JP2519641Y2 - Structure of flange joint - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to the structure of a flange joint portion, and more particularly to a technique for reducing leakage of internal fluid when the flange surfaces are separated by internal pressure.

“Prior Art” Conventionally, many flange portions of various containers and the like have a structure as shown in FIG. In FIG. 5, reference numeral 1 is a container wall, 2 is a flange portion, 3 and 4 are bolts and nuts, and 5 is a sealing member.

Then, the flange portions 2 are fastened by the bolts and nuts 3 and 4, and the O-ring or the like of the seal member 5 is brought into pressure contact with the flange surface of the one flange portion 2 to obtain a required sealing property.

[Problems to be solved by the invention] However, the container wall 1 and the flange portion 2 have sufficient strength so as not to be damaged even if a large internal pressure is applied. Due to this, the container wall 1 expands and the development in which both flange portions 2 are separated is suppressed by the bolts, nuts 3 and 4. Therefore, as shown in FIG. A gap is generated between the O-ring of the member 5 and the flange surface,
An accident may occur in which the fluid inside the container leaks,
If the internal fluid is toxic or dangerous, it may lead to a major disaster.

The present invention has been made in view of the above circumstances, and suppresses a large amount of leakage of internal fluid when an abnormal internal pressure occurs, and controls the amount of leakage when an abnormal internal pressure occurs to cause a major accident. The purpose is to suppress.

“Means for Solving the Problems” As means for solving these problems, a seal member for sealing the gap between both flange surfaces of the container flange is provided, and both flange surfaces at the inner position of the seal member are provided. An annular groove is formed, and an auxiliary seal ring that is in close contact with the side wall of the annular groove due to the internal pressure when the flange surfaces are separated is disposed in the annular groove.

In addition, the structure of the flange joint part in which the auxiliary seal ring is provided with a configuration in which a slit hole is formed which is out of the seam of the flange part at the normal time and along the fastening direction of the flange part is added to the first means. I am trying.

"Operation" When the internal pressure of the container or the like is within the normal design range, the sealing member provides the necessary sealing property.

The container wall expands due to the internal pressure when an abnormal internal pressure occurs,
When development occurs in which both flanges are separated, the auxiliary seal ring expands outward and deforms so as to enter between both flange surfaces, increasing the contact pressure between the auxiliary seal ring and the inner wall surface of the annular groove. Based on this, a sealing property is generated in this portion, and the amount of leakage of the internal fluid is reduced.

Also, if the auxiliary seal ring deforms when an abnormal internal pressure occurs, and the slit hole fits in the position between both flange surfaces, a leakage path through the slit hole is formed, allowing fluid leakage through the slit hole. The leakage amount is controlled when a leakage occurs.

[Embodiment] An embodiment of the structure of the flange joint portion according to the present invention will be described below with reference to FIGS. 1 to 4.

The structure of the flange joint portion in the one embodiment is basically the same as the structure of FIG. 5 described as the conventional example, but as shown in FIG. An annular groove 6 having a larger depth dimension than the width dimension is formed in the annular groove 6, and an auxiliary seal ring 7 made of metal or the like having a cylindrical shape as a whole is axially formed (in the vertical direction in FIG. 1). It is movably loaded.

With such a flange joint structure, bolts and
Both flange portions 2 are fastened with nuts 3 and 4, and the O-ring of the seal member 5 is pressed against the flange surface of one flange portion 2 to obtain the necessary sealability, and the internal pressure of the container is designed to be normal. When it is within the range, the necessary sealability is maintained by the seal member 5, and in such a normal case, the auxiliary seal ring 7 does not function.

When a phenomenon in which the container wall 1 expands and the flange portions 2 separate from each other when an abnormal internal pressure that exceeds the prediction occurs, as shown in FIG. The part also expands outward. Due to this expansion, the auxiliary seal ring 7 is deformed so as to enter between both flange surfaces, so that a part of the inner wall surface of the annular groove 6 and the auxiliary seal ring 7 come into strong contact with each other (second part). The contact pressure of the portion A shown in the figure) becomes high, and the sealing property is generated in this portion although it is not in a perfect state, and the leakage of the internal fluid is stopped or reduced.

