Improved compression sealing washer and sealing system

Abstract

The invention relates to a sealing system comprising two components (10, 10 ', 100, 101) of a gas-isolated part of a high-or medium-pressure device, in which each of the components (10') comprises an end face or assembly face (12 ', 102) facing an end face or assembly face (12, 101) of the other component (10), at least one of the assembly faces comprising at least one recess (16), and in which at least one compression sealing gasket (14, 14', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 '', 14 A compression seal gasket (14, 14 ') disposed at least partially in at least one recess and compressed between the assembly faces (12, 12', 101, 102) of the component (10, 10 '), the compression seal gasket (14, 14') comprising a body (141) extending substantially in a plane or in a plane, the body (141) comprising an inner side (22, 32) and an outer side (20, 30) and an end face (24, 26, 15, 34, 36) defining the gasket along an axis (AA ') perpendicular to the plane and connecting the inner side and the outer side, the body (141) is made of an elastomeric material, the body having a first extension (L14) along the axis (AA '), at least one of the inside and outside being provided with a lip (141), the lip (141) having a second extension (l14) along the axis (AA') perpendicular to the plane that is smaller than the first extension (L14).

Description

Technical Field

[0001] The invention relates to a compression sealing gasket designed to reduce its permeability with respect to gases and / or with respect to external water or water vapor.

[0002] Sealing gaskets are intended for implementation at the connection between two parts on medium and high pressure gas isolation equipment. Background Art

[0003] Some medium voltage and high voltage equipment include hollow members in which conductors are arranged.

[0004] An insulating gas fills these members to isolate the conductors carrying electrical current at high voltage from the hollow members which are at ground potential.

[0005] The insulating gas can also withstand electric fields over short distances between conductors arranged in the component.

[0006] The connection between the two components comprises, for example, a tubular portion for each component and a sealing gasket placed between the tubular portions.

[0007] According to a known embodiment, the sealing gasket is made of an elastomer and is compressed between components, for example two tubular portions or a tubular portion and a flat plate.

[0008] The compression of the two components or parts produces elastic deformation of the gasket, improving the tightness of the connection.

[0009] However, the gasket is generally made of an elastomer having permeability with respect to the barrier gas.

[0010] One object of the present invention is to provide a sealing gasket which has a significantly lower permeability in order to reduce the leakage rate of the entire device.

[0011] The goal is to achieve a leakage rate of less than 0.5% vol / year for the whole arrangement as described in the relevant IEC standards for switchgear, such as IEC 62271-203 for gas-disconnected switchgear.

[0012] This improvement is of particular interest as the industry moves toward barrier gases composed of gases and gas mixtures that may leak differently than the popular SF6 gas used for decades due to the different properties of those new molecules used.

[0013] In particular, a gas called "g3" comprising heptafluoroisobutyronitrile mixed with a diluent gas comprising carbon dioxide and oxygen is used to replace SF6. CO2 has a strong tendency to leak. O2 and N2 also leak, but less than CO2. These three gases have a higher tendency to leak than SF6. These leaks are problematic because CO2 has an adverse effect on the environment; in addition, the lost gas must be replaced, which involves additional costs due to maintenance operations.

[0014] Another object of the present invention is to provide an improved sealing gasket which has a significantly lower permeability to heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethyl ketone (also known as 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone (CAS No. 756-12-7) and / or CO2 and / or O2 and / or N2 and / or to water or water vapor, in particular in gas isolation devices of the type mentioned above or in the present application, more generally in any high or medium pressure component (such as a disconnector, or a switch, or a circuit breaker, or a gas isolation line), in gas isolation devices implemented in medium or high pressure applications.

[0015] In practice, such gases may include:

[0016] - Heptafluoroisobutyronitrile, alone or in a mixture with O2 and / or CO2 and / or N2;

[0017] - and / or heptafluoroisopropyltrifluoromethyl ketone alone or in a mixture with O2 and / or CO2 and / or N2;

[0018] - or CO2 alone or mixed with O2 and / or with N2;

[0019] - N2 alone or mixed with O2 and / or CO2.

