DE3026681A1 - Liq. tight butt joint for concrete pipes - includes sealing rings between thin plastics sleeves and thick plastics bridging sleeve - Google Patents

Abstract

Liq. tight joint between the butting ends of two concrete pipes having a constant outside diameter, includes a plastics sleeve spanning the joint. This sleeve is also enclosed by a much thinner sleeve inserted into a recess in the end of each pipe, with sealing rings between the thick and thin sleeves. The thick sleeve can have a constant outside dia. so that the sealing rings are retained in grooves around the insides of the two thin sleeves, due to the shape of the recesses inside the pipes. Alternatively, the thin sleeves are smooth, and the sealing rings are fitted into grooves around the thick sleeve. A number of alternative arrangements include a stepped formation of the pipe recesses, and the thick ring shaped accordingly to form grooves for the rings.

Description

Liquid-tight connection

The invention relates to a liquid-tight connection of pipes, in particular made of concrete, reinforced concrete or asbestos cement, which at least have a plastic lining in the region of the pipe ends, at least a sealing ring is provided at one end of the pipe.

In DE-PS 20 23 776 is a liquid-tight connection of described with a plastic lining provided sewer socket pipes made of concrete, in which the plastic lining can be pushed over one another in a sealing manner. In the known connection, the plastic lining is at least at one end of the pipe over the face of this pipe end and the inside diameter of one end the plastic lining corresponds to the outer diameter of the plastic lining of the pipe to be connected expanded. The concrete socket pipes are, as they have been for a long time already common, mounted with rolling rings, and the plastic pipes or the plastic lining must also be plugged into one another to form a seal. There are thus two socket connections present, so that two pipe parts are concentric to produce a connection must lie to each other, namely the concrete socket and the concrete insertion end on the one hand as well as a plastic sleeve and a plastic plug-in end on the other hand. The concentric one location of these four pipeline parts must be required, if the concrete pipe is to be laid in a trench and pushed together. With the manufacturing tolerances customary in the concrete pipe standards (DIN 4032 and DIN 4035) such a requirement is practically impossible to meet. For horizontally laid concrete socket pipes without lining, as is known, due to vertically acting forces, the so-called shear loads, axial displacements of 5 to 10 millimeters occur. It it can be seen that shear loads of this kind are present even with small axial displacements can lead to destruction of the thin plastic lining. In addition, should at least one pipe end protrudes from the plastic lining, so that during transport or damage or even destruction can occur during installation. It must also not be overlooked that in the known pipe connection via the inserted sealing ring between the concrete socket and the inserted concrete end Shear load can be absorbed and impermeability to external groundwater can be achieved should and that by means of the plastic lining or its tight construction of the Concrete should be protected from aggressive sewage.

The invention is based on the object for pipes of the above Kind of creating a liquid-tight connection, which as well as the pipes can even be produced in a simple manner and in which the plastic lining must not be destroyed by shear loads. Furthermore, the connection should at least Protect the end faces of the pipes from aggressive sewage, for all areas of application such as full linings of the pipes can be taken over, be operationally safe and be able to cope with the site conditions.

According to the invention, this object is achieved in that within the pipe ends a sleeve, preferably made of plastic, with a comparatively large wall thickness is arranged, which is predetermined so that the occurring Shear loads are transferable, and that the sleeve and / or the plastic lining have at least one groove or bead or receiving surface for the sealing ring.

The compound according to the invention is characterized by a special feature simple structure and guaranteed under all operating conditions, in particular such on construction sites, a secure sealing of the pipe ends connected to one another. At the pipe ends there are no bell sleeves, so that the production of the Pipes is facilitated. Since the pipes to be connected are now predominantly made of concrete are produced, the pipes are hereinafter referred to as concrete pipes. Be it but expressly pointed out that the pipes are also made of other materials, Reinforced concrete and asbestos cement may be mentioned here. In the There are no particular difficulties in manufacturing the socket-free concrete pipes, especially since the manufacturing tolerances customary in the concrete pipe standards are retained can. The sleeve provided in the area of the pipe ends has a large wall thickness can be produced without any particular difficulty, preferably a long, smooth one Cut the plastic pipe with the required wall thickness into appropriately short pieces which in turn is then provided with the necessary beads, bevels, etc. will.

