Valve shaft guide seal structure of floating ball valve and floating ball valve

Abstract

The present invention is a valve shaft guide sealing structure of a floating ball valve and a floating ball valve. The valve shaft guide sealing structure of the floating ball valve includes a spherical shoulder, a spherical universal plug thrust seal ring, which is arranged between the spherical shoulder and the valve body; a spherical groove is arranged in the spherical universal plug thrust seal ring, and the cooperation between the spherical groove and the spherical shoulder is a spherical surface adaptive cooperation; the spherical universal plug thrust seal ring constitutes a first sealing part and a first guiding part; a packing group is arranged in a packing box hole of the valve body, located above the spherical universal plug thrust seal ring and arranged axially spaced from the spherical universal plug thrust seal ring; the packing group constitutes a second sealing part; and a guide sliding bearing constitutes a second guiding part. The present invention eliminates the potential leakage risk caused by uneven wear of the packing during the opening and closing process of the floating ball valve under pressure. The valve shaft guide sealing structure of the floating ball valve of the present invention is a double seal + double guide structure, which effectively improves the sealing performance of the floating ball valve.

Description

Technical Field

[0001] The invention relates to the technical field of floating ball valves, and in particular to a valve shaft guide sealing structure of a floating ball valve and a floating ball valve. Background Art

[0002] Floating ball valves are commonly used in chemical small-diameter pipeline piping due to their small size, easy operation, and reliable sealing.

[0003] At present, the valve shaft seal of the existing floating ball valve usually adopts a herringbone packing structure, and a flat thrust washer 91 ( Figure 3 ), and also with a spherical thrust ring 92 ( Figure 4 ), a packing gland 7 is provided on the packing, and the shaft hole of the packing gland 7 and the valve shaft 8 is usually 0.5mm to 1mm larger than the diameter of the valve shaft.

[0004] The disadvantage of this structure is that the thrust washer or thrust ring on the valve shaft shoulder only reduces the wear between the valve shaft and the ball valve, and does not play a sealing role. In addition, adding a spherical thrust ring can theoretically ensure the free centering of the valve shaft, so that the packing is evenly worn during the opening and closing of the valve. However, the valve shaft head is not constrained, especially during the opening and closing of the valve under pressure, the valve shaft is subjected to unbalanced force, and the valve shaft tilts under the action of the medium force, resulting in uneven wear of the valve shaft packing. Over time, the packing will have a potential risk of leakage and reduce the service life of the valve, posing a safety hazard to the operation of the chemical plant and affecting environmental protection.

[0005] Therefore, the inventor, relying on his many years of experience and practice in related industries, proposes a valve shaft guide sealing structure of a floating ball valve and a floating ball valve to overcome the defects of the prior art. Summary of the invention

[0006] The object of the present invention is to provide a valve shaft guide sealing structure of a floating ball valve and a floating ball valve, so as to eliminate the potential leakage risk caused by uneven wear of the packing during the opening and closing process of the floating ball valve under pressure. The valve shaft guide sealing structure of the floating ball valve of the present invention is a double seal + double guide structure, which effectively improves the sealing performance and service life of the floating ball valve.

[0007] The object of the present invention is achieved by providing a valve shaft guide sealing structure of a floating ball valve, comprising:

[0008] A spherical shoulder is provided on the outer wall of the valve shaft;

[0009] The spherical universal plug thrust seal ring is arranged between the spherical shoulder and the valve body; a spherical groove is arranged in the spherical universal plug thrust seal ring, and the cooperation between the spherical groove and the spherical shoulder is a spherical surface adaptive cooperation; the spherical universal plug thrust seal ring constitutes the first sealing part, and can guide, position and support the valve shaft head, and constitutes the first guide part;

[0010] A packing group is arranged in the packing box hole of the valve body, is located above the spherical universal plug thrust seal ring and is axially spaced from the spherical universal plug thrust seal ring; the packing group constitutes a second sealing portion;

[0011] The guide sliding bearing is arranged between the packing gland and the valve shaft, and is used for supporting, guiding and positioning the valve shaft, forming a second guide part.

[0012] In a preferred embodiment of the present invention, the guide sliding bearing is a self-lubricating sliding bearing.

