DE3407786A1 - Transition piece in a gas line - Google Patents

Abstract

The invention relates to a transition piece in a gas line, consisting of two pipe pieces, which are connected to one another, and of a sealing ring which is arranged between them, of which the end of the one pipe piece has operating means, at a distance in front of its end, for fixing an attachment which grips the end of this pipe piece, is produced integrally with the other pipe piece, and is produced in a casting process which sheaths the end of the other pipe piece. The object of the invention is to prevent such transition pieces becoming unsealed. The invention is for the operating means for fixing to consist of at least one collar ring (5) which is arranged at a distance in front of the end of the pipe (1), for the sealing ring (8) to be located in or in front of a groove (9, 16) which forms a cavity (10) which is sealed by the sealing ring (8) and faces away from the attachment (4), and for the sealing ring (8) to consist of a material which is elastic but is only slightly compressible and is provided with a long-term shape memory. <IMAGE>

Description

PATENT ADVOCATE

DiPL.-PHYS. DR. WALTHER JUNIUS 3 Hanover ^ 4 0 778 6 "

WOLFSTRASSE 1 * ■ TELEPHONE (05 11) 83 45 30

February 11, 1984 Dr. Y / Y

My file: 814

Immanuel Jesehke, St.-Nikolai-Str 4 + 5 _f 32o3 Sarstedt district Heisede

Transitional piece in a gas pipe

The invention relates to a transition piece in a gas line consisting of two pipe pieces connected to one another and a sealing ring arranged between them, of which the end of a pipe section is at a distance in front its front side working means for holding one of the end of this pipe section encompassing, integral with the Has another pipe section produced approach, which in a casting process encasing the end of the other pipe section is made.

Such transition pieces are used wherever gas lines made of different materials connect to each other. Ss are these transitions around transitions from metal gas lines, preferably made of steel, to plastic gas lines or around transitions from plastic gas lines of one material to plastic gas lines of another plastic material, preferably Transitions from polyvinyl chloride to polyethylene.

Such transition pieces "usually consist of a pipe section with a higher melting point and a pipe section with a lower melting point Melting point, the latter usually being a piece of pipe made of polyethylene. This polyethylene is used in a casting process to form a piece of pipe with a neck shaped, which tightly encloses the other end of the pipe. TIm a tight fit of the polyethylene on the end of the pipe reach, this is equipped with tools to hold on, mostly groove-shaped recesses or several collar-shaped projections, which are often designed as a thread because of the simpler production.

During this casting process, the polyethylene is poured in liquid form into a fora under pressure, usually in an injection molding process, When it cools down in the mold and also after it has been removed from the mold, the polyethylene shrinks and thus reaches a particularly tight fit that is also completely gas-tight. The mechanical stress that occurs during this shrinking process arises, remains for a long time, often over years, the cure becomes very slightly less over the years, to finally reach a zero value au. This is where there is a risk that the gas will slowly approach the limit Polyethylene - steel or polyethylene - PTC enters and paves a way to the outside here at the transition point.

Experiments have shown that at this transition point on the pipe end applied, enclosed by the polyethylene Sealing rings, including O-rings, are not capable of this To prevent this transition piece from becoming detached.

It is the object of the invention to ensure the sealing of such To prevent transition pieces.

The invention consists in that the work equipment for holding plague from at least one, at a distance in front of the forehead

side of the tube arranged collar ring that the Sealing ring is in or in front of a hat, "the one closed by the diaphragm ring, turned away from the approach Forms cavity, and that the sealing ring consists of an elastic: but little compressible, but with a long-term 3-oxm memory provided material.

The invention is based on the knowledge that the sealing ring is so deformed during the pouring and shrinking process it must be that its elasticity is constantly trying to restore the ring due to its long-term shape memory to move back into its original shape while letting the ring rest against both materials so that it can seal the transition point between the two materials.

The sealing ring is here in front of or in a hat, in which it changes shape while under pressure Casting process and is pressed in during the shrinking process while changing the shape of its cross-section. From this Beiner's shape-changed position in the hat strives the sealing ring back out in its original position and lies both against the hat walls as also against the cast material · This creates a very secure seal for the transition area between reached the end of the pipe and the encased attachment

If the work equipment for holding on consists of a single, there is a collar ring arranged at a distance in front of the end face of the pipe, arise when the injection molding process shrinks cast material no internal stresses in this material in the axial direction of the transition piece. This increases the service life of a secure connection. This measure is expediently carried out with apply the first measure together, however

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this is not absolutely necessary in all cases, the first-mentioned measure is the one on which the long-term Leak tightness of the connection is primarily due.

