DE102023101409A1 - Pipe connection system - Google Patents

Abstract

The present invention relates to a pipe connection system on a fluid-carrying line made of a plastic. In order to improve a pipe connection system of the type mentioned, it is proposed that the pipe connection system (1) comprises an insertion cone (12) with a flow (13) and a counter ring (14) on an end section (3) of the pressure line (2), wherein the end section (3) of the pressure line (2) is fixed and clamped in a sealing manner with a conically widened region (15) between an outer flank (16) of the insertion cone (12) and the counter ring (14).

Description

The present invention relates to a pipe connection system on a fluid-carrying pressure line made of a plastic. Such a pipe connection system can be used as an aseptic pipe connection and/or flange connection system, for example in the field of pharmaceutical and food technology, advantageously in food processing and here in particular in a food filling plant.

A pipe connection system of this type is used, for example, to connect a plastic pipe to a food processing machine. EP 2 162 384 B1 is a connection system for a pressurized fluid-carrying line that can be used in the food technology sector. An aseptic seal is achieved through a special geometry of the construction. The high demands on pressure and temperature resistance as well as acid and alkali resistance for approval in food technology require the use of special plastics, such as polytetrafluoroethylene, or PTFE for short. In order to enable hygienically perfect cleaning of such a line, including the areas of the line's pipe connection systems, it is proposed that the line, with a constant inner diameter, runs at each end area from a beveled transition via a constriction into an outwardly projecting end flange. This constriction is enclosed by two half-shells that engage with an internal thread of a union nut via an external thread. The union nut is designed as part of a mounting flange, which in turn can have a seal and recesses for screwing to a housing.

The present invention has the object of improving a pipe connection system of the type mentioned.

The above-mentioned object is achieved according to the invention by the features of claim 1 in that the pipe connection system comprises an insert cone with a flow on a flange and a corresponding clamping plate or a counter ring at an end section of the pressure line. An end section of the pressure line is fixed and clamped in a sealing manner with a conically widened area between an outer flank of the insert cone and the counter ring.

A significant disadvantage of the known solution described above is that it is made up of several parts. Handling several parts makes assembly difficult, whereby the safe handling of the two half shells at the end areas is particularly problematic under sometimes difficult installation conditions and parts often fall off and/or get lost. In contrast, a counter ring for each end section of the pressure line is arranged so that it can be moved through the conically widened area on the pressure line itself without the plug-in cone and yet cannot be lost, since an expansion of the conically widened end area advantageously has a larger diameter than the counter ring.

Furthermore, the manufacture of a constriction at each end of the known pressure line is complex. Since sufficient mechanical stability of the fluid-carrying pressure line must also be ensured in this area, an increased wall thickness is required for the entire line, which leads to a significantly increased use of material overall. An alternative in which the fluid-carrying pressure line is made of metal, and in particular of stainless steel, instead of plastic, has the major disadvantage that the pressure line can no longer be made transparent, so that a purely optical inspection is then ruled out. According to the invention, a plastic line is also used, whereby a conically widened end area can be produced from a material deformation without any material removal. The wall thickness of the pressure line can thus be designed over its entire length solely for mechanical stress in regular operation with corresponding safety margins, or without additional material thickenings etc. at an end area.

According to the invention, a reduced number of components is now provided with a simplified preparation of the end areas of the pressure line. This facilitates production and assembly, as will be described below using exemplary embodiments with reference to the drawing.

Advantageous further developments are the subject of the dependent claims. Accordingly, the plug-in cone with the counter ring are designed as metal parts and together form a flange. Metal parts can be designed to withstand mechanical, thermal and chemical stresses sufficiently and can be manufactured inexpensively. The plug-in cone and counter ring can be manufactured as turned parts, among other things. As a structural unit, a flange forms a mechanically reliable closure of a fluid-carrying pressure line to any subsequent connection area, such as a tank.

According to a preferred embodiment of the invention, a sealing ring is provided between an outer flank of the conically widened area of the end section of the pressure line and the counter ring. This area is advantageously never in contact with a medium located or transported in the fluid-carrying pressure line. Therefore, no special material requirements arise for the sealing ring, e.g. with regard to food approval or special chemical resistance. In this case, inexpensive standard components, in particular O-rings made of an elastomer, can be used.

