JPH07119847A - Valve seat ring structure - Google Patents

Abstract

PURPOSE:To prevent a seat retainer from being deformed due to high pressure, prevent sealing performance from being degraded, and also prevent the seat ring from jumping out. CONSTITUTION:A circular set ring 4 having a cut-off and lacked section at one place over the circumference which is compressed so as to be contracted in diameter, and is completely buried in a recessed shaped outer circumferential groove 1b formed in the outer circumferential surface 1a of a seat retainer, is simultaneously engaged with both an inner circumferential groove 2b formed in the inner circumferential surface 2a of an outer ring 2 and the outer circumferential groove 1b of the seat retainer 1 under an incompressive condition, and the seat retainer 1 has the outer ring 2 fixed so as to comprise a ball seat 3 held therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve seat ring structure, and more specifically, it holds a seat between a seat retainer and an outer ring, and abuts the seat on the surface of a closing member such as a ball or a disc. A ball valve configured to seal between the closing member and the seat retainer,
The present invention relates to a seat ring structure of a valve such as a gate valve.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of a seat ring structure in a ball valve. In FIG. 3, a ball seat is held between a seat retainer and an outer ring,
FIG. 7 is a partial cross-sectional view of a ball valve in which the ball seat is brought into contact with the surface of the ball to seal between the ball and the seat retainer. In the figure, the ball seat 1 mounted on the step 11a at the tip of the seat retainer 11
2 is held between the outer ring 13 and the step portion 13a, and the set ring 14 locked to the step portion 11b of the seat retainer 11 is fastened to the outer ring 13 with a bolt 15 so that the seat retainer 11, the ball seat 12 and The outer ring 13 is integrally assembled.

16 is a body or a body cap (hereinafter,
(Simply called a body), 17 is a ball, 18 is a spring, 19
And 20 are O-rings, and the ball seat 12 has the surface 1 of the ball 17 under the action of the force of the spring 18 and the fluid pressure.
The ball 17 and the seat retainer 11 are sealed by abutting against the 7a. In this structure, when the valve is closed and a high pressure is applied to the upstream side on the right side in the figure, the portion on the left side of the position of the O-ring 19 in the seat retainer 11 has an upstream side to the inner diameter side. Since a high pressure is applied and a low pressure of the body cavity 16a is applied to the outer diameter side, the differential pressure acts to spread the seat retainer 11 outward.

Further, in FIG. 4, similarly to the above example, the ball seat is held between the seat retainer and the outer ring, and the ball seat is brought into contact with the surface of the ball so that the space between the ball and the seat retainer is increased. FIG. 7 is a partial cross-sectional view showing another conventional example of the ball valve configured to seal the. In the figure, the ball seat 22 attached to the step portion 21 a at the tip of the seat retainer 21 is the step portion 2 of the outer ring 23.
An annular set ring 24, which is held between the seat retainer 2 and
In the outer peripheral step portion 21b of No. 1, the both ends of the cut missing portion are brought close to each other or the both ends are misaligned to be compressed and reduced in diameter so that the outer ring 23 is inserted into the inner diameter portion 23b. The inner peripheral groove 23c formed in the inner diameter portion 23b of the seat retainer 21 and the instantaneous force thereof releases the compressed and contracted state, so that the set ring 24 is fitted into the inner peripheral groove 23c and the tip of the outer peripheral groove 21b of the seat retainer 21. It is attached by being locked to the side surface 21c on the side.

25 is a body or a body cap (hereinafter,
(Simply called a body), 26 is a ball, 27 is a spring, 28
And 29 are O-rings, and the ball seat 22 has the surface 26 of the ball 26 under the action of the force of the spring 27 and the fluid pressure.
It abuts a and seals between the ball 26 and the seat retainer 21. In this structure, the valve is closed,
In the figure, when a high pressure is applied to the upstream side on the right side, a high pressure on the upstream side is applied to the inner diameter side in the portion of the seat retainer 21 on the left side of the position of the O-ring 28, while, On the outer diameter side, the body cavity 25a
Since a low pressure is applied to the seat retainer 2
1 acts to spread outward.

[Problems to be Solved by the Invention]

However, in the conventional example shown in FIG.
It has the following problems. The seat retainer 11 or the outer ring 13 is provided on the inner diameter surface 16b or 16 of the body 16.
Although there is no problem in the portion supported by contacting c, the portion of the seat retainer 11 indicated by H2 in FIG. 3 which is not supported at all receives a large differential pressure. Moreover, in this structure, since the thickness of the set ring 14 and the head of the bolt 15 must be accommodated, H2 is large, and the groove 11c is formed to form the stepped portion 11b for locking the set ring 14. You have to
In addition, the strength of this portion is insufficient, the seat retainer 11 is deformed and the sealing performance is impaired, and the problem of popping out due to poor holding of the ball seat 12 easily occurs. Further, there is a problem that the entire valve becomes large in order to make the ball seat thick, the operating torque becomes large, and the seat retainer becomes thick, so that the entire valve becomes large.