The laying of the concrete pipes or the production of the connection is can be carried out in a simple manner, since here no four, but only two pipe parts must be concentric to each other. Since only the sleeve, which either with to the connected to a pipe end (spigot end) or already is inserted into one end of the pipe (double spigot end), into the other end of the pipe is, there is also no particularly precise concentric position of the sleeve and the concrete pipe required. The sleeve proposed according to the invention serves both for transmission the shear loads as well as the liquid-tight connection of the pipe ends. Important is the relocation of a tight and at the same time strong pipe connection radially inwards, so that an outer concrete pipe socket seal is no longer required is. At least the end faces of the concrete pipes are protected from destruction aggressive sewage protected. The protected area can be enlarged up to the full lining will.

At least one pipe end is preferably designed as a plug-in socket, into which the thick sleeve protrudes. The inside diameter of the socket is expedient twice the wall thickness of the sleeve larger than the normal pipe inside diameter, so that there is no constriction in the area of the connection.

The tubes advantageously have a constant length over their entire length Outer diameter, so that there are socketless concrete pipes in which the connection is made by the sleeve arranged inside. Such socketless concrete pipes are particularly easy to lay, as the usual free shoveling in the sand bed not applicable in the area of sleeves.

The sleeve is preferably made of a thermoplastic plastic, preferably made of hard PVC. Such a sleeve is inexpensive without any special effort manufacturable. For the same reasons, the sleeve can also be made of a thermoset Plastic, preferably made of polyurethane.

The ratio of wall thickness to outside diameter is preferred called # sleeve in the range from 1:20 to 1:50 and preferably about 1:40. Such sleeves can without difficulty and special effort from a commercially available 5-ATU plastic pipe (DIN 19534) or from a 10-ATU pipe (DIN 8062) inexpensive be produced, the said pipes being cut to the necessary length are.

From the parts obtained in this way, suitable Shaping, in particular the introduction of beads or receiving surfaces for the sealing rings, the said short sleeves are formed.

In a preferred embodiment, the sleeve is on at least one End provided with a preferably conical taper on their outer surfaces. This makes the connection when laying the pipes essential relieved.

With this conical taper, the sealing ring is pushed together the concrete pipes are pre-pressed quickly and with less insertion force.

Advantageously, the outer surface of the sleeve is provided with at least one Provide a bead in which the sealing ring is inserted. Thus, in a simple manner prevents the sealing ring from being lost during transport or storage.

In a preferred embodiment, the sleeve and the plastic lining or the concrete pipe itself in the axial direction opposite stop surfaces on, between which the sealing ring is arranged. With a such sealing or rolling ring clamped onto the sleeve is then the establishment of the connection between two pipes when laying the same not slightly relieved.

The sleeve with the spanned sealing rings can be used as a unit up to Laying must be stored separately. The concrete pipes have smooth non-destructive End faces on.

The sleeve is preferably designed as a double plug-in end, which in appropriately designed plug-in sleeves of the concrete pipes or the plastic linings is inserted. The sleeve is thus a single part that is only needed when laying of the pipes is pushed into the said socket joints. The concrete pipes point thus smooth end faces, so that damage during transport and storage is not to be feared.

In another preferred embodiment, the sleeve is with the a pipe end or with the plastic lining present there, preferably by welding or gluing, firmly connected and thus becomes a spigot end. That the other end of the pipe, however, is designed as a socket into which the insertion end is inserted. To protect the insertion end against damage, one can Concrete pipe end can be formed with a protective collar on the outside. The inner surface of this However, the protective collar has a predetermined one to the outer surface of the other pipe end Distance so that by means of the protective collar no load-bearing, but only a protective one Function is exercised. The shear loads are also exclusive in this embodiment absorbed by the sleeve.

The length of the sleeve is preferably twice as great as the length of a Socket. In this way it is ensured that, on the one hand, no impermissibly large Surface pressure occurs between the sleeve and the plastic lining or the end of the concrete pipe and that, on the other hand, little material is required for the sleeve.

