An offset-compensated fluorine-lined ball valve

Abstract

The present invention discloses an offset compensation lined fluorine ball valve, comprising: a valve body having a guiding channel, and a valve cover, a valve seat, a valve stem and a valve ball cooperating with the valve body; wherein: the sealing packing includes a main body portion and an extending portion obliquely extending downward from the bottom of the main body portion; the main body portion has an upwardly opening annular groove coaxial with the valve stem, and a flexible expansion ring is provided in the annular groove and abuts against its inner wall and is pressed by the valve cover; the lower edge of the extending portion forms a clasp with the valve stem, and there is a clearance space between the outer wall of the extending portion and the inner wall of the guiding channel; the extending portion and the main body portion cooperate to form a sealed space annularly arranged around the valve stem between the inner side of the extending portion and the bottom of the main body portion, and the sealed space is filled with a sealing paste. The present invention can enable the valve stem to have a certain offset amount, and the offset will not affect the sealing effect.

Description

Technical Field

[0001] The present invention relates to the technical field of ball valves, and particularly to an offset compensation fluorine-lined ball valve. Background Art

[0002] At present, the operating conditions of domestic fluorine-lined ball valves mostly remain at the technology of manual valves, and the switching life of most fluorine-lined ball valves is short. However, with the rise of fine chemicals, the market prospect of automatic control fluorine-lined valves will be very huge. The conditions required by fine chemicals for valves are diverse, but the most fundamental one is that the valve should have a long switching life and smooth switching to meet the actual working conditions. Since the offset compensation fluorine-lined ball valve uses fluorine-lined rubber (PFA or F46 and PTFE) to prevent the valve from being corroded, the valve ball needs to be connected to the valve stem. When the valve ball is closed, it will be subjected to the pressure of the medium in the pipeline, resulting in the offset of the valve ball, which will cause the valve stem to follow and offset, resulting in external leakage of the valve.

[0003] In the prior art, the valve ball and the valve stem are separated to solve the problem of valve stem offset. However, in this structure, the fluorine-lined rubber at the connection between the valve stem and the valve ball will be twisted and damaged during the opening and closing of the valve, resulting in the valve being unable to prevent corrosion and the valve not being in place during opening and closing. There are also attempts to prevent the valve stem from offsetting by increasing the compression of the valve seat (sealing ring). However, this will cause the valve seat (sealing ring) to wear faster and the service life of the valve to be shorter. Summary of the Invention

[0004] To solve the technical problems in the background art, the present invention proposes an offset compensation fluorine-lined ball valve.

[0005] An offset compensation fluorine-lined ball valve proposed by the present invention includes: a valve body having a guiding channel extending downward from its top and communicating with its interior; a valve cover installed on the top of the valve body to close the guiding channel, and the valve cover has a central hole coaxial with the guiding channel; a valve seat installed inside the valve body; a valve stem having one end passing through the central hole of the valve cover and extending into the valve body through a sealing channel and being slidable in the central hole; a valve ball located inside the valve body and coupled to the valve stem; wherein:

[0006] The sealing packing includes a main body portion and an extension portion extending obliquely downward from the bottom of the main body portion; the main body portion has an upward-opening annular groove coaxial with the valve stem, and a flexible expansion ring is provided in the annular groove and abuts against its inner wall and is pressed by the valve cover; the lower edge of the extension portion forms a clasp with the valve stem, and there is a clearance space between the outer wall of the extension portion and the inner wall of the guiding channel; the extension portion and the main body portion cooperate to form a closed space around the valve stem and arranged in a ring shape between the inner side of the extension portion and the bottom of the main body portion, and the closed space is filled with sealing paste.

[0007] Preferably, the cross-sectional shape of the closed space is a non-right-angled triangle.

[0008] Preferably, a positioning pressure pad is provided between the flexible expansion ring and the valve cover.

[0009] Preferably, the positioning pressure pad is made of metal.

