Flexible conduit element for conveying hydrogen-containing fluids

Abstract

The subject of the invention is a flexible conduit element (12) for transporting a hydrogen-containing fluid, having an inner layer (14) conducting the hydrogen-containing fluid and an outer layer (13) surrounding the inner layer (14). The inner layer (14) consists of a first material and the outer layer (13) consists of a second material. According to the invention, the conduit element has the following features:-the hydrogen permeability of the first material at a temperature of 293 K is 1.5 * 10 <-9 > mol / (msMPa) or less,-the inner layer (14) and the outer layer (13) are designed such that the hydrogen permeability of the inner layer (14) is 2 times or less lower than the hydrogen permeability of the outer layer (13) at a predetermined temperature and a predetermined partial pressure difference, and-the Shore A hardness of the first material and the Shore A hardness of the second material is less than or equal to 90. The conduit element according to the invention can be used in a flexible and reliable manner for transporting hydrogen due to its advantageous properties.

Description

Technical Field

[0001] The subject of the present invention is a flexible conduit element for conveying a hydrogen-containing fluid, comprising an inner layer for conducting the hydrogen-containing fluid and an outer layer surrounding the inner layer, wherein the inner layer is made of a first material and the outer layer is made of a second material. Background Art

[0002] Such conduit elements for conveying hydrogen-containing fluids are used, for example, in gas supply networks, in the field of refueling technology, and as conveyor lines in fuel cells or gas heating systems (operated at least partially with hydrogen). The inner layer material can be designed such that it is as resistant as possible to the conveyed medium, while the outer layer material can be designed such that it is as resistant as possible to prevailing environmental influences (e.g., wear or other mechanical stresses, UV radiation, ozone, etc.). Under the given conditions of use, the conduit element must be sufficiently impermeable to prevent significant amounts of hydrogen from escaping from the conduit element and to prevent the formation of an explosive atmosphere outside the conduit element.

[0003] US Pat. No. 6,213,155 B1 discloses a composite hose through which fluid can flow, the composite hose having a metal film in its wall, wherein a layer forming the hose wall among a plurality of layers is a laminate layer formed by laminating the metal film, a highly tensile-resistant reinforcement material, and a resin film. Summary of the Invention

[0004] Against this background, the object of the present invention is to provide a conduit element for conveying a hydrogen-containing fluid, which conduit element can be used flexibly and ensures a high degree of operational safety.

[0005] The characteristics of the catheter element according to the invention are as follows:

[0006] -The hydrogen permeability of the first material at 293K is

[0007] 4.0·10 -9 mol / (ms MPa) or less,

[0008] - the inner layer and the outer layer are designed so that the hydrogen permeability of the inner layer is 2 times or less lower than the hydrogen permeability of the outer layer at a specified temperature and a specified partial pressure difference, and

[0009] The Shore A hardness of the first material and the Shore A hardness of the second material are less than or equal to 90.

[0010] First, some terms used within this specification are explained. The term "hydrogen-containing fluid" refers to a gaseous, liquid medium, or a mixture of a medium containing gaseous hydrogen, comprising both gaseous and liquid components. A hydrogen-containing fluid can also have other components. For example, a hydrogen-containing fluid can be a mixture of gaseous hydrogen and one or more gaseous hydrocarbons (e.g., natural gas), or a mixture of gaseous hydrogen and a liquid gas (e.g., liquefied petroleum gas (LPG)).

[0011] The temperature-dependent hydrogen permeability of a material (hereinafter also denoted by φ(T), where T denotes the temperature) expresses the amount of hydrogen particles (hereinafter also denoted by N) which escape through a non-porous barrier formed by the material of the material layer under consideration and having a specific layer thickness (hereinafter also denoted by L) per unit time (hereinafter also denoted by t), per unit area (hereinafter also denoted by A), and per partial pressure difference (hereinafter also denoted by (p1-p2), where p1 and p2 denote the hydrogen partial pressures prevailing on both sides of the material layer in question, respectively). H Therefore, the following relationship applies to hydrogen permeability:

[0012] φ(T)=(N H ·L) / (t·A·(p1-p2))

[0013] The hydrogen permeability can be derived in accordance with DIN 53536 and is specified, for example, by the unit mol / (msMPa) (mole per (meter times second times megapascal)).