Further, the other conventional example shown in FIG. 4 has the following problems. There is no problem in the portion where the seat retainer 21 or the outer ring 23 is supported in contact with the inner peripheral surfaces 25b and 25c of the body 25, but it is not supported at all. The seat retainer 2 indicated by H3 in the drawing.
The outer peripheral step portion 21b of No. 1 is formed with a step portion that is wide in the length direction, so that this portion receives a large differential pressure. In this structure, H3 is shorter than H2 in the example shown in FIG.
4 is compressed and reduced and inserted into the inner diameter portion 23b of the outer ring 23, the outer peripheral step portion 21b which is deep and long in the longitudinal direction must be formed in the seat retainer 21, and therefore, the H3 of the seat retainer 21 is increased. The thickness of the part becomes thin. For this reason, the strength of this portion is insufficient, the seat retainer 21 is deformed and the sealing performance is impaired, and the ball seat 22 is poorly held and pops out easily. In addition, there is a problem that the entire valve becomes large in order to make the ball seat thick, the operating torque becomes large, and the seat retainer needs to be made thick, so that the entire valve becomes large.

The present invention was developed in order to solve the above-mentioned conventional problems, and facilitates assembly and disassembly of the valve seat ring structure, and further, each component is manufactured to a required size in a small size. The purpose is to make the seat ring structure compact and durable.

[0009]

In order to achieve the above-mentioned object, the present invention provides a closing member by bringing a ring-shaped seat held between a ring-shaped seat retainer and an outer ring into contact with the surface of the closing member. In a valve configured to seal between a seat retainer and a seat retainer, a concave outer peripheral groove is formed on the outer peripheral surface of the seat retainer described above, and at least one cut lacking portion on the circumference is formed in the outer peripheral groove. A ring-shaped set ring having a ring is embedded in a compressed and reduced state, and the set ring in a non-compressed state is formed both on the inner peripheral groove formed on the inner peripheral surface of the outer ring and the outer peripheral groove of the seat retainer described above. The outer ring is fixed to the seat retainer to hold the seat. Further, it is preferable to form a plurality of through holes radially from the outer peripheral surface of the outer ring to the inner peripheral groove in the radial direction. Furthermore, it is preferable to provide two cut-out portions on the circumference of the above-mentioned set ring.

[0010]

According to the present invention, the seat is mounted on the stepped portion of the tip of the seat retainer, the set ring is assembled in the concave outer peripheral groove formed on the outer peripheral surface, and the set ring is made to approach the cut missing portion of the set ring. After compressing and reducing the diameter, press the outer ring on the seat so that the inner peripheral surface covers the seat, and face the set ring to the inner peripheral groove formed on the inner peripheral surface of the outer ring. The diameter is expanded by elastic force and is inserted into the inner peripheral groove so that the set ring engages with both the inner peripheral groove of the outer ring and the outer peripheral groove of the seat retainer at the same time.

In the seat held between the seat retainer and the outer ring in this manner, the front end of the seat abuts the surface of the closing member to seal between the closing member and the seat retainer. In this case, in order to press the seat against the closing member, the seat retainer and the outer ring are pushed toward the closing member by the force of the spring, and the fluid pressure acts as a pressing force.

In this structure, the seat retainer can have a structure in which most of the outer peripheral surface is supported directly or through the outer ring on the inner peripheral surface of the body or the body cap, and the assembly allowance and the seat compression allowance are provided. The seat retainer is strong enough even if it is thin because it can not be supported only for a short distance.Therefore, the seat retainer does not deform and the sealability is impeded, and the seat retainer does not pop out. Since it is not necessary to make the valve thick, the valve can be made compact, which also leads to a reduction in operating torque.

Next, when the outer ring and the seat retainer are disassembled, a plurality of radial through holes extending from the outer peripheral surface of the outer ring to the inner peripheral groove are used to set the spring pins. By compressing and reducing the diameter of the ring, let it out from the inner circumferential groove of the outer ring,
Pull out the outer ring from the seat retainer.

[0014]

1 is a partial cross-sectional view of a ball valve which is an embodiment of the seat ring structure for a valve according to the present invention. In the figure, 1 is an annular seat retainer, and this seat retainer 1 is located between a body (or body cap) 5 and a ball 6, 2 is an outer ring, 3 is a ball seat, and 4 is a ball seat. Ring-shaped set ring,
7 is a spring, and 8 and 9 are O-rings. The ball seat 3 is held between the seat retainer 1 and the outer ring 2, and contacts the surface 6a of the ball 6 which is a closing member of this valve to seal the space between the ball 6 and the seat retainer 1. Has become.

