gasket

Abstract

A gasket (100) for sealing two mating surfaces is provided, the gasket comprising: a rigid non-metallic core (102) defining a bore (104), the core comprising a first face (106) extending away from the bore and a second face (122) opposite the first face; and at least one sealing layer (108), wherein the first face comprises a substantially planar inner region (112) defining a plane and a serrated region (110) comprising a plurality of serrations (118) extending substantially normal to the plane, wherein the substantially planar inner region is located between the bore and the serrated region, wherein the serrations are recessed from the first face such that the serrations do not pass through the plane, wherein the at least one sealing layer covers at least a portion of the serrated region of the first face.

Description

Technical Field

[0001] This invention relates to a gasket for sealing two mating surfaces and a method for manufacturing the gasket.

[0002] More specifically, the present invention relates to a gasket comprising a non-metallic core for sealing two mating surfaces, the non-metallic core including serrated portions; the present invention also relates to a method of manufacturing a gasket comprising a non-metallic core including serrated portions. Background Technology

[0003] The use of gaskets in sealing applications is common in many industries. A well-known application of gaskets is to provide a fluid seal between two mating surfaces, such as between the two ends of adjacent pipes or conduits, where the ends are typically in the form of flanges, to facilitate assembly and disassembly, and to ensure a better seal.

[0004] Flange joint gaskets typically include a compressible ring that defines an orifice sized to match the dimensions of the conduit being sealed and a body sized to match the dimensions of the flange mating surface.

[0005] In high-pressure sealing applications, a preferred gasket is called a serrated composite (Kammprofile) gasket. This is essentially a gasket with a series of concentric serrations or accordion-like profiles on one or two facing surfaces. This profile is achieved by superimposing a series of concentric serrations onto a robust core, typically metal. During sealing, the softer sealing material covering the compressible ring (often called the face layer) is forced into the gaps between the serrations to improve the seal by inducing stress concentration on the sealing surface and minimizing minor imperfections on the sealing flange. The serrations also minimize lateral movement of the face layer's sealing material, while the core provides rigidity and burst resistance. For high-pressure applications, this profile increases the gasket's strength.

[0006] The surface layer in the gasket needs to be compressible to provide a good seal and resist creep.

[0007] However, a problem associated with these toothed gaskets is that they are made of metal, and because they are conductive, they are not effective insulators. Furthermore, for metal gaskets that include serrations, the serrations are arranged such that the peaks of the serrations are significantly higher than the height of any internal or external region and can cause punctures into the surface layer.

[0008] Non-metallic insulating gaskets are known. Typically, they are glass-reinforced epoxy (GRE) cores and rubber beads (sometimes PTFE beads). However, these beads have some limitations, particularly due to the compressive deformation of the rubber (or the cold flow of PTFE), which can lead to long-term sealing problems. Rubber also has temperature limitations (high temperature (decomposition) and low temperature (glass transition temperature, Tg)). Furthermore, the geometry dictates that the bead must be thin (1 / 8 inch) and wide, which can cause problems, for example, if a flange defect or flaw exists and the seal is located on that defect, the bead may not seal effectively.

[0009] Wider rubber seals may not be ideal because O-ring type seals work best in confined grooves, where the O-ring protrudes from the groove as little as possible when in use.

[0010] The inventors seek to provide a serrated gasket that overcomes some or all of the disadvantages of existing gaskets. Summary of the Invention

[0011] According to a first aspect, a gasket for sealing two mating surfaces is provided, the gasket comprising: a rigid nonmetallic core defining an orifice, the core including a first face extending away from the orifice and a second face opposite to the first face; and at least one sealing layer, wherein the first face includes: a substantially flat internal region defining a plane; and a serrated region including a plurality of serrations, wherein the substantially flat internal region is located between the orifice and the serrated region, wherein the serrations are recessed into the first face such that the serrations do not penetrate the plane, and wherein the at least one sealing layer covers at least a portion of the serrated region of the first face. In one example, the plurality of serrations includes peaks and valleys, and the peaks of the serrations do not penetrate the plane.

[0012] The gasket provides a rigid non-metallic core with a rigid, flat internal region arranged to contact a mating surface during use. The non-metallic core may be made of a compression-resistant material. A sealing layer is arranged to cover the serrations, allowing the sealing layer to be compressed into the serrations during use, thereby providing a better seal between the gasket and the mating surface. Recessed serrations are arranged within the core to minimize or prevent contact with the mating surface during use. The flat internal region provides a bearing surface during contact with the mating surface. The flat internal region also minimizes or prevents contact between the serrations and the mating surface during use.

[0013] The serrated areas of a non-metallic core can be machine-formed. Machine forming is defined as removing material using machine tools. The resulting serrations can have a textured / rough surface. When the sealant is compressed into the serrations, the textured / rough surface provides a more effective seal.

[0014] The serrations can extend substantially perpendicular to the plane.

[0015] Non-metallic cores can be formed from a single piece. A single piece is much easier to form (e.g., through machining) than a core composed of two or more parts. A core formed from a single piece can be structurally stronger than other cores.

[0016] The first surface may include a generally flat outer region, which is typically aligned with the inner region on the plane. The flat inner and flat outer regions cooperate to provide a bearing surface to help minimize or prevent contact between the serrations and the mating surface.