The liquid-tight connection of concrete pipes described is suitable for completely protecting the concrete pipe against aggressive waste water. the Plastic lining then only has to be stretched from one end of the concrete pipe to the other be. Various designs suitable for this are mentioned below.

The complete plastic lining can, for example, consist of a smooth plastic pipe. The ratio is advantageously located from wall thickness to outer diameter of the plastic lining in the range of 1:80 up to 1: 160 and is preferably about 1: 125. The plastic lining can thus in a simple manner from a commercially available plastic pipe, in particular from a 1.6 ATU pipe in accordance with DIN 8062. This is in terms of manufacturing costs really important. For example, if the plastic lining is over the entire length of the pipe from a comparatively thin-walled plastic pipe according to DIN 8062 (1.6-Atü-Rohr), so can without any difficulties with a corresponding stiffening concrete sheathing a concrete pipe can be made with which opposite a PVC sewer pipe according to DIN 19534 (5-Atü pipe) more than 50 percent PVC pipe weight can be saved.

The plastic lining is also made of the sleeve preference made of a thermoplastic material, in particular made of hard PVC. One of those Plastic lining can very easily be made from commercially available synthetic materials will.

If a plastic lining is only provided in the area of the pipe ends the plastic pipes only need to be cut to the appropriate length and if necessary, be deformed accordingly.

If the sealing ring is placed on the sleeve before assembly; so shows the plastic lining plastic lining in the area of the end face of the pipe a preferably conical enlargement, so that the compression of the Dichuringes and the production of the connection when laying the pipes in a simple manner flurchge for is the sealing ring is in a bead in the plastic lining before assembly, so the sleeve has conical tapers on the end faces.

So that E- the plastic lining with respect to the concrete pipe in the axial direction Direction is not displaceable, but rather sits firmly in the tube, points the plastic lining preferably has a radially outwardly extending shoulder on. This approach is expediently formed as an annular rib, which can be molded onto the plastic lining without difficulty.

In a preferred embodiment is a plastic liner only provided in the area of the pipe ends. In the simplest case, the plastic lining is designed as a ring with a U-shaped cross section, in which the sealing ring is inserted so that with a minimum of plastic a functionally reliable and liquid-tight connection can be produced. Appropriately extends the plastic lining approximately over the entire length of the socket, so on the one hand a tight fit of the plastic lining in the pipe is guaranteed and on the other hand closer manufacturing tolerances can be maintained. In addition, a full It is better to clean the lined sleeve of dirt before installing it.

In a preferred embodiment, the plastic lining has over the entire axial length of the smooth tube a substantially constant, low wall thickness and is designed as a socket in the area of the pipe ends. Such a lining protects the concrete against aggressive sewage reduced the abrasion on the pipe bottom and on the other hand enables the production in a simple manner a liquid-tight connection by means of the inserted into the socket comparatively thick sleeve.

In another preferred embodiment, in which the between the pipe ends lying part of the plastic lining outside with in the axial direction The plastic lining is in the area at least one pipe end is designed as a substantially annular plug-in socket. This socket is with said part of the plastic lining, preferably by gluing, potting or welding, firmly connected, so that here too a reliable one Protection of the concrete pipe against aggressive waste water is guaranteed. The sleeve can be designed as a plug-in end (spigot end), which is connected to the one pipe end or the said plastic lining is firmly connected, or as a double plug end be trained, which in the said ring-shaped push-in sleeves is inserted.

