US-12618472-B2 - Compression sealing gasket and sealing system

US12618472B2US 12618472 B2US12618472 B2US 12618472B2US-12618472-B2

Abstract

A compression sealing gasket having a main body of general planar extension, or extending in a plane, including an inner side and an outer side, and end faces, which delimit the gasket along an axis perpendicular to the plane, and connect the inner side and the outer side, made of an elastomer material, the main body having a first extension, along the axis, at least one of the inner side and the outer side being provided with a lip which has a second extension, along the axis perpendicular to the plane, less than the first extension.

Inventors

Lukas Treier
Thomas BERTELOOT
Maxime PERRET
Bernhard SPICHIGER

Assignees

GENERAL ELECTRIC TECHNOLOGY GMBH

Dates

Publication Date: 20260505
Application Date: 20230713
Priority Date: 20220713

Claims (15)

1 . A sealing system comprising two components of a gas insulated portion of a high or medium voltage apparatus, the gas insulated portion forming part of a switch, or of a circuit-breaker, or of a disconnector, or of a transformer, or of a surge-arresters, or of a gas-insulated line, in which each of the components comprises an end or assembly face that faces the end or assembly face of the other component, at least one of the assembly faces comprising at least one recess and wherein at least one compression sealing gasket is at least partly arranged in the at least one recess and is compressed between the assembling faces of the components, the compression sealing gasket comprising a main body of general planar extension, or extending in a plane, comprising an inner side and an outer side, and end faces, which delimit the gasket along an axis perpendicular to the plane, and connect the inner side and the outer side, made of an elastomer material, the main body having a first extension, along the axis, at least one of the inner side and the outer side being provided with a lip which has a second extension, along the axis perpendicular to the plane, less than the first extension.
2 . A sealing system according to claim 1 , wherein the first extension is comprised between 3 mm and 25 mm.
3 . A sealing system according to claim 1 , wherein the second extension is comprised between 0.5 mm and 5 mm.
4 . A sealing system according to claim 1 , wherein the second extension is <50% the first extension.
5 . A sealing system according to claim 1 , wherein the main body, respectively the lip, has a first width, respectively a second width, both widths being measured in the plane containing the axis and along an axis perpendicular to axis, such that the second width is >35% of the first width.
6 . A sealing system according to claim 1 , wherein the gasket has a maximum inner dimension between 50 mm and 1300 mm.
7 . A sealing system according to claim 1 , wherein the lip has an average compression rate higher than the main body.
8 . A sealing system according to claim 1 , wherein: the outer side and the inner side are parallel and/or coaxial to each other; and/or the gasket has in a plane perpendicular to the axis an annular or oval or ellipsoidal shape.
9 . A sealing system according to claim 1 , each of the inner side and the outer side being provided with a lip.
10 . A sealing system according to claim 1 , at least one of the end faces and of the outer side and the inner side has a wavy shape.
11 . A sealing system according to claim 1 , the lip having a side, perpendicular to the axis, extending in a same plane as one of the end faces.
12 . A compression sealing gasket system according to claim 1 , comprising a second sealing gasket, the second sealing gasket comprising a main body of general planar extension, or extending in a plane, comprising an inner side and an outer side, and end faces, which delimit the gasket along an axis perpendicular to the plane, and connect the inner side and the outer side, made of an elastomer material, the main body having a first extension, along the axis, at least one of the inner side and the outer side being provided with a lip which has a second extension, along the axis perpendicular to the plane, less than the first extension, the two sealing gaskets being in series, the lip of one of the gaskets being connected to the inner side or to the outer side of the other one of the gaskets.
13 . A sealing system comprising two components of a gas insulated portion of a high or medium voltage apparatus, the gas insulated portion: containing, or being intended to contain, a gas comprising at least: heptafluoroisobutyronitrile and/or heptafluoroisopropyl trifluoromethyl ketone (also named 2butanone, 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-(CAS No 756-12-7)), possibly mixed with a gas or a dilution gas comprising at least CO 2 and/or O 2 and/or N 2 and/or an oxygenated compound; or to a gas comprising at least CO 2 and/or O 2 and/or N 2 and/or an oxygenated compound and/or water vapor; and/or the gas insulated portion being surrounded, or being intended to be surrounded by an atmosphere containing some water and/or water vapor; in which each of the components comprises an end or assembly face that faces the end or assembly face of the other component, at least one of the assembly faces comprising at least one recess and wherein at least one compression sealing gasket is at least partly arranged in the at least one recess and is compressed between the assembling faces of the components, the compression sealing gasket comprising a main body of general planar extension, or extending in a plane, comprising an inner side and an outer side, and end faces, which delimit the gasket along an axis perpendicular to the plane, and connect the inner side and the outer side, made of an elastomer material, the main body having a first extension, along the axis, at least one of the inner side and the outer side being provided with a lip which has a second extension, along the axis perpendicular to the plane, less than the first extension.
14 . A method for insulating a gas insulated portion of a high or medium voltage apparatus, the portion: containing a gas comprising at least: heptafluoroisobutyronitrile and/or heptafluoroisopropyl trifluoromethyl ketone (also named 2butanone, 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-(CAS No 756-12-7)), possibly mixed with a gas or a dilution gas comprising at least CO 2 and/or O 2 and/or N 2 and/or an oxygenated compound; or to a gas comprising at least CO 2 and/or O 2 and/or N 2 and/or an oxygenated compound and/or water vapor; and/or the gas insulated portion being surrounded, or being intended to be surrounded, by an atmosphere containing some water and/or water vapor; the gas insulated portion comprising a sealing system according to claim 1 .
15 . A method according to claim 14 , wherein the gas is contained in the apparatus at a pressure between 1 bar and 20 bar.