[0017] The flat inner and outer areas also help distribute compressive pressure over a larger surface area. This helps to seal and maintain the integrity of the entire gasket.

[0018] A flat inner region and a flat outer region can be located on opposite sides of a serrated region. Alternatively, the flat inner region and the flat outer region can be positioned adjacent to the serrated region.

[0019] The serrations can terminate before the plane to define a channel in the first face of the core. This helps to minimize or prevent contact between the serrations and the mating surface. In one example, the peak of the serrations can terminate before the plane to define a channel in the first face of the core.

[0020] The channel may extend radially around the hole. The channel may be an annular channel. In one example, the channel extends along a circumferential direction spaced apart from the periphery or similar of the hole.

[0021] The at least one sealing layer may be located at least partially within the channel defined by the serrated region. This helps to secure the sealing layer to the core. Positioning the at least one sealing layer within the channel also helps to minimize or prevent lateral movement of the sealing layer.

[0022] The channel or channel base may be substantially inclined relative to the flat surface defined by the flat inner region. This can increase internal pressure when the sealing layer is pushed outward to provide a more effective seal between the sealing layer and the serrated region. In one example, the channel is inclined substantially away from the orifice. Preferably, the channel adjacent to the inner region has a relatively greater depth compared to the depth of the channel adjacent to the outer region. In other words, the depth of the channel can decrease outward from the inner region to the outer region. The inclined arrangement can help energize the seal, i.e., the internal pressure forces the structure to seal better. Theoretically, the inclination away from the orifice causes the gasket to be "self-reinforcing" as pressure pushes the sealing layer outward into the shallower serrations and thus increases the density of the sealing layer. When the seal is pushed outward, the internal pressure can act on the seal to improve the overall sealing performance.

[0023] The serrations can be configured to extend into the plane defined by the inner region. Therefore, the sealing layer does not need to be of any particular shape, as it does not need to conform to the channel.

[0024] The serrated region may include at least one bridge located between at least a pair of adjacent serrations. The bridge may include a mating surface for the at least one sealing layer. This mating surface can provide a load-bearing surface to help reduce stress on the serrations, which can decrease the effectiveness of the seal.

[0025] The at least one bridge may include a planar portion. This planar surface can provide a load-bearing surface to help reduce stress on the saw teeth, which may reduce the effectiveness of the seal. This planar surface and the flat inner / outer region can cooperate to provide load-bearing surfaces to help minimize or prevent contact between the saw teeth and the mating surface.

[0026] At least one non-zigzag planar portion may be offset relative to the plane defined by the inner region.

[0027] At least one of the bridges can be centrally located within the serrated region relative to its distance from the hole. This centrally located bearing surface within the serrated region minimizes the amount of compressive pressure applied to the serrations. A centrally located bridge also helps minimize or prevent contact between the serrations and the mating surface.

[0028] At least one of the bridges can be positioned non-centrally within the serrated region. This provides a non-central load-bearing surface, resulting in lower compressive stress applied to the central serrated region.

[0029] At least two of the bridges can be positioned symmetrically about the center of the serrated region. This arrangement provides a symmetrical load-bearing surface, thereby applying compressive pressure uniformly. Alternatively, the bridges can be positioned asymmetrically about the center of the serrated region. In other words, there can be multiple bridges arranged asymmetrically about the center of the serrated region. For example, two bridges can be located on one side of the center of the serrated region.

[0030] In one example, one bridge can be located on one side of the sawtooth region, and at least two bridges can be located on the other side of the sawtooth region. In other words, there can be more bridges on one side of the sawtooth region than on the other side.

[0031] In one example, the core includes an asymmetrical arrangement of bridges in the first and second faces. In other words, the serrated region in the first face may have a first number of bridges, while the serrated region in the second face includes a second number of bridges.

[0032] The plurality of saw teeth may include a first set of saw teeth and a second set of saw teeth, wherein the first set of saw teeth is larger than the second set of saw teeth. The larger first set of saw teeth can inhibit or slow down gas permeation through the core of the gasket.

[0033] The at least one sealing layer may include one or more protrusions configured to engage with at least one tooth in the first set of teeth. When engaged with the first set of teeth, the protrusions can provide a more effective seal during compression of the gasket and mating surfaces.

[0034] The non-metallic core may include glass-reinforced epoxy resin, phenolic resin, polytetrafluoroethylene, polyimide, (alkyl)acrylic (co)polymer or other suitable (co)polymer, or be formed from glass-reinforced epoxy resin, phenolic resin, polytetrafluoroethylene, polyimide, (alkyl)acrylic (co)polymer or other suitable (co)polymer.

[0035] The at least one sealing layer may comprise polytetrafluoroethylene, layered silicates, ceramics, or graphite, more typically graphite or vermiculite, or be formed of polytetrafluoroethylene, layered silicates, ceramics, or graphite, more typically graphite or vermiculite, wherein the vermiculite includes expanded vermiculite, biotite, hydrobiotite, and phlogopite.

[0036] In one example, the core has a through-thickness between approximately 1 mm and 8 mm.