In one embodiment of the invention, an annular bulge or concentric ring is arranged on the outer flank of the plug-in cone in an area in which the plug-in cone is in contact with the conically widened area of the end section of the pressure line in an installed position. This ring is preferably formed integrally on the plug-in cone and designed in such a way that the ring presses into the material of the conically widened area of the fluid-carrying pressure line when the flange formed by the plug-in cone and counter ring is closed. In this way, in addition to an additional seal, a further mechanical fixation of the end section of the pressure line to the flange is created at this point.

Preferably, alternatively or additionally, a concentric ring is integrally formed on the counter ring in an area in which the counter ring is in contact with the conically widened area of the end section of the pressure line in an installed position. This creates an additional seal in an outer area that is always free of media and also a further mechanical fixation of the end section of the pressure line to the flange.

In a preferred embodiment of the invention, the ring bead has a triangular cross-sectional area. This ring thus forms a closed groove with a triangular cross-sectional area in the material of the conically widened area of the end section of the pressure line, which can absorb high tensile forces and also forms a reliable sealing surface.

Advantageously, a ring is provided on the counter ring and on the plug-in cone. These rings are arranged offset from one another relative to the conically widened area of the end section of the pressure line. This makes it easy to avoid excessive mechanical stress on the material of the conically widened area of the end section of the pressure line.

Preferably, different or differently sized angles α, β are selected between the insertion cone and the counter ring from an interval of approximately 30° to approximately 60° with the proviso that a main pressure is greatest at an inner diameter of the line and decreases towards the outside.

In a further development of the invention, the plug-in cone and the counter ring are fixed and connected to one another by means of screw bolts. When assembling the flange, no forces act in a radial direction on the conically widened area of the end section of the pressure line, but essentially only along a longitudinal axis. This can also advantageously be used to center the arrangement.

Preferably, the plug-in cone is designed as a connection part to a container and has adapted means for sealing and fixing, as described below by way of example by additional recesses for screw bolts arranged distributed around a circumference.

A pipe connection system as described above is characterized by several cost savings due to a lower processing effort and a smaller number of individual parts per flange element. In addition, a pipe connection system as described can be optimized in terms of flow rate and enables faster filling with a simplified manufacturing process and less use of plastic than with the prior art mentioned thanks to a larger inner diameter with the same outer diameter and a reduced wall thickness. Captive counter rings on the flanges, which are already applied during the manufacture of the pipe, secure and simplify the assembly of a connection that can absorb very high tensile forces. According to preferred embodiments of the invention, an additional seal in the form of an O-ring is located outside of a media-contact area. For simple optical flow control, transparent PTFE pipes can also be used for the pressure-resistant fluid lines, which can be installed better than, for example, elements made of steel due to their flexibility. In addition, a device according to the invention is significantly more resistant to temperature changes that frequently occur during regular operation than metal components.

• 1: eine Schnittdarstellung entlang einer Längsachse eines ersten Ausführungsbeispiels eines Rohr-Anschlusssystems an einer fluidführenden Druck-Leitung;
• 2: eine Einzelheit X von 1;
• 3: eine Schnittdarstellung eines zweiten Ausführungsbeispiels eines Rohr-Anschlusssystems analog 1;
• 4: eine Einzelheit Y von 3;
• 5: eine Draufsicht auf die Ausführungsbeispiele der 1 und 3;
• 6: eine Schnittdarstellung einer Weiterbildung des Ausführungsbeispiels von 3;
• 7: eine Einzelheit Z von 6;
• 8: eine Schnittdarstellung eines bekannten Rohr-Anschlusssystems und
• 9: eine Schnittdarstellung eines Endabschnitts der bekannten Druckleitung aus 8.

Further features and advantages of embodiments according to the invention are explained in more detail below with reference to exemplary embodiments based on the drawing. In this drawing, in a schematic representation:

• 1 : a sectional view along a longitudinal axis of a first embodiment of a pipe connection system on a fluid-carrying pressure line;
• 2 : a detail X of 1 ;
• 3 : a sectional view of a second embodiment of a pipe connection system analogous 1 ;
• 4 : a detail Y of 3 ;
• 5 : a top view of the embodiments of the 1 and 3 ;
• 6 : a sectional view of a further development of the embodiment of 3 ;
• 7 : a detail Z of 6 ;
• 8th : a sectional view of a known pipe connection system and
• 9 : a sectional view of an end section of the known pressure pipe from 8th .

