JPH0718095U - Gasket for pipe flange - Google Patents

Abstract

(57) [Summary] [Structure] The flanges 18a of the two pipes 18, 18,
In the pipe flange gasket 10 that is mounted between the flanges 18a and 18a at the pipe joint portion that connects the 18a with the bolt 19, the first portion having the fitting portion 13 on the outer periphery.
A ring 11 and a second ring 12 fitted to the fitting portion 13 of the first ring 11 and positioned by the bolt 19 are provided, and the thickness of the second ring 12 is the first ring 11. Thinner than the wall thickness. [Effect] Since the second ring is tightened with the bolts, sufficient surface pressure can be applied to the first ring, and the first ring can be used for a pipe joint portion that is not retightened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pipe flange gasket used for a joint portion of a pipe body, and more particularly to a pipe flange gasket for a joint sheet.

[0002]

[Problems to be solved by conventional techniques and devices]

 In the joint portion of the pipe body for piping, as shown in FIG. 7, the flanges 1a and 1a are fastened with bolts 3 with the gasket 2 sandwiched between the flanges 1a and 1a of the pipe bodies 1 and 1, respectively. However, with the passage of time, the stress applied to the gasket is relieved, and the bolt 3 becomes loose. Generally, in plant equipment and the like, bolts 3 are tightened regularly, and gaskets 2 are replaced at regular inspections every 1-2 years, so loose bolts are not a problem.

However, in the piping of building facilities and the like, the actual situation is that gasket replacement and regular retightening are not performed. For this reason, the piping equipment is tightened in advance by applying sufficient surface pressure for the additional tightening. However, if tightened too much at the beginning of construction, the allowable stress of the bolt may be exceeded and the bolt may break. As a method of applying a sufficient surface pressure to the gasket without breaking the bolt, it is conceivable to reduce the area of the gasket, that is, the outer diameter of the gasket. However, if the outer diameter of the gasket is made small enough to provide sufficient surface pressure, it will not be possible to open bolt holes in the gasket. In this case, as shown in FIG. 8, since the mounting position of the small gasket 4 is not fixed by the bolt 3, it is difficult to position the gasket at the time of mounting, and the mounting position may be displaced.

The present invention has been made in view of such a technical background, and an object thereof is to prevent the bolt from being burdened at the time of construction and need not be retightened. The object of the present invention is to provide a gasket that can provide sufficient surface pressure and that can be easily positioned during construction.

[0005]

[Means for Solving the Problems]

 The pipe flange gasket according to claim 1 is a pipe flange that is mounted between the flanges 18a and 18a at a pipe joint portion that connects the flanges 18a and 18a of the two pipe bodies 18 and 18 with bolts. The gasket 10 includes a first ring 11 having a fitting portion 13 on the outer circumference, and a second ring 12 fitted to the fitting portion 13 of the first ring 11 and positioned by the bolt 19. Further, the wall thickness of the second ring 12 is smaller than the wall thickness of the first ring 11.

In the gasket for a pipe flange according to a second aspect, the fitting portion 13 of the first ring 11 is a circular groove provided on the outer peripheral surface of the first ring 11, and the ring is attached to the second ring 12. It is characterized in that one cutting portion 15 for opening the ring is provided.

[0007]

[Action]

 The pipe flange gasket according to claim 1 is fixed at a predetermined position of the flange 18 a of the pipe body 18 by the second ring 12 at the pipe joint portion of the two pipe bodies 18, 18. The gasket is fastened at the time of construction based on the second ring 12 to such an extent that the bolt 19 is not broken. Since the thickness of the second ring 12 is smaller than that of the first ring 11, the tightening of the second ring 12 exerts a sufficient surface pressure on the first ring 11, and the additional tightening is unnecessary.

In the pipe flange gasket according to the second aspect, when the second ring 12 is fitted into the first ring 11, the cut portion 15 of the second ring 12 can slightly open the ring. The fitting work becomes easy.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a gasket 10 according to an embodiment of the present invention. The gasket 10 has the second ring 13 shown in FIG. 3 attached to the outer periphery of the first ring 11 shown in FIG.

The first ring 11 is made of, for example, a material suitable for sealing such as a joint sheet, and a groove serving as a fitting portion 13 is provided on the outer periphery by lathe processing. Here, the joint sheet is generally a mixture of 65% or more by weight of asbestos fibers with 10% or more of rubber and a vulcanizing agent or other compound, or a filler, and heated to a dense and even cardboard shape. Although it refers to a compressed product (JIS R3453), recently there is a sheet using an inorganic fiber other than asbestos fiber, and a sheet using this inorganic fiber is also included. The thickness of the first ring 11 is equivalent to the thickness of the conventional pipe flange gasket, and is a thickness sufficient for sealing the pipe joint portion, specifically, about 1.5 to 3 mm. The depth and width of the groove of the fitting portion are not particularly limited, but from the viewpoint of workability, the depth is about 2 to 8 mm and the width is 0. It is preferably about 5 to 1 mm.