[0037] In one example, the at least one sealing layer comprises one or more of the following materials: expanded graphite, polytetrafluoroethylene (PTFE), or layered silicate materials such as mica or expanded vermiculite. Preferred materials for the sealing layer are inorganic materials, including layered silicates, ceramics, and graphite. Particularly preferred materials for the sealing layer include layered silicates and graphite. The term "layered silicate" in this specification includes mica and vermiculite. Mixtures of these materials may be used. It should be noted that the term "vermiculite" in this specification includes materials that are sometimes referred to as biotite, hydrobiotite, and phlogopite (the nomenclature is controversial in this field). Mica is useful in this invention due to its good dielectric properties.

[0038] The preferred vermiculite used in this invention is expanded vermiculite or includes expanded vermiculite, which may be chemically expanded vermiculite (CEV), thermally expanded vermiculite (TEV), or a mixture of CEV and TEV. Expanded vermiculite may be mixed with other minerals. Therefore, other preferred materials include expanded vermiculite (which may include CEV, or TEV, or a mixture of CEV and TEV) mixed with other minerals (e.g., one or more of talc, mica, and graphite).

[0039] In the case of vermiculite optionally mixed with other mineral materials, particularly preferred materials for the sealing layer include expanded vermiculite, preferably chemically expanded vermiculite and expanded graphite.

[0040] These materials are compressible and are typically compressed to 40% to 80% of their original thickness during assembly and installation of the gaskets. Compression is accompanied by the filling of the serrated valleys and the expansion of the sealing layer.

[0041] As mentioned above, expanded graphite and expanded vermiculite have many excellent properties for use in the face layer of gaskets, especially excellent mechanical properties, high heat resistance and very good chemical resistance.

[0042] The sealing layer can have a thickness of approximately 0.1 mm to 1.25 mm.

[0043] The at least one sealing layer may be made of a compressible material, and may preferably be in granular, sheet, or fibrous form. In use, the sealing layer is compressed when the gasket is placed between the opposing surfaces of the pipe or conduit under compressive load. Typically, the compression of the sealing layer in use is in the range of 30% to 90% ((initial thickness - final thickness) / initial thickness × 100%), more typically in the range of 40% to 80%, and most typically between 50% and 70%. In any case, the sealing layer will typically have a compression of more than 30% in use, more typically more than 40%, and most typically more than 50%. A suitable compression test is performed at room temperature (25°C) according to ASTM F36-15.

[0044] Suitablely, when not compressed before use, the average thickness of the sealing layer is at least 0.2 mm, preferably at least 0.4 mm, preferably at least 0.5 mm, at least 0.6 mm in some embodiments, and at least 0.7 mm in other embodiments.

[0045] Suitablely, when uncompressed before use, the average thickness of the sealing layer is up to 4 mm, preferably up to 2 mm, and most preferably up to 1 mm.

[0046] In one example, the at least one sealing layer is configured to extend to abut at least a portion of the inner region. Therefore, the at least one sealing layer can be configured to extend beyond the serrated region to abut or cover at least a portion of the inner region, typically extending beyond the serrated region to abut or cover a portion of both the inner and outer regions. In use, the portion of the at least one sealing layer that abuts or covers the inner region (and optionally the outer region) has a relatively higher density compared to the remainder of the sealing layer.

[0047] In one example, the density of the at least one sealing layer in its uncompressed state may be between 0.8 g / cc and 1.6 g / cc, typically between 1.2 g / cc and 1.3 g / cc.

[0048] The density of the at least one sealing layer, when compressed (i.e., when compressed against the serrated portion), can be between 1.4 g / cc and 2.2 g / cc, typically between 1.6 g / cc and 1.9 g / cc.

[0049] The second surface may include: a second substantially flat interior region defining a second plane; and a second serrated region comprising a second plurality of serrations, wherein the second substantially flat interior region is located between the hole and the second serrated region, wherein the second plurality of serrations are recessed into the second surface such that the second plurality of serrations do not penetrate the second plane, wherein the at least one sealing layer covers at least a portion of the second serrated region of the second surface. In one example, the second plurality of serrations includes peaks and valleys, and the peaks of the serrations do not penetrate the second plane.

[0050] According to a second aspect of the invention, a method of manufacturing a gasket is provided, comprising the steps of: providing a rigid nonmetallic core defining an aperture, the core including a first surface extending away from the aperture and a second surface opposite to the first surface; and forming a serrated region comprising a plurality of serrations in the first surface of the core, such that the first surface includes a substantially flat inner region defining a plane and a serrated region comprising the plurality of serrations, wherein the substantially flat inner region is located between the aperture and the serrated region, and wherein the serrations are recessed into the first surface such that the serrations do not extend beyond the plane. In one example, the plurality of serrations includes peaks and valleys, and the peaks of the serrations do not penetrate the plane.

[0051] The serrated profile can be machine-formed. Alternatively, the serrated profile can be formed by forging and / or molding (e.g., injection molding).

[0052] The method may also include the step of providing at least one sealing layer and covering at least a portion of the serrated region of the first surface with the at least one sealing layer.

[0053] All features contained in this article can be combined with any of the above aspects, and can be combined in any way. Attached Figure Description

[0054] Examples of this disclosure will now be described with reference to the accompanying drawings.

