JPH1047489A - Soft seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to a casing by winding together an expansion graphite strip and mesh in a ring-like form, abutting a metal grommet against one end, abutting a punched metal provided with a number of holes and projections against the other end, and compressively molding it in a die. SOLUTION: An expansion graphite sheet is cut to obtain a strip-like body 8 having width B twice as height (h) of a product. A mesh 9 is superposed on one of the surfaces. It is wound with the mesh 9 arranged inside by half in its length, and wound with the mesh 9 arranged outside by the remaining half. A ring-like material is thus formed. A metal grommet 10 is abutted against one end of the ring-like material, while a punched metal 11 having a number of holes and projection pieces is abutted against the other end. It is then compressed to a specified shape in a die. A seal ring body 12 is bent in a wave-like form with the strip-like body 8 being mixed with the mesh 9. Its section is rectangularly formed. Its inner and outer peripheries are covered with the mesh 9 embedded in the expansion graphite. The body 12 is soft, with elasticity, and prevents damage to a wall surface of a casing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft seal ring used for a valve of a high-temperature and high-pressure device such as a power plant.

[0002]

2. Description of the Related Art FIGS. 9 to 12 show a conventional seal ring and an example of its use. In the drawings, reference numeral 1 denotes a valve casing, 2 denotes a lid, and 3 (see FIG. 9) denotes a wedge-shaped metal. 4 and 5 (see FIGS. 10 and 11) are soft seal rings having a square cross-sectional shape, 5 is a receiving ring, and 6 (see FIGS.
10) is a spacer ring, 7 is a split ring, 4a
(See FIG. 11) is a seal ring main body mainly made of expanded graphite, 4b and 4c are pre-compressed plate-shaped wire meshes which are applied to the upper and lower sides of the seal ring main body 4a and embedded in the expanded graphite.

[0003]

In the apparatus shown in FIG. 9, when a high pressure is applied, a large stress is generated at the wedge-shaped tip of the metal seal ring 3, so that the wedge has a tip on the inner wall surface of the casing 1. May bite and hurt.
In order to correct this damage, the inner wall surface of the casing 1 must be cut or the lid 2 needs to be remade.

In the apparatus shown in FIG. 10 using the soft seal ring 4 shown in FIG. 11, when a high pressure is applied, the expanded graphite of the seal ring main body 4a causes the receiving ring 5, the spacer ring 6, and the casing 1 or the lid to expand. 2 and expanded graphite comes in contact with the heated outside air and is oxidized and disappears as carbon dioxide gas.
There is a problem that the sealing property is greatly affected.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method in which a polymer of a band made of expanded graphite and a wire mesh is wound in a ring shape, and one end face of the polymer is wound on a metal. A soft seal ring is formed by applying a grommet and applying a punched metal having a large number of holes and protrusions to the other end face in a mold in a predetermined shape.

In the present invention, the exposed portions of the expanded graphite on the inner and outer peripheral surfaces of the above-mentioned soft seal ring may be respectively covered with a wire mesh buried in the expanded graphite.

In the present invention, the metal grommet of the soft seal ring may have bent edges formed on the inner side and the outer side of the metal grommet on the side of the expanded ring made of expanded graphite.

In the present invention, the inner peripheral portion of the above-mentioned soft seal ring on the punched metal side may be cut off obliquely.

Further, in the present invention, a metal grommet is applied to one end face of a polymer obtained by winding a polymer of a strip made of expanded graphite and a wire net into a ring shape,
A metal grommet having a V-shaped cross section applied to the other end face may be formed in a wedge shape in a mold.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the drawing, the same reference numerals as those described above indicate the same components. That is, 1 in FIG. 6 is a valve casing, 2 is a lid, 6 is a spacer ring, and 7 is a split ring.

1 to 6 show a first embodiment of the present invention. In this embodiment, first, as shown in FIG.
The expanded graphite sheet having a thickness of 0.38 to 1.0 mm (0.76 mm in the present embodiment) is placed on the final product at the height (for example, FIG. 1A).
H) is cut into a strip (tape) 8 having a width (for example, B in FIGS. 2 and 3) that is approximately twice as wide as h). FIG. 3 shows a polymerized plain woven wire mesh (metal mesh) 9.
巻 of the required length when wound in a ring as shown in
Is wound with the wire mesh 9 inside, and the other half is wound with the wire mesh 9 outside to form a ring-shaped material.