[0014] The hydrogen permeability of a layer indicates the amount of hydrogen permeable to a hydrogen-containing fluid per unit time, under specified conditions, specifically the parameters of hydrogen partial pressure difference, temperature, area of ​​the barrier formed by the layer, and layer thickness. At a specified temperature and hydrogen partial pressure difference, the hydrogen permeability of a non-porous layer is derived from the hydrogen permeability of the material, the particle weight, the layer area available for permeation, and the layer thickness. If the layer is porous and / or has permeation channels, hydrogen can also pass through these channels. Such channels can be mechanically introduced into the layer, for example, by so-called "puncturing."

[0015] The Shore A hardness can be determined, for example, in accordance with DIN ISO 7619-1.

[0016] The conduit element can be designed for a maximum pressure between 6 bar and 100 bar. Furthermore, the conduit element can be designed for a temperature range between -50°C and 150°C. The inner layer can be connected to the outer layer via an adhesive layer. Furthermore, one or more strength members can be provided between the inner and outer layers.

[0017] The second material is preferably different from the first material.

[0018] The low hydrogen permeability of the first material ensures that, during operation, only a minimal amount of hydrogen can escape from the transmission channel enclosed by the inner layer through the inner layer. However, within the scope of the present invention, it has been recognized that this alone is insufficient to provide a safe and stable conduit element over an extended period of time. In particular, it has been recognized that a certain amount of hydrogen can accumulate between the inner and outer layers over an extended period of time. The resulting pressure buildup between the layers can cause the outer layer to separate from the inner layer, thereby damaging the conduit element. To prevent gas from accumulating in the intermediate space (for example, in the area of ​​the adhesive layer or in the area of ​​the strength member), the inner and outer layers are designed so that the hydrogen permeability of the inner layer (under identical test conditions) is lower than that of the outer layer. This measure ensures that hydrogen particles escaping from the interior space (within the inner layer) through the inner layer at a certain rate migrate further through the outer layer at a higher rate, thereby being discharged to the environment, without accumulating gas between the layers.

[0019] In one advantageous embodiment, it is provided that the ratio of the hydrogen permeability φ1(T) of the first material to the layer thickness L1 of the inner layer is less than the ratio of the hydrogen permeability φ2(T) of the second material (at the same temperature) to the layer thickness L2 of the outer layer. Therefore, in this case, φ1(T) / L1<φ2(T) / L2 applies. Furthermore, the hydrogen permeability of the inner layer can be 2 times lower than the hydrogen permeability of the outer layer, preferably 5 times lower, more preferably 10 times lower, and particularly preferably 15 times lower. It should be understood that the above ratios are based on identical test conditions for the inner and outer layers. The above-described features make it possible to particularly reliably prevent gas accumulation between the inner and outer layers, while at the same time the low hydrogen permeability of the inner layer ensures that overall only a small amount of hydrogen escapes from the conduit element.

[0020] The layer thickness L1 of the inner layer can be, for example, between 0.4 and 5.0 mm, preferably between 1.0 and 3.0 mm. The layer thickness L2 of the outer layer can be between 1.0 and 5.0 mm, preferably between 1.5 and 5.0 mm.

[0021] In the prior art, materials with greater layer thickness are typically used for the inner layer, creating a mechanically stable and secure connection between the inner and outer layers to prevent separation. This often results in low flexibility or bendability of the conduit element. Regular bending of the conduit element leads to increased friction between the inner and outer layers, which promotes separation. Therefore, low bendability offers additional advantages in terms of the durability of the connection between the inner and outer layers. In contrast, within the scope of the present invention, the problem of outer-to-inner layer separation is significantly mitigated due to the different hydrogen permeabilities of the inner and outer layers and the low hydrogen permeability of the first material. For this reason, it is possible to use a first material with a lower Shore A hardness, which tends to be associated with high elasticity, in the conduit element according to the present invention. The present invention makes it possible to manufacture a very flexible conduit element while minimizing the risk of separation between the outer and inner layers. This significantly expands the application range of the conduit element and improves its user-friendliness. In particular, a smaller bending radius can be achieved. For example, the use of this conduit element in refueling applications is significantly facilitated.

[0022] Furthermore, it has been found that the conduit element can be used in a compensator to compensate for or absorb movements, vibrations or length changes of a fixed rigid pipe. Due to the low Shore A hardness of the first material, the absorption of movements and vibrations is achieved in a particularly effective manner.

[0023] The first material can have a Shore A hardness of less than 85, preferably less than 80, and more preferably less than or equal to 75. The second material can also have a Shore A hardness of less than or equal to 85, preferably less than or equal to 80, and more preferably less than or equal to 75. This further increases flexibility. Furthermore, it can be provided that the Shore A hardness of the first material can be greater than 30, preferably greater than 50, and more preferably greater than 60.

