BR202012012311Y1 - sealing joint arrangement - Google Patents

Abstract

sealing joint arrangement, the present invention relates to a practical and innovative type of spiral metal joint, which belongs to the field of industrial seals, to be used more precisely in the sealing of flanged joints, and to which the original constructive arrangement was given. improve their use and performance compared to other models commonly found on the market; the present invention shows an innovative constructive form designed to reduce the value of gas emissions by spiral joints; specifically, this innovative form is obtained by controlling the density of the joint to allow it to be crushed in a controlled manner; This innovation also includes sealing filler, or soft sealing tape (16) protruding beyond the metal tape (15).

Description

(54) Title: PROVISION INTRODUCED IN SEALING BOARD (73) Holder: TEADIT INDÚSTRIA E COMÉRCIO LTDA. CGC / CPF: 36193928000187. Address: AV. SHEPHERD

MARTIN LUTHER KING JUNIOR, 8939, Colégio, Rio de Janeiro, RJ, BRAZIL (BR), 21530-010 (72) Inventor: JOSÉ CARLOS CARVALHO VEIGA; NELSON KAVANAGH.

Validity Period: 15 (fifteen) years from 05/23/2012, subject to legal conditions

Issued on: 12/11/2018

Digitally signed by:

Liane Elizabeth Caldeira Lage

Director of Patents, Computer Programs and Topographies of Integrated Circuits

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PROVISION INTRODUCED TOGETHER

SEALING

APPLICATION FIELD

The purpose of this utility model patent is a practical and innovative model of spiral metal gasket, belonging to the field of industrial gaskets, used more precisely in sealing flanged joints, and which was originally given a constructive disposition, with a view to improving its use and performance in relation to the other models usually found on the market.

Therefore, in the patent application in question, a spiral gasket specially designed and developed to obtain greater sealability by reducing leaks and emissions of polluting gases and brings great advantages of reducing leaks and emission of polluting gases to the environment.

It is also, objective of the present request, to present a gasket model with high sealing capacity, however allied to the requirements of robustness, safety and utilitarian practicality, thus offering the consumer public an option to meet the strict environmental control requirements required by the recent environmental protection laws, which, unlike the usual models, which do not guarantee this sealing capacity.

It was with these inconveniences in mind that, after numerous researches and studies, the inventors, people connected to the branch, created and developed the object of this patent, idealizing a gasket in which not only the mechanical and functional qualities were considered in the design of their

2/11 manufacturing, but also the shape, layout and location of its parts and components which, correctly positioned, brought an increase in efficiency allowing to meet the levels of sealing required by the authorities responsible for the environment.

SUMMARY OF THE INVENTION

The purpose of this utility model patent is a practical and innovative model of spiral metal gasket, belonging to the field of industrial gaskets, used more precisely in sealing flanged joints, and which was originally given a constructive disposition, with a view to improving its use and performance in relation to the other models usually found on the market. The present invention shows an innovative constructive form designed to reduce the value of gas emissions from spiral joints. Specifically, this innovative shape is obtained by controlling the density of the joint in order to allow its crushing in a controlled manner. This innovation also includes the seal filler projecting beyond the metal tape.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1: shows a spiral joint of the state of the art in section with its components.

Figure 2: it is a stretch of pipe section with flanges.

Figure 3: shows a section of piping with the joint in its installation position.

Figure 4: graph of sealability and crushing of a state of the art joint.

Figure 5: selectability graph and

3/11 smashing joints state of the art.

Figure 6: shows the state of the art flange touching the centering ring.

Figure 7: shows a spiral joint, state of the art, with the filling facing the metallic tape.

Figure 8: shows the sealability graph of a joint with the filler facing the metallic tape.

Figure 9: shows the construction details of a spiral joint.

Figure 10: shows in section the construction details of a spiral joint.

Figure 11: shows the construction details in an exploded view of a spiral joint.