[0013] In a preferred embodiment of the present invention, the spherical pan-plug thrust seal ring comprises a seal ring body, the seal ring body is provided with an axially penetrating valve shaft through hole; the bottom end of the valve shaft through hole is provided with the spherical groove upward; the bottom of the seal ring body is located on both sides of the spherical groove to form a pan-plug body, the pan-plug body is provided with a pan-plug cavity with an open bottom end, lips are formed on both sides of the pan-plug cavity, and a spring is provided in the pan-plug cavity; the lips on both sides are respectively pressed against the spherical shoulder and the valve body.

[0014] In a preferred embodiment of the present invention, the spring force of the spring provides an initial sealing pressure ratio for the lip. When the valve is working, the medium pressure enters the flooded cavity, and the medium pressure and the spring force provide a working sealing pressure ratio for the lip, and the working sealing pressure ratio is greater than the initial sealing pressure ratio.

[0015] In a preferred embodiment of the present invention, the packing group includes a first nickel wire flexible graphite braided packing part, a flexible graphite pressed packing part and a second nickel wire flexible graphite braided packing part which are sequentially arranged in the packing box hole of the valve body from bottom to top.

[0016] In a preferred embodiment of the present invention, the number of the flexible graphite pressed packing parts is two, and the two flexible graphite pressed packing parts are sequentially arranged between the first nickel wire flexible graphite braided packing part and the second nickel wire flexible graphite braided packing part.

[0017] In a preferred embodiment of the present invention, the packing group further includes a packing pad, and the packing pad is pressed above the second nickel wire flexible graphite braided packing part.

[0018] The object of the present invention can also be achieved in this way. A floating ball valve includes a ball, a valve shaft, a valve body and a packing gland. A valve shaft guide sealing structure of the floating ball valve as described above is arranged between the valve shaft and the valve body and the packing gland.

[0019] In a preferred embodiment of the present invention, the valve shaft passes through the packing gland and the valve body and is clamped on the sphere, the spherical shoulder is provided on the outer wall of the valve shaft, a valve body stop is provided at the bottom of the valve body, the spherical pan-plug thrust sealing ring is provided between the valve body stop and the spherical shoulder, and the lips of the spherical pan-plug thrust sealing ring respectively press against the spherical shoulder and the valve body stop.

[0020] In a preferred embodiment of the present invention, a stuffing box hole is arranged above the valve body stop, a limiting shoulder is arranged between the valve body stop and the stuffing box hole, and the bottom top and bottom of the stuffing group are supported on the limiting shoulder.

[0021] As described above, the valve shaft guide seal structure of the floating ball valve and the floating ball valve of the present invention have the following beneficial effects:

[0022] In the valve shaft guide sealing structure of the floating ball valve of the present invention, the spherical flood plug thrust seal ring and the packing group constitute a double sealing structure of the valve shaft, thereby increasing the reliability of the valve shaft sealing of the valve;

[0023] The spherical shoulder and the spherical pan-plug thrust seal ring on the valve shaft of the present invention are spherical surface adaptively matched to form an automatic centering structure, which plays a role in guiding, positioning and supporting the valve shaft head;

[0024] In the valve shaft guide sealing structure of the floating ball valve of the present invention, the guide sliding bearing cooperates with the valve shaft head to support, guide and position the valve shaft end. The two guides, positioning and supports of the valve shaft ensure that the valve shaft does not deflect under the action of the medium pressure during the valve opening and closing process, forming a double guide, completely eliminating the phenomenon of uneven wear of the packing group caused by the unbalanced force caused by the tilt of the valve shaft due to the action of the medium, thereby improving the sealing performance of the dynamic seal at the valve shaft and the service life of the entire valve.

[0025] The packing group of the present invention is made of fire-safe sealing material, which completely eliminates the potential safety hazard of herringbone fluoroplastic packing being burned in the event of a fire and causing a major accident, and is a fire-safe structural design;

[0026] The present invention eliminates the potential leakage risk caused by uneven wear of the packing during the opening and closing process of the floating ball valve under pressure. The valve shaft guide sealing structure of the floating ball valve of the present invention is a double sealing structure of a self-lubricating sliding bearing with support on the valve shaft head, thereby improving the sealing performance of the floating ball valve.

[0027] The floating ball valve of the present invention has reliable sealing performance, reduces the fugitive leakage of the valve shaft dynamic seal, and the valve shaft guide sealing structure is an environmentally friendly dynamic sealing structure, meeting the "dual carbon" target requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0029] in:

[0030] Figure 1 : is a schematic diagram of the valve shaft guide sealing structure of the floating ball valve of the present invention.