[0024] The flexible conduit element can have at least one of the following additional features:

[0025] -The hydrogen permeability of the first material at 293K is 2.4·10 -9 mol / (ms MPa) or less, preferably 1.8·10 -9 mol / (ms MPa) or less, more preferably 1.2·10 -9 mol / (ms MPa) or less, more preferably 1.0·10 -9 mol / (ms MPa) or less,

[0026] The hydrogen permeability of the first material at a temperature of 293K is lower than the hydrogen permeability of the second material at a temperature of 293K.

[0027] It can be provided that the outer layer has mechanically produced hydrogen passages, which are designed to increase the hydrogen permeability of the outer layer. The hydrogen passages are perforations in the outer layer and can be produced by so-called "piercing," i.e., by piercing the outer layer with a dimensionally stable needle of very small diameter.

[0028] The first material is preferably an elastomer or exhibits elastomer properties within a temperature range of -50°C to 150°C. This temperature range is preferably between -40°C and 120°C, more preferably between -30°C and 100°C, and even more preferably between -20°C and 90°C. This means that under tensile or compressive load, the material deforms rubbery (i.e., "entropy elastic") and essentially returns to its original shape after the load is removed. Below the glass-to-rubber transition temperature, the first material exhibits thermoplastic properties. In particular, at the transition, the material's elasticity decreases by several orders of magnitude. In the case of elastomers, there is a fixed relationship between Shore A hardness and compressive modulus (see, for example, "Determination of the Compressive Modulus of Elasticity of Elastomers via Shore A Hardness," reproduced in the specialist journal "Synthetic Materials," June 2006, pp. 92-94, Carl Hanser Verlag, Munich, 2006). This indicates that, particularly when the first material is an elastomer, a low Shore A hardness according to the present invention is accompanied by a low modulus of elasticity.

[0029] In an advantageous embodiment, the first material comprises chlorosulfonated polyethylene rubber or epichlorohydrin rubber. Provision can be made that the first material consists mainly or exclusively of chlorosulfonated polyethylene rubber or epichlorohydrin rubber.

[0030] The second material is preferably an elastomer in the temperature range of -65°C to 150°C or has elastomer properties in this temperature range. In one embodiment, the second material comprises chloroprene rubber. It can be provided that the second material consists primarily or exclusively of chloroprene rubber. This material enables the production of a conduit element that is sufficiently impermeable while simultaneously exhibiting the ratio of hydrogen permeability according to the present invention, low hardness, and high flexibility.

[0031] In one embodiment, the flexible conduit element comprises one or more strength members arranged between the inner layer and the outer layer. Alternatively, the strength members can also be embedded in the inner layer or the outer layer, or applied to the outer layer. This design is particularly suitable for conveying fluids under high pressure, for example for conveying gases liquefied under pressure. The strength members or parts of the strength members can be made of metal. It is preferably provided that the strength member comprises or consists of chromium-nickel-molybdenum steel. The carbon content of the chromium-nickel-molybdenum steel can more preferably be 0.03% by weight or less. Alternatively or additionally, the nickel content of the chromium-nickel-molybdenum steel can be 12% by weight or more. Alternatively or additionally, the chromium-nickel-molybdenum steel can be X2CrNiMo17-12-2 according to AISI 316L, X2CrNiMo18-14-3 according to AISI 316L, or X6Cr-Ni-Mo-Ti17-12-2 according to AISI 316Ti. The above-mentioned metal strength members are characterized by low hydrogen embrittlement.