The collar is an annular »the outer surface of the one Pipe section surrounding, usually rectangular in cross-section ■ projection, which is made in one piece with the pipe section is.

It is advantageous if the sealing ring consists of an O-ring Rubber is. This is particularly suitable for being printed in grooves Sr has a good long-term memory

It is advantageous if the outer diameter of the collar is larger than that of the sealing ring. This increases the strength of the seat of the attachment on the pipe end enlarged. At the same time a prerequisite is created that the sealing ring immediately next to the Bund can be arranged on the end face of the pipe encompassed by the pipe socket. And this arrangement has significant advantages, which consist in the fact that the sealing ring is in its position during the pressing in of the liquid Plastic does not change with caution. Because liquid plastic material should not get into this groove. The air remaining in the hat is released when you are back of the sealing ring is compressed and thus forms an additional suspension that pushes the sealing ring outwards.

The hat can be designed in various ways. It has proven to be very beneficial when at the transition from the collar to the pipe surface an inclined, preferably wedge-shaped cross-section, annular recess is provided, its maximum

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Width is slightly less than the diameter of the sealing ring. This recess can be made parallel to the axial direction. But it can also be vertical or at an angle to the axial direction.

Another possibility is that the sealing ring at a distance from the collar above a rectangular, preferably square groove in the surface of the tube whose cross-sectional dimensions are smaller than the cross-sectional dimensions of the sealing ring «

TJm an anti-rotation lock of the two pipe sections against each other To achieve, it can be useful that the collar has a polygonal outer circumference.

Another protection against gas leakage in the focal area between the approach and the end of the pipe section encompassed by approach can consist in that in the outer peripheral surface of the collar a hat is arranged is, into which a sealing ring with a round cross-section is inserted. Here, too, it is essential that on the side of the groove facing away from the shoulder is a cavity in which air is enclosed by the sealing ring which is compressed during the injection molding process with simultaneous deformation of the sealing ring.

Another safeguard against gas penetration in this one The boundary surface can consist in the fact that the collar has a groove on both sides at its root into which a A sealing ring with a round cross-section is inserted. Thus there is a seal on both sides of the collar instead, which, however, does not exclude the possibility of a further one Sealing is made on the circumference of the collar.

It is useful if the run of the groove, measured on the highest point of their base, slightly larger than the radius

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of the sealing ring is. The sealing ring is spellbound slightly over the groove and is pressed deeper into the hat by the flowing liquid injection molding material. At the same time it is ensured that "when the liquid injection molding material flows in, the sealing ring does not can be carried away by the flow of the material. But it is also possible that the depth of the groove is greater than the diameter of the sealing ring · This gives the injection molding material additional hold in the groove, however this training usually leads to a weakening of the overmolded pipe stick end due to the depth of the groove.

The But is expediently U-shaped in cross section rectangular or tapering downwards or backwards formed, namely trapezoidal, semi-elliptical or V-shaped. In the case of a U-shaped, right-angled groove, if an O-ring is inserted as a sealing ring to both Sides of the sealing ring from the circumferential surface touching the base of the hat a ring-shaped, air-filled gusset. When taking in the liquid Injection molding material, the sealing ring is deformed, the gussets are smaller and the air in these ring-shaped Gusset is compressed. More air, which also acts on a larger area of the sealing ring, is but then compressed if the hat is trapea-shaped or semi-elliptical or V-shaped in cross-section is.

More air than with a U-shaped groove with a right-angled cross-section is also compressed when the bottom the groove is made in its center, be it that the base of the groove is curved in cross section or has a raised annular projection in its center. Because then the ring-shaped gussets in which air enters the groove through the sealing ring

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In all cases, however, it is essential that the hat points has, at which it has a width that is less than the diameter of the sealing ring, so that the seal: ring under radial tension or tension in the circumferential direction lies in the hat and this tension creates an airtight seal through its surface with the hat walls forms.

