A fixed ball valve

Abstract

A fixed ball valve, which comprises: a housing, formed by covering a valve body with a valve cover. Inside the housing, valve seats are respectively installed on the valve body and / or the valve cover, and the valve seats are soft-sealing valve seats; a valve ball, arranged between the valve seats; the valve seat includes a self-sealing part and an installation part, the installation part is fixedly installed on the housing, and the self-sealing part abuts against the valve ball and makes the valve seat have a pre-tightening force that tightly seals against the valve ball through its self-deformation. The soft-sealing valve seat is directly fixed on the valve cover, with a simple structure and low cost; compared with the existing floating valve seat, the valve seat structure of the present invention has better elasticity and is not easily deformed during the opening and closing process, and can be applied to fixed ball valves with larger diameters.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and particularly to a fixed ball valve. Background Art

[0002] In the prior art, the ball of a fixed ball valve is fixed and does not move under pressure; all fixed ball valves are provided with floating valve seats. After being subjected to the medium pressure, the floating valve seats move, and the seals are tightly pressed on the balls to ensure sealing.

[0003] As Figure 1 shown, it is a typical structure of a fixed ball valve in the prior art, in which the ball 3' is fixed in the valve through a support plate 4'; the soft seal valve seat 5' is fixed in the groove of the metal valve seat 6', and the soft seal valve seat 5' is in interference fit with the groove to achieve the seal between the soft seal valve seat 5' and the metal valve seat 6'; the O-ring 7' is placed in the groove of the metal valve seat 6' to achieve the seal between the metal valve seat 6' and the valve cover 2'. A graphite gasket 1' is added between the pressure ring 9' and the metal valve seat 6' to achieve fire protection of the valve; the spring 8' provides the pre-tightening force of the valve seat to ensure the seal between the ball 3' and the valve seat 5'.

[0004] The floating valve seats are usually adopted in the fixed ball valves in the prior art, in which a spring is arranged in the floating valve seat to provide the pre-tightening force for the valve seat to fit with the ball; generally, the pre-tightening force provided by the compression spring is large, but the soft seal valve seat is made of a plastic material with low strength, such as PTFE, nylon, PEEK, PCTFE, etc.; during the opening and closing process of the valve ball, the above-mentioned soft seal valve seat made of plastic material with low strength will be subjected to the bidirectional forces from the spring and the valve ball, and will be continuously squeezed by the edge of the valve ball during the opening and closing rotation process of the valve ball, thus accelerating the deformation and failure of the soft seal valve seat and reducing its service life.

[0005] On the other hand, due to the low strength of the valve seat made of the above-mentioned plastic material, it is easy to deform during the opening and closing process. Usually, it is relatively reliable for the sealing of valves with low pressure ratings and small diameters. The larger the diameter, the more difficult it is to achieve sealing. For example: currently in the market, PTFE is generally used as the valve seat of a fixed ball valve up to a maximum of 10" valves.

[0006] Therefore, how to reduce the extrusion force on the soft seal valve seat, extend the service life of the soft seal valve seat, and meet the use of ball valves with larger diameters on the basis of ensuring the sealing performance between the soft seal valve seat and the ball has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that in order to ensure the sealing performance between the soft-sealing valve seat and the ball, the extrusion force on the soft-sealing valve seat is relatively large, resulting in a relatively low service life. Thus, a fixed ball valve is provided that can both ensure the sealing performance between the soft-sealing valve seat and the ball and reduce the external extrusion force thereon.

[0008] The technical solution of the present invention is as follows:

[0009] A fixed ball valve, which comprises:

[0010] A housing, which is formed by covering a valve body with a valve cover. Inside the housing, valve seats are respectively installed on the valve body and / or the valve cover, and the valve seats are soft-sealing valve seats;

[0011] A valve ball, which is arranged between the valve seats;

[0012] The valve seat includes a self-sealing part and a mounting part. The mounting part is fixedly installed on the housing, and the self-sealing part abuts against the valve ball and has a pre-tightening force that tightly seals against the valve ball through its self-deformation.

[0013] Further, an annular recessed relief groove is provided in the housing corresponding to the self-sealing part and recessed away from the valve ball. A relief space is formed in the relief groove to allow the self-sealing part to yield outwardly towards the outside of the valve ball.