Further features and advantages of the invention that are essential to the invention liquid-tight connection are in the exemplary embodiments according to the drawing and are explained below. They show: Fig. 1 a connection with a sleeve as a double plug-in end, the sealing rings in plug-in sleeves to the Pipe ends are arranged, Fig. 2 a connection with a sleeve which grooves for sealing rings, Fig. 3 shows a connection in which the sleeve and the plastic lining or the concrete pipe is provided with opposing stop surfaces, Fig. 4 shows a connection for pipes, which over the entire length a thin-walled Contain plastic lining and a socket or sleeve at the ends as the insertion end (spigot end), Fig. 5 shows a connection for pipes similar Fig. 4, but the socket has a reinforced plastic lining, 6 shows a connection in which the sleeve is used as an insertion end within a protective collar of the pipe is arranged, Fig. 7 shows a connection for concrete pipes similar to FIG. 4, the sleeve being designed as a double plug-in end according to FIG. 1 is, Fig. 8, 9 connections in which the concrete pipes are thickened at the ends on the outside autweise, Fig. 10, 11 connections for concrete pipes, which one with axial anchoring ribs have provided lining, wherein the sleeve is designed as a double insertion end and FIG. 12 shows a connection for concrete pipes similar to FIG. 10 or 11, the Sleeve designed as an insertion end and connected to the plastic lining is.

In Fig. 1 a connection of two pipes 2 and 4 is shown, whose axial end faces 6 and 8 are opposite one another. The pipes 2, 4, which hereinafter referred to as concrete pipes for better understanding, are made in a known manner from concrete or reinforced concrete. The concrete pipes 2, 4 are in the area of their ends 10, 12 inside as particularly flat plug-in sleeves 14, 16, in contrast to the well-known push-in socket pipes according to DIN 4032 and DIN 4036, formed and provided with plastic linings 18, 20. The plastic linings 18, 20 contain annular beads 22, 24 into which sealing rings 26, 28 are inserted are. The sleeve insert or plastic lining 18 of the pipe 2 extends practically over the entire length of the socket 14 and is in the concrete of the pipe 2 poured. It can be seen that due to the bead 22 a loosening of the Plastic lining 18 is prevented. It should be noted that also for the Concrete pipe 4 one of the plastic lining 18 corresponding lining is provided can be so that the concrete pipes at both pipe ends each have the same structure Alternatively, however, a plastic lining is provided for the pipe 4, which is designed as a ring with a U-shaped cross section. For such a trained plastic lining, a minimal cost of materials is required. It can be seen that there are numerous embodiments of plastic linings can give. In all cases, however, it is crucial that, on the one hand, the plastic linings are firmly connected to the pipes and on the other hand a liquid-tight Connection can be established or guaranteed because the sealing ring 26, 28 rests on smooth surfaces. The plastic lining 18, 20 consist of one thermoplasti's plastic, especially hard PVC, so that the desired shapes can be produced without difficulty. A sleeve 30 is inserted into the socket 14, 16 inserted as a double spigot end. The length 1 of the sleeve 30 is about twice that as large as the length of one of the mentioned push-in sleeves. The plastic pipe 30 has a comparatively large wall thickness s, which is predetermined such that the occurring shear loads can be absorbed or transferred. It has shown that the connection according to the invention with a thick sleeve made of plastic is made, these shear loads or loads can safely withstand. Appropriately is the ratio of wall thickness s to outside diameter a when using for example of hard PVC according to DIN 8061 in the range from 1:50 to 1:20. So through the sleeve the free flow cross-section is not reduced, the inside diameter is b of the sockets 14, 16 by at least twice the wall thickness s greater as the concrete pipe inside diameter c. The concrete pipes 2, 4 point over the entire Length to a constant outer diameter d. The concrete pipes are thus outside smooth and there are no bell sleeves according to DIN 4032, 4035 provided, so that When laying such sleeveless, smooth pipes, shoveling free in the area the pipe ends is not required. Unless the concrete pipes come with one here the reinforcement shown are provided, the generally quite expensive Work on the production of the reinforcement in the area of the bell sockets. Due to the Formation of the pipe ends according to the invention is thus particularly simple and Inexpensive production of the concrete pipes guaranteed. The compound of the invention ensures a highly functional seal with a minimum of effort the pipe ends, especially since neither during transport nor during laying damage # n or destruction of the completely covered plastic lining or the Concrete pipes themselves are to be feared. While the concrete pipes are often on for months Store construction sites, the sleeve with the sealing rings is only provided when laying, so that they are not destroyed or lost either. The sleeve 30 has at the ends conical tapers 44, 46 on the outside. These tapers 44, 46 are used for rapid Pressing the sealing rings 26, 28 when laying the concrete pipes 2, 4.