Figure 12: shows in section the construction details of the sealing spiral.

Figure 13: shows in section the sealing spiral with the soft filler projecting beyond the metallic tape.

Figure 14: Sealability graph of a state of the art joint compared to a joint of the present invention.

Figure 15: joint sealing graph of the present invention in three different densities.

Figure 16: State-of-the-art joint sealability graph with joints of the present invention with different values of soft filler projecting beyond the metallic tape.

STATE OF ART

This invention relates to seals and joints, and more particularly to a spiral wound joint. THE

4/11 Spiral joint of the present invention includes improvements to reduce leaks and gas emissions when the joint is installed in hydrocarbon pipes.

Spiral joints are well known in industries that process liquids, gases and, in particular, gaseous hydrocarbons. In the descriptions below, the numbers refer to the attached figures.

Typically, a spiral joint is composed of a thin metal strip (1) between which the filler strips (2) are interspersed by winding itself around a central axis. A large number of different metals can be used for thin metal tape. Each material offers its specific characteristics to meet the desired specifications. In the same way, various filler materials can be used. Typically, the filler material used is a strip of soft material, which is deformed when the spiral joint is compressed between the pipe flanges, thus providing desired sealing characteristics.

In the vast majority of applications, the outer rings (3) are used in conjunction with the spiral joint becoming part of it. The outer rings are mounted around the outer circumference of a spiral joint. The outer guide rings are generally made from carbon steel and serve several functions in the joint formed by the joint. A primary function of the outer ring is that of a compression limiter, so that the spiral joint is not compressed beyond the design limits. In addition, the outer guide ring provides increased joint radial resistance. In addition, the guide ring

External 5/11 facilitates installation, providing an effective way of centering the joint on the pipe flanges.

Internal rings are also used that become part of the joint. The inner ring (4) prevents the extrusion of the sealing spiral in the internal direction of the pipe, a phenomenon known to those skilled in the art with buckling of the sealing spiral. In addition to this function, the inner ring reduces turbulence in the joint region caused by the passage of fluid through the pipeline.

The entire development of this innovation was carried out with joints with inner and outer rings as they are the most used by the industry in general.

Spiral joints are normally arranged between flanges (5) installed on pipe ends (6). The flanges are fastened together using circumferentially spaced screws (7) or any other suitable fastening material. The gasket (8) is centered by the screws and the outer ring.

By design, a spiral joint can be compressed from its original manufacturing thickness of approximately 4.45 mm to an outer guide ring thickness of 3.20 mm. As the spiral joint is tightened between the flanges, the soft filler is also compressed, increasing its density. Depending on the compressibility of the filler material, the joint can be compressed by reaching the outer guide ring before the crush pressure on the joint is sufficient to provide an adequate seal. In these situations, small volume leaks, called Fugitive Emissions, can occur.

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With the technological advancement of processes, joints are required for applications in increasingly stringent conditions, forcing the development of new products to meet the requirements of Fugitive Emissions from volatile organic components. One of the requirements to meet environmental control requirements is the maximum emissions of volatile organic components when the gasket is installed between the flanges of a pipe that carries hydrocarbons in an oil refinery, petrochemical industry or even in a gas pipeline. . Environmental protection organizations typically define this value as 500 parts per million in volume (ppmV) measured with an instrument known as a toxic vapor analyzer. With more stringent environmental control requirements, some regions have already reduced this value to 100 ppmV.

In order to simulate the working conditions in the most real way possible, the hydrocarbon used in the tests carried out to develop the spiral joint of the present invention was Methane gas and the measurements made with a gas analyzer model TVA-1000 manufactured by Thermo Fisher Scientific Inc .

The joints found on the market typically present the leakage and deformation curve as shown in Figure 4. In the lower axis of the graph, the value of the clamping pressure on the gasket in megapascals (MPa) is shown, on the left vertical axis the volumetric leakage of the joint in parts per million (ppmV), right vertical axis the crushing of the joint in millimeters (mm), that is, its deformation when it is compressed between the flanges.

