DE202022101573U1 - Arrangement for filling and topping up a heating circuit - Google Patents

Abstract

Fitting arrangement (10) for filling and/or topping up heating circuits, containing
(a) a multi-part fitting housing (12, 28, 38) with a connection housing part (12) which can be installed in a pipeline leading to the heating circuit and has a lockable inlet (14) and a lockable outlet (16);
(b) a system separator assembly (40) having upstream and downstream check valves (42, 44) and a drain assembly (48); and
(c) a pressure reducer (30); characterized in that
(e) the system separator arrangement (40) and the pressure reducer (30) are arranged in different housing parts (28, 38) which can be detached from one another; and
(f) the housing parts (28, 38) of the system separator arrangement (40) and the pressure reducer (30) each have a flange for a flange connection (36) via which the flow path between the system separator arrangement (40) and the pressure reducer (30) can be established and which is separable, so that an adapter housing part (88) can optionally be installed between the flanges, which has additional connections for a water treatment device (104) in the flow path.

Description

technical field

1. (a) ein mehrteiliges Armaturengehäuse mit einem in eine zu dem Heizkreislauf führende Rohrleitung einbaubaren Anschlussgehäuseteil, welches einen absperrbaren Einlass und einem absperrbaren Auslass aufweist;
2. (b) eine Systemtrenneranordnung mit einem stromaufwärtigen und einem stromabwärtigen Rückflussverhinderer und einer Ablaufanordnung; und
3. (c) einen Druckminderer.

The invention relates to a fitting arrangement for filling and/or topping up heating circuits, containing

1. (a) a multi-part fitting housing with a connection housing part that can be installed in a pipeline leading to the heating circuit and has a lockable inlet and a lockable outlet;
2. (b) a system separator assembly having upstream and downstream backflow preventers and a drain assembly; and
3. (c) a pressure reducer.

Heating systems are filled with water by means of such an arrangement of fittings and refilled if there is a loss of water. It is important that the water meets all the requirements of a modern heating system. This includes treating the water in various ways. Treatment is, for example, softening, desalination, stabilization of a pH value, disinfection, irradiation, addition of chemicals, and the like. A stable pH value can be set with a stabilizer. This avoids corrosion. Depending on the manufacturer's requirements, the water can be softened or desalinated to prevent limescale deposits. If the specifications do not require full desalination but a certain degree of hardness, the water treated in an ion exchanger can be blended with raw water to a desired degree of hardness. The water can also be filtered and stabilized to the required pH. Important aspects of water treatment and purification are explained in the VDI guideline VDI2035 "Avoidance of damage in hot water heating systems". It is advantageous if the water is available at a desired pressure.

A system separator arrangement ensures that no water from the heating circuit can flow back into the water supply. If the non-return valve is defective and the inlet pressure drops, a drain valve opens and water flows out. The filling pressure is regulated with a pressure reducer.

State of the art

The applicant sells heating fittings for filling heating circuits under the name “Füllkombi”. Under the name "heating center" the applicant sells combination fittings in which a system separator and a filter are arranged in separate housings one behind the other. Examples of heating fittings are in EP 2 988 069 B1 and EP 2 778 560 B1 described.

The blending of treated drinking water with raw water is known. EP 3 406 806 B1 , for example, describes a blending fitting that has a flat connection flange for connecting to a drinking water supply, a flat connection flange parallel thereto for connecting a filter and, in addition, two socket-shaped connections for connecting a water treatment unit.

DE 20 2009 001 957 U1 discloses a modular arrangement in which backflow preventers, water softening arrangements, filters and pressure reducers can be assembled as modules one behind the other with flange connections to form an arrangement. Each module has its own housing. The installation effort is comparatively high.

Heating fittings have to be adapted to different installation situations and requirements. For example, the water may flow through the pipe in different directions, or softening may or may not be necessary. In the case of fittings with freedom of choice, there is a risk of incorrect installation, for example if the connection hoses of the decalcifying device have been mixed up.