[0031] Figure 2 : is a schematic diagram of the spherical flooded plug thrust seal ring of the present invention.

[0032] Figure 3 : It is a schematic diagram of the structure of the plane thrust washer of the existing floating ball valve.

[0033] Figure 4 : It is a schematic diagram of the structure of the spherical thrust ring of the existing floating ball valve.

[0034] In the figure:

[0035] 100. Floating ball valve;

[0036] 1. Spherical flood plug thrust seal ring; 10. Seal ring body; 11. Spherical groove; 12. Lip; 13. Spring;

[0037] 2. Packing group; 21. First nickel wire flexible graphite braided packing part; 22. Flexible graphite pressed packing part; 23. Second nickel wire flexible graphite braided packing part; 24. Packing pad;

[0038] 3. Spherical shoulder;

[0039] 4. Guide sliding bearing;

[0040] 5. Sphere;

[0041] 6. Valve body; 61. Stuffing box hole; 62. Valve body stop; 63. Limiting shoulder;

[0042] 7. Packing gland;

[0043] 8. Valve shaft.

[0044] 91. Flat thrust washer; 92. Spherical thrust ring. DETAILED DESCRIPTION

[0045] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0046] The specific embodiments of the present invention described herein are only used to explain the purpose of the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be considered to belong to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0048] like Figure 1 , Figure 2 As shown, the present invention provides a valve shaft guide sealing structure of a floating ball valve, comprising:

[0049] A spherical shoulder 3 is provided on the outer wall of the valve shaft 8;

[0050] The spherical universal plug thrust seal ring 1 is arranged between the spherical shoulder 3 and the valve body 6; a spherical groove 11 is arranged in the spherical universal plug thrust seal ring 1, and the cooperation between the spherical groove 11 and the spherical shoulder 3 is a spherical surface adaptive cooperation, and the valve shaft 8 can realize automatic centering; the spherical universal plug thrust seal ring 1 constitutes the first sealing part, and can guide, position and support the valve shaft head, and constitutes the first guide part;

[0051] The packing group 2 is arranged in the packing box hole 61 of the valve body, is located above the spherical universal plug thrust seal ring 1 and is axially spaced from the spherical universal plug thrust seal ring 1; the packing group 2 constitutes a second sealing portion;

[0052] The guide sliding bearing 4 is arranged between the packing gland 7 and the valve shaft 8, and is used for supporting, guiding and positioning the valve shaft, constituting a second guide portion.

[0053] In the valve shaft guide sealing structure of the floating ball valve of the present invention, the spherical pan-plug thrust sealing ring and the packing group constitute a double sealing structure of the valve shaft, thereby increasing the reliability of the valve shaft sealing of the valve; the spherical shoulder and the spherical pan-plug thrust sealing ring on the valve shaft are spherical surface adaptively matched to form an automatic centering structure, which guides, positions and supports the valve shaft head, eliminates the potential risk of the valve shaft tilting, thereby making the packing group wear evenly and improving the sealing performance of the valve shaft.

[0054] In the valve shaft guide sealing structure of the invented floating ball valve, the guide sliding bearing and the valve shaft head cooperate to support, guide and position the end of the valve shaft. The two-point guidance, positioning and support of the valve shaft ensure that the valve shaft does not deflect under the action of the medium pressure during the opening and closing of the valve, forming a double guide, and completely eliminating the uneven wear phenomenon caused by the unbalanced force on the packing group caused by the tilt of the valve shaft due to the action of the medium, thereby improving the sealing performance of the dynamic seal at the valve shaft and the service life of the entire valve.

[0055] Further, if Figure 1 As shown, the guide sliding bearing 4 is a self-lubricating sliding bearing, which can effectively lubricate the valve shaft 8 and avoid wear of the valve shaft 8 .

[0056] The guide sliding bearing 4 cooperates with the valve shaft head to support, guide and position the valve shaft, preventing the valve shaft from tilting when the valve is opened and closed under pressure, completely eliminating the phenomenon of uneven wear of the packing group caused by unbalanced force on the valve shaft due to tilt, and improving the sealing performance of the valve shaft.