[0032] In one embodiment, the catheter element is designed such that the electrical resistance measured between the inner layer and the outer layer is less than 10 9 Ohms, preferably less than 10 6 Ohms. The resistance between the inner and outer layers can be measured by electrically contacting the conduit element at a first surface element on the outer surface of the outer layer and at a second surface element on the inner surface of the inner layer, opposite the first surface element, and measuring the resistance between the surface elements. Furthermore, the resistance measured between the ends of the conduit element can be less than 10 9 Ohms, preferably less than 10 6 Ohms, more preferably less than 10 5 Ohms. The resistance measured between the ends of the catheter element is obtained by making a common electrical contact at each end of the inner and outer layers and measuring the resistance between the two contacts. The resistivity of the catheter element can be less than 10 10 Ohm / meter, preferably less than 10 7 Ohm / meter, more preferably less than 10 6 Ohm / m. The above resistivity is obtained by simultaneously electrically contacting the two layers at two surface elements spaced apart from each other in the longitudinal direction and determining the resistance per unit length between the two surface elements. In one embodiment, the resistivity of the outer layer or the inner layer of the catheter element is less than 10 10 ohm / m (ohm / meter), preferably less than 10 7 ohm / m, more preferably less than 10 ·6ohm / m. The above-mentioned resistivity of the layers is obtained by measuring the respective layer independently of the respective other layer (i.e., not electrically conductively connected to the respective other layer). This shows that the above-mentioned resistance (resistivity) enables reliable charge discharge, so that the formation of sparks can be prevented. In this case, it is preferably ensured that sufficient charge discharge occurs in each of the two layers in the longitudinal direction, and that charge discharge from one layer to the other is also possible. The above-mentioned resistance values ​​(resistance along the conduit element and between the conduit elements) can be obtained in a manner known in principle, for example, by adding a conductive additive material (e.g., industrial carbon black) to the material of the respective layer. The above-mentioned resistance values ​​can be measured in particular in the manner described in DIN EN ISO 8031. By preferably forming the inner and outer layers to be electrically conductive as explained above, the present invention differs from the provisions of DIN EN ISO 8031, according to which, in the case of a layered hose, only the inner layer or only the outer layer should be electrically conductive.

[0033] Furthermore, the present invention provides a compensator comprising a flexible conduit element according to the present invention, a first compensator fitting connected to a first end of the flexible conduit element, and a second compensator fitting connected to a second end of the flexible conduit element. The compensator fitting preferably has an outwardly projecting flange element. The flange element can be plate-shaped and extend outward from a circumferential surface of the conduit element substantially perpendicularly to the axial direction of the conduit element. The flange element can have a plurality of through-holes extending in the axial direction and, viewed in the axial direction, can have a thickness of between 0.5 cm and 5 cm, preferably between 1 cm and 3 cm.

[0034] Compensator fittings can be connected to matching counterparts. For example, this connection can be achieved via a screw connection. In this way, compensators can be connected, in particular, to fixed rigid pipes and used to absorb or compensate for movements, length changes, or vibrations of the fixed rigid pipes. This demonstrates that the conduit element according to the present invention is particularly suitable for this purpose due to its low stiffness.

[0035] In one embodiment, the inner diameter of the conduit element can be between 20 mm and 500 mm, preferably between 25 mm and 150 mm. The inner diameter of the conduit element is determined by the inner diameter of the inner layer. In the prior art, conduit elements with inner diameters of this order of magnitude are not suitable for compensators because, at these diameters, the flexibility and bendability of the conduit element are too low.

[0036] In one embodiment, the resistance measured between the compensator components is less than 10 9 Ohms, preferably less than 10 6 Ohms, more preferably less than 10 5This measure ensures that even in compensators, electrical charges on the conduit element are safely dissipated via the conduit element and that no large electrostatic charges build up. This prevents spark formation and the resulting risk of explosion.

[0037] Furthermore, the present invention relates to a flexible hose conduit comprising a flexible conduit element according to the invention and at least one, preferably two, hose fittings connected to the flexible conduit element at the end. The hose conduit can be connected to a matching connector by means of the hose fittings. In one embodiment, the electrical resistance measured between the hose fittings (which resistance is essentially given by the electrical resistance of the conduit element) is less than 10 9 Ohms, preferably less than 10 6 Ohms, more preferably less than 10 5 Ohm. The above advantages are also achieved here.

[0038] The inner diameter of the conduit element can be, for example, between 8 mm and 50 mm, preferably between 13 mm and 25 mm.Conventional conduit elements for transporting hydrogen are extremely inflexible, especially in the case of larger inner diameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Below, advantageous embodiments of the present invention are explained by way of example with reference to the accompanying drawings.

[0040] Figure 1 A partial cross-sectional view showing one embodiment of a catheter element according to the present invention;

[0041] Figure 2 shows a partial cross-sectional side view of a compensator according to the present invention;

[0042] Figure 3 Shown is a side view of two hose elements according to the invention. DETAILED DESCRIPTION

[0043] Figure 1 A partial cross-sectional three-dimensional side view of a conduit element 12 for conveying a hydrogen-containing fluid according to the present invention is shown. The conduit element 12 includes a cylindrical inner layer 14 for conveying the hydrogen-containing fluid. The inner layer 14 is made of chlorosulfonated polyethylene rubber having a Shore A hardness of 75 and a hydrogen permeability of 1.0·10 at a temperature of 293K. -9 mol / (m sMPa). The inner layer thickness is 2 mm. The inner diameter of the inner layer is 20 mm.