The same reference numerals are used for the same elements throughout the various illustrations of the drawing. Without limiting the invention, only one use of embodiments of the invention in food technology in the form of a pipe connection system is shown and described below, whereby a disclosed connection system can also be used for even more flexible lines and in particular also for hoses with non-round cross-sectional contours, such as square on the outside.

The illustration of 8th presented a sectional view of a pipe connection system 1 according to the EP 2 162 384 B1 Here, a PTFE tube 2 is enclosed at an end region 3 in the region of a taper or constriction 4 by two half-shells 5. A union nut 6 is pushed over the two half-shells 5 and screwed to a connection flange 7, which can also be part of a container or similar not shown in more detail. The connection flange 7 has a groove in which a seal 8 in the form of an O-ring ensures a dead space-minimized seal of the connection flange 7 with a front edge 9 of a projecting end flange 10 of the end region 3 of the PTFE tube 2, designed as a sealing surface.

9 shows a sectional view of the end section of the PTFE pressure line of 8th before installation. From this it can be seen that with an outer diameter D a comparatively small inner diameter d is available for a free flow of a fluid, because a sufficiently strong wall of the pipe 2 must also be available in the area of the taper or constriction 4. To facilitate assembly, the taper or constriction 4 is extended, whereby a transition in the form of a ramp from the outer diameter D to the taper 4 must be manufactured by turning off excess material to increase mechanical load-bearing capacity. The projecting end flange 10 of the end region 3 is arranged opposite this ramp, on which an expansion 11 of the free flow area is also manufactured by turning on the front edge 9.

In addition to the complex manufacturing of the end areas 3 of a pipe 2, the handling of the many individual parts during assembly and installation of this known pipe connection system 1 is particularly disadvantageous. In order to improve a pipe connection system of the type described above, 1 a first embodiment of a pipe connection system 1 on a fluid-carrying pressure line 2 is shown in a sectional view along a longitudinal axis. The pipe connection system 1 comprises an insert cone 12 with an axial bore as a flow 13 at an end section 3 of the pressure line 2, the inner diameter of which corresponds to the inner diameter d of the pressure line 2. The pipe connection system 1 also comprises a counter ring 14, wherein the end section 3 of the pressure line 2 is fixed and clamped in a sealing manner with a conically widened region 15 between an outer flank 16 of the insert cone 12 and the counter ring 14.

The plug-in cone 12 and the counter ring 14 are designed as metal parts, here as turned parts. Together, the plug-in cone 12 and the counter ring 14 form a tight flange on the pressure line 2 that can withstand high mechanical loads, even under tensile stress. To increase the pressure resistance, a sealing ring 8 is provided between an outer surface 17 of the conically widened area 15 of the end section 3 of the pressure line 2 and the counter ring 14 in a groove 18, as shown enlarged as detail X in 2 shown. In this area, the sealing ring 8 - in contrast to the known pipe connection system 1 - is advantageously never in contact with the fluid guided in the pressure line 2. Since this creates an aseptic seal, an inexpensive standard part made of an elastomer can be used as an O-ring for the sealing ring 8, which does not necessarily have to comply with strict food-related regulations, such as FDA, but is nevertheless preferable. The hardness of this sealing ring 8 is approximately 60-90 Shore A.

Furthermore, in 2 It can be seen that on the counter ring 14 in an area in which the counter ring 14 in the illustrated installation position is in contact with the conically widened area 15 of the end section 3 of the pressure line 2, a ring 19 or annular bead is arranged. This ring 19 is formed integrally on the counter ring 14. Formed as a concentric ring 19, it also has a triangular cross-sectional area which, when the flange is tightened, is pressed into the material of the pressure line 2 to form a mechanical toothing and an additional seal.

Contact surfaces on the plug-in cone 12 and the counter ring 14 are at an angle of between approximately 30° and approximately 60°. Furthermore, the surfaces on the plug-in cone 12 and the counter ring 14 that are in contact with the conically widened area 15 are set at different angles α, β. This ensures that a main pressure on an inner diameter of the line 2 is greatest by using a steeper angle α and decreases outwards towards an annular cavity 21 within the flange by using a less steep angle β.