In Fig. 2 a connection is shown in which the sleeve 30 has two annular grooves 34, 36 on its outer surface 38. In the grooves 34, 36 sealing rings 26, 28 are in turn inserted to provide a seal with respect to the pipe ends 10, 12 or the plastic linings 18, 20. The plastic linings 18, 20 are in the area of the end faces 6, 8 with conical extensions 40, 42 provided. With this conical enlargement, the sealing ring is pushed together the concrete pipes are quickly pre-pressed with low insertion force. The sleeve 30, however, is at their ends with conical tapers 44, 46 for threading the sleeve 30 and Concrete pipes 2 4 provided. By means of the mentioned extensions or tapering, the laying of the pipes 2, 4 or the establishment of the connection is not insignificant relieved. For the plastic linings 18, 20 is the ratio of the wall thickness e to outer diameter f in the range from 1:80 to 1: 160 and is preferably about 1: 125. The wall thickness e is at least 2 to 3 millimeters. So that the linings can not slip out of the pipes, are expediently radially outward-facing approaches provided. The plastic linings 18, 20 instruct their ends remote from the end faces 86 have such an approach, which is designed as an annular rib 48, 49.

In the connection shown in Fig. 3, the sleeve 30 is axial Stop surfaces 50, 52 are provided. Each is opposite in the axial direction the plastic lining 18 or the pipe 4 with corresponding stop surfaces 54, 56 provided. The sealing rings 26, 28 are located between the abovementioned stop surfaces, wherein the sealing rings also on receiving surfaces opposite one another in the radial direction 60 to 66 of the plastic lining 18, 20 or the sleeve 30 rest. In the The connection shown in Fig. 3 are the concrete pipes 2, 4 in the region of the pipe ends Provided on the outside with thickenings 69, 70, if the pipe statics so require.

4 shows a connection in which the sleeve 30 designed as an insertion end (spigot end) and with the concrete pipe 2 at its end 10 itself is connected. here are the concrete pipes 2 and 4 with plastic linings 18, 20, which extend over the entire length of the pipe.

The sleeve 30 is firmly connected to the plastic lining 18. With the appropriate choice of material, the connection can be made by gluing or welding or potting. The plastic lining 20, however, is in the area of the Pipe end 12 designed as a socket into which the insertion end is inserted is, achieved by means of a single sealing ring 28 a reliable seal can be. Since the sleeve 30 protruding beyond the pipe end 10 is a comparatively has a large wall thickness s, there is no risk of damage or destruction.

In the connection according to FIG. 5, in the region of the pipe end 12 there is a compared to the rest of the plastic lining in the wall thickness reinforced plastic lining 20 is provided, which in turn is designed as a socket. Also this plastic lining 20 is similar to the sleeve by welding or gluing to the rest of the plastic lining of the pipe connected.

In Fig. 6 a connection is shown which essentially corresponds to the connection according to FIG. To protect the sleeve 30 is on the concrete pipe 2, however, a protective collar 68 is provided. The inner surface 72 of the protective collar 68 has a predetermined distance from the outer surface 74 of the pipe end 12. The mentioned Surfaces 72 and 74 therefore do not come into contact under any circumstances and the connection between concrete pipes 2 and 4 is used exclusively by means of the internal Sleeve 30 causes.

Fig. 7 shows a connection in which the sleeve 30 again as Doppeleinsteckende is formed. The plastic liners 18, 20 extend each over the entire length of the pipes 2, 4 and they are in the region of the pipe ends 10, 12 designed as plug-in sleeves, with annular beads for the sealing rings 26, 28 are provided.

The embodiments of the connection shown in FIGS. 8 and 9 contain, similar to the connection according to FIG. 3, reinforcements in the region of the pipe ends 69, 70. The linings 18, 20, which extend over the entire length of the pipe are designed as plug-in sleeves in the region of the pipe ends 10, 12. The sleeve 30 corresponds largely to the sleeve explained in connection with FIG. 2 and FIG. 3 and the the relevant explanations are also applicable here.