Disclosure of Invention

• (e) die Systemtrenneranordnung und der Druckminderer in unterschiedlichen, voneinander lösbaren Gehäuseteilen angeordnet sind; und
• (f) die Gehäuseteile der Systemtrenneranordnung und des Druckminderers jeweils einen Flansch für eine Flanschverbindung aufweisen, über welche der Strömungsweg zwischen Systemtrenneranordnung und Druckminderer herstellbar ist und welche trennbar ist, so dass zwischen den Flanschen optional ein Adaptergehäuseteil installierbar ist, welches zusätzliche Anschlüsse für eine Wasserbehandlungseinrichtung im Strömungsweg aufweist.

It is the object of the invention to create a fitting arrangement of the type mentioned at the outset, which can be flexibly adapted and is easy to install. According to the invention, the object is achieved in that

• (e) the system separator arrangement and the pressure reducer are arranged in different housing parts which can be detached from one another; and
• (f) the housing parts of the system separator arrangement and the pressure reducer each have a flange for a flange connection, via which the flow path between the system separator arrangement and the pressure reducer can be established and which can be separated, so that an adapter housing part can optionally be installed between the flanges, which provides additional connections for a water treatment device has in the flow path.

In this way, the fittings are suitable for both heating circuits that require water treatment and those that do not require water treatment. There are installation situations where no water action is required. This can be the case if the heating circuit does not require it, the water has already been softened elsewhere, or because the raw water has a particularly low lime content. Then the fitting arrangement can be used in a simpler variant without water treatment, in which the housing parts of the system separator and the pressure reducer are connected directly to the flange connection. If water treatment is required, the flange connection can be split and an adapter body installed in between. A water treatment device can be integrated into the flow path via the adapter housing part. In this way, the arrangement of the fittings allows adaptation to the installation requirements. The fitting arrangement can be manufactured in larger quantities and thus more cost-effectively.

In one embodiment of the invention, the inlet and outlet are arranged coaxially. System separator and pressure reducer can be arranged on the axis. This leads to a large overall length. It is therefore advantageous if the flow is guided out of the axis along a section, for example downwards, and the system separator and pressure reducer are arranged below the pipe axis. A compact arrangement is achieved when the plane of the flange connection extends perpendicularly to the connection axis between the inlet and the outlet.

It is particularly advantageous if at least one of the further housing parts is rotatably connected to the connection housing part. This enables easy access to the housing parts with system separator and pressure reducer, regardless of the installation situation. Pivotability can be achieved with a clip connection that allows rotation but prevents movement in the axial direction.

The housing part, in which the pressure reducer is arranged, is advantageously connected to the connection housing part so that it can rotate about an axis which extends perpendicularly to the connection axis between the inlet and the outlet. If the fitting arrangement is installed in a pipeline routed on the wall, the housing part with the pressure reducer can be moved away from the wall.

Provision is advantageously made for the fitting arrangement to additionally have one or more of the following functionalities: pressure sensor, conductivity sensor, volume flow meter, test connection. One or more pressure sensors enable the pressure prevailing in the heating circuit to be recorded. If the pressure drops, the shut-offs can be opened and water can be refilled until the pressure reaches a desired value again. Test connections for testing the inlet pressure, the medium pressure between the non-return valves and the outlet pressure can be provided to test the functionality of the system separator. The conductivity can be determined with a conductivity sensor. A high conductivity is an indication of depletion of the ion exchange granulate in an ion exchange water treatment device. A volume flow meter determines the volume flow through the valve arrangement. If the hardness of the raw water is known, the degree of exhaustion of the ion exchanger can be determined. In addition, a volume flow meter enables leakage detection.

The shut-off at the inlet can be manually operated. However, it is also possible for the inlet to be provided with a controllable, motor-operated shut-off. A control unit can be provided, with which sensor signals can be evaluated and displayed and on which manipulated variables of the functionalities can be set. In particular, the motor-driven barrier can also be operated with the control unit.

An adapter housing part can be installed between the flanges, which adapter housing part has additional connections for a water treatment device in the flow path. The adapter housing part can advantageously be provided with a blending device. With the blending device, raw water can be added to the treated water in a determinable mixing ratio, so that it has the desired water hardness or other properties.

A water treatment device, for example an ion exchanger, has an inlet and an outlet that are to be connected to the fitting arrangement with pressure-resistant hoses. The risk of mixing up the two separate connections can be avoided if the connection for the water treatment device is arranged coaxially in the other of the connections. The inner hose is connected to the inlet and the outer hose to the outlet or vice versa. Then only a single connection needs to be made and the connections cannot be mixed up.