An outer peripheral surface 1a of the seat retainer 1 is formed with a concave outer peripheral groove 1b, and as shown in FIG. 2, an annular set having a cut-out portion 4a at one (or two) locations on the circumference. When the ring 4 is fitted in the outer peripheral groove 1b and the set ring 4 is compressed and reduced so that both ends of the cutout portion 4a come close to each other, the set ring 4 can be completely embedded in the outer peripheral groove 1b. The set ring 4 is simultaneously engaged with both the inner peripheral groove 2b formed on the inner peripheral surface 2a of the outer ring 2 and the outer peripheral groove 1b of the seat retainer 1 in a non-compressed state, so that the outer ring 2 is It is fixed to the seat retainer 1 and holds the ball seat 2.

Further, a plurality of through holes 2d, which are shown by broken lines in FIG. 1 and extend from the outer peripheral surface 2c of the outer ring 2 to the inner peripheral groove 2b, are radially formed in the radial direction.

Next, regarding this embodiment shown in FIG.
The operation will be described. Step 1 at the tip of the seat retainer 1
The ball seat 3 is attached to c, the set ring 4 is assembled in the outer peripheral groove 1b formed in the outer peripheral surface 1a, and the set ring 4 is compressed and reduced in diameter so that both ends of the cut missing portion 4a of the set ring 4 come close to each other. The outer ring 2 is attached to the ball seat 3, and the inner peripheral surface 2a of the outer ring 2 is the ball seat 2
The inner ring 2b formed on the inner peripheral surface 2a of the outer ring 2 so that the set ring 4 faces the inner ring groove 2b to be expanded in diameter to enter the inner ring groove 2b. 4 is engaged with both the inner peripheral groove 2b of the outer ring 2 and the outer peripheral groove 1b of the seat retainer 1 at the same time. In this case, the outer peripheral surfaces 1a on both sides of the outer peripheral groove 1b of the seat retainer 1 are assembled in contact with the inner peripheral surface 2a of the outer ring 2.

In the ball seat 3 thus held between the seat retainer 1 and the outer ring 2, the tip 3a of the ball seat 3 contacts the surface 6a of the ball 6 so that the space between the ball 6 and the seat retainer 1 is made. Seal it. In this case,
In order to press the ball seat 3 against the ball 6, the outer ring 2 is pressed in the direction of the ball 6 by the force of the spring 7, and the fluid pressure acts as a pressing force.

In this structure, most of the outer peripheral surface of the seat retainer 1 is supported by the inner peripheral surfaces 5b and 5a of the body 5 directly and through the outer ring 2. H1 in the figure is a gap for assembling allowance and a compression allowance for the ball seat 3, and since the length of H1 by this short distance is short, the seat retainer 1 has sufficient strength even if it is thin, Since the retainer 1 is not deformed to impair the sealing performance and the ball seat 1 does not pop out, and it is not necessary to make the seat retainer 1 thick, the valve can be manufactured in a small size. This also leads to a reduction in operating torque.

Next, when the outer ring 2 and the seat retainer 1 are disassembled, a plurality of radial through holes 2 communicating from the outer peripheral surface 2c of the outer ring 2 to the inner peripheral groove 2b are formed.
By using d, the set ring 4 is compressed and reduced by hitting a spring pin, and the inner peripheral groove 2 of the outer ring 2
The outer ring 2 is pulled out from the seat retainer 1 by taking it out from b.

[0021]

As described above, according to the present invention, the seat retainer is not deformed and the sealability is not impaired, the seat is not held in the seat ring badly, and the seat retainer does not pop out. Therefore, the entire valve can be manufactured compactly, and the operating torque can be reduced. Therefore, the valve of the present invention can provide a valve having high performance, high reliability, high durability, and excellent economical efficiency.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a ball valve that is an embodiment of a valve seat ring structure according to the present invention.

FIG. 2 is a front view showing a set ring in FIG.

FIG. 3 is a partial cross-sectional view showing a conventional example.

FIG. 4 is a partial cross-sectional view showing another conventional example.

[Explanation of symbols]

 1 seat retainer 1a outer peripheral surface 1b outer peripheral groove 2 outer ring 2a inner peripheral surface 2b inner peripheral groove 2c outer peripheral surface 2d through hole 3 ball seat 4 set ring 4a cut missing portion 6 ball (closing member)

Claims (3)

[Claims] 1. A valve constructed such that a ring-shaped seat held between a ring-shaped seat retainer and an outer ring is brought into contact with the surface of a closing member to seal between the closing member and the seat retainer. A concave outer peripheral groove is formed on the outer peripheral surface of the above-mentioned seat retainer, and a ring-shaped set ring having at least one cutout notch on the circumference is embedded in the outer peripheral groove in a compressed and reduced state. While being inserted, the set ring in the uncompressed state is engaged with both the inner peripheral groove formed on the inner peripheral surface of the outer ring and the outer peripheral groove of the seat retainer, and the outer ring is fixed to the seat retainer. The valve seat ring structure is characterized in that the seat is thereby retained. 2. The seat ring structure for a valve according to claim 1, wherein a plurality of through holes communicating from the outer peripheral surface of the outer ring to the inner peripheral groove are radially formed in the radial direction. 3. A cut-out missing portion is provided at two locations on the circumference of the set ring described above.
Seat ring structure for the valve described.