A seal can also be obtained by using the miadesteins another collar ring is seen and that a sealing ring in the space between the two collar * ring formed groove is arranged

The pipe sections themselves can be any length or short, as required by the application · They can also be used as sleeves, nipples or other pipe connectors with paddles or similar work equipment. It is useful if at least one piece of pipe on the the side facing away from the comprehensive approach as an adhesive Threaded sleeve or nipple is formed or with a flange or other fastening means for further Pipe sections or fittings

The essence of the invention is explained below with reference to in the drawing in cross-section schematically illustrated embodiments explained in more detail. Show it:

Fig. 1 shows a transition steel pipe-polyethylene pipe,

Pig «2 shows the position of the sealing ring in a large enlargement before injection molding,

Pig 3 the location of the sealing ring after injection molding and shrinking,

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Fig. 4 a piece of PVC pipe,

Pig · 5 the PVC-Rohrstüok encased by the approach of a Polyethylene tube,

Fig. 6 is an end view of the PVC pipe piece, 7 shows a section through a transition piece PVC-PE,

Fig. 8 is a section through another transition piece PE-PVC,

9 shows the position of the Q-ring in an enlarged bar position before injection molding,

Fig, Io the position of the O-ring after injection molding and Shrink,

11 shows a connector made of PE for two PVC pipes,

12 shows a transition from a plastic-coated steel pipe to a polyethylene pipe socket,

13 shows the position of the sealing rings in a large enlargement . in Fig. 12 before injection molding,

Fig. 14 shows the position of the sealing rings in Fig. 12 after injection molding, '

15 shows another arrangement of three sealing rings on a collar before injection molding;

16 shows the position after injection molding,

17 shows a transition between a sheathed steel pipe and a polyethylene flange piece,

18 shows the position of the sealing rings on a collar with hats semi-elliptical in cross section,

19 shows the position of the sealing rings of FIG. 18 after Injection molding,

2o the position of sealing rings on a collar ring with grooves whose base is raised or a central one Has a head start before injection molding,

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Pig. 21 after injection molding,

22 shows a transition between steel roller and polyethylene screw socket with three sealing rings on the collar,

Pig »23 a transition piece steel pipe-polyethylene., Bsi that the steel pipe with a splash, the polyethylene socket part however, with internal and external threads,

Pig. 24 a transition piece of steel pipe with splash "resp. PVC pipe with paddling - polyethylene welding sleeves for internal welding,

Pig. 25 a transition piece steel pipe or PVC pipe aiii Plansch - polyethylene socket for external welding,

Pig. 26 Transition piece, metal nipple with external thread, polyethylene socket for internal welding,

Pig · 27 a transition piece metal socket with internal thread polyethylene welding socket for internal welding,

Pig. 28 a transition piece PVC sleeve with internal thread polyethylene nipple for external welding,

Pig. 29 a transition piece PVC adhesive socket - polyethylene welding socket for external welding,

Pig. 3o a transition piece PVC adhesive nipple - polyethylene welding nipple,

Pig. 31 PYC adhesive nipple - polyethylene welding socket, Pig · 32 a different design of the transition piece.

In the exemplary embodiment of Figures 1 to 3, a steel tube 1 is provided with a plastic casing 2 is firmly connected to a polyethylene tube 3, which carries at its end a projection 4, which the end of the steel tube 1 tightly encased · This approach 4 has the shape of a hollow cylinder. Far ahead of the

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The end face of the steel tube has a collar 5, which thereby the result is that at the end of the steel pipe on both sides of the collar 5 material is turned off » so that the surface 6 as well as the surface 7 have a smaller outer diameter than the collar 5 * The O-ring acts as a sealing ring in front of the collar 5

How to get out of Pig. 2 sees, a recess 9 is provided at the transition from the plane 7 to the collar 5, the is ring-shaped and is wedge-shaped in cross-section. While During the injection molding process, the O-ring 8 is deformed into the cap 9, whereby the air enclosed in the remaining cavity Io is compressed. This air forms a suspension which tries to push the O-ring 8 outwards. This supports them Suspension the shape memory of the O-ring and ensures that the O-ring is always on the cast material of the Ansatses 4 · and the walls of the groove 9 rests.

