JPH0814329B2 - Structure of valve seat - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a valve seat, such as a butterfly valve or a ball valve, which is opened and closed by a rotating operation, and particularly, a heterogeneous material having a special laminated structure. The present invention relates to the structure of the formed valve seat.

(Prior art and its problems)) Like butterfly valves and ball valves,
Various structures have been proposed for valve seats in which the flow path is opened and closed by a 180 ° turning operation in order to effectively exert a disc and ball sealing action.

Among them, the laminated sheet structure includes a laminated type in which ring-shaped flat plate gaskets are laminated and a spiral type in which a spiral compression molding is performed. This laminated type has a higher compression strength and sealability than the spiral type. Excellent, but not sufficient in terms of strength.

In FIG. 6, the laminated ring seat 32 is attached to the body 30 of the butterfly valve with the seat retainer 31,
When this ring sheet 32 is used in sealing contact with the disc 33, a part of the ring sheet 32 may be deformed as shown by the chain line in the figure, and eventually the sealing performance may be deteriorated.

Conventionally, in order to eliminate the drawbacks of this laminated type, for example,
As shown in Japanese Patent Laid-Open No. 52-103030, there is known a structure in which gasket plates and metal plates are alternately laminated.

However, according to this conventional example, from the viewpoint of reinforcement, there is a temporary effect, but since a gasket plate and a metal plate having a low friction coefficient are slippery at the joint surface, the contact surface leak easily occurs, and The protrusion of the metal plate may damage the contact surface of the disc, the ball or the body sheet.

The structure of Japanese Utility Model Publication No. 59-8042 has been proposed as a means for preventing the above slip, but the structure of the publication is a valve seat having a structure in which a corrugated metal plate is inserted between flat gasket plates. Therefore, the corrugated shape of the metal plate causes non-uniformity of the density of the gasket plate during mutual lamination molding with the gasket plate, and the surface pressure between the gasket plate and the corrugated metal plate varies. When the above is repeatedly used, a gap is generated on the joint surface, which causes inconvenience such as wetting of the joint surface.

The present invention was developed in order to solve these drawbacks in view of the above-mentioned conventional problems, and it is intended to improve not only strength but also sealing property by completely integrating the laminated members of the sheet. It is intended for.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a ring-shaped gasket plate made of expanded graphite and a ring-shaped porous metal foil that are alternately laminated with a thermosetting resin interposed therebetween. Then, the ring-shaped sheet body is formed by bonding, and the insertion density distribution of the above-mentioned porous metal foil is high near both sides in the laminating direction of the sheet body, and the central portion is low to form a sheet body by being inserted and laminated. .

Furthermore, at least one sheet of non-perforated metal foil is arranged in the vicinity of the surface on both sides of the sheet body in the stacking direction, and the perforated metal foil has pores with a diameter of φ2 mm or less with a porosity of 20% to 4%.
It was configured to be uniformly dispersed in the range of 0%.

(Operation) Therefore, according to the present invention, a ring-shaped gasket plate made of expanded graphite and a ring-shaped porous metal foil are alternately laminated and bonded via a thermosetting resin to form a ring-shaped sheet body. Therefore, if this seat body is mounted at the sealing position of, for example, a butterfly valve or a ball valve, the gasket plate and the porous metal foil are integrated and there is no fear of contact surface leakage, etc., and it has an appropriate strength. Therefore, there is no risk of deformation during use, and the sealing performance at the valve sealing position can be significantly improved.
Further, even if the metal foil comes into direct contact with the contact surface of the disc, the ball, or the body sheet, since the metal foil is in a foil shape,
It does not damage them.

In particular, according to the present invention, the insertion density distribution of the porous metal foil is high near both sides in the laminating direction of the seat body, and the central portion is low so that the seat body is inserted and laminated to enhance the strength of the surface portion of the valve seat. Therefore, the valve seat is durable, and the central portion of the valve seat can maintain the sealing performance of the sealing surface without losing elasticity, and the operating torque performance can be maintained.

Further, if at least one sheet of non-perforated metal foil is arranged in the vicinity of the surface of the sheet body, the phenomenon of permeation leakage of the sheet can be surely prevented.