As shown in FIGS. 1 and 4, a ring-shaped metal grommet 10 capable of covering one end face (upper case in FIG. 1A) of the completed soft seal ring is formed. Bent edges 10a, 10 of about 1 mm or more bent toward the seal ring body side made of expanded graphite on the inner peripheral edge and the outer peripheral edge of the metal grommet 10, respectively.
b is formed.

As shown in FIGS. 1 and 5, the other end of the completed soft seal ring (the lower side in the case of FIG. 1A)
Ring-shaped punched metal 11 that can cover the end face of
To form The punched metal 11 is, for example, 0.1
A large number of holes and protruding pieces 11a are formed on a 5 mm thick stainless steel plate.
Is formed as a material, and is punched out in a ring shape.

Next, as described above, a metal grommet 10 is applied to one end surface of a material obtained by winding a polymer of the band 8 made of expanded graphite and the wire netting 9 into a ring shape, and the other end surface is applied. A punched metal 11 having a large number of holes and protruding pieces 11a is put into a mold (not shown) and compressed at 700 to 1000 kgf / cm ² to a predetermined shape. Molding.

As described above, as shown in FIGS. 1 and 6, the metal grommet 10 and the punched metal 11
The seal ring main body 12 located between them is formed so as to be bent in a waveform in a state where the above-described expanded graphite strip 8 and the wire mesh 9 are mixed, and have a rectangular cross section. Then, as shown in FIG. 1A, the inner and outer peripheral surfaces of the seal ring main body 12 are covered with the wire mesh 9 embedded in the expanded graphite.

FIG. 7 shows a second embodiment of the present invention.
In this embodiment, a punched metal 13 having a larger inner diameter than the punched metal 11 of the first embodiment is used, and the inner peripheral portion of the seal ring main body 12 of the soft seal ring on the punched metal 13 side is inclined. (Approximately 45 degrees).

FIG. 8 shows a third embodiment of the present invention.
In this embodiment, the metal grommet 14 below the soft seal ring is formed so that its cross-sectional shape along the axis of the seal ring is approximately V.
The seal ring main body 12 made of expanded graphite is formed in a wedge shape that fits the metal grommet 14.

[0018]

The soft seal ring of the present invention is obtained by applying a metal grommet 10 to one end face of a polymer obtained by winding a polymer of a band 8 made of expanded graphite and a wire mesh 9 into a ring shape. A punched metal 11 having a number of holes and protruding pieces 11a applied to the other end face is compression-molded into a predetermined shape in a mold.

As described above, in the seal ring of the present invention, since the seal ring main body 12 is made of expanded graphite as a main material and is sufficiently soft and highly elastic, the initial tightening force of the metal seal ring is reduced. Smaller than that of the above, and can sufficiently follow pressure fluctuations. Further, unlike the conventional metal seal ring 3, the wall of the casing 1 and the lid 2 of the valve is not damaged. Therefore, according to the present invention, it is not necessary to cut the casing 1 and the lid 2 for correction.

Since the metal grommet 10 is applied to one end face of the soft seal ring of the present invention and the punched metal 11 (12, 13) is applied to the other end face, an intermediate expansion is achieved. The seal ring body 12 mainly composed of graphite can be protected from high temperature and high pressure. That is, 400 to 450 ° C., which is the use limit temperature of expanded graphite.
Can be expanded to 600 to 650 ° C. because the expanded graphite and oxygen gas do not come into direct contact with each other.
It can also be applied to 0 to 260 kg / cm ² . A bent edge 10a,
By providing 10b, the protection performance of the expanded graphite can be further enhanced.

If the exposed portions of the expanded graphite on the inner and outer peripheral surfaces of the soft seal ring of the present invention are covered with wire meshes 9 buried in the expanded graphite, the metal grommet 10 and the punched metal 11 ( 13,1
In combination with the effect of 4), the expanded graphite does not protrude to the outside even during the high pressure operation. Therefore, according to the present invention, the receiving ring 5 requiring special dimensional accuracy as shown in FIG. 10 becomes unnecessary, and the dimensional accuracy of the spacer ring 6 can be processed within a general tolerance range. Therefore, the cost is reduced accordingly.