In Fig. 4 a molded piece made of polyvinyl chloride is shown » This also has a collar 5,

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the surface of which, however, has a plurality of flat surfaces 11 in order to achieve a rotation reduction. 5 ¹ Ig, 5 shows how this molded part of the Pig 4 made of PTO is sheathed by the attachment 4 of a tube 3 made of polyethylene. The end view of FIG. 5 shows that the diameter of the collar 5 is in the area of the tips between the flat surfaces U is greater than the outside diameter of the head 12, into which a PVÖ pipe can be glued. to screw a pipe with an external thread to this transition piece

In the exemplary embodiment in FIGS. 7 and 8, there are two Transition pieces PE-PVO shown · Here it is a Insert 13 made of PVC, which carries the collar 5 and is encased by the extension 4 of the PE pipe 3 · Here is the Sealing ring arranged again at the transition of the surface of the insert 13 in the collar 5, in this transition area a courage 9 is located · This insert 13 has an inwardly facing flange 14, which acts as a stop serves for the end face of the PTO tube to be glued · - In the embodiment shown, however, also the PE pipe 3 at the point where the extension 4 the pipe 3 is followed by an inwardly directed one Flange 15, which acts as a stop for the face of a Polyethylene pipe to be pushed into the pipe section 3 and to be welded to the pipe section 3 is used. The transition piece shown in Fig. 7 can be provided with a longer pipe section 3, to which then further PE pipes can be attached. But it can also with be provided such a short Rohrsttick 3, as it is shown and then serves as a transition fitting between a PE and a PVC pipe

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At-

A similar transition piece is in Pig. 3 shown. Here is the sealing ring 8 in front of a groove 16 with a square Cross-section which is located at a distance in front of the collar 5 in the illustrated embodiment. This groove 16 could also be located directly in front of the federal government 5. In Pig. 9 is shown in high magnification » how the O-ring 8 is before the injection molding process and in Pig · Io is also shown enlarged, as it is after the injection molding process and shrinkage into the groove is squeezed under deformation, with cavities Io remaining in which air is compressed.

In the embodiment of the Pig. 11 shows how a double transition piece is a coupling sleeve made of polyethylene for the connection of two PVC pipes represents

In all the exemplary embodiments, the sealing ring is arranged between the collar 5 and that point 17 on which is the transition surface between the two pipe pieces with the interior of the. Comes into contact with the gas pipe.

Per se, the diaphragm ring 8 could also be concentric to the pipe axis 18 extending hat in the end face of the flange 14 are arranged. In this case the Stand the pipe axis vertically during the injection molding process. - The arrangement of the sealing ring on an axially parallel Tfinfangaflache has the advantage that the sealing ring has a better fit here during injection molding. This seat is particularly good when the sealing ring rests directly on the collar 5.

The anti-rotation of the cast pipe part in the approach can also be achieved in that the. Federation has axially parallel projections or hats or has other projections on the outer circumference.

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Such a transition piece can also be made twist-proof wall in when looking at the outside of the neckline and / or the pipe section adjoining this attaches outwardly directed gate projections.

The transition piece shown in Pig »12 τοπ a steel pipe 1 with plastic jacket 2 on a polyethylene« muffenstüek 4 has in addition to the Sing 8 already present in Pig O-ring 19 as a sealing ring which lies in a circumferential groove 2o d © a collar ring 5. This hat 2o is U-shaped in cross-section and has an axially parallel base to which the groove walls adjoin at right angles on both sides. Like from Pig. 2, when the sealing ring 19 is inserted, gussets 21 are formed on both sides of the central point of contact between the sealing ring 19 and the base of the groove 2ο, in which air remains which is compressed after the injection molding material has been injected (Pig · 14) * This one here Compressed air supports the endeavors of the O-ring _f to move back into the original position according to Pig 13. This creates a permanent seal between the material of the attachment 4 and the walls of the hat 2o in the collar 5 on the steel pipe 1.

Approach 4 is here in Pig. 12 on a socket piece 23, which has an inner surface 24 that acts as an adhesive surface for an inserted end of a plastic pipe can serve. An inwardly directed annular projection 22 serves as a stop for the end face of the plastic pipe to be glued. Instead of the adhesive surface However, an internal thread can also be provided. But the outer surface 25 can also be used to attach a Slid-over pipe serve, for example, as an adhesive

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area. This surface 25 can also be threaded be provided. The shoulder 26 serves as a stop for Face of the pipe pushed over. If the surface 24 or 25 is provided with a thread, a Steel pipe are screwed in or screwed on, the transition piece then serves as an insulating piece, the ring-shaped Inner protrusion 22 a secure insulation between the steel pipe 1 and one in an internal thread on the surface 24 screwed in another steel tube is used.

