Low-temperature butterfly valve sealing pair compensation structure

Abstract

The utility model provides a low-temperature butterfly valve sealing pair compensation structure, and relates to the technical field of butterfly valves. The valve seat adopts a special-shaped axial moving structure to lock the sealing gasket; the arranged valve seat moves along the direction of a flow channel in the valve body, so that the valve seat and the valve body are contacted and form a pre-tightening force, a gap between the valve seat and the valve body due to the action of a reverse medium is eliminated, and excellent reverse sealing performance is provided; according to the structure, the local shape of the valve seat is changed, the valve seat is pushed by media, effective rigid constraint is provided during mutual extrusion, and the structural reliability is ensured; the structure is convenient to machine and daily maintain, and the forward sealing requirement of the butterfly valve is not affected while the reverse sealing performance is guaranteed; the overall opening and closing torque of the butterfly valve can be reduced, and great economic benefits are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of butterfly valves, in particular to a sealing pair compensation structure of a low-temperature butterfly valve. Background Art

[0002] Cryogenic butterfly valves, with their light weight, compact structure, rapid opening and closing, and easy maintenance, are critical equipment for ensuring the safe and reliable operation of natural gas receiving station pipeline systems. The sealing ring and valve seat eccentricity of triple-eccentric butterfly valves are often designed with a positive taper angle. When subjected to positive media, the sealing ring and valve seat are tightened, effectively achieving a positive seal with zero leakage. Natural gas receiving station pipeline systems often experience media backflow, placing extremely high demands on cryogenic butterfly valves to achieve zero reverse leakage. However, the tapered design of existing sealing pairs results in poor reverse sealing performance, making them prone to leakage. Utility Model Content

[0003] The purpose of the utility model is to provide a low-temperature butterfly valve sealing pair compensation structure, which is capable of solving the problems raised by the above-mentioned background technology in view of the shortcomings of the existing technology.

[0004] The technical solution of the present utility model is achieved as follows:

[0005] The utility model provides a low-temperature butterfly valve sealing pair compensation structure, including a valve body and a valve stem installed in the valve body, including a disc plate installed on the valve stem, a sealing pressure plate installed on the disc plate, a sealing gasket installed between the sealing pressure plate and the disc plate, and a sealing structure installed between the outer wall of the sealing gasket and the valve body.

[0006] In some technical solutions of the present invention, the sealing structure includes a valve seat installed in the valve body, and the side wall of the valve seat in contact with the valve body is stepped; an installation groove adapted to the valve seat is provided on the inner wall of the valve body, a blind hole is provided on the bottom of the installation groove, a spring abutting the valve seat is provided in the blind hole, and a valve cover abutting the valve seat is provided in the valve body.

[0007] In some technical solutions of the present utility model, a first sealing ring is provided between the horizontal section of the valve seat and the valve body.

[0008] In some technical solutions of the present invention, the spring and the vertical section of the valve seat abut against each other.

[0009] In some technical solutions of the present invention, a first inclined surface is provided on the side wall where the valve seat and the sealing gasket abut each other, and the angle between the reverse extension line of the first inclined surface and the axis of the circle where the valve seat is located is an acute angle; a second inclined surface is provided on the side wall where the sealing gasket and the valve seat abut each other; the angle between the reverse extension line of the second inclined surface and the axis of the circle where the valve seat is located is an acute angle.

[0010] In some technical solutions of the present invention, a third inclined surface is provided on the side of the valve seat opposite to the valve cover, and an obtuse angle is formed when the third inclined surface intersects the axis of the circle where the valve seat is located.

[0011] Some technical solutions of the present invention further include a bolt, which passes through the sealing pressure plate and is placed in the disc plate. A nut is provided on the bolt, and a thrust pad is provided between the nut and the sealing pressure plate.

[0012] In some technical solutions of the present invention, a second sealing ring is provided between the sealing gasket and the disc plate.

[0013] In some technical solutions of the present utility model, a positioning hole is provided on the valve stem, and a positioning pin connected to the disc plate is passed through the positioning hole.

[0014] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0015] To solve the above problems, the patent of this invention proposes a reliable sealing pair compensation structure, which can effectively make up for the gap between the sealing ring and the valve seat when reverse pressure is applied, thereby achieving the reverse zero leakage function; at the same time, it can effectively reduce the opening and closing torque under reverse working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic cross-sectional view of the utility model;

[0018] Figure 2 It is a partial enlarged structural schematic diagram of the utility model.