A water treatment device can be connected to the additional connections of the adapter housing part via a single-tube hose arrangement, which comprises a pressure-resistant outer hose and an inner hose guided coaxially therein, the inner hose and the space between inner and outer hose are separated from each other and flow-guiding. A single-tube hose arrangement has the particular advantage that only a single pressure-resistant hose with additional reinforcement using a metal mesh or similar has to be used. The inner hose is exposed to approximately the same pressure from the outside and the inside and can therefore be designed as a simple plastic hose.

There are various water treatment options mentioned at the beginning. In conventional heating circuits, it is advantageous if the water treatment device includes ion exchange granules for softening the water that is passed through. Water is completely softened with ion exchange granulate. A desired degree of hardness can be set by blending with raw water. Alternatively, physical softening devices, filters, dosing devices and the like can be used instead or in addition.

A water treatment device which can be connected to connections of a water fitting via a single-pipe hose arrangement, which comprises a pressure-resistant outer hose and an inner hose guided coaxially therein, with the inner hose and the space between the inner and outer hose being separate from one another and designed to conduct flow not only be used in the heating fitting mentioned, but also for drinking water fittings.

Refinements of the invention are the subject matter of the dependent claims. An embodiment is explained in more detail below with reference to the accompanying drawings.

character list

• 1 Figure 12 is a side view of a fitting assembly for filling and topping up heating systems.
• 2 Figure 12 is a plan view of the assembly 1 .
• 3 Figure 12 is a longitudinal vertical section through the assembly 1 .
• 4 is a compared to the cutting plane in 3 Vertical section offset by an angle of 90° through the arrangement 1 .
• 5 Fig. 12 is a side view of the arrangement 1 with thermal insulation shell.
• 6 Figure 12 is a plan view of the assembly 5 .
• 7 shows the arrangement of the fittings 1 with adapter for connecting a water treatment assembly.
• 8th Figure 12 is a plan view of the assembly 7 .
• 9 Figure 12 is a longitudinal vertical section through the assembly 7 .
• 10 shows a detail 9 .
• 11 Figure 12 is a plan view of the assembly 7 , whereby parts of the fitting are screwed out of the pipe axis.
• 12 12 is a perspective view of the assembly of FIG 11 .
• 13 indicates an enlargement 3 .

Description of the embodiment

The figures show a fitting arrangement, generally designated 10, for filling and refilling heating circuits with water from a water supply, such as a drinking water supply. The arrangement 10 comprises a multi-part fitting housing with a connection housing part 12. Raw water from the water supply flows into the connection housing part 12 at an inlet 14 in the direction of arrow 22 and treated water flows out of the fitting housing 10 in the direction of arrow 24 at a coaxial outlet 16 . The fitting assembly 10 is installed in a conventional manner in a pipeline (not shown) which supplies water to the heating circuit. The inlet 14 can be shut off with a ball valve 18 . The outlet 16 can be shut off with a ball valve 20 .

A socket 26 is formed on the underside of the connection housing part 12 . A housing part 28 with a pressure reducer 30 is attached to the socket 26 . The housing part 28 is connected to the socket 26 of the connection housing part 12 such that it can be rotated about a vertical axis 27 . A clip 32 is pushed through openings in the housing part 28 onto the socket 26 for fastening. The clamp 32 sits in an annular groove on the outside of the socket 26. In this way the connection is freely rotatable and secured in the axial direction.

A receptacle for the pressure reducer 30 is provided coaxially to the connecting piece 26 on the underside of the housing part 28 . Pressure reducers are well known and therefore do not need to be explained in more detail here. With the pressure reducer 30, the pressure behind the pressure-reducing valve is regulated to a desired outlet pressure. The adjusting handle 34 for setting the desired outlet pressure protrudes downwards and is easily accessible there. The housing part 28 has a lateral flange 36 on. The flange 36 is in the in 3 shown position in a vertical plane, which is perpendicular to the connection axis between inlet 14 and outlet 16.

A further housing part 38 with a system separator 40 is flanged onto the flange 36 . this is in 3 clearly visible. The system separator 40 comprises an upstream non-return valve 44 and a downstream non-return valve 42. Between the non-return valves is an intermediate pressure chamber 46 which is connected to the atmosphere via a discharge funnel 48. System separators are generally known and therefore do not need to be described in more detail here. The system separator 40 ensures that no water from the heating circuit can flow back into the water supply, even if the inlet pressure drops.