The illustration of 3 shows a sectional view of a second embodiment of a connection system analogous 1 Here, the counter ring 14 has a lower height. The groove 18 for the sealing ring 8 has an adapted geometry to match this. In the installed position, the counter ring 14 and the plug-in cone 12 no longer lie flat or clamped together "on block", but rather a hollow space 21 that is open to the outside now adjoins the conically widened area 15 of the end section 3 of the pressure line 2.

As can be seen from the enlarged detail Y of 3 in 4 As can be clearly seen, a ring 20 is arranged on the outer flank 16 of the plug-in cone 12 in an area in which the plug-in cone 12 in the indicated installation position is in contact with the conically widened area 15 of the end section 3 of the pressure line 2. The ring 20 is again formed concentrically in one piece on the plug-in cone 12 as an annular bead. The height of the ring 19, 20 or the annular closed bead is approximately 10-30% of the wall thickness of the pipe 2.

As a comparison with the figure of 2 shows, in an embodiment not shown in detail, at least one ring 20 on the counter ring 14 and at least one ring 19 on the plug-in cone 12 can be arranged relative to the conically widened region 15 of the end section 3 of the pressure line 2, preferably offset from one another.

5 finally shows a top view of the embodiments of the 1 and 3 Accordingly, the counter ring 14 has radially distributed recesses 22 which correspond to corresponding threaded holes 23 on the plug-in cone 12 for receiving screw bolts. For this purpose, in this embodiment, recesses 24 are provided which are offset by 90° on the circumference and pass through both components of the flange, via which a flange connection described above with a pressure line 2 fixed in a sealing manner can be screwed onto a container (not shown in more detail), for example using an additional seal.

The illustration of 6 shows a sectional view of a further development of the embodiment of 3 Here, the counter ring 14 has been supplemented by a protective seal 25 that acts outwards. This component is intended to facilitate cleaning in the area of the pipe connection system 1, among other things. In addition, mechanical stability in the transition from the pipe connection system 1 to the pipe 2 is increased by the protective seal 25.

7 represents as detail Z of 6 Details of a structure of the protective seal 25 and an adaptation of the counter ring 14 by adding an additional radial groove 26, into which a part of an inner lip 27 of the protective seal 25 engages. An outer lip 28 of the protective seal 25, arranged opposite the inner lip 27, rests against the pipe 2 in order to simplify cleaning of the pipe connection system 1 on the outside.

• PVC: ~ 130 N/mm²
• PP: ~ 72 N/mm²
• PE: ~ 38 N/mm²
• PVDF: ~ 95 N/mm²

oder unter Angabe von jeweiligen Werten einer Shore-Härte:

• PP: 70 Shore D
• PE: 64 Shore D
• UHMWPE: 61 Shore D
• PFA: 60 Shore D
• PVDF 78 Shore D
• FEP: 60 Shore D
• PK: 75-85 Shore D

In the embodiments described above, PTFE HS 11007 with a ball indentation hardness of approximately 22.5 N/mm ² to approximately 35 N/mm ² is preferably used as the material for the tube 2. Other materials that can potentially be used for other applications with their typical ball indentation hardnesses are, for example:

• PVC: ~ 130 N/ ^mm2
• PP: ~ 72 N/ ^mm2
• PE: ~ 38 N/ ^mm2
• PVDF: ~ 95 N/ ^mm2

or specifying the respective Shore hardness values:

• PP: 70 Shore D
• PE: 64 Shore D
• UHMWPE: 61 Shore D
• PFA: 60 Shore D
• PVDF 78 Shore D
• FEP: 60 Shore D
• PK: 75-85 Shore D

Pipe 2 is designed for an operating pressure of between 1-8 bar, although a larger range cannot be ruled out in an application. For safety reasons, a bursting pressure of pipe 2 is set at 30 bar. An operating temperature of the medium carried in pipe 2 in the pressure range mentioned is between approx. 4-140°, although larger temperature ranges cannot be ruled out here either. In the exemplary embodiments, a wall thickness of around 3.5 mm with d≈15.5 mm and D≈22.5 mm has been provided, which can also be flexibly adjusted depending on the required operating or bursting pressure. For this purpose, it is advantageously not necessary to make any changes to the dimensions of the plug-in cone 12 and the associated counter ring 14.