In Figs. 10-12 are preferred embodiments of the connection shown. Here, the points between the respective ends of the tubes 2 and 4, respectively located parts 76 and 78 of the plastic linings extending in the axial direction Anchoring ribs 80, 82 which extend radially into the concrete of the pipes 2 or 4 extend. In the area of the pipe ends 10, 12, the plastic linings have substantially annular plug-in sleeves 84, 86. The push-in sleeves 84, 86 are with said parts 76, 78 of the plastic lining by gluing, potting or welding firmly connected. In the connections according to FIG. 10 and FIG the sleeve 30 in turn as a double insertion end educated. Furthermore the sleeve 30 largely corresponds to the embodiments shown in Fig. 3 and Fig. 2, so that the relevant statements also apply here. When connecting according to FIG. 12, however, the sleeve is designed as an insertion end which is in the area of the pipe end 10 with said part 76 of the plastic lining of the pipe 2 is connected. The insertion end of the sleeve 30 is in the socket 86 of the concrete pipe 4 inserted. There is only a single sealing ring for the latter connection 28 required.

In the connection according to the invention, the measures explained above can be used or different embodiments are combined with one another without this the scope of the invention is left. In all cases, however, it is decisive that in the area of the pipe ends inside the same a sleeve with a comparative wire large wall thickness is provided, with which on the one hand the shear loads occurring transferred or

can be included and with which on the other hand a functionally reliable Sealing of the pipes is achievable. The embodiments relate to concrete pipes with circular cross-sections, but this does not limit the invention takes place on such cross-sections. Rather, the concrete pipes can also be used with the outside be provided with a foot or have egg-shaped (oval) cross-sections without that this leaves the scope of the invention.

LIST OF REFERENCE NUMERALS 2, 4 concrete pipes a sleeve outer diameter 6, 8 End faces b socket inside diameter 10, 12 pipe ends c concrete pipe inside diameter 14, 16 push-in sleeves d concrete pipe outer diameter 18, 20 plastic linings e Wall thickness 22, 24 beads f outside diameter 26, 28 sealing rings 1 length 30 sleeve see p Wall thickness 32 longitudinal axis 34, 36 grooves 38 outer surface 40, 42 extensions 44, 46 Tapers 48 49 approach 50, 52, 54, 56 stop surfaces 60, 62, 64, 66 receiving surfaces 68 protective collar 69, 70 thickenings 72 inner surface 74 outer surface 76, 78 parts 80, 82 anchoring ribs 84, 86 socket sleeves Blank page

Claims (22)