To check the functionality of the system separator 40 three test connections 47, 50 and 52 are provided in the usual way. The test connection 47 is located on the inlet side upstream of the non-return valve 44 on the upper side of the housing part 38. The test connection 50 ( 1 ) is arranged on the side of the housing part 38 and connected to the medium-pressure chamber 46 between the non-return valves 42 and 44. The test terminal 52 is provided on the terminal housing part 12 . The outlet pressure behind the pressure reducer 30 can be recorded at the test connection 52 or water can be taken for the titration.

A control unit 54 is arranged on the upper side of the connection housing part 12 . The controller 54 receives the signals from various sensors 56 , 62 , 70 , 74 . A pressure sensor 56 is connected to the input channel 60 of the connection housing part 12 via a bore 58 . A pressure sensor 62 is connected to the outlet channel 66 of the connection housing part 12 via a bore 64 . Inlet channel 60 and outlet channel 66 are separated from one another by a wall 68 . A conductivity sensor 70 determines the conductivity in the outlet channel 66. A turbine 72 is arranged in the outlet channel 66 downstream of the conductivity sensor 70. FIG. The turbine movement generated by the flow is detected with a reed contact 74 and the signal is transmitted to the control unit 54 .

The signals from the sensors 56, 62, 70, 74 are transmitted to the control unit 54, where they can be evaluated, stored and displayed on a display 76 ( 6 ) are displayed. For example, the outlet pressure detected by the pressure sensor 62 can be shown on the display 76 while it is being adjusted with the adjusting handle 34 on the pressure reducer 30 . Leakage or undesired flow conditions can be determined from the volumetric flow through the outlet channel 66 detected with the turbine 72 and the reed contact 74 . The degree of hardness can be determined from the conductivity measured with the conductivity sensor 70 . Undesirably high degrees of hardness are an indication that desalting or softening is necessary or that the softening is not sufficient.

The condition of the water can be indicated with a red and green LED 78, 81 next to the display 76 on top of the controller. A red LED 78 illuminates when the water is not in the desired condition, such as because a reading is outside of the set point. A green LED 81 lights up when everything is ok.

The arrangement described works as follows: Water flows at the inlet 14 and through the opened ball valve 18 into the inlet channel 60 of the connection housing part 12. In front of the wall 68, the water flows via the connection piece 26 into the housing part 28. In the connection piece 28 there is a pipe part 80 out, which is connected to the outlet channel 66. From the inlet channel 60, the water flows down past the pipe part 80 on the outside and over the flange 36 into the housing part 38. The flange 36 connects a central channel 84 and an annular channel 82, which is routed around the central channel 84. From the flange, the water flows outside in the annular channel 82 from left to right in the illustration into the housing part 38 and in the central channel 84 from right to left in the illustration back out again into the housing part 28.

The system separator 40 with the backflow preventers 42 and 44 is arranged in the central channel 84 . After passing through the system separator 40, the water flows through the valve of the pressure reducer 30 upwards in the illustration into the pipe part 80. The pipe part 80 is connected to the in 3 horizontal outlet channel 66 in the connection housing part 12 connected. The pressure, the conductivity and the volume flow are determined in the outlet before the water flows through the open ball valve 20 into the heating circuit. When the target pressure in the heating circuit is reached, the ball valve 18 can be closed. Then no more water flows into the heating circuit.

In order to automate the filling and refilling process, the ball valve 18 on the inlet side can be operated with a motor which is controlled by the control unit 54 . If the pressure sensor 62 detects a drop in pressure in the outlet area and thus in the heating circuit, the ball valve 18 is opened and water is refilled. A motor-driven ball valve, together with the volumetric flow measurement through the turbine 72, can also form leakage protection. A permanent or strong Loss of water in the heating circuit is then interpreted by the control unit 54 as a leak. In the event of a leak, the heating circuit is not refilled, but the ball valve 18 is shut off. After the cause of the water loss has been clarified and, if necessary, eliminated, the ball valve 18 can be opened again.

The assembly described above may be encased in a removable, insulating sleeve 86 made of several parts, such as polystyrene or the like. this is in 5 , 11 and 12 illustrated.