(Embodiment) FIGS. 1 to 5 show respective embodiments of the structure of a valve seat according to the present invention, and FIG. 1 is a partial sectional view showing an example in which a seat is attached to a body side of a butterfly valve. 2 and 3 are partial cross-sectional views showing an example in which a seat is attached to the disc side of a butterfly valve, FIG. 3 is a partial cross-sectional view showing an example in which a seat is attached to a ball valve, and FIG. 4 is a partial enlarged view of the seat. Sectional views, FIGS. 5A, 5B and 5C are partial sectional views showing respective examples of the sheet.

In the drawings, 1 is a seat body, and this seat body 1
Is formed by alternately laminating a ring-shaped gasket plate 2 made of expanded graphite and a ring-shaped porous metal foil 3 (or a thin metal net) via thermosetting resin 4 and adhering the ring-shaped gasket plate 2 to each other. And a shoulder portion that is inserted into the mounting portion of the valve (disc in FIG. 2) on the outer peripheral portion (inner peripheral portion in FIG. 2)
A tapered seal surface 1b is formed on the inner peripheral surface 1a and the outer peripheral surface in FIG.

The porous metal foil 3 has a function of integrating the gasket plate 2 and a reinforcing action of the sheet body 1, and has an opening area of 20% or more (preferably 20% to 40%) and a diameter of φ.
Thickness of 20 μm to 100 μm with holes of 2 mm or less uniformly dispersed
A metal foil (preferably 20 μm to 50 μm) or a thin metal net is used, and an austenitic stainless steel, ferritic stainless steel, and copper or copper alloy are suitable as the material.
Further, the insertion ratio of the porous metal foil 3 is effectively 8 to 16 when the thickness of the sheet body 1 is, for example, 10 mm.

Furthermore, the insertion density distribution of the porous metal foil 3 is determined by the sheet body 1
In the case of inserting and laminating the sheet body 1 near both sides in the laminating direction to be high and the central portion to be low, the strength near the both sides of the sheet body 1 and the sealing performance of the central portion can be effectively exhibited.

As shown in FIG. 4, the thermosetting resin 4 has an adhesive function for firmly bonding the gasket plate 2 made of expanded graphite and the porous metal foil 3 to each other, and is permeable to the expanded graphite. It is preferable to use a strong phenol type or furan type.

Further, the amount of the thermosetting resin 4 is 5 wt% to 15 wt% in terms of solid content with respect to the expanded graphite in order to obtain sufficient bonding strength. When used at 200 ° C. or higher, if necessary, heat treatment is performed in advance to perform degassing and carbonization. In this case, sufficient anchorage strength is maintained by the anchoring effect of the carbonized resin.

Further, if at least one sheet of non-perforated metal foil 5 is arranged at a position near the surface of the sheet body 1, permeation leakage of the sheet body 1 can be reliably prevented. In this example, one sheet of non-perforated metal foil 5 is provided in the vicinity of both laminated surfaces of the sheet body 1.

FIG. 5 shows an example of stacking the porous metal foils 3.
The figure (a) shows a laminate of flat plate-like porous metal foils 3, and the figure (b) shows a laminate of flat plate-like porous metal foils 3 and corrugated porous metal foils 3 alternately. In this case, either one may be a non-perforated metal foil. The same figure (c) is a laminate of corrugated porous metal foils 3.
Also in this case, the non-porous metal foil 3 and the porous metal foil 3 may be alternately laminated.

Next, a case where the seat body 1 is mounted on a butterfly valve and a ball valve will be described. FIG. 1 shows an example in which a seat retainer 7 is held on the body 6 side of a butterfly valve and a seat body 1 is attached by a bolt 8. In this case, the outer peripheral surface of a disc 13 is rotated by operating a stem 12. The sealing surface 1b of No. 1 is contacted and the valve is closed. 9 is a gasket provided between the body 6 and the seat retainer 7, and 10 is a gasket provided between the seat retainer 7 or the body 6 and the seat body 1. The gasket 10a may be attached. Reference numeral 11 is a bearing in which the stem 12 is inserted. Second
The illustration shows the seat retainer 1 on the disc 13a side of the butterfly valve.
This is an example in which the seat body 1 is held by the bolts 4 and attached by the bolts 15. In this case, the disc 12 is rotated by operating the stem 12.
The seat body 1 provided on the outer peripheral portion of 13 is attached to the valve seat surface 6a of the body 6.
To close the valve. Reference numeral 16 denotes a gasket provided between the seat retainer 14 or the disc 13a and the seat main body 1. The gasket 16 is provided on the seat main body 1 side separately from the gasket 16.
16a may be attached.