The second ring 12 has an inner diameter substantially equal to the outer diameter of the first ring 11, and the outer diameter is large enough to open a bolt hole for fixing to the flange. The thickness of the second ring 12 is about the same as the groove width of the fitting portion 13 of the first ring 11. As a result, the second ring 12 can be fitted into the fitting portion 13 of the first ring 11. Bolt holes 14, 14 ... For fixing to the flange are formed in the second ring 12. The second ring 12 is cut at the cutting portion 15. When the second ring 12 is inserted into the fitting portion 13 of the first ring 11 while slightly opening the cutting portion 15, the second ring 12 is inserted. It becomes easy to attach the first ring 11 to the first ring 11.

The constituent material of the second ring is not particularly limited, and may be the same material as the first ring, or a material that is cheaper and harder than the material of the first ring may be selected. The state in which the gasket 10 having the above structure is fixed between the flanges of the tubular body is as shown in FIG. The flanges 18a, 18a of the tubular bodies 18, 18 are fastened and fixed by inserting the bolts 19 into the bolt holes 14 of the second ring 12. At this time, since the thickness of the second ring 12 is thinner than that of the first ring 11, a sufficient surface pressure is applied to the portion of the first ring 11 even with a tightening force that is not enough to break the bolt 19. Therefore, according to the gasket 10 of the present invention, since sufficient surface pressure can be obtained at the seal portion, the retightening is not required and the position of the gasket 10 can be easily adjusted because it is fixed to the flange by the bolt 19. Do not shift.

In the above embodiment, the thickness of the second ring 12 is made equal to the groove which is the fitting portion 13 of the first ring 11, but the present invention is not limited to this, and the second ring 12 is fitted. If the inner circumference of the second ring has a convex portion for fitting with the portion 13, the ring portion may be slightly thicker. In short, the second ring 12 may be thinner than the first ring 11 so that the second ring 12 can be tightened to obtain a sufficient surface pressure in the first ring 11 portion.

Further, the cutting portion 15 of the second ring 12 is for facilitating the work of inserting the first ring 11 into the first ring 11, and the second ring 12 is pushed in by a slight amount of force and the first ring 12 is pushed. The cutting portion 15 may be omitted as long as the fitting portion 11 can be fitted. Further, the bolt holes 14, 14 ... Are opened in the second ring 12, but this is not essential in the present invention, and it is sufficient if the second ring 12 can be fixed to a predetermined position of the flange by the bolt. For example, as shown in FIG. 5, the outer diameter of the second ring may be in a bolting position and may be fixed by three or more bolts.

Furthermore, in the above embodiment, the fitting portion of the first ring is a groove, but it may be a cut portion. In the gasket 20 shown in FIG. 6, the fitting portion 23 of the first ring 21 is broken, and the gasket 20 is attached to the second ring 22 so as to abut against the broken portion 23.

[0016]

[Effect of device]

 Since the gasket for pipe flange of the present invention is tightened with the bolt based on the second ring which is thinner than the first ring, sufficient surface pressure can be applied to the first ring without breaking the bolt. Therefore, it is suitable as a gasket used for a joint portion of a pipe body, which is generally not retightened in building piping equipment and the like. However, since the gasket of the present invention is mounted at a predetermined position of the flange by the second ring and the bolt, the ease of the gasket mounting work is the same as the conventional one, and the position does not shift even after the lapse of days.

Further, since the constituent material of the second ring has nothing to do with the sealing property, the material can be appropriately selected and the cost can be reduced. Further, in the pipe flange gasket in which the second ring is provided with the cut portion, the work of mounting the second ring on the first ring becomes easy.

[Brief description of drawings]

FIG. 1 is a plan view of a pipe flange gasket according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a first ring of the pipe flange gasket according to the present embodiment.

FIG. 3 is a perspective view showing a second ring of the pipe flange gasket according to the present embodiment.

FIG. 4 is a cross-sectional view showing a state in which the pipe flange gasket according to the present embodiment is mounted between the flanges of the pipe body.

FIG. 5 is a cross-sectional view showing a state in which a pipe flange gasket according to another embodiment of the present invention is mounted between the flanges of the pipe body.

FIG. 6 is a perspective view (a) and a sectional view (b) of a pipe flange gasket according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a state in which a conventional gasket is attached between flanges of a tubular body.

FIG. 8 is a cross-sectional view showing a state in which a conventional gasket is attached between the flanges of the tubular body.

[Explanation of symbols]

 10 Pipe Flange Gasket 11 First Ring 12 Second Ring 13 Fitting Part 15 Cutting Part 18 Tubular Body 18a Flange 20 Pipe Flange Gasket 21 First Ring 22 Second Ring 23 Fitting Part

Claims (2)

[Scope of utility model registration request] 1. A pipe joint portion connecting two flanges (18a), (18a) of two pipes (18), (18) with a bolt (19), and the flanges (18a), (18a).
A pipe flange gasket (10) mounted between the first ring (11) having a fitting portion (13) on the outer periphery;
A second ring (12) fitted to the fitting portion (13) of the first ring (11) and positioned by the bolt (19), and the thickness of the second ring (12) Is thinner than the wall thickness of the first ring (11), a gasket for pipe flanges. 2. The fitting part (13) of the first ring (11) comprises a circular groove provided on the outer peripheral surface of the first ring (11), and the second ring (12) has an open ring. The gasket for pipe flanges according to claim 1, characterized in that one cutting portion (15) is provided.