A metal fastener

Abstract

The utility model discloses a kind of metal fasteners, belong to pipeline sealing technical field, including flange main body and be used for fixed bolt group on the flange main body, by stepped composite limiting slot and stepped convex annular sealing washer adaptation, the matching structure of the embedding of positioning key and limiting key, limit flange piece circumferential rotation and sealing washer radial migration, resist vibration, medium impact and other dynamic load influence, simultaneously, annular sealing washer built-in liquid storage cavity and capillary groove, under the bolt pretightening force, sealing medium penetrates to sealing contact surface by capillary effect, dynamically fills up the micro gap generated by temperature dramatic change, and the embedding sealing of annular flange and annular groove, double protection is formed by collaborative sealing medium, collocation circumferential evenly distributed bolt group, ensure that fastening force and sealing pressure are balanced, improve the sealing stability under high temperature and high pressure, alternating load condition, avoid the leakage risk caused by sealing failure in pipeline transportation.

Description

Technical Field

[0001] This utility model relates to the field of pipeline sealing technology, and more specifically, to a metal fastener. Background Technology

[0002] Metal fasteners are mechanical components made from metal materials and used to connect, fix, position, or lock two or more parts. In modern industry, especially in key areas such as deep-sea oil and gas transportation, high-temperature and high-pressure reaction pipelines, and long-distance transportation pipelines, flange connections are one of the most common and weakest links in pipeline systems. These operating conditions are characterized by frequent pressure changes, large temperature ranges, strong media corrosiveness, and long-term exposure to dynamic loads (such as vibration and foundation settlement).

[0003] Traditional sealing technologies, such as metal flat gaskets, spiral wound gaskets, or conventional rubber O-rings, are essentially "static seals." They rely on the huge initial preload provided by the bolts to cause the gasket material to undergo plastic or elastic deformation, filling the microscopic unevenness of the flange surface and thus forming a static sealing barrier. In steam pipeline transportation, start-up, shutdown, and load changes cause the pipe wall and flanges to undergo drastic rapid cooling and heating cycles. Due to the difference in thermal expansion coefficients, the metal flanges and bolts expand and contract asynchronously under drastic temperature changes, causing periodic micro-separation and collision of the critical flange sealing surfaces. With each cycle, high-pressure steam will invade the instantaneously generated micro-gap and cause a thermo-mechanical coupled impact on the sealing material. Under this cyclic stress, traditional rigid or elastic sealing structures will permanently lose their resilience due to material creep relaxation, or develop micro-cracks due to fatigue. Ultimately, they will fail and leak due to the inability to dynamically compensate for pressure under frequent thermal shocks. Utility Model Content

[0004] To achieve the above objectives, the present invention provides the following technical solution: A metal fastener includes a flange body and a bolt assembly disposed on the flange body for fixing. The flange body includes a left flange and a right flange disposed opposite to each other, and a gasket groove structure is formed between the left flange and the right flange. The gasket groove structure includes an inner annular groove and an outer annular groove arranged coaxially. The depth of the inner annular groove is greater than that of the outer annular groove. The inner annular groove and the outer annular groove are connected by a radial step surface, so that the bottom of the inner annular groove and the bottom of the outer annular groove form a height difference in the axial direction. The gasket groove structure is provided with a positioning part and an annular sealing gasket. The annular sealing gasket has a liquid storage cavity and a capillary groove for containing the sealing medium, and the liquid storage cavity is connected to the capillary groove. The other end of the capillary groove extends to the sealing contact surface of the annular sealing gasket.

[0005] Furthermore, the annular sealing gasket has a stepped convex structure and a groove is coaxially provided on the side facing the right flange.

[0006] Furthermore, the left flange has an annular pressure boss on the side facing the right flange. The annular pressure boss is arranged circumferentially along the right flange and is adapted to the groove shape of the annular sealing gasket.

[0007] Furthermore, a number of limiting keys are constructed on the groove wall of the inner annular groove. The limiting keys are evenly distributed along the circumference of the inner annular groove. A positioning key is provided on the side of the annular pressure boss facing the left flange. The positioning key and the limiting key are fitted together. A hole groove is opened in the annular sealing gasket for the positioning key to pass through.

[0008] Furthermore, the left flange, the right flange, and the annular sealing gasket each have several through holes equidistantly spaced on one side, and the bolt assembly is placed in several through holes located in the same axial direction.

[0009] Furthermore, both the inner edge of the inner annular groove and the outer edge of the outer annular groove are provided with annular flanges. The annular flanges are fitted into the annular grooves, and the mating surfaces of the annular flanges and the annular grooves are tightly fitted to form a sealing fit.

