CN112066028A - A valve seat structure of a top-loading ball valve - Google Patents

Abstract

The invention discloses a valve seat structure of a top-loading ball valve, which relates to the technical field of ball valves and includes a valve body, a valve seat, a thrust ring and a retaining ring. A spring is arranged between the retaining ring and the valve body, and the valve seat is away from the thrust One side of the ring is in contact with the valve ball to form a sealing pair, a packing ring is embedded on the side of the thrust ring close to the valve seat, the outer diameter of the packing ring is larger than the outer diameter of the sealing pair, the inner diameter of the packing ring is smaller than that of the sealing pair, and the inner diameter of the sealing packing is larger Outer diameter of packing ring. Through the design of the valve seat structure of the present invention, the influence caused by the technical error, processing error, assembly process and other factors in the prior art is eliminated. When the valve seat is in contact with the valve ball, it can freely capture the tangent point to form a seal, and the valve seats on both sides of the valve ball are only subjected to the pressure generated in the horizontal direction of the spring. When maintenance is required, connect the eye bolts to the fixing holes, disassemble the valve seat and separate the valve body, and use the holding force of the valve seats on both sides to remove the valve ball together with the valve seat. The operation process is simple and fast, and the operation efficiency is effectively improved.

Description

A valve seat structure of a top-loading ball valve

technical field

The present invention relates to the technical field of ball valves, and more particularly, to a valve seat structure of a top-loading type ball valve.

Background technique

With reference to Figures 1, 2, and 3, there are mainly three structures of the top-loading ball valve in the prior art.

Figure 1 shows the structure of the wedge-shaped valve seat. In this structure, the valve seat is designed into a wedge-shaped structure that is wide at the top and narrow at the bottom. The spring is in a compressed state, and the valve ball is squeezed downward to generate a pre-tightening force. The valve seat is also subjected to a downward pre-tightening force. The bodies are in close contact to form a seal. When maintenance is required, the ball and seat can be pulled up together and removed.

The shortcomings of the above structure: 1) It is not suitable for high temperature and high pressure conditions. The valve seat needs to be elastically deformed to form a seal with the valve body, which limits the selection of valve seat materials and can only be used for soft sealing. However, when the medium temperature or pressure is too high, the valve seat is easily burned out or squeezed, resulting in permanent deformation of the valve seat and leakage. 2) The sealing effect between the valve seat and the valve body is poor. Since the two are in wedge-shaped contact, the valve seat will be subjected to an upward reaction force. During the opening and closing process of the valve ball, the valve seat will bounce slightly, and it will not be able to closely fit the valve body, resulting in leakage.

Figure 2 shows the structure of the threaded regulating valve seat. The valve body and the adjusting nut are matched with the thread, and the adjusting nut is rotated with an auxiliary tool, the valve seat is stretched to both sides, and the spring is compressed at the same time. Operation.

Disadvantages of the above structure: 1) The spring is easy to fail. The impact of the spring is large, which can easily lead to the reduction or failure of the spring force, which affects the sealing performance between the valve ball and the valve seat. In addition, after the ball is installed, it is necessary to turn the adjusting nut in the opposite direction to pull the valve seats on both sides to the center, and form a seal in contact with the ball. 2) The thread is easy to get stuck. The adjusting nut is a threaded transmission. As the pipe medium is immersed in the thread of the adjusting nut, a larger operating force is required to rotate the adjusting nut in the later stage. The entire valve must be removed from the pipeline for maintenance, and online maintenance cannot be achieved.

Figure 3 shows the structure of the hydraulic regulating valve seat. Unscrew the liquid injection plug and inject the liquid medium. Due to the sealing circuit formed by the O-ring, the liquid medium can only push the valve seat to move to both sides, and the spring is compressed. When the valve seat has a certain displacement, the valve ball can be taken out.

Disadvantages of the above structure: 1) Leakage points increase. 2) The working conditions are limited. O-rings are easily damaged by heat and affect the sealing effect.