Description

TECHNICAL FIELD The invention concerns a compression sealing gasket designed to reduce its permeability to gas and/or to outer water or water vapor. The sealing gasket is intended to be implemented on medium and high voltage gas insulated apparatuses, at the connection between two parts. PRIOR ART Some medium and high voltage apparatuses comprise hollow components in which conductors are arranged. An insulating gas fills these components, to isolate the conductors carrying current at a high voltage from the hollow components which are at ground potential. The insulating gas is also able to withstand the electric field over short distances between conductors arranged in the component. The connection between two components comprises for example a tubular part for each component and a sealing gasket placed between the tubular parts. According to a known embodiment, the sealing gasket is made of an elastomer and is compressed between components, for example two tubular parts or one tubular part and a flat plate. The compression of the two components or parts produces an elastic deformation of the gasket, improving the tightness of the connection. However, the gasket is generally made of an elastomer that has a permeability to the insulating gas. One object of the invention is to provide a sealing gasket having a significantly lower permeability, in order to reduce the leakage rate for a complete apparatus. The aim is to reach for the overall arrangement a leakage rate less than 0.5% vol/year as described in the relevant IEC standards for switchgear, for example IEC 62271-203 for gas insulated switchgear. This improvement is of particular interest since the industry moves towards insulating gases, consisting of gases or gas mixtures, that may leak differently due to the different characteristics of those new molecules used compared to the prevailing SF6 gas that has been used for decades. In particular, a gas called “g3” comprising heptafluoroisobutyronitrile mixed with a dilution gas comprising carbon dioxide and oxygen is used in replacement of SF6. CO2 has a strong propensity to leak. O2 and N2 also leak, but less than CO2. These 3 gases have a higher susceptibility to leak than SF6. These leaks pose problems because of the adverse effect of CO2 on the environment; furthermore, the lost gas must also be replaced, which involves further costs due to maintenance operations. Another object of the invention is to provide an improved sealing gasket having a significantly lower permeability to heptafluoroisobutyronitrile and/or heptafluoroisopropyl trifluoromethyl ketone (also named 2-butanone, 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-(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 insulated apparatuses of the type mentioned above or in this application, more generally in any high voltage or medium voltage components, like disconnectors, or switches, or circuit breakers, or gas insulated lines, implemented in medium or high voltage applications. Indeed such a gas may contain: heptafluoroisobutyronitrile, alone or mixed with with O2 and/or CO2 and/or N2;and/or heptafluoroisopropyl trifluoromethyl ketone, alone or mixed with O2 and/or CO2 and/or N2;or CO2, alone or in a mixture with O2, and/or with N2;N2, alone or in a mixture with O2 and/or CO2. Furthermore, H2O is not wanted inside such devices, and another object of the invention is to provide a sealing gasket reducing or limiting or avoiding permeation of H2O from the outside of such a gas insulated apparatus implemented in medium or high voltage applications. BRIEF DESCRIPTION OF THE INVENTION The invention concerns 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 can be used in the rest of this description), comprising a main body of general planar extension, or extending in a plane, comprising an inner side and an outer side, made of an elastomer material, said main body having a 1st extension (or 1st thickness) (L14), along an axis perpendicular to said plane, at least one of said inner and outer side being provided with a lip which has a 2nd extension (or 2nd thickness), along said axis perpendicular to said plane, less than the 1st extension (or 1st thickness). The lip offers a smaller surface area to gas and/or water permeating in a direction contained in the plane of the main body. Preferably, the lip(s) and the main body are homogeneous in terms of composition. Permeation (molecules going through the gasket by diffusion) is linked to the surface area under pressure. Due to its smaller extension or thickness along the axis perpendicular to the plane in which the gasket extends, the lip offers a reduced surface to permeation. The main body, which has a larger extension along the axis, is to ensure ageing, thermal dilatation, manufacturing tolerances, factory handling and envi