[0010] In summary, this utility model has the following beneficial effects: This invention utilizes a stepped composite limiting groove (inner + outer annular groove) that is adapted to a stepped convex annular sealing gasket. Combined with the interlocking structure of the positioning key and the limiting key, it restricts the circumferential rotation of the flange and the radial movement of the sealing gasket, resisting the effects of dynamic loads such as vibration and media impact. Simultaneously, the annular sealing gasket has a built-in liquid storage chamber and capillary grooves. Under the action of bolt pre-tightening force, the sealing medium permeates to the sealing contact surface through capillary action, dynamically filling the micro-gaps caused by drastic temperature changes. Furthermore, the interlocking seal of the annular flange and the annular groove, along with the sealing medium, forms a double protection. Combined with a circumferentially evenly distributed bolt group, it ensures a balance between tightening force and sealing pressure, improving sealing stability under high temperature, high pressure, and alternating load conditions, and avoiding the risk of leakage due to seal failure during pipeline transportation. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of the left flange and the right flange in this utility model; Figure 3 This is a schematic diagram of the sealing surface of the right flange in this utility model; Figure 4 This is a schematic diagram of the gasket groove structure in the left flange of this utility model; Figure 5 This is a structural breakdown diagram of the present invention; Figure 6 This is a schematic diagram of the structure of the annular sealing gasket of this utility model; Figure 7 This is a schematic diagram of the cross-sectional structure of the annular sealing gasket of this utility model.

[0013] In the picture: 1. Flange body; 11. Left flange; 12. Right flange; 121. Annular pressure boss; 122. Locating key; 123. Annular groove; 13. Gasket groove structure; 131. Inner annular groove; 132. Outer annular groove; 133. Limiting key; 134. Annular flange; 14. Annular sealing gasket; 141. Liquid storage chamber; 142. Capillary groove; 143. Groove; 2. Bolt assembly. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0015] Example: The following is in conjunction with the appendix Figure 1-2 The present invention will be described in further detail below.

[0016] Please see Figure 1-2 This utility model provides a technical solution: a metal fastener, such as... Figure 1-2 As shown, it includes a flange body 1 and a bolt group 2 for fixing provided on the flange body 1. The flange body 1 includes a left flange 11 and a right flange 12 arranged opposite to each other. A gasket groove structure 13 is constructed between the left flange 11 and the right flange 12. The left flange 11, the right flange 12 and the annular sealing gasket 14 are all provided with several through holes at equal intervals on one side, and the bolt group 2 is placed in several through holes located in the same axial direction. The bolts are tightened by nuts, so that the tightening force is evenly distributed along the circumference. The left flange 11 and the right flange 12 are tightly fitted along the axial direction, and at the same time, a uniform axial pressure is formed on the annular sealing gasket 14.

[0017] like Figure 3-4 As shown, the gasket groove structure 13 includes an inner annular groove 131 and an outer annular groove 132 arranged coaxially. The groove depth of the inner annular groove 131 is greater than that of the outer annular groove 132. The inner annular groove 131 and the outer annular groove 132 are connected by a radial step surface, so that the bottom of the inner annular groove 131 and the bottom of the outer annular groove 132 form a height difference in the axial direction, thereby forming a stepped composite limiting groove. After the annular sealing gasket 14 is embedded, its radial edge fits against the radial step surface, restricting the radial movement of the sealing gasket. The annular sealing gasket 14 is provided in the gasket groove structure 13. The inner annular groove 131 has several limiting keys 133 on its groove wall. The limiting keys 133 are evenly distributed along the circumference of the inner annular groove 131. The pressure boss 121 has a positioning key 122 on the side facing the left flange 11. The positioning key 122 and the limiting key 133 fit together to achieve circumferential positioning of the flange body 1 and prevent relative rotation between the two under conditions such as vibration and impact of medium flow. The annular sealing gasket 14 has a hole groove for the positioning key 122 to pass through. The inner edge of the inner annular groove 131 and the outer edge of the outer annular groove 132 are both provided with annular flanges 134. The annular flanges 134 and the annular grooves 123 are fitted together, and the mating surfaces of the annular flanges 134 and the annular grooves 123 are tightly fitted to form a sealing fit. They also work together with the sealing effect of the annular sealing gasket 14 to form a double seal.

