipe end (154, 704, 804, 904, 1004) in the closed position of the welding head (104, 806, 906, 1006) and with a joining area (705, 905) of a pipe end (154, 704, 804, 904, 1004) in such a way that the joining area (705, 905) of the pipe end is held in the pipe position by positive and / or force-locking means.

17. Orbital welding device according to claim 15 or 16, characterized in that at least a part of the fitting fixing contour (750) and / or a part of the pipe fixing contour (760) is formed by a movable fixing element (402, 403; 404, 405) which, in the open position of the welding head (104, 806, 906, 1006), is positioned in an open position in which the fixing element (402, 403; 404, 405) defines the joining area (708, 709, 908) of the fitting (152, 702, 802, 902, 1002) and / or the joining area (705, 905) of the pipe end (154, 704, 804, 904, 1004) releases, and that in the closed position of the welding head (104, 806, 906, 1006) is positioned in a closed position in which the fixing element (402, 403; 404, 405) holds the joining area (708, 709, 908) of the fitting (152, 702, 802, 902, 1002) in the specified fitting position and / or the joining area (705, 905) of the pipe end (154, 704, 804, 904, 1004) in a, in particular, specified pipe position.

18. Orbital welding device according to one of claims 15 to 17, characterized in that the fitting fixing contour (750) comprises a fitting clamping contour (755) and the pipe fixing contour (760) comprises a pipe clamping contour (765), wherein in the closed position of the welding head (104, 806, 906, 1006) the inner cross-section of the fitting clamping contour (755) is adapted to the inner cross-section of the pipe clamping contour (765), in particular the inner diameter of the inner cross-section of the fitting clamping contour (755) differs from the inner diameter of the inner cross-section of the pipe clamping contour (765) by less than 1 mm.

19. Orbital welding device according to one of claims 15 to 18, characterized in that the orbital welding device (100, 101, 801, 901, 1001) comprises a hand device (102) comprising the welding head (104, 806, 906, 1006) and preferably a handle part (108) connected to the welding head (104, 806, 906, 1006).

20. System (700, 800, 900, 1000) comprising an orbital welding device (100, 101, 801, 901, 1001) according to any one of claims 15 to 19 and a fitting (152, 702, 802, 902, 1002), in particular according to any one of claims 1 to 14.

21. System according to claim 20, characterized in that in the predetermined fitting position of the fitting (152, 702, 802, 902, 1002) the fitting opening (710, 711) or the joining section (914) is located in the area of ​​the welding electrode (126).

22. Orbital welding process, in particular carried out with an orbital welding device (100, 101, 801, 901, 1001) according to one of claims 15 to 19 or a system according to one of claims 20 or 21, in which two joining partners, in particular a fitting (152, 702, 802, 902, 1002) and a pipe end (154, 704, 804, 904, 1004), which are tubular in at least one joining area (150), are arranged relative to each other, in particular in an overlap joint, and in which one or more joining points (210) are produced in the joining area (150) which connect the joining partners materially, or a chain (211) of joining points (210) extending in the circumferential direction of the joining partners is produced which connect the joining partners materially. connects.

23. Use of a fitting (152, 702, 802, 902, 1002) according to any one of claims 1 to 14 for permanently connecting to a pipe end (154, 704, 804, 904, 1004) of a pipeline by means of orbital welding, in particular with an orbital welding device (100, 101, 801, 901, 1001) according to any one of claims 15 to 19.

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