Reducing octagonal sealing gasket for butt joint of flanges with different specifications

Abstract

The utility model relates to the technical field of petrochemical engineering and mechanical sealing, and discloses a variable-diameter octagonal sealing gasket for butt joint of flanges with different specifications, which comprises an annular sealing gasket body formed by integrally connecting an upper gasket, a middle gasket and a lower gasket. The cross section of the upper gasket and the cross section of the lower gasket are both hexagonal faces composed of five edges with one ends open, the open ends of the upper gasket and the lower gasket are opposite, the upper gasket and the lower gasket are arranged in a staggered mode, and the upper gasket and the lower gasket are connected through an obliquely-arranged middle gasket. And the cross section of the middle gasket is a quadrangular surface formed by two inclined edges which are inclined from inside to outside. The sealing gasket can be directly installed between flanges which need to be in butt joint and have different specifications and standards, reliable sealing connection is achieved, and the overall strength and the anti-extrusion capacity of the sealing gasket are greatly improved through the design of the chamfer structure.

Description

Technical Field

[0001] This utility model relates to the fields of petrochemical and mechanical sealing technology, and more specifically, to a variable diameter octagonal sealing gasket for connecting flanges of different specifications. Background Technology

[0002] In industries such as salt production, it is often necessary to flange-connect equipment that conforms to petroleum standards (such as GB / T22513) with equipment that conforms to chemical standards (such as HG / T20592~20635). Because different standards have different requirements for flange dimensions (such as sealing surface width, bolt hole pitch circle diameter, inner diameter, etc.), dimensional deviations occur when directly connecting them, making it difficult to achieve an effective seal. The traditional solution is to use specially designed reducing flanges or reducers for transition connections.

[0003] However, the reducing flange or reducing pipe connection schemes used in the existing technology have significant drawbacks: non-standard parts need to be customized, resulting in high material and processing costs; the extensive use of non-standard equipment increases the difficulty of subsequent maintenance and spare parts management; the length of the reducing pipe itself (usually >300mm) requires additional installation space, which is limited in compact situations; lengthening the pipeline will reduce the overall rigidity of the system; in addition, the installation process usually requires additional flanges and fasteners, which increases complexity. Utility Model Content

[0004] In view of this, this utility model proposes a variable diameter octagonal sealing gasket for connecting flanges of different specifications. It is a sealing structure for connecting flanges of different specifications and standards (such as chemical industry standard HG / T20592~20635 and oil and gas industry standard GB / T22513). The specific technical solution is as follows:

[0005] An octagonal gasket for connecting flanges of different diameters includes an annular gasket body, which is integrally formed by an upper gasket, an intermediate gasket, and a lower gasket. The upper and lower gaskets each have a hexagonal cross-section consisting of five sides open at one end. The open ends of the upper and lower gaskets face each other and are arranged in a staggered manner. The upper and lower gaskets are connected by an inclined intermediate gasket, the cross-section of which is a quadrangular surface formed by two inclined sides sloping from the inside out. The top surface of the upper gasket is the pressure-sealing contact surface for the smaller inner diameter flange, and the bottom surface of the lower gasket is the pressure-sealing contact surface for the larger inner diameter flange.

[0006] Preferably, the tilt angle of the intermediate washer is in the range of 40° to 50°.

[0007] Preferably, the length of the inclined side of the intermediate gasket is determined based on the different inner diameter values ​​of the two flanges to be connected.

[0008] The core purpose of this utility model, a variable-diameter octagonal sealing gasket for connecting flanges of different specifications, is that it can be directly installed between flanges of different specifications and standards that need to be connected, so as to achieve a reliable sealing connection.

[0009] Compared with the prior art, this utility model has specially designed chamfers (i.e., inclined middle gaskets) at the inner and outer edges of the upper and lower sealing surfaces of the sealing gasket. Although the chamfer slightly increases the overall height of the sealing gasket, the chamfer structure can effectively disperse the stress generated when the sealing surface is under pressure, especially preventing the sharp edges from curling, cracking or plastic deformation under high pressure, which greatly improves the overall strength and compression resistance of the sealing gasket.

[0010] This invention also improves the sealing contact. The chamfer helps guide the flange sealing surface to contact the gasket more smoothly and generates a small radial component force under the action of preload, which has a certain ability to compensate for the small parallelism deviation of the flange sealing surface. 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 embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0012] Figure 1 This is a partial structural diagram of a variable-diameter octagonal sealing gasket for connecting flanges of different specifications according to this utility model.