[0055] Figure 1 A perspective view showing an example of a gasket;

[0056] Figure 2 An example perspective view of the gasket is shown, in which the sealing layer has been removed;

[0057] Figure 3 An exploded view of an example gasket is shown;

[0058] Figures 4A to 4E An example of a cross-sectional view through the core is shown, in which the sealing layer has been removed;

[0059] Figures 5A to 5E An example of a cross-sectional view through the core is shown;

[0060] Figure 6 An example of a cross-sectional view through the core is shown; and

[0061] Figure 7 An example flowchart of the method steps for manufacturing gaskets is shown. Detailed Implementation

[0062] This disclosure relates to a gasket for sealing two mating surfaces. In the example given below, the gasket is made of a non-metallic core. This is in contrast to most gasket cores formed of metal, and thus presents some different challenges.

[0063] The non-metallic core includes a serrated region comprising multiple serrations. A sealing layer is configured to engage with the serrated region to provide a seal on the gasket. The non-metallic core also includes a substantially flat internal region located between the serrated region and the orifice. This substantially flat internal region is situated adjacent to the orifice to isolate the serrated region from the orifice of the gasket. This isolation means that the material of the sealing layer will be isolated from any fluid passing through the gasket, thus significantly reducing the likelihood of any chemical reaction occurring between the sealing layer and the fluid passing through the gasket.

[0064] The serrated area provides a good seal for the gasket. It has been found that limiting the size of the serrations so that they do not extend beyond the rest of the core means that the serrations will not be subjected to excessive stress during use. This means that the serrations are less likely to deform and / or break during use, as deformation and breakage of the serrations could lead to a poor seal.

[0065] Figure 1 An example of a gasket 100 according to one example is shown. The gasket 100 includes a non-metallic core 102 that defines a hole 104 therethrough. In use, fluid can flow through the hole 104.

[0066] The non-metallic core has a first surface 106 and a second surface ( Figure 1 (Not shown in the image). The first face 106 extends away from the hole 104. In Figure 1 In the example shown, the first surface is depicted vertically above the second surface, i.e., the gasket 100 is arranged in a vertical orientation. However, in practice, the gasket 100 is suitable for use in any orientation (e.g., a horizontal configuration where the first surface 106 and the second surface are side by side). The second surface (not shown) is opposite the first surface 106.

[0067] exist Figure 1 In the example shown, hole 104 is substantially circular, but other shapes of hole 104 are conceivable. For example, the hole could be polygonal, elliptical, rectangular, and / or square. Other shapes are also conceivable.

[0068] Gasket 100 also includes at least one sealing layer 108. Figure 1In the example shown, the at least one sealing layer 108 is in the form of a ring coupled to the core 102. This at least one sealing layer 108 is designed to engage with serrations formed in the first surface 102, which will... Figures 5A to 5E The following describes the details in more detail. In one example, the at least one sealing layer 108 is concentric with the hole 104.

[0069] When assembling the gasket 100, the at least one sealing layer 108 engages with the serrations of the serrated region 100. The at least one sealing layer 108 can be bonded to the serrated region 100 by spraying an adhesive. The sprayed adhesive can be a contact adhesive, such as an acrylic contact adhesive. An example of an acrylic contact adhesive is 3M Super 77.

[0070] Figure 2 An example of the core 102 of the gasket 100 is shown. Figure 2 In the image, for clarity, sealing layer 108 has been removed from gasket 100. (See image below.) Figure 2 As shown, the first surface 106 may include a generally flat interior region 112. The generally flat interior region 112 defines a plane that extends along and beyond the interior region 112.

[0071] The first surface 106 also includes a serrated region 110, which comprises a plurality of serrations. The outline of the serrations is... Figures 4A to 4E It is shown in more detail below.

[0072] A substantially flat internal region 112 lies between the serrated region 110 and the orifice 104. In other words, the substantially flat internal region 112 provides isolation between the orifice 104 and the serrated region 110. This is important because the sealing layer 108 is positioned away from the medium (e.g., fluid) flowing through the conduit. This prevents the accumulation of the medium between the sealing layers 108, which could create conduction paths or corrosive areas. Furthermore, providing a flat internal region helps prevent or mitigate turbulence and the problems that turbulence can cause. The inner ring 112 separates the sealing layer 108 from the medium flowing through the gasket 100. Moreover, having an inner ring 112 extending into the orifice 104 is useful for avoiding turbulence (and the problems that arise from it), which is caused by an unsmooth path of fluid through the orifice 104.

[0073] The first surface 106 may also include a substantially flat outer region 114 aligned with the inner region 112 on the plane. In one example, the non-metallic core 102 is substantially annular. In this example, the inner region 112, the serrated region 110, and the outer region 114 may be configured as concentric rings surrounding the central hole 104. In one example, the outer region 114 substantially surrounds the serrated region 110, which in turn substantially surrounds the inner region 112, which in turn substantially surrounds the hole 104.

[0074] The at least one sealing layer 108 covers at least a portion of the serrated region 110 of the first surface 106. In one example, the at least one sealing layer 108 covers all the serrated regions 110 of the first surface 106.

[0075] exist Figure 1 and Figure 2 The invisible second side can be substantially the same as the first side 106 and have substantially the same features.

[0076] Figure 3 An exploded view of an example of gasket 100 is shown. In this example, a second sealing layer 116 is present, which is coupled to a second side of the core 102. For example, the second sealing layer 116 covers at least a portion of the serrated area of ​​the second surface.