[0020] Furthermore, H2O is undesirable inside such devices, and another object of the present invention is to provide a sealing gasket that reduces or limits or avoids the permeation of H2O from the outside of such gas isolation devices implemented in medium or high pressure applications. Summary of the invention

[0021] The invention relates to a gasket, or a sealing gasket, or a sealing system, or a sealing gasket system, or a compression sealing gasket, or a compression sealing gasket system (any of these expressions may be used in the rest of this specification), comprising a body extending substantially in a plane or in a plane, the body comprising an inner side and an outer side, made of an elastomeric material, the body having a first extension (or a first thickness) (L) along an axis perpendicular to the plane 14 ), at least one of the inner and outer sides is provided with a lip having a second extension (or second thickness) along the axis perpendicular to the plane that is smaller than the first extension (or first thickness).

[0022] The lip provides a smaller surface area for gas and / or water to permeate in directions contained in the plane of the body.Preferably, the lip(s) and the body are homogenous in composition.

[0023] Permeation (molecules passing through the gasket by diffusion) is related to the surface area under pressure. The lip provides a reduced permeation surface due to its smaller extension or thickness along the axis perpendicular to the plane in which the gasket extends.

[0024] A body with a greater extension along the axis will ensure aging, thermal expansion, manufacturing tolerances, factory handling and environmental constraints.

[0025] The gasket, or sealing gasket, or sealing gasket system, or compression sealing gasket, or compression sealing gasket system according to the invention is very tight and effectively resists leakage of heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethyl ketone (also known as 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone (CAS No. 756-12-7)) and / or CO2 and / or O2 and / or N2 and / or oxygen-containing compounds and / or water vapor and / or ingress of water leakage and / or ingress of water vapor, for example in applications involving gases comprising both CO2 and fluorinated compounds (heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethyl ketone) at pressures between 1 bar and 20 bar.

[0026] According to a preferred embodiment, the lip has a higher compressibility or average compressibility than the body.

[0027] Preferably:

[0028] - a first extension (or thickness of the gasket) comprised between 2 mm and 25 mm,

[0029] - and / or the second extension is comprised between 0.5 mm and 5 mm.

[0030] The gasket, or sealing gasket, or sealing gasket system, or compression sealing gasket, or compression sealing gasket system according to the invention may have internal dimensions (dimensions of the inner part of the gasket) comprised, for example, between 40 mm (or 100 mm) and 500 mm (or even 1300 mm).

[0031] For example, if it has an annular shape, the internal diameter of the gasket may be comprised between 40 mm or 100 mm and 500 mm or even 1300 mm.

[0032] The gasket, or sealing gasket, or sealing gasket system, or compression sealing gasket, or compression sealing gasket system according to the invention is assembled at the interface between two components, at least one of which comprises a recess comprising a first portion receiving the body and a possible second portion receiving the lip.

[0033] Each of the portions may have a rectangular shape, and the length of a first portion along an axis perpendicular to the plane of the gasket may be equal to, greater than, or less than the length of a second portion along said axis.

[0034] In a particular embodiment of the gasket, or sealing gasket, or sealing gasket system, or compression sealing gasket, or compression sealing gasket system according to the invention:

[0035] - the outer side and the inner side may be parallel and / or coaxial with each other;

[0036] - and / or the gasket has an annular or oval or elliptical shape in a plane perpendicular to said axis (AA').

[0037] In another embodiment of the gasket, or the sealing gasket, or the sealing gasket system, or the compression sealing gasket, or the compression sealing gasket system according to the present invention, at least one of the outer side, the inner side and the end surface axially defining the gasket and connecting the inner side and the outer side has a wave or corrugated shape.

[0038] In a particular embodiment of the gasket, or the sealing gasket, or the sealing gasket system, or the compression sealing gasket, or the compression sealing gasket system according to the invention, each of said inner side and said outer side may be provided with a lip.

[0039] In another particular embodiment of the gasket, or the sealing gasket, or the sealing gasket system, or the compression sealing gasket, or the compression sealing gasket system according to the invention, the lip has a side perpendicular to the axis extending in the same plane as one of the end faces; thus, the gasket has an "L" shape.

[0040] In another particular embodiment of the gasket, or sealing gasket, or sealing gasket system, or compression sealing gasket, or compression sealing gasket system according to the present invention, the extension (or thickness) L of the body 14 It may be greater than the distance between its inside and its outside (measured in a plane perpendicular to the axis AA' or in the plane of the gasket). This applies to "L"-shaped gaskets as well as to any other embodiment.

[0041] The present invention also relates to a gasket, or a compression sealing system, or a sealing gasket, or a sealing gasket system, or a compression sealing gasket, or a compression sealing gasket system, which comprises two gaskets according to the present invention connected in series, the lip of one of the gaskets being connected to one of the inner side and the outer side of the other of the gaskets. For example, the lip of the inner side of one of the gaskets is connected to the outer side of the other gasket; or the lip of the outer side of one of the gaskets is connected to the inner side of the other gasket.