The arrangement described can be equipped or retrofitted with water treatment equipment in the form of a softening device. The arrangement with softening device is in the 7 until 12 illustrated. It can be seen that the housing part 38 is not directly flanged to the housing part 28, but an adapter housing part 88 is installed in between. The adapter housing part 88 has two parallel flanges 90 and 92 for this purpose. The flange 90 connects the adapter housing part 88 to the housing part 28 with the pressure reducer 30. The housing part 38 with the system separator is connected to the flange 92.

10 shows the adapter housing part 88 in detail. The water flows from the ring channel 82 into a corresponding ring channel in the adapter housing part 88 and from there, as described above, into the housing part 38 and through the system separator back into the adapter housing part 88.

The adapter housing part 88 has a socket 94 for a single-tube connection on the underside. An inner tube 96 is guided in the socket 94 . A pressure-resistant hose 98 with a metal mesh reinforcement is connected to the socket 94 . A threaded nut 109 is provided for this purpose. A simple plastic hose 100 with a smaller diameter is guided in the hose 98 . The plastic tube 100 is connected to the inner tube 96 . Water emanating from the housing portion 38 flows through the stub 94 on the outside of the inner tube 96 and past the plastic hose downwardly in the illustration. From there it reaches a one-pipe connection 102 of a water treatment device 104. In the present exemplary embodiment, the water treatment device 104 consists of ion exchange granules in a container 106 ( 8th ) educated.

The water flows outside through the ring channel of the single-pipe connection 102 and through the water treatment device 104. The treated water flows through the inner channel of the single-pipe connection 102 and the plastic hose 100 back into the inner pipe 96 in the adapter housing part 88. This is in 9 and 10 illustrated. At the upper end, the inner tube 96 opens into the central channel of the flange 90 and can flow back into the housing part 28 from there.

The one-pipe connection has the advantage that only one pressure-resistant hose 98 has to be used. The pressure difference across the inner hose 100 is small. An inexpensive hose 100, for example made of plastic, can therefore be used here. Mixing up the inlet hose and outlet hose is not possible. The one-pipe connection ensures that the hose connection is always in the right place.

In the present exemplary embodiment, a blending device 108 is provided on the upper side of the adapter housing part 88 . The blending device 108 comprises a piece of pipe which can be rotated from the outside by means of a tool and has an opening 110 which tapers in the circumferential direction. The piece of pipe 108 is open at the bottom and ends in the inner pipe 96 through which treated water flows. Opening 110 is level with an opening to central channel 84 through which untreated water flows. Depending on the angular position of the blending device 108, the openings overlap and untreated water is mixed with the treated water. If no intersection is to take place, an angular position is selected in which the openings do not overlap at all. The adjustment is made with a tool, for example an Allen key engaging in a polygonal recess 112 on the upper side of the blending device 108 . The angular position of the opening 110 can be indicated by a marking 114 on the top of the adapter housing part 88 .

It is desirable that the adjustment of the degree of blending is not done unintentionally or by unqualified laymen. The arrangement therefore provides that the polygonal recess in the operating state as in 7 until 9 illustrated, is arranged below the connection housing part 12 . Then the polygonal recess is practically inaccessible. The housing part 28 can be rotated about the axis 27 to change the setting. This is in the 11 and 12 illustrated. With a rotation through an angle of 90°, for example, the polygonal recess 114 is easily accessible. After the adjustment has been made, the housing part 28 is rotated back into its original position and is arranged below the connection housing part 12 in a space-saving manner. The rotation about the axis 27 can take place in both directions. The degree of blending can therefore be adjusted independently of the installation position. Also for installing and removing the adapter housing part 88, connecting the Wasserbe handling device and/or the housing part 38 with the system separator or for measurement and maintenance purposes, the arrangement can be turned forward. Then the test connection 47 for the inlet pressure on the system separator is easily accessible.

The volume flow meter that includes the turbine 72 and the reed contact 74 can be used to determine the amount of water that has flowed through the fitting. Together with the degree of blending, the hardness of the raw water and the amount of ion exchange granules in the water treatment device 104, it can be determined when the ion exchange granules are exhausted and should be regenerated or replaced. The conductivity sensor detects an increase in conductivity, for example when there is a breakthrough in hardness, and thus a higher hardness of the water at the outlet. This is also an indication of the need to regenerate or replace the ion exchange granules. This ensures that no hard water gets into the heating circuit if the settings do not correspond to the properties of the ion exchanger or if the inlet hardness has changed.