SUMMARY OF THE INVENTION

In view of this problem in practical application, the purpose of the present invention is to propose a valve seat structure of a top-loading ball valve, and the specific scheme is as follows:

A valve seat structure of a top-loading ball valve includes a valve body, a sealing space is formed on opposite sides of the valve body, a fixed component is installed in the sealed space, and a valve ball is installed between the two fixed components, so the The fixing assembly includes a valve seat, a thrust ring, and a blocking ring, the blocking ring is in contact with the valve body, and a spring is arranged between the blocking ring and the valve body, and one end of the spring is connected to the blocking ring. The ring is in contact, the other end is in contact with the valve body, the thrust ring is installed on the side of the blocking ring away from the valve body, and the valve seat is mounted on the thrust ring away from the blocking ring one side of the valve seat and the valve seat extends outside the sealing space, the side of the valve seat facing away from the thrust ring is in contact with the valve ball to form a sealing pair, and the thrust ring is close to the A packing ring is embedded on one side of the valve seat, a cavity is formed between the blocking ring and the thrust ring, a sealing packing is arranged in the cavity, and the outer diameter of the packing ring is larger than the outer diameter of the sealing pair , the inner diameter of the packing ring is smaller than the inner diameter of the sealing pair, and the inner diameter of the sealing packing is larger than the outer diameter of the packing ring.

Further preferably, a dust ring is provided between the blocking ring and the valve body, and the dust ring is located on the side of the spring away from the sealing packing.

Further preferably, both the valve seat and the abutting side corners of the thrust ring are formed with chamfers.

Further preferably, a side of the valve seat facing away from the valve ball is provided with a fixing hole for hoisting.

Further preferably, the valve body is convex along a direction close to the valve seat to form a step, and the step and the valve seat are spaced to form a first gap.

Further preferably, the width of the first gap is 1mm-3mm.

Further preferably, the thrust ring and the retaining ring are spaced apart to form a second gap.

Compared with the prior art, the beneficial effects of the present invention are as follows:

Through the design of the valve seat structure of the present invention, the valve seat does not need to cooperate with the valve body, that is, the valve seat can perform both axial and radial motion, which eliminates the problems caused by technical errors, processing errors, assembly processes and other factors in the prior art. Impact. When the valve seat is in contact with the valve ball, it can freely capture the tangent point to form a seal, and the valve seats on both sides of the valve ball are only subject to the pressure generated in the horizontal direction of the spring. When maintenance is required, connect the eye bolts to the fixing holes, disassemble the valve seat and separate the valve body, and use the holding force of the valve seats on both sides to remove the valve ball together with the valve seat. The operation process is simple and fast, and the operation efficiency is effectively improved.

Description of drawings

1 is a schematic diagram showing the structure of a wedge-shaped valve seat in the background art;

2 is a schematic diagram showing the structure of a threaded regulating valve seat in the background;

FIG. 3 is a schematic diagram showing the structure of the hydraulic regulating valve seat in the background art;

FIG. 4 is a schematic structural diagram of the whole of this embodiment;

Fig. 5 is the enlarged schematic diagram of part A in Fig. 4;

FIG. 6 is a schematic diagram showing the force of the sealing pair.

Reference numerals: 1, valve body; 2, sealing space; 3, valve ball; 4, valve seat; 5, thrust ring; 6, retaining ring; 7, spring; 8, sealing pair; 9, packing ring; 10 11, dust ring; 12, lead angle; 13, fixed hole; 14, step; 15, first gap; 16, second gap.

Detailed ways

The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

As shown in Figure 1, Figure 2 and Figure 3, the existing wedge-shaped valve seat 4 structure can only perform radial movement, and the threaded regulating valve seat 4 structure and the hydraulic regulating valve seat 4 structure can only perform axial movement. The structure of the valve seat 4 is an installation structure that is sleeved in the valve body 1, which requires high coaxiality between the valve ball 3 and the valve seat 4, especially for hard seals, the coaxiality between the valve ball 3 and the valve seat 4 is high. More than 0.05mm may affect the sealing effect and cause leakage.

4 and 5, the present embodiment proposes a valve seat structure of a top-loading ball valve, which includes a valve body 1, and sealing spaces 2 are formed on opposite sides of the valve body 1, and a fixing component is installed in the sealing space 2. A valve ball 3 is installed between the two fixed assemblies. The fixed assembly includes a valve seat 4 , a thrust ring 5 , and a blocking ring 6 . Specifically, the blocking ring 6 is installed at the bottom of the sealed space 2 in abutment with the valve body 1 , a spring 7 is provided between the blocking ring 6 and the valve body 1 , one end of the spring 7 is in contact with the blocking ring 6 , and the other end is in contact with the valve body 1 . catch. Preferably, the spring 7 in this embodiment is made of a leaf spring.