In the embodiment of Figures 15, 16, are on the collar 5 three O-rings are provided as sealing rings. The sealing ring 27 lies in a groove 3o which is cut into the pipe section 1 directly next to the one end face of the collar 5 is. The sealing ring 28 lies in a XJmfangsnutjln the ümfangaflache of the collar 5. This TSnfangsnut 31 has a trapezoidal cross-section, which has the advantage that a relatively large amount of air is inserted between the tightly inserted Sealing ring 28 and the bottom of the hat 31 remains. The sealing ring 29 is located in a hat 32 which is axially in the Root of the collar 5 is pierced, in such a way that the surface 6 of the Sisenrohrstückes 1 is in the Groove wall continues immediately.

The transition piece of the Pig, 17 is formed similarly to the transition piece of the Pig · 12, but the one made of ELyäthylea manufactured socket part both an inner surface 24 serving as an adhesive surface and a flange 33, which optionally can be used.

In the embodiment of Figures 18 and 19 are the Grooves 34 of semi-elliptical cross-section. In the exemplary embodiments in FIGS. 2o and 21, the grooves 35, 36 a raised base, in the case of the groove 35

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a hat engrund, the In. Cross section the shape of a Part of a circle has, in the Palle the hat 36 is a annular projection 37 is provided for the reason the hat 36 protrudes · Here too, the air space around the base of the hat and the diaphragm ring is enlarged ·

In the exemplary embodiment of the Pig. 22 is a section through a transition piece with three sealing rings on the collar 5 _s are the all-shaped U-into herding, rectangular cross-section, in Pig x 23 comprises the pipe member 1 made of steel a Plansch 33 'also made of steel and is integral with the tube piece 1, on · Here, four collar rings 38 are provided on the pipe section 1. Between p sswei collar rings 58 there is an O-ring 39 as a sealing ring in a groove 4o of semi-elliptical cross section. On the plastic part with the extension 4 there is a sleeve-shaped end 41 which has both an external thread 42 and an internal thread 45. Such parts with several connection options have the advantage of lower storage.

Note I3T in the embodiments of figures 22 and 23, that the wall thickness of the polyethylene gefertig "th part is almost the same everywhere, so that unequal ^c shrinkage stresses do not occur.

In Pig. 24 is a tubular piece 5o made of metal or made of polyvinyl chloride-PYO in one piece with the Plansch 51, which has holes 52 for connecting screws. Also, this pipe section 5o has a collar 5 which laterally has a recess Io, in front of which a 0 <-ring 8 is arranged. This collar ring 5 with the O-ring 8 and part of the pipe section 5o is encapsulated in the injection molding process by the projection 4 of the sleeve 53, the inner wall of which 54 on the side facing away from the pipe section 5o 'for a

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Welding a polyethylene pipe is prepared. Before the welding process, this is not shown The polyethylene tube is inserted in such a way that its end face rests against the annular inner projection 55.

In Pig. 25 iat an identically shaped3 piece of pipe 5o with Plansch 51 and collar 5 »that's an outward one annular projection »used. The collar together with the O-ring 8 is here from a tosatz 4 of a nipple 56 uragoQ3ön »The outer surface 57 of this Nipple is for welding one over the outer surface 57 pushed polyethylene pipe prepared. - The nipple 57 can also be very long and represents then a pipe *

In Pig · 26 is a metal nipple 58 which is on one Side an external thread 59 and a hexagonal surface 6o for engaging a wrench on the the other side has a collar 5, in front of the recess Io an O-ring 8 is encased by the approach 4 a welding bead 53, the inner surface 54 · for a Welding of an inserted polyethylene pipe is prepared

In Pig, 27 is a metal sleeve 61 with an internal thread 62 provided with a paragraph 65. Behind this paragraph is the socket with a different diameter is designed as a pipe section 64 with a collar 5 on its surface, an O-ring 8 is located in front of the lateral recess Io. The collar 5 and the pipe section 64 are encased by the same polyethylene welding sleeve 53 with approach 4, which already in the Pig. 24 and 26 is shown.

In Pig. 28 is the same metal sleeve shown in FIG is, of the approach 4 deB polyethylene nipples

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encased in pig. 25 is also used and there is described in more detail

This same polyethylene nipple is found in the Pig. 29 «ad 3o use · In Pig · 29 it completely encases a ring 65 used as an adhesive sleeve, which carries a collar 5 with a lateral recess Io, in front of which the Q-ring 8 is arranged · The inner wall 66 is designed so that it can be connected to the outside of a PVC pipe by adhesive · - In the embodiment of the Pig. 3o i3t into the approach 4 of the SehweiS nipple 56 made of polyethylene, one end of the PYC sipple

67 cast in with the collar 5 · The free outer surface

68 of this PYC nipple 67 is prepared with the The inside of a slid-on PVC tube must be glued

In the exemplary embodiment of the Pig 31 is a PVC-ITipple 67 - corresponding to that in Pig · 3o - of the approach 4 of a welding socket. 53 - according to Pig. 24, 26, 27 - coated.