The above-mentioned flexible seal ring of the first embodiment of the present invention and various types of conventional expanded graphite molded packings A,
The amount of the extruded graphite extruded when B, C, and D were subjected to a high load under the same conditions was measured, and the results were as follows.

[0023]

[Table 1]

Sample A: As shown in FIG. 12 (a), a 0.38-mm-thick expanded graphite tape wound to an appropriate length is 1.5 to 1.6 g / cm ³ . Compression molded. Sample B: As shown in FIG. 12 (b), an expanded graphite sheet having a thickness of 0.76 mm was punched out to a predetermined size, and they were joined with an adhesive and then compressed in a molding die to be integrally molded. thing. Sample C: As shown in FIG. 12 (c), an expanded graphite sheet with a wire mesh pressed thereon was formed into a tape having a width of 13 mm, wound in a ring shape, and compression-molded in a molding die. Sample D: As shown in FIG. 12 (d), a sample obtained by punching a stainless steel nail standing steel plate into a predetermined size and pressing the sample C on the upper and lower sides and integrally compression-molding.

Test conditions Sample size: 20 mmφ × 33 mmφ × 6.5 mmH Load: 1800 kgf / cm ² Gap at the protruding point: 0.07 mm Measurement of protruding amount: Cut out the expanded graphite protruding above the outer periphery of the sample with scissors. The measured value was precisely measured with an electronic balance and expressed as the protruding weight per 1 cm of the outer circumference. As can be seen from the above test results, it was confirmed that the flexible seal ring of the present invention had an extruded amount of expanded graphite of 0 even under a high pressure of about 1800 kgf / cm ² .

[Brief description of the drawings]

FIG. 1A is a partial elevational sectional view taken along line XX of FIG. 1B, showing a first embodiment of a soft seal ring of the present invention;
(B) is a plan view of (a).

FIG. 2 is a perspective view of a belt-shaped body that is a material of the flexible seal ring of the present invention.

FIG. 3 is a perspective view showing a state where the belt-shaped body of FIG. 2 is wound in a ring shape.

FIG. 4 is a partially cutaway perspective view of a metal grommet of the soft seal ring of the present invention.

FIG. 5 is a perspective view of a punched metal of the soft seal ring of the present invention.

FIG. 6 is a partial cross-sectional view of a valve showing a use state of the soft seal ring of the present invention.

FIG. 7 is a partial sectional view of a second embodiment of the flexible seal ring of the present invention.

FIG. 8 is a partial sectional view of a third embodiment of the flexible seal ring of the present invention.

FIG. 9 is a partial sectional view of a valve showing an example of use of a conventional metal seal ring.

FIG. 10 is a partial sectional view of a valve showing an example of use of a conventional soft seal ring.

FIG. 11 is a partial perspective sectional view of a conventional soft seal ring.

FIGS. 12 (a) to 12 (d) are cross-sectional views showing various conventional expanded graphite molded body packings.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve casing 2 Lid 3 Metal seal ring 4 Soft seal ring 5 Receiving ring 6 Spacer ring 7 Split ring 8 Band 9 Metal net 10 Metal grommet 10a, 10b Folded edge 11 Punched metal 11a Projection piece 12 Seal ring main body 13 Punched metal 14 Metal grommet

Claims (5)

[Claims] A metal grommet is applied to one end face of a belt-shaped polymer made of expanded graphite and a wire mesh wound in a ring shape, and a large number of holes and projections are provided on the other end face. A soft seal ring obtained by compressing a punched metal having a shape into a predetermined shape in a mold. 2. The flexible seal ring according to claim 1, wherein the exposed portions of the expanded graphite on the inner and outer peripheral surfaces of the flexible seal ring are covered with a wire mesh embedded in the expanded graphite. 3. The flexible seal ring according to claim 1, wherein a bent edge is formed on an inner peripheral edge and an outer peripheral edge of the metal grommet of the flexible seal ring. 4. A soft seal ring according to claim 1, wherein an inner peripheral portion of the soft seal ring on the punched metal side is cut off obliquely. 5. A metal grommet is applied to one end face of a belt-shaped polymer made of expanded graphite and a wire mesh wound in a ring shape, and the cross section of the other end face is substantially V-shaped. A soft seal ring formed by applying a metal grommet formed in a shape into a wedge shape in a mold.