[0077] Figures 4A to 4E As shown Figure 2 An example of a cross-sectional view through core 102, as shown by the mid-section view mark AA. Figures 4A to 4E The different contours of the serrated edges in the serrated region 110 of the first surface 106 are shown. Figures 4A to 4E In the example shown, the at least one sealing layer 108 is not shown for clarity.

[0078] The serrated region 110 includes a plurality of serrations 118. The core 102 including the serrations 118 is referred to as a toothed composite core. The serrations 118 of the serrated region 110 may be a series of concentric serrations or an accordion-shaped profile on the first surface 106. The profile is superimposed on the core 102 by a series of concentric serrations.

[0079] During the sealing process, the covered sealing layer 108 is forced into the gap between the serrations 118 to improve the seal by causing stress concentration on the sealing surface.

[0080] The serrations 118 also minimize lateral movement of the sealing layer 108, while the core 102 provides rigidity and burst resistance. For high-pressure applications, this profile increases the strength of the gasket 100.

[0081] The saw teeth 118 can be considered as a series of peaks and valleys. In one example, the saw teeth are essentially saw blade tooth-shaped or sinusoidal. In one example, the saw teeth 118 have an amplitude of approximately 0.1 mm to 0.6 mm.

[0082] In one example, when internal pressure is applied, the serrations 118 hold the at least one sealing layer 108 in place and prevent so-called bursting.

[0083] Surprisingly, the non-metallic core 102 (e.g., a glass fiber-filled epoxy sheet) can be machined to the level of precision required to form these serrations 118, enabling an effective seal to be formed in the gasket 100. Those skilled in the art might expect the rough portions of the glass fiber and epoxy to be a problem, but this is not the case.

[0084] like Figure 4A As shown, a generally flat interior region 112 defines a plane 120. The plane 120 extends beyond the end of the interior region 112. The serrations 118 extend in a direction substantially perpendicular to the plane 120.

[0085] exist Figure 4A In the example shown, the serrations 118 are recessed into the first surface 106 such that they do not cross the plane 120 defined by the generally flat interior region 112. In other words, the serrations 118 are recessed into the first surface 106 such that all the serrations 118 are located on one side of the plane 120. In other words, the serrations 118 terminate before the plane 120 and do not cross the plane 120.

[0086] Cutting the serrations 118 below the plane 120 of the inner region 112 of the core 102 means protecting the serrations 118 from the direct effects of loads and bearing the load only through the compression of the at least one sealing layer 108. Furthermore, since the sides of the serrations 118 are not as smooth as metal, the uneven surface can contribute to sealing capability.

[0087] exist Figure 4A In this case, the serrated region 110 is located in the channel within the first surface 106. In other words, the penetration thickness of the core 102 in the serrated region 110 is less than the penetration thickness of the core 102 in the non-serrated region (e.g., the inner region 112 or the outer region 114).

[0088] In one example, the channel is recessed into the first layer 106 by approximately 0.1 mm to 0.4 mm. In other words, the top of the serrations can be offset relative to the plane 120 defined by the inner region 112 by approximately 0.1 mm to 0.4 mm.

[0089] Because the serrations 118 are recessed from the first surface 106 of the core 102, the serrations 118 will not be subjected to the considerably high pressure resulting from the mating of the two surfaces. Instead, more pressure can be applied to the non-serrated portions, such as the inner region 112 and the outer region 114. This protects the serrated region 110 from deformation, and the serrations are able to provide an effective seal together with the at least one sealing layer 108. In one example, at least one sealing layer 108 is at least partially located within the channel defined by the serrated region 110. For clarity, in Figure 4A The at least one sealing layer 108 is not shown in the diagram. The at least one sealing layer 108 may be completely or at least partially located over the inner region 112 and / or the outer region 114. Therefore, more pressure will be applied to the sealing layer covering the inner region 112 and / or the outer region 114. This protects the serrated region 110 from deformation, and the serrations 118 are able to provide an effective seal together with the at least one sealing layer 108, which is pressed into the serrations by compressive force.

[0090] Figure 4A The second surface 122 is shown. The second surface 122 may include all the elements of the second group of the first surface 106, namely the second inner region defining the second plane, the second serrated region, and the second substantially flat outer region.

[0091] exist Figure 4A In the middle, the size and shape of the saw teeth 118 are basically similar. In other words, the saw teeth have roughly the same distance between the peaks and valleys.

[0092] exist Figure 4A In this context, the outer region 114 lies on the plane 120 defined by the inner region 112. In other words, the outer region 114 is at approximately the same height as the inner region 112.

[0093] Figure 4B As shown Figure 2 Another example of a cross-sectional view through core 102, as shown by the sectional view mark AA.

[0094] In addition to the serrated region 110 including one or more non-serrated regions or bridges 124 located between at least a pair of adjacent serrations 118, Figure 4B The example shown is the same as Figure 4A The example shown is essentially the same. Bridge 124 can be considered as a connector between adjacent teeth 118, extending the interval between adjacent teeth 118. In one example, bridge 124 includes a generally flat area or planar portion.

[0095] In use, the bridge 124 will experience higher stress concentration than the serration 118, making the serration 118 less likely to deform significantly during use. This means that the serration 118 is more likely to remain engaged with the at least one sealing layer 108 to form a seal. The bridge 124 helps with load distribution, which aids in sealing and will help maintain the overall integrity of the gasket 100.