[0042] The present invention also relates to a sealing system, or a sealing gasket system, or a compression sealing gasket, or a compression sealing gasket system, which comprises two components, wherein each of the components comprises an end face or assembly face facing the end face or assembly face of the other component, at least one of them having a recess as mentioned above, and wherein the gasket, or compression sealing gasket, or sealing gasket, or sealing gasket system, or compression sealing gasket system according to the present invention is arranged at least partially in the recess. Parts of the compression sealing gasket (e.g. one or more lips) may be arranged outside the recess.

[0043] Preferably, the gasket, or the compression sealing gasket, or the sealing gasket, or the sealing gasket system, or the compression sealing gasket system is axially compressed by the end face or the assembly face.

[0044] For example, at least in the area surrounding the recess and / or the gasket, the end faces or assembly surfaces of the two components may contact each other, or may not contact each other (in which case, part of the gasket, such as one or more lips, or at least part of one or more lips may not be in the recess).

[0045] The member may form part of a gas isolation section of a high or medium pressure apparatus, said section:

[0046] * containing or intended to contain a gas, for example at a pressure between 1 bar and 20 bar, said gas for example comprising at least:

[0047] Heptafluoroisobutyronitrile and / or heptafluoroisopropyl trifluoromethyl ketone (also known as 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone (CAS No. 756-12-7)), possibly mixed with a gas or diluent gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound;

[0048] - or at least CO2 and / or O2 and / or N2 and / or oxygen-containing compounds;

[0049] * and / or the gas isolation portion is surrounded or intended to be surrounded by an external atmosphere containing some water and / or water vapor.

[0050] The components may be at least partially cylindrical and may be arranged coaxially with each other and with the main axis AA', the end face or assembly face of each component extending in a plane perpendicular to the main axis AA'.

[0051] The invention also relates to a method for insulating a gas-insulated section of a high-voltage or medium-voltage installation, said gas-insulated section:

[0052] * containing a gas, which for example comprises at least a fluorinated compound, for example heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethylketone, possibly mixed with a gas or diluent gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound and / or water vapor, or the gas for example comprises at least CO2 and / or O2 and / or N2 and / or a fluorinated compound, for example heptafluoroisobutyronitrile, the gas isolation part comprising a gasket according to the invention, or a sealing system, or a sealing gasket, or a sealing gasket system, or a compression sealing gasket, or a compression sealing gasket system;

[0053] * and / or the gas isolation portion is surrounded or intended to be surrounded by an external atmosphere containing some water and / or water vapor.

[0054] The invention also relates to a method for insulating a gas-insulated section of a high-voltage or medium-voltage installation, said gas-insulated section:

[0055] * containing gas, the gas comprising at least:

[0056] - fluorinated compounds, such as heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethylketone, possibly mixed with a gas or diluent gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound and / or water vapor,

[0057] - or CO2 and / or O2 and / or N2 and / or oxygen-containing compounds and / or water vapor,

[0058] * and / or the gas-insulated portion is surrounded or is intended to be surrounded by an external atmosphere containing some water and / or water vapour;

[0059] The gas isolation part comprises two components, at least one of which has a recess as mentioned above, wherein each of the components comprises an end face or an assembly face facing the end face or the assembly face of the other component, and wherein at least a portion of the gasket, or the compression sealing gasket, or the sealing gasket, or the sealing gasket system, or the compression sealing gasket system, or the sealing system according to the present invention is arranged in the at least one recess and compressed between the end faces or the assembly faces of the components.

[0060] The invention also relates to a method for isolating a gas-insulated section of a high- or medium-pressure installation, said gas-insulated section containing a gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound and / or water vapor and / or a fluorine compound (e.g. heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethylketone) and / or said gas-insulated section being surrounded or intended to be surrounded by an external atmosphere comprising some water and / or water vapor,

[0061] The gas isolating part comprises a gasket according to the invention, or a sealing system according to the invention, or a sealing gasket, or a sealing gasket system, or a compression sealing gasket, or a compression sealing gasket system.

[0062] The gas may be contained in the apparatus at a pressure between 1 bar and 20 bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 is a schematic diagram of a high-voltage device comprising two components assembled together using a gasket according to the invention.