[0057] Further, if Figure 1 , Figure 2 As shown, the spherical universal plug thrust seal ring 1 comprises a seal ring body 10, on which an axially penetrating valve shaft through hole is arranged; a spherical groove 11 is arranged upwardly from the bottom end of the valve shaft through hole; the bottom of the seal ring body 10 is located on both sides of the spherical groove to form a universal plug body, on which a universal plug cavity with an open bottom end is arranged, lips 12 are formed on both sides of the universal plug cavity, and a spring 13 is arranged in the universal plug cavity; the lips 12 on both sides respectively press against the spherical shoulder and the valve body.

[0058] Furthermore, the spring force of the spring 13 provides an initial sealing pressure ratio for the lip. When the valve is working, the medium pressure enters the flooding cavity, and the medium pressure and the spring force provide a working sealing pressure ratio for the lip, which is greater than the initial sealing pressure ratio. Under the action of the working sealing pressure ratio, the lip 12 is tightly attached to the spherical shoulder of the valve shaft and the valve body, the sealing pressure ratio is increased, and the seal is more reliable.

[0059] Further, if Figure 1 As shown, the packing group 2 includes a first nickel wire flexible graphite braided packing part 21, a flexible graphite pressed packing part 22 and a second nickel wire flexible graphite braided packing part 23 which are sequentially arranged in the packing box hole of the valve body from bottom to top.

[0060] Furthermore, the number of the flexible graphite pressed packing parts 22 is two, and the two flexible graphite pressed packing parts are sequentially arranged between the first nickel wire flexible graphite braided packing part 21 and the second nickel wire flexible graphite braided packing part 23 .

[0061] Further, if Figure 1 As shown, the packing group 2 further includes a packing pad 24, which is pressed above the second nickel wire flexible graphite braided packing part 23. The packing pad 24 can compact the packing group 2, which is more conducive to the stability of the seal.

[0062] The first nickel wire flexible graphite braided packing part 21, the flexible graphite pressed packing part 22 and the second nickel wire flexible graphite braided packing part 23 in the packing group are made of fire-safe sealing materials, which completely eliminates the potential safety hazard of herringbone fluoroplastic packing burning in the event of a fire and causing major accidents, and is a fire-proof safety structure design.

[0063] like Figure 1 As shown, the present invention also provides a floating ball valve 100, including a ball 5, a valve shaft 8, a valve body 6 and a packing gland 7, and a valve shaft guide sealing structure of the floating ball valve as described above is arranged between the valve shaft 8 and the valve body 6 and the packing gland 7.

[0064] Furthermore, the valve shaft 8 passes through the packing gland 7 and the valve body 6 and is clamped on the ball 5. A spherical shoulder 3 is provided on the outer wall of the valve shaft 8. A valve body stop 62 is provided at the bottom of the valve body 6. The spherical flooded plug thrust sealing ring 1 is provided between the valve body stop 62 and the spherical shoulder 3. The lip 12 of the spherical flooded plug thrust sealing ring 1 presses against the spherical shoulder 3 and the valve body stop 62 respectively.

[0065] Furthermore, a stuffing box hole 61 is provided on the valve body 6 above the valve body stop 62 , a limiting shoulder 63 is provided between the valve body stop 62 and the stuffing box hole 61 , and the bottom of the stuffing group 2 is supported on the limiting shoulder 63 .

[0066] As described above, the valve shaft guide seal structure of the floating ball valve and the floating ball valve of the present invention have the following beneficial effects:

[0067] In the valve shaft guide sealing structure of the floating ball valve of the present invention, the spherical flood plug thrust seal ring and the packing group constitute a double sealing structure of the valve shaft, thereby increasing the reliability of the valve shaft sealing of the valve;

[0068] The spherical shoulder and the spherical pan-plug thrust seal ring on the valve shaft of the present invention are spherical surface adaptively matched to form an automatic centering structure, which plays a role in guiding, positioning and supporting the valve shaft head;

[0069] In the valve shaft guide sealing structure of the floating ball valve of the present invention, the guide sliding bearing cooperates with the valve shaft head to support, guide and position the valve shaft end. The two guides, positioning and supports of the valve shaft ensure that the valve shaft does not deflect under the action of the medium pressure during the valve opening and closing process, forming a double guide, completely eliminating the phenomenon of uneven wear of the packing group caused by the unbalanced force caused by the tilt of the valve shaft due to the action of the medium, thereby improving the sealing performance of the dynamic seal at the valve shaft and the service life of the entire valve.