Further, the thrust ring 5 is installed on the side of the blocking ring 6 away from the valve body 1 , and a second gap 16 is formed between the thrust ring 5 and the blocking ring 6 to be spaced apart, and the second gap 16 can be used as the spring 7 The buffer space when the elastic potential energy is released to reduce the mechanical friction between the thrust ring 5 and the stop ring. The valve seat 4 is installed on the side of the thrust ring 5 away from the blocking ring 6 and the valve seat 4 extends outside the sealing space 2 , and a packing ring 9 is embedded on the side of the thrust ring 5 close to the valve seat 4 . In order to improve the supporting force of the valve body 1 to the valve seat 4 or the whole fixed assembly, the valve body 1 close to the lower valve seat 4 in the height direction is convex in the direction close to the valve seat 4 to form a step 14, and the step 14 is connected to the valve seat. A first gap 15 of 2 mm is formed therebetween.

A cavity is formed between the blocking ring 6 and the thrust ring 5, and a sealing packing 10 is arranged in the cavity. A dust ring 11 is provided between the blocking ring 6 and the valve body 1 , and the dust ring 11 is located on the side of the spring 7 away from the sealing packing 10 . The dust ring 11 is used to prevent impurities in the pipeline from entering the space where the spring 7 is installed, thereby avoiding affecting the elastic performance of the spring 7 or causing the spring 7 to be stuck, and prolonging the service life of the spring 7 .

At the same time, a fixing hole 13 for hoisting is provided on the side of the valve seat 4 facing away from the valve ball 3 . When maintenance is required, connect the eye bolts to the fixing holes 13, disassemble the valve seat 4 and separate the valve body 1, and use the holding force of the valve seats 4 on both sides to remove the valve ball 3 together with the valve seat 4. The operation process is simple and fast. Effectively improve work efficiency. The chamfer 12 is used to facilitate the assembly and disassembly between the valve seat 4 and the thrust ring 5 to avoid scratching the abutment surface of the two or the packing ring 9 . Preferably, the packing ring 9 is made of a composite material of flexible graphite and metal mesh. The composite material has high strength and toughness, so as to avoid physical brittleness caused by the disassembly and assembly of the valve seat 4 and the debris falling into the pipeline, and the composite material Can be used multiple times, thus reducing costs.

In order to explain the sealing performance of the valve seat 4 structure in this embodiment in more detail, the following data are used for explanation.

As shown in FIG. 6 , the side of the valve seat 4 facing away from the thrust ring 5 is in contact with the valve ball 3 to form the sealing pair 8 , the outer diameter of the packing ring 9 is larger than the outer diameter of the sealing pair 8 , and the inner diameter of the packing ring 9 is smaller than that of the sealing pair 8 The inner diameter of the sealing packing 10 is larger than the outer diameter of the packing ring 9 .

Seal pair 8, force description of seal pair 8: P is the medium pressure; F _H is the total force of the medium pressure and the pre-tightening force of the spring 7; F _L is the effective force; a is the angle between the seal pair 8 and the horizontal line; D1 is the outer diameter of the sealing pair 8; D2 is the inner diameter of the sealing pair 8; D3 is the outer diameter of the sealing packing 10; D4 is the inner diameter of the sealing packing 10; D5 is the outer diameter of the packing ring 9; D6 is the inner diameter of the packing ring 9; d is the diameter.

P=10Mpa; a=47°; D1=88mm; D2=82mm; D3=100mm; D4=91mm;

D5=89mm; D6=81mm; d=76mm.

The valve ball 3 is under the combined action of the medium pressure and the pre-tightening force of the spring 7, and a certain pressure is generated in the sealing pair 8 to form a seal. It is less than the allowable specific pressure Q2 of the sealing pair 8, that is, Q1<Q<Q2.