[0010] Preferably, the flexible expansion ring is made of soft rubber.

[0011] Preferably, the flexible expansion ring is a rubber ring with a liquid medium wrapped inside.

[0012] Preferably, an angle smaller than 180° is formed between the extension portion and the inner wall of the guide channel to form a gap space.

[0013] Preferably, the angle between the extension portion and the inner wall of the guide channel is an acute angle.

[0014] Preferably, a positioning groove is provided on the valve seat; and a positioning protrusion which is inserted into the positioning groove is provided on the valve body.

[0015] Preferably, an anti-drop-out groove is provided on the valve body, and the anti-drop-out groove is an annular groove coaxial with the inlet and outlet of the valve body; an anti-drop-out protrusion which is inserted into the anti-drop-out groove is provided on the valve seat.

[0016] Preferably, the valve body comprises a main valve body and a sub-valve body, a clearance groove is provided at the joint surface of the main valve body and the sub-valve body, and the clearance groove is filled with sealing paste.

[0017] Preferably, the joining surface between the main valve body and the auxiliary valve body is divided into a metal joining surface and a plane compression sealing surface, and the plane compression sealing surface is located between the metal joining surface and the clearance groove.

[0018] In the present invention, the packing seal at the valve stem is arranged into a structure of a main body and an extension, and a gap space is provided between the outer wall of the extension and the inner wall of the guide channel, so that when the valve is opened, the inflowing medium can enter the gap space to apply pressure to the extension from the outside so that the extension holds the valve stem tightly to form a first seal, i.e., a self-pressure seal; at the same time, a sealing paste is injected into the enclosed space between the extension and the bottom of the main body to form a second seal; a flexible expansion ring is arranged in the annular groove of the main body, which abuts against the main body and is pressurized by the valve cover, so that the valve cover is used to squeeze the flexible expansion ring to push the inner part of the main body toward the valve stem to form a third seal. The arrangement of the three-seal structure can make the valve stem have a certain offset, and the offset will not affect the sealing effect, so that the valve ball can compensate for the wear of the valve seat by offset to meet the sealing conditions, thereby extending the service life of the ball valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of an offset-compensated fluorine-lined ball valve proposed for the invention;

[0020] Figure 2 for Figure 1Cross-sectional view taken along line B-B;

[0021] Figure 3 is Figure 2 a partially enlarged view of;

[0022] Figure 4 a schematic structural view of the valve seat in an offset compensation fluorine-lined ball valve proposed by the invention;

[0023] Figure 5 a schematic structural view of the positioning gasket in an offset compensation fluorine-lined ball valve proposed by the invention. Detailed implementation manners

[0024] Next, the technical solutions of the present invention will be described in detail through specific embodiments.

[0025] As Figures 1-5 shown, Figure 1 is Figure 2 a schematic structural view of an offset compensation fluorine-lined ball valve proposed by the invention; Figure 1 is Figure 3 a Figure 2 cross-sectional view taken along line B-B; Figure 4 is Figure 5 a schematic structural view of the valve seat in an offset compensation fluorine-lined ball valve proposed by the invention;

[0026] Referring to Figures 1-5 , an offset compensation fluorine-lined ball valve proposed by the present invention includes: a valve body 1, the valve body 1 having a guiding channel extending downward from its top and communicating with its interior; a valve cover 2 installed on the top of the valve body 1 to fit and close the guiding channel, and the valve cover 2 having a central hole coaxial with the guiding channel; a valve seat 3 installed inside the valve body 1; a valve stem 4 having one end passing through the central hole of the valve cover 2 and extending into the valve body 1 through a sealing channel and being slidable in the central hole; a valve ball 5 located inside the valve body 1 and coupled to the valve stem 4; wherein:

[0027] The sealing packing 6 includes a main body portion 61 and an extension portion 62 extending obliquely downward from the bottom of the main body portion 61; the lower edge of the extension portion 62 forms a clasp with the valve stem 4, and there is a clearance space between the outer wall of the extension portion 62 and the inner wall of the guiding channel, so that when the valve is opened and the medium enters the valve body 1, pressure is applied to the extension portion 62 from the outside to make it hold the valve stem 4 tightly to form the first seal, i.e., self-pressure seal.