[0064] Figure 2 yes Figure 1 Detail of the assembly of the components of FIG. 1 , showing how a gasket according to the invention is received between the two components.

[0065] Figure 3A , 3B 4A show an embodiment of a gasket according to the present invention.

[0066] Figure 4B A gasket according to the prior art is shown.

[0067] Figure 5 Another embodiment of a gasket according to the invention is shown.

[0068] Fig. 6A and 6B Further embodiments of gaskets according to the invention are shown.

[0069] Figures 7A to 7B are front views of various embodiments of gaskets according to the present invention.

[0070] Figures 8A to 8B An embodiment of a gasket according to the invention is shown in the case of a system using a single recess.

[0071] Figures 9A to 9C A further embodiment of a gasket according to the invention is shown in the case of a system using radial recesses instead of axial recesses.

[0072] Fig.10 is a schematic diagram of a high-pressure device comprising a hole of a gas compartment closed by a flange and comprising a gasket according to the invention.

[0073] Fig.11A and 11B Alternative shapes for the lip(s) are shown. DETAILED DESCRIPTION

[0074] Figure 1 An example of a system according to the invention is shown, to which a gasket, or a compression sealing gasket, or a sealing gasket, or a sealing gasket system, or a sealing system, or a compression sealing gasket system according to the invention can be applied. It comprises a portion of a high-voltage device, which comprises components 10, 10' assembled to each other. Here, each component 10, 10' is presented as a cylindrical and tubular component and extends coaxially with the main axis AA' of the high-voltage device. It will be understood that the two components may be of any other shape; for example, they may be non-cylindrical tubular parts.

[0075] Alternatively, one or both of the components may be a non-tubular portion, such as a hole 100 of a gas compartment closed by a flange 101 ( FIG. 9 ).

[0076] Alternatively, the gasket, or compression sealing gasket, or sealing gasket, or sealing gasket system, or sealing system, or compression sealing gasket system according to the invention can be used, for example, at the interface between two flanges. The following description is made with reference to tubular elements, but the invention is applicable to any other pair of elements whose interface must be sealed, in particular with respect to:

[0077] - gases which may be mixed with a gas or diluent gas comprising at least CO2 and / or O2 and / or N2 and / or and / or an oxygen-containing compound, such as heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethylketone (also known as 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone (CAS No. 756-12-7));

[0078] - or a gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound and / or water vapor;

[0079] - and / or incoming water and / or incoming water vapor, said interface being surrounded or intended to be surrounded by an external atmosphere containing some water and / or water vapor.

[0080] The gas may have a pressure (P2) between 1 bar and 20 bar, such as 5 bar or 15 bar.

[0081] If available Figure 2 As seen in more detail in FIG. 1 , each member 10 includes an end face (or assembly face) 12 that faces an end face (or assembly face) 12 ′ of another member 10 ′ and may be connected to an end face (or assembly face) 12 ′ of another member 10 ′.

[0082] The gasket, or sealing system, or compression sealing gasket, or sealing gasket, or sealing gasket system, or compression sealing gasket system for connecting members 10, 10' comprises a gasket, or sealing gasket, or compression sealing gasket, or sealing system 14 (in the rest of this specification, gasket, or sealing gasket, or sealing system), which is axially arranged between the faces 12, 12' of the two members 10, 10' (or, in the example of Figure 9, between the hole 100 and the flange 101). The sealing gasket 14 extends substantially in a plane perpendicular to the axis AA'. In this example and in some of the examples below, the sealing gasket has circular symmetry around the axis AA'.

[0083] The sealing gasket or system comprises fastening means 30 , such as bolts and nuts or bolting means, which press one component 10 axially towards the other component 10 ′.

[0084] The fastening means 30 also axially compresses the sealing gasket 14 to provide a gas-tight connection between the two components 10 , 10 ′.

[0085] according to Figure 2 In the embodiment presented above, the face 12 , 12 ′ of each member 10 , 10 ′ comprises an annular recess 16 , 16 ′ in which at least a portion of the sealing gasket 14 , 14 ′ is received.

[0086] The combined axial depth of the recesses 16 and 16' is less than the height or axial height of the gasket 14 before the two components 10, 10' are assembled (the height or axial height is measured along the axis AA' or along an axis perpendicular to the plane in which the gasket extends). If only one recess is present, such as the recess 16, its axial depth is less than the axial height of the gasket 14 before the two components 10, 10' are assembled.

[0087] The compression of the washer 14 ′ by the fastening means 30 produces an axial deformation of the washer 14 and maintains the pressure of the washer 14 on the bottom of each recess 16 , 16 ′.