[0070] The packing group of the present invention is made of fire-safe sealing material, which completely eliminates the potential safety hazard of herringbone fluoroplastic packing being burned in the event of a fire and causing a major accident, and is a fire-safe structural design;

[0071] The present invention eliminates the potential leakage risk caused by uneven wear of the packing during the opening and closing process of the floating ball valve under pressure. The valve shaft guide sealing structure of the floating ball valve of the present invention is a double sealing structure of a self-lubricating sliding bearing with support on the valve shaft head, thereby improving the sealing performance of the floating ball valve.

[0072] The floating ball valve of the present invention has reliable sealing performance, reduces the fugitive leakage of the valve shaft dynamic seal, and the valve shaft guide sealing structure is an environmentally friendly dynamic sealing structure, meeting the "dual carbon" target requirements.

[0073] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A valve shaft guide sealing structure of a floating ball valve, characterized in that: include, A spherical shoulder is provided on the outer wall of the valve shaft; The spherical universal plug thrust seal ring is arranged between the spherical shoulder and the valve body; a spherical groove is arranged in the spherical universal plug thrust seal ring, and the cooperation between the spherical groove and the spherical shoulder is a spherical surface adaptive cooperation; the spherical universal plug thrust seal ring constitutes the first sealing part, and can guide, position and support the valve shaft head, and constitutes the first guide part; A packing group is arranged in the packing box hole of the valve body, is located above the spherical universal plug thrust seal ring and is axially spaced from the spherical universal plug thrust seal ring; the packing group constitutes a second sealing portion; A guide sliding bearing is arranged between the packing gland and the valve shaft, and is used to support, guide and position the valve shaft, constituting a second guide portion; The spherical pan-plug thrust seal ring comprises a seal ring body, on which an axially penetrating valve shaft through hole is arranged; the bottom end of the valve shaft through hole is upwardly provided with the spherical groove; the bottom of the seal ring body is located on both sides of the spherical groove to form a pan-plug body, on which a pan-plug cavity with a bottom opening is arranged, and lips are formed on both sides of the pan-plug cavity, and a spring is arranged in the pan-plug cavity; the lips on both sides are respectively pressed against the spherical shoulder and the valve body; The spring force of the spring provides an initial sealing pressure ratio for the lip. When the valve is working, the medium pressure enters the flooded plug cavity, and the medium pressure and the spring force provide a working sealing pressure ratio for the lip, and the working sealing pressure ratio is greater than the initial sealing pressure ratio. The packing group includes a first nickel wire flexible graphite braided packing part, a flexible graphite pressed packing part and a second nickel wire flexible graphite braided packing part which are arranged in sequence from bottom to top in the packing box hole of the valve body; the first nickel wire flexible graphite braided packing part, the flexible graphite pressed packing part and the second nickel wire flexible graphite braided packing part are made of fire safety sealing material.

2. The valve shaft guide seal structure of the floating ball valve according to claim 1, characterized in that: The guide sliding bearing is a self-lubricating sliding bearing.

3. The valve shaft guide seal structure of the floating ball valve according to claim 1, characterized in that: The number of the flexible graphite pressed packing parts is two, and the two flexible graphite pressed packing parts are sequentially arranged between the first nickel wire flexible graphite braided packing part and the second nickel wire flexible graphite braided packing part.

4. The valve shaft guide seal structure of the floating ball valve according to claim 1, characterized in that: The packing group further includes a packing pad, which is pressed above the second nickel wire flexible graphite braided packing part.

5. A floating ball valve, characterized in that: The invention comprises a ball, a valve shaft, a valve body and a packing gland, wherein a valve shaft guide sealing structure of a floating ball valve as claimed in any one of claims 1 to 4 is arranged between the valve shaft and the valve body and the packing gland.

6. The floating ball valve according to claim 5, characterized in that: The valve shaft passes through the packing gland and the valve body and is clamped on the ball. The spherical shoulder is provided on the outer wall of the valve shaft. A valve body stop is provided at the bottom of the valve body. The spherical pan-plug thrust sealing ring is provided between the valve body stop and the spherical shoulder. The lips of the spherical pan-plug thrust sealing ring are respectively pressed against the spherical shoulder and the valve body stop.

7. The floating ball valve according to claim 6, characterized in that: The valve body is provided with a stuffing box hole above the valve body stop, a limiting shoulder is provided between the valve body stop and the stuffing box hole, and the bottom top and bottom of the stuffing group are supported on the limiting shoulder.

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