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As can be seen, this joint only reaches a value below 100 ppmV of emissions with a tightening value above 170 MPa. This value is very high for different types and dimensions of flanges. For example, a flange manufactured in accordance with the American Society of Mechanical Engineers (ASME) piping standards in pressure class 150 and nominal diameter of 3 inches can reach a maximum tightness of 132 MPa, which is insufficient to achieve, with the together with the current state of the art, the maximum level of emissions required by environmental authorities.

The density of a spiral joint is defined as the number of metal and fill turns per millimeter width of the joint. The joints found on the market typically have a density of 0.80 turns per millimeter (v / mm) to 1.35 v / mm. The graph in Figure 5 shows the test result with joints with a density of 0.869 mm / v, 0.994 mm / v and 1.132 mm / v. As can be seen in the graph, there is a great reduction in leakage as the joint density increases.

Another aspect of the joints on the market is that their low density makes the sealing surfaces of the flanges (9) make contact with the centering ring (10). This characteristic limits the joint's clamping capacity and, consequently, reduces its sealability. When making contact with the flange, the centering ring acts as a support point causing the flange to rotate in the plane of the pipe axis. In this situation, there is a reduction in the tightness in the region of the internal diameter (11) of the joint, further reducing its sealability.

Another important characteristic is the amount of filling (2) that protrudes beyond the steel tape or

8/11 thin metal tape (1). In joints found on the market, this feature is not controlled, joints are allowed where the filling is facing the thin metal tape (1). Figure 8 shows a graph of a joint manufactured with the filler facing the metal tape. As can be seen, the joint only starts to seal with values above 140 MPa of tightness, values that are impossible to reach in most of the flanges existing in the industries.

DETAILED DESCRIPTION OF THE INVENTION

The following references will be made to the drawings that illustrate this invention. It should be understood that the invention is not limited to these examples. Others familiar with this art may make modifications or changes after reading and understanding this specification.

Figure 9 shows a spiral joint and its main components. In this figure it is possible to see the profile of each component. The object of the present invention is the sealing spiral (12). The outer ring (13) is manufactured from solid metal plates in the thickness of 2.97 to 3.33 mm. Its main functions are to limit the maximum compression of the sealing spiral and to center the joint on the flange. This and other illustrations show circular spiral joints. It should be understood by those skilled in the art that other shapes such as ovals can be manufactured. The manufacturer only has to pre-select the shape and use a corresponding mandrel to wind the spiral joint over it.

Figure 10 shows the spiral joint with its components in section. In this figure it is possible to see the profile of each component. The object of the present invention is the spiral of

9/11 seal (12). To center the joint on the flange, the outer ring (13) is manufactured from solid metal plates in the thickness of 2.97 to 3.33 mm, its main function is to properly position the sealing spiral on the surface of the flange. The centering ring also provides stability to the joint and acts as a deformation limiter preventing damage to the sealing spiral by over tightening. The inner ring (14) prevents the extrusion of the sealing spiral in the internal direction of the pipe, a phenomenon known to those skilled in the art as buckling of the spiral. In addition to this function, the inner ring reduces turbulence in the region of the joint caused by the passage of fluid through the piping and for large joints, it provides greater stability to the spiral sealing and ring assembly. The inner ring is manufactured from solid metal plates in the thickness of 2.97 to 3.33 mm.

Figure 11 shows the spiral joint with its components in an exploded view with the sealing spiral (12) object of the present invention, the outer centering ring (13) and the inner ring (14).