[0096] In one example, the planar portion of bridge 124 is offset relative to plane 120 defined by inner region 112. The size of serration 118 is configured to terminate at the same height as the non-serrated region 124. In other words, serrated region 110 defines a channel in the first face 106 of core 102.

[0097] In one example, at least one of the bridges 124 is centrally located within the serrated region 110.

[0098] In another example, at least one bridge 124 of the bridge is positioned offset relative to the center of the sawtooth region 110. For example, at least two bridges 124 of the bridge may be positioned symmetrically offset relative to the center of the sawtooth region 110.

[0099] Figure 4C As shown Figure 2 Another example of a cross-sectional view through core 102, as shown by the sectional view mark AA.

[0100] Except that the planar area of ​​bridge 124 is basically aligned with the planar area of ​​the inner area 120, Figure 4C The example shown is similar to Figure 4B The example shown is essentially the same. In this example, the size of the serration 118 is also aligned with the height of the planar region of the bridge 124.

[0101] / / Figure 4D

[0102] Figure 4D As shown Figure 2 Another example of a cross-sectional view through core 102, as shown by the sectional view mark AA.

[0103] Except that the serrated region 102 is substantially inclined relative to the plane 120 defined by the flat interior region 112, Figure 4D The example shown is the same as Figure 4A The examples shown are essentially the same. This can increase internal pressure when the seal is pushed outward to provide a more effective seal between the seal and the serrated area. As the seal is pushed outward, the internal pressure can act on the seal to improve overall sealing performance.

[0104] In one example, the serrated region 102 slopes from the inner region 112 to the outer region 114. In other words, the penetration thickness of the serrated region 102 adjacent to the outer region 114 is smaller than the penetration thickness of the serrated region 102 adjacent to the outer region 114. This can increase internal pressure when the sealing layer is pushed outward to provide a more effective seal between the sealing layer and the serrated region. In one example, the channel slopes substantially away from the orifice. In other words, the depth of the channel adjacent to the inner region is relatively large compared to the depth of the channel adjacent to the outer region. In other words, the channel can slope outward from the inner region to the outer region. This sloped arrangement can help strengthen the seal, i.e., internal pressure forces the structure to seal better. Theoretically, the slope away from the orifice causes the gasket to be "self-reinforcing" as pressure pushes the sealing layer outward into the shallower serrations and thus increases the density of the sealing layer.

[0105] Figure 4E As shown Figure 2 Another example of a cross-sectional view through core 102, as shown by the sectional view mark AA.

[0106] In addition to the plurality of saw teeth 118 including the first group of saw teeth and the second group of saw teeth, Figure 4E The example shown is the same as Figure 4C The examples shown are essentially the same. The first group of serrations is larger than the second group of serrations. Figure 4E In this configuration, one of the saw teeth includes a deeper valley compared to the others. In one example, the at least one sealing layer includes one or more protrusions configured to engage with at least one saw tooth in the first set of saw teeth.

[0107] Figures 4A to 4E Each example also illustrates a second surface 122. The second surface 122 may include all elements of the second set of first surfaces 106, namely, the second inner region defining the second plane, the second serrated region, and the second substantially flat outer region, and Figures 4A to 4E Various elements in each embodiment. A second sealing layer 116 may be provided, which is configured to cover or conceal at least a portion of the serrated area of ​​the second surface.

[0108] Figures 5A to 5E As shown Figure 2 The example shown by section mark AA is a cross-sectional view through the core 102, but with a first sealing layer 108 covering a serrated region 110 of the first surface 106 and a second sealing layer 116 covering a serrated region of the second surface 122. Figures 5A to 5E In each of the examples shown, the at least one sealing layer 108 is substantially stress-free. In use, the sealing layer 108 will be pressed into the serrations to form a seal in the gasket 100.

[0109] Generally, the at least one sealing layer 108 covers at least a portion of the serrated region 110 of the first surface 106. In one example, the at least one sealing layer 108 substantially covers all of the serrated region 110 of the first surface 106.

[0110] In one example, the at least one sealing layer 108 extends beyond the serrated region 110, thereby abutting at least a portion of the inner region 112. In another example, the at least one sealing layer 108 extends beyond the serrated region 110, thereby abutting at least a portion of the outer region 114. In the examples where the at least one sealing layer 108 abuts at least a portion of the inner region 112 and / or the outer region 114, the adjacent regions of the inner region 112 and / or the outer region 114 play a crucial role in bearing loads and densifying the sealing layer 108 to a higher-than-normal level, thus providing a surprisingly good sealing level. It should be understood that densification means compressing the sealing layer 108, making it denser relative to the uncompressed sealing layer.

[0111] In the example where the serrated region 110 includes one or more bridges 124, under load, the sealing layer 108 is densified in the region adjacent to the one or more bridges 124. This densification process provides a good seal between the sealing layer 108 and the serrated region 110.

[0112] In one example, the region of the inner region 112 and / or outer region 114 adjacent to the at least one sealing layer 108 may be formed of a material with a higher density compared to the remainder of the inner region 112 and / or outer region 114. In other words, the portion of the inner region 112 and / or outer region 114 adjacent to the serrated region 110 comprises a material with a higher density compared to the remaining regions of the inner region 112 and / or outer region 114.