[0013] In the diagram: 1-upper washer, 2-middle washer, 3-lower washer, 4-pressure-bearing sealing contact surface. Detailed Implementation

[0014] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0015] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0016] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0017] Example:

[0018] This embodiment provides a variable diameter octagonal sealing gasket for non-standard flange connections. Through the special design of the variable diameter octagonal sealing gasket with chamfer, it solves the problems of high cost, large number of non-standard equipment, and lack of installation space for some equipment when using variable diameter flanges or reducers in the prior art.

[0019] The advantage of the variable diameter octagonal gasket in this embodiment is that it can be directly installed into the flange interface of different specifications without the need for costly equipment, and the gasket has high strength, which can meet the docking requirements of different specifications of equipment.

[0020] Specifically, the variable diameter octagonal sealing gasket for non-standard flange connection includes an annular sealing gasket body, which is integrally connected by an upper gasket 1, an intermediate gasket 2, and a lower gasket 3. The cross-section of the upper gasket 1 and the lower gasket 3 is a hexagonal surface composed of five sides open at one end. The open ends of the upper gasket 1 and the lower gasket 3 are opposite each other and the upper and lower gaskets are arranged in a staggered manner.

[0021] If the upper washer 1 and the lower washer 3 are not misaligned, but are arranged directly opposite each other, then the two can be joined to form an integral octagonal ring structure with the eight edges evenly distributed around the circumference.

[0022] The upper washer 1 and the lower washer 3 are connected by an inclined intermediate washer 2. The cross section of the intermediate washer 2 is a quadrilateral surface composed of two inclined sides that are inclined from the inside to the outside. In other words, the intermediate washer 2 is a chamfered structure that connects the upper washer 1 and the lower washer 3.

[0023] The top surface of the upper gasket 1 is the pressure-sealing contact surface 4 of the small inner diameter flange, and the bottom surface of the lower gasket 3 is the pressure-sealing contact surface 4 of the large inner diameter flange.

[0024] In a further specific embodiment, the tilt angle of the intermediate gasket 2 ranges from 40° to 50°. Meanwhile, the length of the tilted side of the intermediate gasket 2 is determined based on the different inner diameters of the two flanges to be connected.

[0025] In this embodiment, the inner bore of the gasket is designed as a stepped variable diameter structure, which can simultaneously match the inner diameter requirements of two flanges with different specifications (for example, one end is adapted to DN150 PN160 size, and the other end is adapted to R46 size), achieving a smooth transition of the nominal diameter. Additionally, in this embodiment, chamfers are machined along the inner and outer edges of both the upper and lower main sealing surfaces of the gasket, increasing the thickness of the gasket's edge.

[0026] During installation, the octagonal reducing gasket is placed directly between the sealing surfaces of two flanges of different specifications. When the flange bolts are tightened to apply preload, the gasket bears axial compressive force. The chamfered structure plays a crucial role in this process: on the one hand, its enhanced edge strength effectively resists crushing deformation; on the other hand, the chamfered bevel generates a slight radial expansion tendency (or guiding force) under pressure, helping to fill the small gaps or uneven contact between the sealing surfaces caused by specification differences or flange machining errors, thus forming a more uniform and reliable sealing line. The stepped inner bore ensures a smooth connection of the fluid passage.

[0027] In practice, as long as the number of bolt holes on the two flanges being connected is the same and the deviation of key dimensions (such as the bolt hole pitch circle diameter) is within the allowable range, the gasket in this embodiment can be used for connection without the need for reducing flanges, reducers or other high-cost auxiliary equipment.

[0028] Therefore, the variable-diameter octagonal sealing gasket in this utility model is particularly suitable for solving the problem of dimensional deviation when connecting chemical standard flanges and petroleum standard flanges. It provides a zero-space-occupying, low-cost, and standardized solution, effectively avoiding the generation of non-standard equipment parts.

[0029] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0030] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A reducing octagonal sealing gasket for connecting flanges of different specifications, characterized in that, The device includes a ring-shaped sealing gasket body, which is integrally formed by an upper gasket, an intermediate gasket, and a lower gasket. The cross-section of the upper and lower gaskets is a hexagonal surface composed of five sides open at one end. The open ends of the upper and lower gaskets are opposite each other and are arranged in a staggered manner. The upper and lower gaskets are connected by an inclined intermediate gasket, the cross-section of which is a quadrilateral surface composed of two inclined sides that slope from the inside out. The top surface of the upper gasket is the pressure-sealing contact surface of a small inner diameter flange, and the bottom surface of the lower gasket is the pressure-sealing contact surface of a large inner diameter flange.

2. The octagonal sealing gasket for non-standard flange connection according to claim 1, characterized in that, The tilt angle of the intermediate washer is in the range of 40° to 50°.

3. A variable-diameter octagonal sealing gasket for non-standard flange connection according to claim 1 or 2, characterized in that, The length of the inclined edge of the intermediate gasket is determined based on the different inner diameters of the two flanges to be connected.

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