Figure 12 shows the construction details of the sealing spiral (12). In its traditional constructive form the sealing spiral has a V-shaped profile and its dimensions follow international standards such as ASME B16.20 - 2007, Metallic Gaskets for Pipe Flanges published by the American Society of Mechanical Engineers. According to this standard, the thickness of the sealing spiral measured in the metal strip is 4.31 to 4.57 mm. The spiral is initiated with three internal turns of metallic tape (15) over a matrix with the desired shape and dimensions. These initial turns are welded together in order to guarantee the dimensional integrity of the spiral. The standard

10/11 mentioned above establishes that there is a weld point for every 76 mm of internal perimeter with a minimum of three welds on the internal perimeter of the sealing spiral.

The sealing region of the spiral is then wound with alternating turns of metal or metal tape (15) and soft filler or soft filler tape (16) until it reaches the desired dimension. The profile of these loops has the same V shape as the initial loops. The number of alternating turns of metal tape will depend on the desired size of the joint.

Finally, the spiral is completed with three final turns only of the metal tape (15) welded together, thus ensuring the stability of the joint sealing spiral. These three sections of the spiral are referred to as a spiral joint.

In the construction object of this invention, the width of the soft filler tape (16) is greater than that of the metallic tape (15). In this way, the soft filler tape projects in the direction of the joint axis at least 0.2 mm on each face of the sealing spiral. Figure 14 shows the sealability graphs of a joint of the current state of the art with the same joint constructed in accordance with this invention. The great difference in the sealability of your joints can be seen. The joint of the present invention has values below 10 ppmV with tightening values of 40 MPa. In contrast, the state-of-the-art gasket only shows values below 10 ppmV with tightnesses greater than 190 MPa.

The thickness of the metallic tape is established by international standards and its value is from 0.15 mm to 0.23 mm.

However, the thickness of the filling tape is not standardized, and its thickness is at the discretion of the manufacturers. Because of this

11/11 normative provision manufacturers, in order to reduce costs, use the largest possible thickness. In this way the density of the joint is reduced, since the metal tape is the heaviest and most resistant component of the sealing spiral. In the present invention the density of the joint is controlled in such a way that it presents from 1.40 turns of metallic tape and soft filling per millimeter (v / mm) to 1.85 v / mm. In this way, the joint has enough density to resist crushing pressures, preventing the flanges from touching the sealing ring. Figure 15 shows the graph of joints constructed in accordance with the present invention with densities 1.491 v / mm, 1.509 v / mm and 1.863 v / mm. It can be seen that the joints reach values on the order of 10 ppmV with crushing pressures below 100 MPa.

In the current state of the art the soft filling is facing the metallic tape. In the present invention, the soft filler protrudes beyond the metallic tape ensuring a compressible surface with the flange. In this way, there is a greater conformation of the sealing spiral with the flange surface. The graph in Figure 16 shows the leakage graph of a state of the art joint with joints with a soft filler projecting beyond the 0.4 mm and 0.8 mm metallic tape. As can be seen, there is a great reduction in leakage with this innovation.

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Claims (4)

1. SPIRAL JOINT composed of a sealing spiral, an outer ring and an inner ring, characterized by the sealing spiral being composed of initial turns of thin metal tape or metallic tape (15) having the inner periphery a pre-selected shape; these initial turns are welded together and then the same metallic tape (15) is wound by inserting a soft filling tape (16) until reaching the desired dimension, when then final turns are made only of the metallic tape (15) welded together ; the rings are made from solid metal plates; the number of turns of the metallic tape (15) interspersed with soft filling (16) has a minimum of 1.40 turns per millimeter and 1.90 turns per millimeter. SPIRAL JOINT according to claim 1, characterized in that the width of the soft filler tape (16) is greater than the width of the thin metal tape or metallic tape (15). SPIRAL JOINT according to claim 2, characterized in that the soft filler tape (16) protrudes in the direction of the joint axis of at least 0.2 mm to and at most 0.8 mm in addition to the thin metal tape (1 ). 4. SPIRAL JOINT according to claims 1, 2 and 3, it is characterized by the fact that: where there is no inner ring, it is composed only by the sealing spiral (12) and outer ring (13). 1/8