The above invention has been described here using a specific exemplary embodiment. However, the description is only intended to illustrate the invention. The scope of the invention admits of numerous variations, which are determined solely by the scope of the appended claims. Thus, certain features with regard to construction, material, arrangement and structure of the exemplary embodiment are merely meaningful configurations. Backflow preventers can be used in other places. Measurements can be taken at other locations. An ion exchanger can be replaced by other suitable water treatment methods and the connections can take any configuration known to those skilled in the art. This applies to all features and their combinations as long as the claims do not disclose a specific combination of features as being essential to the invention.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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 assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2988069 B1 [0004]
• EP 2778560 B1 [0004]
• EP 3406806 B1 [0005]
• DE 202009001957 U1 [0006]

Claims (14)

Fitting arrangement (10) for filling and/or topping up heating circuits, containing (a) a multi-part fitting housing (12, 28, 38) with a connection housing part (12) which can be installed in a pipeline leading to the heating circuit and which has a lockable inlet (14) and a closable outlet (16); (b) a system separator assembly (40) having upstream and downstream check valves (42, 44) and a drain assembly (48); and (c) a pressure reducer (30); characterized in that (e) the system separator arrangement (40) and the pressure reducer (30) are arranged in different housing parts (28, 38) which can be detached from one another; and (f) the housing parts (28, 38) of the system separator arrangement (40) and the pressure reducer (30) each have a flange for a flange connection (36), via which the flow path between the system separator arrangement (40) and the pressure reducer (30) can be established and which can be separated, so that an adapter housing part (88) can optionally be installed between the flanges, which adapter housing part has additional connections for a water treatment device (104) in the flow path. Fitting arrangement according to claim 1 , characterized in that the inlet (14) and outlet (16) are arranged coaxially. Fitting arrangement according to claim 2 , characterized in that the plane of the flange connection (36) extends perpendicularly to the connection axis between the inlet (14) and the outlet (16). Fitting arrangement according to claim 2 or 3 , characterized in that at least one of the further housing parts (28) is rotatably connected to the connection housing part (12). Fitting arrangement according to claim 4 , characterized in that the housing part (28), in which the pressure reducer (30) is arranged, is rotatably connected to the connection housing part (12) about an axis (27) which is perpendicular to the connection axis between the inlet (14) and the outlet ( 16) extends. Fitting arrangement according to one of the preceding claims, characterized in that it has one or more of the following functionalities: pressure sensor (56, 62), conductivity sensor (70), volume flow meter (72, 74), test connection (47, 50, 52). Fitting arrangement according to any one of the preceding claims, characterized in that the inlet (14) is provided with a controllable, motor-operated shut-off. Fittings arrangement according to one of the preceding claims, characterized in that a control unit (54) is provided with which sensor signals can be evaluated and displayed and on which manipulated variables of the functionalities can be set. Fitting arrangement according to one of the preceding claims, characterized in that an adapter housing part (88) is installed between the flanges (90, 92) and has additional connections (94, 96) for a water treatment device (104) in the flow path. Fitting arrangement according to claim 9 , characterized in that the adapter housing part (88) is provided with a blending device (108). Fitting arrangement according to claim 9 or 10 , characterized in that one of the connections (96) for the water treatment device (104) is arranged coaxially in the other of the connections (94). Fitting arrangement according to claim 11 , characterized in that a water treatment device (108) is connected to the additional connections (94, 96) of the adapter housing part (88) via a single-tube hose arrangement (98, 100), which has a pressure-resistant outer hose (98) and a coaxially guided hose (98). inner tube (100), wherein the inner tube (100) and the space between the inner and outer tube are separated from each other and flow-conducting. Fitting arrangement according to claim 11 or 12 , characterized in that the water treatment device (104) comprises an ion exchange granulate for softening the water passed through. Water treatment device (108), which can be connected via a single-pipe hose arrangement (98, 100) to connections (94, 96) of a water fitting (88), which comprises a pressure-resistant outer hose (98) and an inner hose (100) guided coaxially therein , wherein the inner hose (100) and the space between the inner and outer hose are separated from one another and designed to conduct flow.

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