[0088] If available from Figure 3A , 3B As seen in FIG. 4A , the gasket 14 includes a body 141 that is made of, for example, a single material, such as, for example, an elastomer, such as, as a non-limiting example, an unmodified butyl rubber or a modified butyl rubber, such as chlorobutyl (CIIR) or bromobutyl (BIIR) rubber.

[0089] The permeability of this elastomer with respect to the gas intended to fill the member 10 , 10 ′ leads to a loss of gas over time.

[0090] If available Figure 3A ,3B 4A , the body 141 of the gasket 14 may have a generally rectangular shape in cross-section along an axial plane containing the major axis AA′.

[0091] The body 141 of the gasket 14 comprises a radially outer side 20 , a radially inner side 22 and two planar end faces 24 , 26 axially delimiting the gasket 14 and connecting the inner side 22 to the outer side 20 .

[0092] One or more of the sides 20, 22, 24, 26 of the body may be wavy to enhance sealing. The wavy shape includes (see Figure 4A ) at least one protrusion or peak 24a and at least one recess or depression or valley 24b, 24c. Due to this complex shape, the air pressure has a positive effect by generating a force that increases the contact pressure of the gasket to the surface of the recesses 16 and 16'. Alternatively, as Figure 5 As shown above (see the sides 30 , 32 or the end faces 34 , 36 ), the sides and / or the end faces may have different shapes, or be rectilinear.

[0093] To reduce the permeability of the gasket 14 with respect to:

[0094] - gases which may be mixed with a gas or diluent gas comprising at least CO2 and / or O2 and / or N2 and / or water vapour and / or oxygen-containing compounds, such as heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethylketone (also known as 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone (CAS No. 756-12-7));

[0095] - or a gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound and / or water vapor,

[0096] - and / or incoming water and / or incoming water vapor, the interface or the system is surrounded or intended to be surrounded by an external atmosphere containing some water and / or water vapor, at least one (or both) of the outer side 20 and the inner side 22 includes a lip 142 (about Figure 3A The inner lip of the example of the embodiment of the present invention may have a substantially rectangular shape in a plane containing the axis AA' (such as may be Figure 3A , 3B , 4A and 5; other shapes are possible, such as at least partially circular or at least partially circular or semicircular, as can be seen in Fig.11A and 11B Preferably, the lip(s) and the body have the same composition (see above example of the material of the body, the lip(s) are preferably made of the same material as the body), so the composition of the gasket is homogenous.

[0097] The inner lip has an extension (or thickness) l measured along an axis parallel to the AA' axis. 14 , which is less than the extension (or thickness) L of the body along the same axis 14 , for example less than or equal to the extension (or thickness) L 14 50% of the extension (or thickness) l 14 The smaller the diameter (or cross-section), the better the efficiency.

[0098] For example: the extension (or thickness) of the body L 14 Between 3 mm and 25 mm, and the extension (or thickness) of the lip is l 14 ( <L 14 ) is between 0.5mm and 5mm.

[0099] Compared with the known gasket without lip 142 ( Figure 4B ) compared to the surface area S1 of the inner side 22 and / or the outer side 21 of the lip 142, the lip 142 provides a smaller surface area S2 for gas (particularly from the list mentioned above) and / or incoming water and / or water vapor penetrating in a direction perpendicular to the axis AA'.

[0100] The permeation (the passage of molecules through the gasket) is related to the surface area under pressure: due to its smaller extension l along the axis AA' 14 , so the lip 142 provides a reduced surface area S2 with respect to penetration.

[0101] exist Figure 3A and 4A In the embodiment of the present invention, the lip is an inner lip, which is oriented toward the part of the device having the highest pressure P2 under the use condition (the external pressure of the device is P1 <P2)。

[0102] In other embodiments, such as in e.g. Figure 3B On the other hand, the lip is an outer lip, which is oriented toward the outer part of the device having the lowest pressure P1 under the use condition. Figure 3B The gasket on the outer lip is particularly effective in limiting or preventing the penetration of water and / or water vapor of H2O from outside the device provided with the gasket, and also effectively resists the penetration of gases (especially from the list mentioned above) in a direction perpendicular to the axis AA'.

[0103] Temporary reversal of the direction of the pressure difference is tolerated by the design of the invention, but preferably at a lower amplitude ((P1-P2) < 2 bar). Preferably, the device is able to withstand a vacuum (0 bar absolute internal pressure (P2) and 1 bar absolute external pressure (P1)) before filling.