[0113] Figure 5A Corresponding to Figure 4A The cross-section shown is shown, but the at least one sealing layer 108 is shown covering at least a portion of the serrated region 110.

[0114] exist Figure 5A In the example shown, the sealing layer 108 is adjacent to the serrations 118 during use. Furthermore, at least a portion of the sealing layer 108 is located within the channel defined by the serrated region 110.

[0115] Figure 5A A second sealing layer 116 is shown in a channel defined by a serrated region 110 in the second surface 122 of the core 102.

[0116] Figure 5B Corresponding to Figure 4BThe cross-section shown is illustrated, but the at least one sealing layer 108 is shown covering at least a portion of the serrated region 110. (As shown...) Figure 5B As shown, the at least one sealing layer 108 is adjacent to a bridge 124 between adjacent saw teeth 118, and also adjacent to the saw teeth 118. The bridge 124 can provide support for the sealing layer 108 to reduce the stress applied to the saw teeth 118.

[0117] Figure 5C Corresponding to Figure 4C The cross-section shown is illustrated, but the at least one sealing layer 108 is shown covering at least a portion of the serrated region 110. (As shown...) Figure 5C As shown, in its uncompressed state, the sealing layer 108 can substantially extend beyond the first surface 106. In other words, when the sealing layer 108 is not compressed, it is on the other side of the plane 120 where the serrations 118 are located. However, when the sealing layer 108 is compressed, it will at least partially fill the gaps between the serrations 118 in the serrated region 110.

[0118] Figure 5D Corresponding to Figure 4D The cross-section shown is illustrated, but the at least one sealing layer 108 is shown covering at least a portion of the serrated region 110. (As shown...) Figure 5D As shown, the sealing layer 108 may be tilted relative to the plane 120 defined by the inner surface 112.

[0119] Figure 5E Corresponding to Figure 4E The cross-section shown is illustrated, but the at least one sealing layer 108 is shown covering at least a portion of the serrated region 110. (As shown...) Figure 5E As shown, the sealing layer 108 may include a protrusion 126 or an additional layer that protrudes into the deeper valley defined by the first set of serrations.

[0120] In addition to the plurality of saw teeth 118 including the first group of saw teeth and the second group of saw teeth, Figure 4E The example shown is the same as Figure 4E The examples shown are essentially the same. The first group of serrations is larger than the second group of serrations. Figure 4E In this configuration, one of the saw teeth includes a valley that is deeper than the others. In one example, the at least one sealing layer 108 includes one or more protrusions configured to engage with at least one saw tooth in the first set of saw teeth.

[0121] Figure 6 Corresponding to Figure 4C The cross-section shown is shown, but the at least one sealing layer 108 is shown covering at least a portion of the serrated region 110.

[0122] and Figure 5Ccompared to, Figure 6 The at least one sealing layer 108 shown extends beyond the size of the serrated region 110. In this example, the at least one sealing layer 108 adjoins at least a portion of the inner region 112. In one example, the at least one sealing layer 108 extends beyond the serrated region 110, thereby adjoining at least a portion of the outer region 114. In the example where the at least one sealing layer 108 adjoins at least a portion of the inner region 112 and / or the outer region 114, the adjoining regions of the inner region 112 and / or the outer region 114 play a significant role in bearing loads and densifying the sealing layer 108 to a higher-than-normal level, thus providing a surprisingly good sealing level. It should be understood that densification means compressing the sealing layer 108, making it denser relative to the uncompressed sealing layer.

[0123] Surprisingly, using a non-metallic core 102 with serrated areas 110 and at least one suitable sealing layer 108, the core 102 is effective in sealing the gasket 100 and is able to withstand fairly high loads.

[0124] Generally, the gaskets of the present invention are annular and typically define a centrally located hole. However, other gasket shapes are also contemplated. For example, the gaskets may have a square, rectangular, oval, elliptical, or generally any polygonal cross-section.

[0125] Regardless of the gasket type, the gaskets of this invention may need to be operated at normal operating pressures between 100 kPa and 43,000 kPa (more typically between 1,000 kPa and 20,000 kPa).

[0126] Figure 7 An example of method steps for manufacturing a gasket 100 is shown. Step 200 involves providing a rigid nonmetallic core 102 defining a hole 104, the core 102 including a first surface 106 extending away from the hole 104 and a second surface opposite to the first surface 122.

[0127] Step 202 involves forming a serrated region 110 comprising a plurality of serrations 118 in a first surface 106 of the core 102. In this example, the first surface 106 includes: a generally flat interior region 112 defining a plane 120; and the serrated region 110 comprising the plurality of serrations 118, wherein the generally flat interior region 112 is located between the hole 104 and the serrated region 110. The serrations 118 are recessed into the first surface 106 such that the serrations 118 do not penetrate the plane 120.

[0128] The serrated profile 110 can be machine-formed.

[0129] The method may include the steps of providing at least one sealing layer 108 and covering at least a portion of the serrated region 110 of the first surface 106 with said at least one sealing layer 108.

[0130] Preferably, the gasket is a fireproof gasket.

[0131] Please note all documents relating to this application that were submitted concurrently with or prior to this application’s description, which are available for public inspection along with this description, and whose contents are incorporated herein by reference.