On the other hand, FIGS. 3 and 4 show another embodiment of the auxiliary seal ring 7, in order to intentionally remove the sealability regardless of the deformation degree of the container wall 1 and the flange portion 2. , As shown in FIG. 3, in the auxiliary seal ring 7,
A plurality of slit holes 8 are formed vertically above and below (in the fastening direction of the bolts / nuts 3/4) by the closing dimension δ and at intervals in the circumferential direction.

In the auxiliary seal ring 7, as shown in FIG. 4, when the internal pressure causes a phenomenon in which the flange portions 2 are separated from each other, the auxiliary seal ring 7 is deformed as shown by a chain line. Due to the phenomenon of separation of the flange surfaces, the gap G between both flange surfaces becomes larger than the closing dimension δ, or one of the slit holes 8 is displaced to a position intersecting the flange surface, as shown by arrows,
A leak path passing through the slit hole 8 is formed, and fluid leakage through the slit hole 8 is allowed. By intentionally causing this leakage, the amount of leakage at the time of occurrence of leakage is controlled so that the container wall 1 and the flange portion 2 are not damaged by an abnormal internal pressure.

In the description so far, the auxiliary seal ring 7 is
Although it is assumed that it is movable in both directions of the axis, for example, when one edge portion such as a lower edge is fixed to the flange portion 2 by means such as welding, and both flange portions 2 form a gap, Alternatively, only the other may be moved. Further, in the above-mentioned embodiment, the container is described as an example, but the container is not limited to this, and may be a pipe, a device, or the like.

[Advantage of Invention] As described above, according to the structure of the flange joint portion according to the present invention, (1) the annular groove and the auxiliary seal ring are arranged at the inner position of the seal member, and the flange surface is formed by the internal pressure. Even if they are separated from each other, the sealing property is obtained to prevent a large amount of fluid from leaking. Therefore, especially when the fluid in the container is toxic or dangerous, it is possible to suppress the occurrence of a major disaster. You can

(2) Since a slit hole is formed in the auxiliary seal ring, if the internal pressure is close to the limit and there is leakage from the flange joint portion due to abnormal internal pressure generation, the leakage amount is controlled. To reduce damage to the container wall and flange joints, to provide the sealability with the auxiliary seal ring at the initial stage when unexpected internal pressure occurs, and when the amount of deformation of the container increases, It is possible to suppress the occurrence of a major disaster by allowing the leakage of

It has excellent effects such as.

[Brief description of drawings]

1 to 4 show an embodiment of the structure of the flange joint portion according to the present invention, and FIG. 1 is a front sectional view of a main portion,
2 is a front sectional view of a deformed state due to abnormal internal pressure, FIG. 3 is a development view in which a part of another example of the auxiliary seal ring is omitted, and FIG. 4 is pressure release by the auxiliary seal ring of the example of FIG. FIG. 5 is a front sectional view showing a conventional example of the structure of the flange joint portion, and FIG. 6 is a front sectional view showing a deformed state due to abnormal internal pressure in the example of FIG. 1 ... Container wall, 2 ... Flange part, 3 ... Bolt, 4 ...
... nut, 5 ... sealing member, 6 ... annular groove, 7 ... auxiliary seal ring, 8 ... slit hole, δ ... closing dimension,
G: Gap.

Claims (1)

(57) [Scope of utility model registration request] 1. A seal member (5) for sealing the gap between both flange surfaces of a flange portion (2) is provided,
An annular groove (6) is formed on both flange surfaces inside the seal member.
Is formed, and an auxiliary seal ring (7) that is brought into close contact with the side wall of the annular groove by the internal pressure when the flange surfaces are separated is disposed in the annular groove, and the auxiliary seal ring is
A structure of a flange joint portion, characterized in that a slit hole (8) is formed which is out of a joint portion of the flange portion at a normal time and along a fastening direction of the flange portion.