[0104] The width w of the gasket (path of the gas through the gasket) is measured along an axis perpendicular to AA' in a plane containing the AA' axis; for example, it is between 4 mm and 10 mm or 40 mm.

[0105] In any embodiment according to the present invention, the width w=w 141 +w 142 , w 141 (or w 142 ) is the width of the body 141 (or the width of the lip 142), w 141 and w 142 (For example, w 141 ≥w 142 ) are both measured in a plane containing the axis AA' but along an axis perpendicular to AA'. Preferably: w 142 ≥35%w 141 or 141 ≥w 142 ≥35%w 141 (The longer the path the gas takes through the gasket, the more efficient the gasket is).

[0106] The body 141 performs several functions: It is adapted to maintain sufficient pressure on the surface to ensure tightness taking into account thermal expansion, aging, manufacturing tolerances and environmental constraints. It also allows easier handling of the gasket during the assembly process.

[0107] Preferably, the inner or outer lip 142 generally has a higher average compression rate (e.g. between 15% and 40%) than the average compression rate of the body 141 (e.g. between 10% and 25%). The respective recesses 161, 162 are preferably designed so that the lip is more compressed than the body of the gasket. This preferably ensures sufficient compression under all conditions and with respect to the constraints mentioned above. It may be noted that in the body, those portions A1 (see Figure 4A ) has a smaller compression ratio than the largest part A2.

[0108] The recess for the gasket according to the invention has:

[0109] - a first large parallelepiped shape (for the body of the gasket) having an extension (or thickness) L measured along an axis parallel to the axis AA' 16 ;

[0110] - and a second smaller parallelepiped shape having an extension (or thickness) l also measured along an axis parallel to AA' 16 , l 16 <L 16 .

[0111] Preferably, the ratio l 16 / l 14 Between 0.60 and 0.85, and / or the ratio L 16 / L 14 Between 0.75 and 0.9;

[0112] In general, the ratio l 16 / l 14 <L 16 / L 14 is preferred (for a higher compression ratio on the lip than on the body).

[0113] Fig. 6A and 6B A particular embodiment of a gasket or gasket system according to the invention is shown, comprising two gaskets according to the invention connected in series:

[0114] - a first (outer) gasket having ( Fig. 6A and 6b) a body 14a (having an extension or thickness L 14 and width w 141 ) and inner lip 14'a (having an extension or thickness l 14 and width w 142 ),or( Figure 6B ) body 14a (having an extension or thickness L 14 and width w 141 ), outer lip 14'a1 (having an extension or thickness of l 141 and width w' 142 ) and inner lip 14'a (having an extension or thickness l 14 and width w 142 );

[0115] - and the second (inner) gasket ( Fig. 6A and 6b), which has a body 14b (having an extension or thickness L' 14 and width w' 141 ) and inner lip 14'b (having an extension or thickness l' 14 and width w 142a ), the inner lip 14'a of the first (outer) gasket is connected to the outer side of the body 14b of the second (inner) gasket.

[0116] exist Fig. 6A and 6B In both embodiments, the inner gasket is located on the side of the device having the highest pressure P2 under the use condition (the external pressure of the device is P1 <P2)。

[0117] The first (outer) gasket has a lateral extension ( Fig. 6A D 14a , Figure 6B D' 14a), which is larger than the second (inner) gasket ( Fig. 6A and 6B D on both 14b ).

[0118] like Fig. 6A and 6B As shown above, the two washers fit into the corresponding double recesses 16a, 16b, 16'a, 16'b.

[0119] Fig. 6A and 6B The double structure of the gasket or of the gasket system ensures a very high tightness with respect to the gas located on the pressure side of the device (at pressure P2>P1).

[0120] Extension or thickness L 14 ,l 14 ,L' 14 ,l' 14 ,l 141 Each of is measured along an axis parallel to the AA' axis.

[0121] l 14 and l 141 Each of which is less than the extension (or thickness) L 14 , for example, less than the extension (or thickness) L 14 50% of.

[0122] l' 14 Less than extension (or thickness) L' 14 , for example, less than the extension (or thickness) L' 14 50% of.

[0123] Preferably: 14 = l 141 =l' 14 and / or L 14 =L' 14 .