FIG. 3 shows an example in which the seat body 1 is attached to the step portion 18 formed on the body 17 of the ball valve, and the outer peripheral surface of the ball 20 having the through hole 20a is brought into contact with the seat body 1 by rotating the stem 21. It opens and closes. Reference numeral 19 denotes a gasket provided between the body 17 and the seat body 1, and a gasket 19a may be attached to the seat body 1 side separately from the gasket 19.

 Next, the operation of the above embodiment will be described.

When the seat body 1 is mounted at the sealing position of, for example, a butterfly valve or a ball valve, the seat body 1 includes a ring-shaped gasket plate 2 made of expanded graphite and a ring-shaped porous metal foil 3 via a thermosetting resin 4. Since they are formed by alternately laminating and adhering, the gasket plate 2 and the porous metal foil 3 are integrated so that there is no fear of leakage on the contact surface, and since they have sufficient strength, deformation etc. occur during use. There is no fear, and the sealing performance at the valve sealing position can be effectively exerted.

Further, since the non-perforated metal foil 5 is arranged in the vicinity of both surfaces of the sheet body 1, the permeation leakage phenomenon of the sheet body 1 can be surely prevented.

(Effects of the Invention) As is apparent from the above, according to the present invention, the ring-shaped gasket plate made of expanded graphite and the holes having a diameter of φ2 mm or less are uniformly dispersed in the range of the opening rate of 20% to 40%. The ring-shaped porous metal foil and the ring-shaped porous metal foil are alternately laminated and bonded via a thermosetting resin to form a ring-shaped sheet body, and the insertion density distribution of the porous metal foil is high near both sides of the sheet body, and the center part Since the seat height is lowered, the seat body is securely prevented from being deformed, and the laminated surface does not slip, so the sealing performance does not deteriorate and the valve seat surface of the disc, ball or body does not elastically move with the seat body. Since it makes uniform contact without loss, the operability does not deteriorate, the sealing property is significantly improved compared to the conventional one, wear is reduced, and deformation is prevented, and it is particularly excellent in terms of durability. And so on. Even if the metal foil comes into direct contact with the contact surface of the disc, the ball, or the body sheet, the metal foil is in the form of a foil and is not damaged.

[Brief description of drawings]

1 to 5 show the respective embodiments of the structure of the valve seat according to the present invention, and FIG. 1 is a partial sectional view showing an example in which the seat is attached to the body side of the butterfly valve. The figure is a partial cross-sectional view showing an example in which a seat is attached to the disc side of a butterfly valve, FIG. 3 is a partial cross-sectional view showing an example in which a seat is attached to a ball valve, and FIG. 4 is a partially enlarged cross-sectional view of the seat. 5 (a), (b), and (c) are partial cross-sectional views showing respective examples of seats, and FIG. 6 is a partial cross-sectional view showing an example of mounting a conventional seat on a butterfly valve. 1 ... Sheet body, 2 ... Gasket plate, 3 ... Porous metal foil, 4 ... Thermosetting resin, 5 ... Non-porous metal foil.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Teruyuki Tanigaki 4-28-4 Miwa, Mita City, Hyogo Prefecture (56) References Japanese Patent Publication No. 52-103030 (JP, A) Japanese Patent Publication No. 40-16927 (JP, B1) )

Claims (3)

[Claims] 1. A ring-shaped gasket plate made of expanded graphite and a ring-shaped porous metal foil are alternately laminated via a thermosetting resin and bonded to each other to form a ring-shaped sheet body. The structure of the valve seat is characterized in that the insertion density distribution of the foil is high near both sides in the stacking direction of the seat body, and the center part is low so that the seat body is formed by stacking. 2. The structure of the valve seat according to claim 1, wherein at least one non-perforated metal foil is arranged at positions near the surfaces on both sides of the seat body in the stacking direction. 3. The valve according to claim 1 or 2, wherein the porous metal foil has pores with a diameter of 2 mm or less uniformly dispersed in a porosity of 20% to 40%. Seat structure.