[0028] The extension portion 62 cooperates with the main body portion 61 to form a closed space 8 arranged in a ring around the valve stem 4 between the inner side of the extension portion 62 and the bottom of the main body portion 61, and the closed space 8 is filled with a sealing paste to form the second seal.

[0029] The main body portion 61 has an annular groove with an upward opening and coaxial with the valve stem 4. A flexible expansion ring 10 is provided in the annular groove, which abuts against its inner wall and is pressed by the valve cover 2, so as to form a third seal by squeezing the main body portion 61 to make the inner side wall of the main body portion 61 abut against the valve stem 4.

[0030] As can be seen from the above, by setting the packing seal 6 at the valve stem 4 into the structure of the main body portion 61 and the extension portion 62, and having a clearance space between the outer wall of the extension portion 62 and the inner wall of the guiding channel, when the valve is opened, the inflowing medium can enter the clearance space to press the extension portion 62 from the outside to hold the valve stem 4 tightly to form a first seal, that is, self-pressure seal; at the same time, seal paste is injected into the closed space 8 between the extension portion 62 and the bottom of the main body portion 61 to form a second seal; a flexible expansion ring 10 that abuts against the annular groove of the main body portion 61 and is pressed by the valve cover is provided in the annular groove of the main body portion 61, so as to use the valve cover 2 to press the flexible expansion ring 10 to push the inner part of the main body portion 61 towards the valve stem 4 to form a third seal. The setting of the three-seal structure can make the valve stem 4 have a certain offset amount, and the sealing effect will not be affected when offset, so that the valve ball 5 can compensate for the wear of the valve seat 3 by offsetting to meet the sealing conditions, thereby extending the service life of the ball valve.

[0031] In addition, in this embodiment, the cross-sectional shape of the closed space 8 is a non-right triangle to enhance the sealing effect.

[0032] In this embodiment, a metal positioning gasket 7 is provided between the flexible expansion ring 10 and the valve cover 2, so that the pressure applied by the valve cover 2 is transmitted to the flexible expansion ring 10 through the metal positioning gasket 7.

[0033] In this embodiment, the flexible expansion ring 10 is made of soft rubber, or the flexible expansion ring 10 is a rubber ring wrapped with a liquid medium inside.

[0034] In this embodiment, there is an included angle between the extension portion 62 and the inner wall of the guiding channel to form a clearance space, and the included angle is an acute angle.

[0035] In this embodiment, a positioning groove 301 is provided on the valve seat 3; a positioning protrusion that is snapped into the positioning groove 301 is provided on the valve body 1. The setting of this structure makes the valve seat 3 unable to rotate, so that the valve seat 2 will not rotate when the valve is opened and closed, thereby preventing the damage area from expanding when the valve seat 3 has slight damage locally.

[0036] In this embodiment, an anti-detachment groove is provided on the valve body 1. The anti-detachment groove is an annular groove coaxial with the inlet and outlet of the valve body 1; an anti-detachment protrusion 302 that is snapped into the anti-detachment groove is provided on the valve seat 3. The setting of this structure makes the valve seat 3 unable to move axially, avoiding affecting the valve opening and closing torque due to the axial movement of the valve seat 3.