[0019] Icons: 1. Valve body; 2. Set screw; 3. Valve cover; 4. Valve seat; 5. Valve stem; 6. First sealing ring; 7. Spring; 8. Disc plate; 9. Sealing gasket; 10. Second sealing ring; 11. Locating pin; 12. Thrust washer; 13. Round nut; 14. Bolt; 15. Sealing pressure plate. DETAILED DESCRIPTION

[0020] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0022] Example 1

[0023] Please refer to Figure 1-Figure 2 shown.

[0024] The utility model provides a low-temperature butterfly valve sealing pair compensation structure, such as Figure 1 、 Figure 2 As shown, it includes a valve body 1 and a valve stem 5 installed in the valve body 1, including a disc plate installed on the valve stem 5, a sealing pressure plate 15 is installed on the disc plate 8, a sealing gasket 9 is installed between the sealing pressure plate 15 and the disc plate 8, and a sealing structure is installed between the outer wall of the sealing gasket 9 and the valve body 1.

[0025] In some technical solutions of the present invention, the sealing structure includes a valve seat 4 installed in the valve body 1, and the side wall of the valve seat 4 in contact with the valve body 1 is stepped; an installation groove adapted to the valve seat 4 is opened on the inner wall of the valve body 1, and a blind hole is opened on the bottom of the installation groove, and a spring 7 abutting the valve seat 4 is provided in the blind hole, and a valve cover 3 abutting the valve seat 4 is provided in the valve body 1.

[0026] In some technical solutions of the present utility model, a first sealing ring 6 is provided between the horizontal section of the valve seat 4 and the valve body 1 .

[0027] In some technical solutions of the present invention, the spring 7 and the vertical section of the valve seat 4 abut against each other.

[0028] In some technical solutions of the present invention, a first inclined surface is provided on the side wall where the valve seat 4 and the sealing gasket 9 abut against each other, and the angle between the reverse extension line of the first inclined surface and the axis of the circle where the valve seat 4 is located is an acute angle; a second inclined surface is provided on the side wall where the sealing gasket 9 and the valve seat 4 abut against each other; the angle between the reverse extension line of the second inclined surface and the axis of the circle where the valve seat 4 is located is an acute angle.

[0029] In some technical solutions of the present invention, a third inclined surface is provided on the side of the valve seat 4 opposite to the valve cover 3 , and the angle between the third inclined surface and the axis of the circle where the valve seat 4 is located is an obtuse angle.

[0030] The aforementioned seal pair compensation structure facilitates reverse sealing of low-temperature butterfly valves. The eccentric angles of the butterfly valve's seal ring and valve seat 4 are designed with a positive taper angle; when positive media is applied, the seal ring and valve seat 4 are increasingly compressed, effectively achieving zero leakage in the positive seal.

[0031] The valve seat 4 adopts a special-shaped structure, taking the form of a stepped ladder with multiple steps, at least three in number. The sealing ring is positioned on the horizontal section within the steps, creating a multi-layer seal. When reverse flow acts on surface A (the third inclined surface) of the valve seat 4, the valve seat 4 exerts a rightward thrust due to the area difference. This creates a wedge-shaped fit between the valve seat 4 and the sealing gasket 9, utilizing the combination of the first and second inclined surfaces. This creates a sealing force between the valve seat 4 and the sealing gasket 9, ensuring a seal during reverse flow. Therefore, this reverse seal compensation structure safeguards the reverse seal of the low-temperature butterfly valve and reduces the overall valve opening and closing torque during reverse operation.

[0032] Some technical solutions of the present invention further include a bolt 14 , which passes through the sealing pressure plate 15 and is placed in the disc plate 8 . A nut is provided on the bolt 14 , and a thrust washer 12 is provided between the nut and the sealing pressure plate 15 .

[0033] In some technical solutions of the present invention, a second sealing ring is provided between the sealing gasket 9 and the disc plate 8. The second sealing ring is a spiral wound gasket.

[0034] In some technical solutions of the present utility model, a positioning hole is provided on the valve stem 5 , and a positioning pin 11 connected to the disc plate 8 is passed through the positioning hole.

[0035] The specific installation steps are as follows:

[0036] The disc plate 8 passes through the valve stem 5, and a locating pin 11 is used to ensure its relative position with the valve body 1; a sealing groove is provided on the disc plate 8, and the spiral wound gasket (second sealing ring 10) is placed therein, and then the sealing gasket 9 is placed therein to ensure that the disc plate 8 is leak-free; the sealing pressure plate 15 and the disc plate 8 are installed through the locating stop, and the two are connected together with bolts 14, and the nuts and thrust washers 12 can lock the position of the sealing pressure plate 15 and the disc plate 8; a sealing groove is provided on the valve seat 4, and the first sealing ring 6 is placed on the horizontal section of the step to ensure that two seals are formed between the valve body 1 and the valve seat 4; the valve body 1 is provided with a spring 7 hole, and the spring 7 is placed in the spring 7 hole. The spring 7 provides a horizontal pre-tightening force for the valve seat 4, and the valve seat assembly is placed in the valve body 1; the valve body 1 is provided with a threaded hole, the valve cover 3 is screwed in, and locked with a set screw 2.