[0124] The above considerations regarding the width of the body and the width of the lip(s) may apply to Fig. 6A or the embodiment of 6B; preferably:

[0125] ·w 142 ≥35%w 141 or w' 142 ≥35%w 141 ; or 141 ≥w 142 ≥35%w 141 or 141 ≥w' 142 ≥35%w 141 or 142 +w' 142≥35%w 141 or 141 ≥w 142 +w' 142 ≥35%w 141 ;

[0126] And / or: w 142a ≥35% w' 141 , or w' 141 ≥w 142a ≥35% w' 141 .

[0127] Fig. 7A is a front view (or a view in the plane of the gasket) of a circular or annular gasket or gasket system according to the invention in a plane perpendicular to the axis (AA'). It has an internal diameter D1 (internal diameter of the lip 141) which may for example be comprised between 40 mm or 50 mm or 100 mm on the one hand and 500 mm or even 1300 mm on the other hand. Such large gaskets are more critical in terms of tightness than the usual smaller gaskets (with a diameter comprised between 10 mm and 40 mm).

[0128] Alternatively, the gasket or gasket system according to the invention may have an elongated or oval or elliptical shape in a plane perpendicular to the axis (AA') (or in the plane of the gasket). Figure 7B ), whose maximum internal dimension D2 may for example be comprised between 40 mm or 50 mm or 100 mm on the one hand and 500 mm or even 1300 mm on the other hand.

[0129] In general (for any of the embodiments of a gasket or gasket system according to the invention):

[0130] - the lip extends along the entire length of the inside or outside (or the entire inside or outside circumference) of the body of the gasket;

[0131] - and / or the lip is made of the same material as the body.

[0132] A variation of the present invention is Fig. 8A , 9A and 9B , at the interface between the two parts 10 , 10 ′: these washers have an “L” shape, the lip 142 having a face 140 , perpendicular to said AA′ axis, extending in the same plane as one of the lateral end faces 24 , 26 of the body 142 of the washer.

[0133] Figure 8B Show Fig. 8A The gasket is located in the corresponding recess having an "L" shape. Figure 8B In the embodiment of FIG. 5 , only one of the two parts 10 , 10 ′ has a recess.

[0134] exist Fig. 9C In the embodiment, only Fig. 9A 9B or the body of the gasket or part of the body is located in the recess. As can be seen in this figure, the assembly faces of the two parts or two components do not touch each other (with other Figure 2 , 3A , 3B, 6A, 6B). More generally (the gasket has an "L" shape or any other shape), at least in the area surrounding the recess and / or the gasket, at least part of the end faces or assembly faces of the two components:

[0135] - can touch each other;

[0136] - or may not contact each other; in this latter case, parts of the gasket (eg one or more lips or at least parts of one or more lips) may not be located in the recess, but may for example be located between said assembly faces.

[0137] Fig. 8A , 8B These embodiments of 9A-9C are applicable to smaller gaskets, for example, with an inner dimension or inner diameter between 40 mm (or 50 mm) and 200 mm, with a more compact implementation than the previously proposed embodiments. They can replace O-rings and are easier to integrate than the gaskets described above in conjunction with the previous figures.

[0138] like Figures 9A-9C As shown above, the body of the gasket according to the invention may have an extension (or thickness or axial height) L 14 , which is greater than the distance between its inner side 22 and its outer side 20 (measured in a plane perpendicular to the axis AA' or in the plane of the gasket). This applies to "L"-shaped gaskets as well as to any other embodiment.

[0139] The gasket according to the invention may be formed by injecting a non-vulcanized (or uncured) material into a mould, followed by a compression step.

[0140] The present invention is applicable, for example, to a switch, or to a circuit breaker, or to an isolating switch, or to a transformer, or to a surge arrester, or to a gas-isolated line . . .

Claims

1. A sealing system comprising two components (10, 10', 100, 101) of a gas isolation part of a high-pressure or medium-pressure device, wherein each of the components (10') comprises an end face or assembly surface (12', 102) facing an end face or assembly surface (12, 101) of the other component (10), at least one of the assembly surfaces comprises at least one recess (16), and wherein at least one compression sealing gasket (14, 14') is at least partially arranged in the at least one recess and is compressed at the assembly surface (12, 16) of the components (10, 10'). 2', 101, 102), the compression sealing gasket (14, 14') comprises a body (141) extending substantially in a plane or in a plane, the body (141) comprising an inner side (22, 32) and an outer side (20, 30) and end faces (24, 26, 34, 36), the end faces (24, 26, 34, 36) defining the gasket along an axis (AA') perpendicular to the plane and connecting the inner side and the outer side, the body (141) being made of an elastomeric material, the body having a first extension (L) along the axis (AA'). 14 ), at least one of the inner side and the outer side is provided with a lip portion (141), the lip portion (141) having a smaller diameter than the first extension (L 14 ) along a second extension (l ) of said axis (AA') perpendicular to said plane 14 ).