[0044] There is also a cylindrical outer layer 13 outside the inner layer 14, which is in contact with the inner layer 14 around the entire circumference and is fused to the inner layer 14 during the manufacturing process. The outer layer 13 is made of chloroprene rubber with a Shore A hardness of 60 and a hydrogen permeability of 10·10 at a temperature of 293K.-9 mol / (ms MPa). The outer layer 13 is also 2 mm thick. Currently, the hydrogen permeability of the inner layer is approximately 10 times lower than that of the outer layer. In an alternative embodiment, the hydrogen permeability of the outer layer can also be (additionally) increased by introducing hydrogen passages, so it is not necessary to have a 10-fold difference in hydrogen permeability between the inner and outer layer materials.

[0045] During the manufacture of the catheter element, a first strength member 15 formed from a metal braid and a second strength member 16 formed from a metal coil are embedded between the inner and outer layers. Strength members 15 and 16 are formed from X2CrNiMo17-12-2. In one embodiment, a further strength member formed from a metal braid can be provided, arranged outside the metal coil (not shown). In this case, the metal coil is surrounded on either side by the metal braid.

[0046] Figure 2 A partial cross-sectional side view of a compensator according to the invention is shown. The compensator comprises a conduit element 12 according to the invention, wherein the above-mentioned Figure 1 The proposed components Figure 2 1 and 2. The compensator is provided with the same reference numerals. Furthermore, the compensator comprises a compensator fitting 18, which is connected to the ends 20, 21 of the conduit element and is formed in the present case by a flange element projecting outwardly perpendicularly to the axial direction of the conduit element 12. The compensator fitting 18 comprises a through-hole 19 extending in the axial direction, through which a fastening element can be introduced in order to establish a connection with the corresponding flange element.

[0047] and Figure 1 The implementation methods are different. Figure 2 In the embodiment of the present invention, the conduit element 12 is not cylindrically configured, but rather is arched outwards in the middle between the expansion joint fittings 18. As a result, movements and vibrations of the rigid conduit element connected to the expansion joint by means of the expansion joint fittings 18 can be better compensated.

[0048] and Figure 1 Unlike the conduit elements, additional reinforcement members 17 are embedded in the material of the inner layer 14 at the ends 20 and 21 of the conduit element 12. These reinforcement members 17 are formed from wires made of X2CrNiMo18-14-3 and extend circularly around the circumference of the conduit element 12. Annular grooves are embedded at the end faces of the compensator fittings 18, into which the reinforcement members 17, along with the respective ends 20 and 21 of the conduit element, are embedded. When establishing the connection between the compensator fitting 18 and the corresponding flange element, the end face of the compensator fitting 18 presses against the end face of the corresponding flange element. In this process, the portion of the conduit element (connecting section 23) embedded in the groove is clamped between the compensator fitting and the corresponding flange element and thus secured.

[0049] Figure 3 Two flexible hose conduits according to the invention are shown in side views. Each hose conduit comprises a conduit element 12 according to the invention and a hose fitting 22 mounted at one end of the conduit element 12.

Claims

1. A flexible conduit element (12) for conveying a hydrogen-containing fluid, the conduit element comprising an inner layer (14) conducting the hydrogen-containing fluid and an outer layer (13) surrounding the inner layer (14), the inner layer (14) being composed of a first material and the outer layer (13) being composed of a second material, characterized in that Features include: -The hydrogen permeability of the first material at 293K is 4.0·10 -9 mol / (ms MPa) or less, - the inner layer (14) and the outer layer (13) are designed so that, at a specified temperature and a specified partial pressure difference, the hydrogen permeability of the inner layer (14) is 2 times lower than or lower than the hydrogen permeability of the outer layer (13), and The Shore A hardness of the first material and the Shore A hardness of the second material are less than or equal to 90.

2. The flexible conduit element (12) according to claim 1, wherein The Shore A hardness of the first material and / or the Shore A hardness of the second material is less than or equal to 85, preferably less than or equal to 80, more preferably less than or equal to 75.

3. The flexible conduit element (12) according to claim 1 or 2, wherein: The hydrogen permeability of the inner layer (14) is 5 times lower or less than the hydrogen permeability of the outer layer (13), preferably 10 times lower or less, more preferably 15 times lower or less.