[0037] Preferably, the valve seat assembly is a valve seat 4 and a plurality of first sealing rings 6 mounted on the valve seat 4 .

[0038] Working principle:

[0039] When the valve seat 4 is subjected to the reverse medium, such as Figure 2 As shown, the valve seat 4 is in the valve body 1 (attached Figure 2 The medium pushes rightward within the L region (in the valve seat 4), pushing the valve seat 4 against the reaction force of spring 7 and moving it to the right, pressing against sealing gasket 9. The first and second inclined surfaces cooperate to reduce the gap between them, achieving a reverse seal. The medium's thrust compresses the valve seat 4 and the sealing ring, eliminating the need for operating torque when opening the valve, effectively reducing the opening and closing torque during reverse operation.

[0040] Furthermore, to ensure that the valve seat 4 and the sealing ring are always in an extruded state under the action of the reverse medium, firstly, the medium force is used to act on the third inclined plane to increase the force area of ​​the medium acting on the valve seat 4, causing the valve seat 4 to produce a small axial displacement to the right; secondly, the valve seat 4 and the sealing ring are extruded by the thrust of the medium, and no longer rely on the operating torque, which effectively reduces the opening and closing torque of the valve when working in the reverse direction. The valve seat 4 uses a special-shaped axial movable structure to lock the sealing gasket 9; the valve seat 4 is set to move along the flow direction in the valve body 1, so that the two come into contact and form a pre-tightening force, eliminating the gap between the two caused by the action of the reverse medium, and providing excellent reverse sealing performance; this structure changes the local shape of the valve seat 4, uses the medium to push the valve seat 4, and provides effective rigid constraints when squeezing each other, ensuring structural reliability; the structure is easy to process and maintain, and while ensuring the reverse sealing performance, it does not affect the forward sealing requirements of the butterfly valve; it can reduce the overall opening and closing torque of the butterfly valve, with great economic benefits.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A low-temperature butterfly valve sealing pair compensation structure, comprising a valve body and a valve stem installed in the valve body, characterized in that: It comprises a disc plate installed on the valve stem, a sealing pressure plate is installed on the disc plate, a sealing gasket is installed between the sealing pressure plate and the disc plate, and a sealing structure is installed between the outer wall of the sealing gasket and the valve body.

2. A low-temperature butterfly valve sealing pair compensation structure according to claim 1, characterized in that: The sealing structure includes a valve seat installed in the valve body, and the side wall of the valve seat in contact with the valve body is stepped; a mounting groove adapted to the valve seat is provided on the inner wall of the valve body, a blind hole is provided on the bottom of the mounting groove, a spring abutting the valve seat is provided in the blind hole, and a valve cover abutting the valve seat is provided in the valve body.

3. A low-temperature butterfly valve sealing pair compensation structure according to claim 2, characterized in that: A first sealing ring is provided between the horizontal section of the valve seat and the valve body.

4. A low-temperature butterfly valve sealing pair compensation structure according to claim 2, characterized in that: The spring and the vertical section of the valve seat abut against each other.

5. The low-temperature butterfly valve sealing pair compensation structure according to claim 2 is characterized in that: A first inclined surface is provided on the side wall where the valve seat and the sealing gasket abut each other, and the angle between the reverse extension line of the first inclined surface and the axis of the circle where the valve seat is located is acute; a second inclined surface is provided on the side wall where the sealing gasket and the valve seat abut each other, and the angle between the reverse extension line of the second inclined surface and the axis of the circle where the valve seat is located is acute.

6. A low-temperature butterfly valve sealing pair compensation structure according to claim 2, characterized in that: A third inclined surface is provided on a side of the valve seat opposite to the valve cover, and an angle formed between the third inclined surface and the axis of the circle where the valve seat is located is an obtuse angle.

7. The low-temperature butterfly valve sealing pair compensation structure according to claim 1 is characterized in that: It also includes a bolt, which passes through the sealing pressure plate and is placed in the disc plate. A nut is provided on the bolt, and a thrust pad is provided between the nut and the sealing pressure plate.

8. The low-temperature butterfly valve sealing pair compensation structure according to claim 1 is characterized in that: A second sealing ring is provided between the sealing gasket and the disc plate.

9. The low-temperature butterfly valve sealing pair compensation structure according to claim 1, characterized in that: A positioning hole is provided on the valve stem, and a positioning pin connected to the disc plate is passed through the positioning hole.

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