2. The sealing system according to claim 1, wherein: The first extension (L 14 ) included between 3 mm and 25 mm.

3. A sealing system according to any one of claims 1 or 2, wherein: The second extension (l 14 ) included between 0.5 mm and 5 mm.

4. The sealing system according to any one of claims 1 to 3, wherein: l 14 ≤50％L 14 。 5. The sealing system according to any one of claims 1 to 4, wherein: The body and the lip have a first width w respectively. 141 and the second width w 142 , the two widths are measured in the plane containing the axis AA' and along an axis perpendicular to AA', so that w 142 ≥35%w 141 .

6. The sealing system according to any one of claims 1 to 5, wherein: The gasket has a maximum internal dimension (D1 - D2) between 50 mm and 1300 mm.

7. The sealing system according to any one of claims 1 to 6, wherein: The lip portion (142) has a higher average compressibility than the body (141).

8. The sealing system according to any one of claims 1 to 7, wherein: - the outer side (20, 30) and the inner side (22, 32) are parallel and / or coaxial with each other; - and / or said gasket has an annular or oval or elliptical shape in a plane perpendicular to said axis (AA').

9. The sealing system according to any one of claims 1 to 8, each of the inner side and the outer side being provided with a lip (14'a, 14'a1).

10. The sealing system according to any one of claims 1 to 9, the end surface (24, 26, 34, 36) and at least one of the outer side (20) and the inner side (22) having a wave shape.

11. The sealing system according to any one of claims 1 to 10, the lip (142) having a side perpendicular to the axis (AA') extending in the same plane as one of the end faces (24, 26, 34, 36).

12. A compression sealing gasket system according to one of claims 1 to 11, comprising a second sealing gasket (14'), the second sealing gasket (14') comprising a body (141) extending substantially in a plane or in a plane, the body (141) comprising an inner side (22, 32) and an outer side (20, 30) and end faces (24, 26, 34, 36), the end faces (24, 26, 34, 36) delimiting the gasket along an axis (AA') perpendicular to the plane and connecting the inner side and the outer side, the body (141) being made of an elastic material, the body having a first extension (L') along the axis (AA'). 14 ), at least one of the inner side and the outer side is provided with a lip (141), the lip (141) having a length smaller than the first extension (L' 14 ) along a second extension (l') of said axis (AA') perpendicular to said plane 14 ), the two sealing gaskets are connected in series, and the lip (14'a) of one of the gaskets is connected to the inner side or the outer side of the other gasket.

13. The sealing system according to any one of claims 1 to 12, wherein the gas isolation portion: * contains or is intended to contain a gas, said gas comprising at least: Heptafluoroisobutyronitrile and / or heptafluoroisopropyl trifluoromethyl ketone (also known as 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone (CAS No. 756-12-7)), possibly mixed with a gas or diluent gas comprising at least CO2 and / or O2 and / or N2 and / or and / or an oxygen-containing compound; - or a gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound and / or water vapor; * and / or the gas isolation portion is surrounded or is intended to be surrounded by an atmosphere containing some water and / or water vapor.

14. A sealing system according to any one of claims 1 to 13, the gas-insulated part forming part of a switch, or part of a circuit breaker, or part of a disconnector, or part of a transformer, or part of a surge arrester, or part of a gas-insulated line.

15. A method for isolating a gas-insulated portion of a high- or medium-pressure installation, said portion: * containing gas, the gas comprising at least: - heptafluoroisobutyronitrile and / or heptafluoroisopropyltrifluoromethylketone (also known as 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone (CAS No. 756-12-7)), possibly mixed with a gas or diluent gas comprising at least CO2 and / or O2 and / or N2 and / or and / or an oxygen-containing compound; - or a gas comprising at least CO2 and / or O2 and / or N2 and / or an oxygen-containing compound and / or water vapor; * and / or the gas isolation portion is surrounded or intended to be surrounded by an atmosphere containing some water and / or water vapour; The gas isolation portion comprises a sealing system according to any one of claims 1 to 14.

16. The method according to claim 15, wherein: The gas is contained in the device at a pressure between 1 bar and 20 bar.

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