(1) Specific pressure check of sealing pair 8

Table 1 Spring 7 stiffness calculation table

①Calculation of spring 7 preload force F _T ;

Spring 7 Material: 17-7PH, Compression H0: 8mm;

According to Table 1, the stiffness C of spring 7 is calculated: 4252.3N/mm;

F _T =C*H0=34018N;

②Calculation of medium pressure F _P ;

③ Calculate the area S of the sealing pair 8;

④ Calculate the specific pressure Q of the sealing pair 8;

Q= _FL /S=FH*sina/S=( _FT +FP)sina/S ₌ 54.54Mp;

⑤ The sealing pair 8 must have a specific pressure Q1, and the sealing pair 8 has a width bm;

⑥The allowable specific pressure Q2 of the sealing pair 8;

Looking up the table, it can be concluded that Q2=80Mp;

Conclusion: Q1<Q<Q2, that is, the sealing pair 8 of the valve seat 4 is safe and reliable.

(2) Check the packing ring 9 compression ratio ρ1

The initial thickness of the packing ring 9 is T1=3.5mm, the thickness after compression is T2=3.0mm, and the inner and outer diameters of the packing ring 9 remain unchanged.

ρ1=(T1-T2)/T1=14.3%;

Looking up the table, it can be concluded that the compression ratio ranges from 7% to 20%, that is, it meets the requirements.

(3) Check the compression ratio ρ2 of the packing 10

The section of the sealing packing 10 is compressed from a rectangle into a trapezoid with no change in thickness (inner and outer diameters remain unchanged), the initial section width B=7.4mm, the maximum section width B1 = 7.4mm after compression, and the minimum section width B2 = 5.0mm;

Looking up the table, it can be concluded that the compression ratio ranges from 10% to 25%, that is, it meets the requirements.

The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims (7)

1. The valve seat structure of the upper-mounted ball valve comprises a valve body (1), sealing spaces (2) are formed in the valve body (1) on opposite sides, fixed assemblies are mounted in the sealing spaces (2), a valve ball (3) is mounted between the two fixed assemblies, and the upper-mounted ball valve is characterized in that each fixed assembly comprises a valve seat (4), a thrust ring (5) and a baffle ring (6), the baffle ring (6) is abutted to the valve body (1), a spring (7) is arranged between the baffle ring (6) and the valve body (1), one end of the spring (7) is abutted to the baffle ring (6), the other end of the spring is abutted to the valve body (1), the thrust ring (5) is mounted on one side, deviating from the valve body (1), of the thrust ring (5), and the valve seat (4) extends to be arranged outside the sealing spaces (2), one side of the valve seat (4) departing from the thrust ring (5) is abutted with the valve ball (3) to form a sealing pair (8), the thrust ring (5) is close to one side of the valve seat (4) and is embedded with a packing ring (9), a cavity is formed between the retaining ring (6) and the thrust ring (5), a sealing packing (10) is arranged in the cavity, the outer diameter of the packing ring (9) is larger than the outer diameter of the sealing pair (8), the inner diameter of the packing ring (9) is smaller than the inner diameter of the sealing pair (8), and the inner diameter of the sealing packing (10) is larger than the outer diameter of the packing ring (9).

2. Valve seat structure of a top-loading ball valve according to claim 1, characterized in that a dust ring (11) is arranged between the baffle ring (6) and the valve body (1), and the dust ring (11) is located on the side of the spring (7) facing away from the sealing packing (10).

3. The seat structure of a top-loading ball valve according to claim 1, wherein the seat (4) and the thrust ring (5) are formed with chamfered corners (12) at abutting side corners.

4. The valve seat structure of the upper-mounted ball valve according to claim 1, wherein a fixing hole (13) for hoisting is formed in one side of the valve seat (4) away from the valve ball (3).

5. A seat structure of a top-loading ball valve in accordance with claim 1, wherein the valve body (1) is convex in a direction close to the seat (4) to form a step (14), and the step (14) is spaced apart from the seat (4) to form a first gap (15).

6. A seat structure of a top-loading ball valve in accordance with claim 5, wherein the width of the first gap (15) is 1mm-3 mm.

7. A seat structure of a top-loading ball valve according to claim 1, wherein the thrust ring (5) is spaced apart from the retainer ring (6) to form a second gap (16).

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