[0037] In this embodiment, the valve body 1 includes a main valve body and a sub-valve body. A clearance groove 9 is provided at the joint surface between the main valve body and the sub-valve body, and the clearance groove 9 is filled with sealant paste, thereby effectively improving the sealing performance of the joint surface. At the same time, in this embodiment, the joint surface between the main valve body and the sub-valve body is divided into a metal joint surface 101 and a planar compression sealing surface 102, and the planar compression sealing surface 102 is located between the metal joint surface 101 (i.e., the material at the mutually fitting part) and the clearance groove 9. The setting of the metal joint surface 102 can ensure that the distance between the main valve body and the sub-valve body is fixed and will not affect the torque and sealing performance of the valve due to the tightening of the joint surface bolts.

[0038] In this embodiment, the sealant paste is an anti-corrosion sealant paste.

[0039] As described above, the above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An offset compensation fluorine-lined ball valve, characterized in that, Comprising: A valve body (1), the valve body (1) having a guiding channel extending downward from its top and communicating with its interior; a valve cover (2) mounted on the top of the valve body (1) to fit and close the guiding channel, and the valve cover (2) having a central hole coaxial with the guiding channel; a valve seat (3) mounted inside the valve body (1); a valve stem (4) with one end passing through the central hole of the valve cover (2), extending into the valve body (1) through a sealing channel and being slidable in the central hole; a valve ball (5) located inside the valve body (1) and coupled to the valve stem (4); wherein: A sealing packing (6) is provided between the inner wall of the guiding channel and the outer wall of the valve stem (4), the sealing packing (6) including a main body portion (61) and an extension portion (62) extending obliquely downward from the bottom of the main body portion (61); the main body portion (61) has an upward-opening annular groove coaxial with the valve stem (4), and a flexible expansion ring (10) that abuts against its inner wall and is pressed by the valve cover (2) is provided in the annular groove; the lower edge of the extension portion (62) forms a clasp with the valve stem (4), and there is a clearance space between the outer wall of the extension portion (62) and the inner wall of the guiding channel; the extension portion (62) and the main body portion (61) cooperate to form a closed space (8) that is annularly arranged around the valve stem (4) between the inner side of the extension portion (62) and the bottom of the main body portion (61), and a sealing paste is filled in the closed space (8); The cross-sectional shape of the closed space (8) is a non-right triangle; A positioning pressure pad (7) is provided between the flexible expansion ring (10) and the valve cover (2); the positioning pressure pad (7) is made of metal.

2. The offset compensation lined fluorine ball valve according to claim 1, characterized in that, The flexible expansion ring (10) is made of soft rubber.

3. The offset compensation lined fluorine ball valve according to claim 1, characterized in that The flexible expansion ring (10) is a rubber ring with a liquid medium wrapped inside.

4. The offset compensation lined fluorine ball valve according to claim 1, characterized in that, The extension portion (62) and the inner wall of the guiding channel have an angle less than 180° to form a clearance space.

5. The offset compensation lined fluorine ball valve according to claim 1, characterized in that, A positioning groove (301) is provided on the valve seat (3); a positioning projection that is snapped into the positioning groove (301) is provided on the valve body (1).

6. The offset compensation fluorine-lined ball valve according to claim 1, wherein An anti-detachment groove is provided on the valve body (1), and the anti-detachment groove is an annular groove coaxial with the inlet and outlet of the valve body (1); an anti-detachment projection (302) that is snapped into the anti-detachment groove is provided on the valve seat (3).

7. The offset compensation lined fluorine ball valve according to any one of claims 1-6, characterized in that, The valve body (1) includes a main valve body and a sub-valve body, and a clearance groove (9) is provided at the joint surface between the main valve body and the sub-valve body, and a sealing paste is filled in the clearance groove (9).

8. The offset compensation lined fluorine ball valve according to claim 7, characterized in that, The joint surface between the main valve body and the sub-valve body is divided into a metal joint surface (101) and a flat compression sealing surface (102), and the flat compression sealing surface (102) is located between the metal joint surface (101) and the clearance groove (9).

9. The offset compensation lined fluorine ball valve according to claim 1, characterized in that, The angle between the extension portion (62) and the inner wall of the guiding channel is an acute angle.

Images