Claims 1., liquid-tight connection of pipes, in particular made of concrete, reinforced concrete or asbestos cement, which at least in the area of the pipe ends have a plastic lining, a sealing ring at least at one end of the pipe is provided, characterized in that within the pipe ends (10, 12) a Sleeve (30), preferably made of plastic, with a comparatively large wall thickness (s) is arranged, which is predetermined in such a way that the shear loads occurring are transferable, and that the sleeve (30) and / or the plastic lining (18, 20) at least one groove (34, 36) or bead (22, 24) or receiving surface (60 to 66) for the sealing ring (26, 28). 2. Liquid-tight connection according to claim 1, characterized in that that the pipe ends (10, 12) with their end faces (6, 8) each other in the axial direction opposite and that at least at one pipe end (10, 12) the plastic lining (18, 20) is designed as a socket and has an inner diameter (b), which is at least twice the wall thickness (s) of the sleeve (30) greater than the inner diameter of the pipe (c) is. 3. Liquid-tight connection according to claim 1 or 2, characterized in that that the tubes (2, 4) have a substantially constant over their entire length Have outer diameter (d). 4. Liquid-tight connection according to claim 1 or the following, characterized characterized in that the ratio of wall thickness (s) to outside diameter (a) of the Sleeve (30) is in the range from 1:20 to 1:50 and is preferably about 1:32. 5. Liquid-tight connection according to claim 1 or the following, characterized characterized in that the sleeve (30) made of a thermoplastic material, preferably made of hard PVC, or a thermosetting plastic, preferably polyurethane, is made. 6. Liquid-tight connection according to claim 1 or the following, characterized characterized in that the sleeve (30) at least one end on the outside, preferably one having a conical taper (44, 46). 7. Liquid-tight connection according to one of claims 1 to 6, characterized in that the sleeve (30) on its outer surface (38) at least has a groove (34, 36) for the sealing ring (26, 28). 8. Liquid-tight connection according to one of claims 1 to 6, characterized in that the sleeve (30) has at least one stop surface (50, 52) which has a stop surface (54, 56) of the concrete pipe or the plastic lining is assigned, and that between the said stop surfaces of the sealing ring (26, 28) is arranged (Fig. 2, 9, 10). 9. Liquid-tight connection according to one of claims 1 to 8, characterized in that the sleeve (30) is designed as a double insertion end and that at the pipe ends (10, 12) the pipes (2, 4) and / or the plastic linings (18, 20) are designed as plug-in sleeves into which the sleeve (30) is inserted (Figs. 1, 2, 3, 7, 8, 9, 10, 11). 10. Liquid-tight connection according to one of claims 1 to 8, characterized in that the sleeve (30) is designed as an insertion end, which with one end of the pipe or the plastic lining (18, 76) provided there, preferably by welding, casting or gluing, is firmly connected and that the pipe end (12) of the other pipe (4) and / or its plastic lining (20) is designed as a plug-in sleeve into which the sleeve (30) is inserted (Fig. 4, 5, 6, 12). 11. A liquid-tight connection according to claim 1 or the following, characterized in that the length (1) approximately twice the sleeve (30) as long as the length of a socket. 12. A liquid-tight connection according to claim 1 or the following, characterized in that in the case of the plastic lining (18, 20) the ratio from wall thickness (e) to outside diameter (f) is in the range from 1:80 to 1: 160 and is preferably about 1: 125. 13. Liquid-tight connection according to claim 1 or the following, characterized in that the plastic lining (18, 20) is made of a thermoplastic Plastic, preferably made of hard PVC, is made. 14. A liquid-tight connection according to claim 1 or the following, characterized in that the plastic lining (18, 20) has at least one bead (22, 24) for the sealing ring (26, 28) (Fig. 1, 4, 5, 6, 7). 15. A liquid-tight connection according to claim 1 or the following, characterized in that the plastic lining (18, 20) in the area of the end face (6, 8) of the tube (2, 4) (inside preferably conical enlargement (40, 42) (Fig. 3). 16. A liquid-tight connection according to claim 1 or the following, characterized in that the plastic lining at least one substantially has radially outwardly extending shoulder (48, 49) (Fig. 2, 3). 17. A liquid-tight connection according to claim 16, characterized in that that the projection (48, 49) is designed as an annular rib. 18. Liquid-tight connection according to claim 16 or 17, characterized characterized in that the projection (48, 49) on that of the end face (6, 8) of the pipe distal end of the plastic liner (18, 20) is arranged. 19. Liquid-tight connection according to one of claims 1 to 18, characterized in that the plastic lining (18, 20) only in the area of the Pipe end (10, 12) is provided (Fig. 1, 2, 3). 20. Liquid-tight connection according to one of claims 1 to # 8, characterized in that the plastic lining (1C, 20) over the entire axial length of a tube (2, 4) an essentially constant small wall thickness and designed as a socket in the region of at least one pipe end (10, 12) (Fig. 5g 6, 7, 8, 9). 21. Fluid-tight connection according to one of claims 1 to 18, the part of the plastic lining lying between the pipe ends on the The outer surface is provided with anchoring ribs running in the axial direction, characterized in that the plastic lining in the region of at least one pipe end (10, 12) is designed as a substantially annular plug-in sleeve (84, 86) which with said part (76, 78) of the plastic lining, preferably by gluing Potting or welding, firmly connected (Fig. 10, 11, 12). 22. A liquid-tight connection according to claim 21, characterized in that that the sleeve (30) is designed as an insertion end, which at the pipe end (10) of the a pipe (2) with said part (76) of the plastic lining, preferably by gluing, casting or welding, is firmly connected (Fig. 12).