[0132] All features disclosed in this specification (including the accompanying claims, abstract, and drawings), and / or all steps of any disclosed method or process, may be combined in any combination except for combinations in which at least some features and / or steps are mutually exclusive.

[0133] Each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature serving the same, equivalent, or similar purpose, unless otherwise expressly stated. Therefore, unless otherwise expressly stated, each disclosed feature is merely one example of a series of equivalent or similar features.

[0134] This invention is not limited to the details of the foregoing embodiments. The invention extends to any novel alternative features or any novel combination of features having those disclosed in this specification (including the accompanying claims, abstract, and drawings), or any novel alternative steps or any novel combination of steps having those of any method or process so disclosed.

Claims

1. A gasket for sealing two mating surfaces, comprising: A rigid nonmetallic core defining a hole, the core comprising a first surface extending away from the hole and a second surface opposite to the first surface; as well as At least one sealing layer, The first surface includes: The internal region that defines the plane is essentially flat; and A serrated region comprising multiple serrations, wherein the substantially flat internal region lies between the hole and the serrated region. The saw teeth are recessed into the first surface, so that the saw teeth do not penetrate the plane. Wherein, the at least one sealing layer covers at least a portion of the serrated region of the first surface, and The non-metallic core comprises one or more of the following materials: Glass-reinforced epoxy resin, Phenolic resin, Polytetrafluoroethylene, Polyimide, (alkyl)acrylic acid copolymer, (alkyl)acrylic polymer.

2. The gasket according to claim 1, wherein, The first surface includes a substantially flat outer region aligned with the inner region on the plane.

3. The gasket according to claim 1 or 2, wherein, The serrations are configured to extend into the plane defined by the inner region.

4. The gasket according to claim 1 or 2, wherein, The serrations terminate before the plane to define a channel in the first surface of the core.

5. The gasket according to claim 4, wherein, The at least one sealing layer is located at least partially within the channel defined by the serrated region.

6. The gasket according to claim 2, wherein, The serrations terminate before the plane to define a channel in the first face of the core, wherein the channel is substantially inclined relative to the plane defined by the flat inner region, such that the depth of the channel decreases from the inner region to the outer region.

7. The gasket according to claim 1 or 2, wherein, The serrated region includes at least one bridge located between at least one pair of adjacent serrations.

8. The gasket according to claim 7, wherein, The bridge includes a planar portion.

9. The gasket according to claim 8, wherein, The planar portion of the at least one bridge is offset relative to the plane defined by the inner region.

10. The gasket according to claim 8, wherein, The at least one bridge is aligned with the inner region on the plane.

11. The gasket according to claim 1 or 2, wherein, The plurality of saw teeth includes a first group of saw teeth and a second group of saw teeth, wherein the first group of saw teeth is larger than the second group of saw teeth.

12. The gasket according to claim 11, wherein, The at least one sealing layer includes one or more protrusions configured to engage with at least one tooth in the first set of teeth.

13. The gasket according to claim 1 or 2, wherein, The at least one sealing layer is configured to extend beyond the serrated region to adjoin at least a portion of the interior region.

14. The gasket according to claim 2, wherein, The at least one sealing layer is configured to extend beyond the serrated region to adjoin a portion of the inner region and a portion of the outer region.

15. The gasket according to claim 13, wherein, The portion of the at least one sealing layer adjacent to the internal region has a relatively higher density compared to the rest of the sealing layer.

16. The gasket according to claim 14, wherein, The portion of the at least one sealing layer adjacent to the inner region and the outer region has a relatively higher density compared to the rest of the sealing layer.

17. The gasket as claimed in claim 1 or 2, wherein, The at least one sealing layer comprises polytetrafluoroethylene, layered silicate, ceramic or graphite, or the at least one sealing layer is formed of polytetrafluoroethylene, layered silicate, ceramic or graphite.

18. The gasket of claim 17, wherein, The at least one sealing layer comprises graphite or vermiculite, or the at least one sealing layer is formed of graphite or vermiculite, wherein the vermiculite includes expanded vermiculite, biotite, hydrobiotite, and phlogopite.

19. The gasket as claimed in claim 1 or 2, wherein, The second side includes: A second, substantially flat interior region, which defines a second plane; and The second serrated region includes a second plurality of serrations, wherein the second substantially flat internal region is located between the hole and the second serrated region. The second plurality of saw teeth are recessed into the second surface, such that the second plurality of saw teeth do not penetrate the second plane. The at least one sealing layer covers at least a portion of the second serrated region of the second surface.

20. A method for manufacturing a gasket, comprising the following steps: A rigid nonmetallic core is provided that defines a hole, the core including a first face extending away from the hole and a second face opposite to the first face; as well as A serrated region comprising a plurality of serrations is formed in the first surface of the core, such that the first surface includes a substantially flat internal region defining a plane, and The generally flat internal region is located between the hole and the serrated region. Wherein, the saw teeth are recessed into the first surface, so that the saw teeth do not pass through the plane, and The non-metallic core comprises one or more of the following materials: Glass-reinforced epoxy resin, Phenolic resin, Polytetrafluoroethylene, Polyimide, (alkyl)acrylic acid copolymer, (alkyl)acrylic polymers; and Provide at least one sealing layer and cover at least a portion of the serrated region of the first surface with the at least one sealing layer.

21. The method according to claim 20, wherein, The serrated profile is machine-formed.

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