It does not always need to be 5 serving the firm connection of these two parts are not welded together or bonded a collar. In a kinematic reversal, the fastening can also be carried out as shown in Pig 32: The pipe section 5 o with plan 51 has an annular recess 69 here, the side edges 7 o of the attachment 4 of the adhesive sleeve 53 made of polyethylene a firm hold ge ^ Provide axial displacement · A hat 71 is then milled into the recess 6S , which can have the shape of the grooves 34 or 35 or 36 with the projection 37 or the pomn of the groove Io or also the di trapo-shaped shape of the groove 31. In front of this hat there is an O-ring 8

Claims (16)

A η s ό r U c he: / χ /, transition piece in a gas line, consisting of two tube pieces connected to one another and a diaphragm ring arranged between them, of which the end of one tube piece at a distance in front of its end face work means for holding a piece encompassing the end of this tube piece * in one piece with the other tube has manufactured approach »which is produced in a casting process encasing the end of the other pipe section, characterized in that that the work equipment for keeping the plague consists of at least one, there is a collar (5) arranged at a distance in front of the end face of the pipe (1), that the sealing ring (8) is in or in front of a hat (9, 16) * the one closed by the sealing ring (8) 'from which Approach (4) facing away cavity (Io) forms, and that the sealing ring (S) consists of an elastic, however little compressible, but with long-term Pormgedächtnia provided material. 2. transition piece according to claim 1,
characterized,
that the sealing ring (8) is a rubber O-ring 3 transition piece according to claim 1,
characterized, that a single collar (5) is provided and that the outer diameter of the collar (5) is larger than that of the sealing ring (8) 4 transition piece according to claim 1,
characterized, COPY that the sealing ring (8) immediately next to the collar (5) on the end face of the pipe encompassed by the pipe socket (4) (l) is arranged « 5. transition piece according to claim 1 and 4, characterized! that at the transition from the collar (5) to the pipe surface (7) a sloping, preferably wedge-shaped cross-section, annular recess (9) is provided, the maximum width of which is slightly less than the diameter of the The ring is 6 transition piece according to claim 1,
characterized, that the sealing ring (8) is above a rectangular hat (16), preferably with a square cross-section is arranged in the surface of the tube (13), the cross-sectional dimensions of which are smaller than the cross-sectional dimensions of the sealing ring (8). 7 transition piece according to claim 1,
characterized, that the collar (5) has a multifaceted outer circumference having" 8 transition piece according to claim 1,
characterized, that in the outer peripheral surface of the collar (5) one according to (2o), in which a sealing ring (19) with a round cross-section is inserted 9. transition piece according to claim 1,
characterized, that the collar (5) at its root on both sides one Has hat (3o, 32) into which a sealing ring of round cross section is inserted. " ⁵ " copy 3407788 10. Transition piece to. Claim 1, characterized in that the run of the groove (2o _f 3o, 31, 32), measured at the highest point of its base, is somewhat larger than the radius of the sealing ring (19, 27 »23, 29). 11. Transition piece according to claim 1, characterized in that the groove (2o) has the same depth as the height of the Has collar ring (5) 12. Transition piece according to claim 1, characterized in that that the groove (lo, 2o, 3o, 31, 32) is U-shaped in cross section right angled or look down "or tapering backwards is formed, namely gate preferably trapezoidal or haTbelliptic or Y-shaped. 13. Transition piece according to claim 1, characterized in that that the Qrund of the groove (35, 36) is raised. 14. Transition piece according to claim 1, characterized in that that the groove has places where it has a width which is less than the diameter of the sealing ring. 15. Transition piece according to claim 1, characterized in that that at least one further collar (38) is provided, and that a sealing ring (39) in the space between the two collar rings (38) formed groove (4o) is arranged. 16. Transition piece according to "Claim 1, characterized in that at least one Hohrstiiclc on the over-detecting Approach (4) applied side is designed as an adhesive or threaded sleeve or nipple or with a puddle (33) or any other connecting means is provided COPy