[0018] like Figure 5-7 As shown, the annular sealing gasket 14 is provided with a liquid storage cavity 141 and a capillary groove 142 for containing the sealing medium. The liquid storage cavity 141 and the capillary groove 142 are connected. The liquid storage cavity 141 extends circumferentially along the sealing gasket. The capillary groove 142 is evenly distributed on the outside of the liquid storage cavity 141. The other end of the capillary groove 142 extends to the sealing contact surface of the annular sealing gasket 14. When bolt group 2 is tightened, the left flange 11 and the right flange 12 approach each other, and the pressure boss 121 applies axial pressure to the sealing gasket 14, so that the sealing medium in the liquid storage cavity 141 is evenly permeated to the sealing contact surface through the capillary groove 142 under pressure, filling the small gaps that may exist on the contact surface and forming a continuous and effective sealing layer. At the same time, the stepped gasket groove structure 13 cooperates with the sealing gasket, so that the sealing medium is confined in the annular area. The annular sealing gasket 14 has a stepped convex structure and a groove 143 is coaxially opened on the side facing the right flange 12. The right flange 11 is provided with a pressure boss 121 on the side facing the left flange 12. The pressure boss 121 is arranged along the circumference of the right flange 12, and the shape of the pressure boss 121 is adapted to the groove 143 of the annular sealing gasket 14.

[0019] Working principle: First, the annular sealing gasket 14 is placed stably in the gasket groove structure 13 of the left flange 11, so that the stepped convex structure of the annular sealing gasket 14 is precisely fitted with the inner annular groove 131, the outer annular groove 132 and the radial stepped surface, ensuring that the annular sealing gasket 14 is installed in place without deviation. Then, the right flange 12 is slowly moved toward the left flange 11. During the docking process, the pressure boss 121 is precisely aligned with the groove 143 of the annular sealing gasket 14, and the positioning key 122 and the limit key 133 are aligned one by one. The annular flange 134 is aligned with the annular groove 123. The flange body 1 is continued to be pushed forward until the pressure boss 121 is completely embedded in the groove 143, the positioning key 122 and the limit key 133 form a tight fit, and the annular flange 134 is completely embedded in the annular groove 123 with the mating surfaces in contact. At this time, the through holes opened on the left flange 11, the right flange 12 and the annular sealing gasket 14 are automatically coaxially aligned. Finally, the bolts of bolt group 2 are passed through the coaxially aligned through holes in sequence, and nuts are put on the other end of the bolts and tightened gradually. Preload is applied through the threaded engagement of the nut and the bolt. Under the action of the preload, the annular sealing washer 14 undergoes elastic deformation and fits tightly against each sealing contact surface, thus completing the overall assembly.

[0020] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example that is included in at least one embodiment or example of the present invention.

[0021] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples.

[0022] Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0023] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A metal fastener, characterized in that, Includes a flange body (1) and a bolt group (2) for fixing provided on the flange body (1); The flange body (1) includes a left flange (11) and a right flange (12) arranged opposite to each other, and a gasket groove structure (13) is constructed between the left flange (11) and the right flange (12). The gasket groove structure (13) includes an inner annular groove (131) and an outer annular groove (132) arranged coaxially. The groove depth of the inner annular groove (131) is greater than that of the outer annular groove (132). The inner annular groove (131) and the outer annular groove (132) are connected by a radial step surface, so that the bottom of the inner annular groove (131) and the bottom of the outer annular groove (132) form a height difference in the axial direction. The gasket groove structure (13) is provided with a positioning part and an annular sealing gasket (14). The annular sealing gasket (14) is provided with a liquid storage cavity (141) for containing the sealing medium and a capillary groove (142), and the liquid storage cavity (141) is connected to the capillary groove (142), and the other end of the capillary groove (142) extends to the sealing contact surface of the annular sealing gasket (14).

2. A metal fastener according to claim 1, characterized in that, The annular sealing gasket (14) has a stepped convex structure and a groove (143) is coaxially provided on the side facing the right flange (12).

3. A metal fastener according to claim 2, characterized in that, The left flange (11) is provided with an annular pressure boss (121) on the side facing the right flange (12). The annular pressure boss (121) is arranged along the circumference of the right flange (12), and the annular pressure boss (121) is adapted to the shape of the groove (143) of the annular sealing gasket (14).

4. A metal fastener according to claim 3, characterized in that, The inner annular groove (131) has several limiting keys (133) on its groove wall. The limiting keys (133) are evenly distributed along the circumference of the inner annular groove (131). The annular pressure boss (121) has a positioning key (122) on the side facing the left flange (11). The positioning key (122) fits into the limiting key (133). The annular sealing gasket (14) has a hole groove for the positioning key (122) to pass through.

5. A metal fastener according to claim 1, characterized in that, The left flange (11), right flange (12) and annular sealing gasket (14) are each provided with several through holes at equal intervals on one side, and the bolt group (2) is placed in several through holes located in the same axial direction.

6. A metal fastener according to claim 1, characterized in that, The positioning part includes an annular flange (134) located on the inner edge of the inner annular groove (131) and the outer edge of the outer annular groove (132). The right flange (12) is provided with an annular groove (123) for sealing at a position opposite to the annular flange (134).

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