4. The flexible conduit element (12) according to any one of claims 1 to 3, characterized in that At least one of the following additional features is provided: The first material has a hydrogen permeability of 2.4·10 at a temperature of 293K. -9 mol / (ms MPa) or less, Preferably 1.8·10 -9 mol / (ms MPa) or less, More preferably 1.2·10 -9 mol / (ms MPa) or less, More preferably 1.0·10 -9 mol / (ms MPa) or less, The hydrogen permeability of the first material at a temperature of 293K is lower than the hydrogen permeability of the second material at a temperature of 293K.

5. The flexible conduit element (12) according to any one of claims 1 to 4, wherein The outer layer (13) has mechanically manufactured hydrogen passages, and the hydrogen passages are designed to improve the hydrogen permeability of the outer layer (13).

6. The flexible conduit element (12) according to any one of claims 1 to 5, wherein: The Shore A hardness of the first material is greater than 50, preferably greater than 60.

7. The flexible conduit element (12) according to any one of claims 1 to 6, wherein: In a temperature range between -50°C and 150°C, preferably between -40°C and 120°C, more preferably between -30°C and 100°C, more preferably between -20°C and 90°C, said first material has elastomeric properties.

8. The flexible conduit element (12) according to any one of claims 1 to 7, wherein The first material includes or consists of chlorosulfonated polyethylene rubber or epichlorohydrin rubber.

9. The flexible conduit element (12) according to any one of claims 1 to 8, wherein In a temperature range between -50°C and 150°C, preferably between -40°C and 120°C, more preferably between -30°C and 100°C, more preferably between -20°C and 90°C, the second material has elastomeric properties.

10. The flexible conduit element (12) according to any one of claims 1 to 9, wherein The second material preferably comprises or consists of neoprene.

11. A flexible conduit element (12) according to any one of claims 1 to 10, further comprising at least one strength member (15, 16, 17), which is arranged between the inner layer (14) and the outer layer (13) or is embedded in the inner layer (14) and / or the outer layer (13) or is applied to the outer layer.

12. The flexible conduit element (12) according to claim 11, wherein At least one of the strength members (15, 16, 17) is formed from metal and preferably comprises or consists of chromium-nickel-molybdenum steel, wherein the carbon content of the chromium-nickel-molybdenum steel is more preferably 0.03% by weight or less and / or the nickel content of the chromium-nickel-molybdenum steel is 12% by weight or more and / or the chromium-nickel-molybdenum steel is X2CrNiMo17-12-2 according to AISI 316L or X2CrNiMo18-14-3 according to AISI 316L or X6Cr-Ni-Mo-Ti17-12-2 according to AISI 316Ti.

13. The flexible conduit element according to any one of claims 1 to 12, wherein the conduit element is designed such that - the electrical resistance measured between the inner layer (14) and the outer layer (13) is less than 10 9 Ohms, preferably less than 10 6 Ohms, and / or - the electrical resistance measured between the ends of the conduit element is less than 10 9 Ohms, preferably less than 10 6 Ohms, more preferably less than 10 5 Ohms, and / or - the electrical resistivity of the outer layer or the inner layer of the catheter element is less than 10 10 ohm / m, preferably less than 10 7 ohm / m, more preferably less than 10 6 ohm / m, and / or - The electrical resistivity of the conduit element is less than 10 10 ohm / m, preferably less than 10 7 ohm / m, more preferably less than 10 6 ohm / m.

14. A compensator, comprising: A flexible conduit element (12) according to any one of claims 1 to 13, a first compensator fitting (18) which is or can be connected to a first end (20) of the flexible conduit element (12), and a second compensator fitting (18) which is or can be connected to a second end (21) of the flexible conduit element (12), wherein the flexible conduit element preferably has an end-side connecting section (23) which can be clamped between the compensator fitting and the corresponding connecting element when a connection is established between one of the compensator fittings and the corresponding connecting element, wherein the compensator fitting preferably also has a circumferential groove fixed in the end face for accommodating the connecting section, wherein the connecting section (23) preferably also has a reinforcing element (17) embedded in the conduit element, wherein the electrical resistance measured between the compensator fittings (18) after the connection has been established is preferably less than 10 9 Ohm, more preferably less than 10 6 Ohm, more preferably less than 10 5 ohm.

15. A flexible hose conduit comprising a flexible conduit element (12) according to any one of claims 1 to 12 and two hose fittings (22) mounted on the flexible conduit element (12) at the end sides, wherein: The resistance measured between the hose fittings is preferably less than 10 6 Ohms, more preferably less than 10 5 ohm.

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