The embodiments described above offer not only simplified production with less material used, but also advantages in handling, which enable simpler, faster and safer assembly of an aseptic connection to a pressure fluid line. The respective geometry and type of fastening and in particular the number of recesses are only examples. Furthermore, a design in the form of an oval or square flange can also be easily implemented, depending on the requirements of an application.

List of reference symbols

1

Pipe connection system

2

Polytetrafluoroethylene (PTFE) tube

3

End area / end section of pipe 2

4

Tapering / constriction at the end area 3 of the pipe 2

5

Half shell

6

Union nut

7

Connection flange

8th

Seal in the form of an O-ring in the connection flange 7

9

Front edge, designed as a sealing surface

10

protruding end flange 10 of the end section 3

11

Widening of a free flow area at the front edge 9

12

Insert cone

13

Flow in the form of an axial bore

14

Counter ring

15

conically widened area 15 of the end section 3

16

Outer flank of the insert cone 13

17

Outer surface of the conically widened area 15

18

Groove for receiving the sealing ring 8

19

Ring, integrally formed on the plug-in cone 12

20

Ring, integrally formed on the counter ring 14

21

Cavity within the flange

22

Recess in the counter ring 14

23

Threaded hole in the insert cone 12

24

Recess for fixing the flange

25

Protective seal

26

additional radial groove of the counter ring 14

27

inner lip of the protective seal 25

28

outer lip of the protective seal 25

d

Inner diameter

D

outer diameter

α

Angle on the insertion cone 12

β

Angle on the counter ring 14

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• EP 2162384 B1 [0002, 0020]

Claims (10)

Pipe connection system on a fluid-carrying pressure line made of a plastic, characterized in that the pipe connection system (1) comprises an insertion cone (12) with a flow (13) and a counter ring (14) on an end section (3) of the pressure line (2), wherein the end section (3) of the pressure line (2) is fixed and clamped in a sealing manner with a conically widened region (15) between an outer flank (16) of the insertion cone (12) and the counter ring (14). Pipe connection system according to the preceding claim, characterized in that the plug-in cone (12) with the counter ring (14) are designed as metal parts and together form a flange. Pipe connection system according to one of the preceding claims, characterized in that a sealing ring (8) is provided between an outer surface (17) of the conically widened region (15) of the end section (3) of the pressure line (2) and the counter ring (14). Pipe connection system according to one of the preceding claims, characterized in that a ring (19) or a closed ring bead is arranged on the counter ring (14) in a region in which the counter ring (14) in an installed position is in contact with the conically widened region (15) of the end section (3) of the pressure line (2), which ring is preferably formed in one piece on the counter ring (14). Pipe connection system according to one of the preceding claims, characterized in that a ring (20) is arranged on the outer flank (16) of the plug-in cone (12) in a region in which the plug-in cone (12) in an installed position is in contact with the conically widened region (15) of the end section (3) of the pressure line (2), which ring is preferably formed in one piece on the plug-in cone (12). Pipe connection system according to one of the two preceding claims, characterized in that the concentric ring (19, 20) has a triangular cross-sectional area. Pipe connection system according to one of the three preceding claims, characterized in that a ring (20) on the counter ring (14) and a ring (19) on the insertion cone (12) are arranged offset from one another relative to the conically widened region (15) of the end section (3) of the pressure line (2). Pipe connection system according to one of the preceding claims, characterized in that different or differently large angles (α, β) are selected from an interval of approximately 30° to approximately 60° between the plug-in cone (12) and the counter ring (14) with respect to one another, with the proviso that a main pressure is greatest at an inner diameter of the line (2) and decreases towards the outside. Pipe connection system according to one of the preceding claims, characterized in that the plug-in cone (12) and the counter ring (14) are fixed to one another by screw bolts and are connected to one another in a centering manner. Pipe connection system according to one of the preceding claims, characterized in that the plug-in cone (12) is designed as a connection part to a container or the like and has means for sealing and fixing adapted thereto.

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