[0014] Further, a limiting unit for preventing the self-sealing part from disengaging from the relief groove is further provided on the side of the self-sealing part facing away from the valve ball.

[0015] Further, a support mechanism is further provided in the housing. The support mechanism provides a supporting force for the valve seat to make it close to the valve ball; the valve seat further includes a deformable part that is supported by the support mechanism and is adapted thereto, and the deformable part is connected between the self-sealing part and the mounting part in a transitional manner.

[0016] Further, the support mechanism includes a plurality of annular protrusions extending towards the valve ball on the inner wall of the housing; the deformable part is an annular groove clamped on the annular protrusions.

[0017] Further, an annular mounting groove adapted for the mounting part to be inserted into is provided on the valve body and / or the valve cover, and the mounting groove and the relief groove are respectively arranged on the axial two sides of the annular protrusions.

[0018] Further, the axial cross-section of the valve seat is in a hook shape.

[0019] Further, a strengthened sealing unit is further provided between the valve cover and the mounting part.

[0020] Further, the enhanced sealing unit includes a plurality of grooves, which are provided on one side surface of the mounting portion in contact with the mounting groove, or the grooves are provided on one side surface of the mounting groove in contact with the mounting portion.

[0021] Further, the enhanced sealing unit includes a plurality of protrusions, which are provided on one side surface of the mounting portion in contact with the mounting groove, and the protrusions are embedded in the mounting groove; alternatively, the protrusions are provided on one side surface of the mounting groove in contact with the mounting portion, and the protrusions are embedded in the mounting portion.

[0022] Further, a fastening compression ring is provided on one side of the mounting portion close to the valve ball, and the compression ring is fixed to the housing by a fixing member.

[0023] Further, both the valve body and the valve cover are made of metal materials, and the valve seat is made of plastic material.

[0024] The technical solution of the present invention has the following advantages:

[0025] 1. The fixed ball valve provided by the present invention includes: a housing formed by covering a valve body and a valve cover, in the housing, a valve seat is respectively installed on the valve body and / or the valve cover, and the valve seat is a soft-sealing valve seat; a valve ball is arranged between the valve seats; the valve seat includes a self-sealing portion and a mounting portion, the mounting portion is fixedly installed on the housing, and the self-sealing portion abuts against the valve ball and makes the valve seat have a pre-tightening force for tightly sealing against the valve ball through its self-deformation. The structure of "metal valve seat + soft-sealing valve seat + O-ring + spring" in the prior art is cancelled, and the soft-sealing valve seat is directly fixed on the valve cover, with a simple structure and low cost; compared with the existing floating valve seat, the valve seat structure of the present invention has better elasticity and is not easily deformed during the opening and closing process, and can be applied to fixed ball valves with larger diameters.

[0026] 2. In the fixed ball valve provided by the present invention, a ring-shaped retreat groove recessed away from the valve ball is provided at a position corresponding to the self-sealing portion in the housing, and a retreat space allowing the self-sealing portion to retreat to the outside of the valve ball is formed in the retreat groove. By providing an anti-twist retreat space for allowing the self-sealing portion in sealing contact with the valve ball on the valve seat to retreat to the outside of the valve ball after being stressed, it can ensure the sealing contact between the valve seat and the valve ball during the rotation of the valve ball and avoid the valve seat from twisting with the valve ball; thereby effectively reducing the failure of the valve seat caused by twisting.

[0027] 3. The fixed ball valve provided by the present invention further comprises a support mechanism disposed within the housing, and the support mechanism provides a supporting force to the valve seat to make it close to the valve ball; the valve seat further includes a deformation portion supported by and adapted to the support mechanism, and the deformation portion is transitionally connected to the self-sealing portion and the mounting portion. By providing this support mechanism, a supporting effect in the direction of the valve ball is exerted on the valve seat, avoiding the problem that the valve seat cannot provide sufficient pre-tightening force due to insufficient stiffness, and thus avoiding the problem of insufficient sealing between the valve seat and the valve ball.

[0028] 4. For the fixed ball valve provided by the present invention, a strengthened sealing unit is further disposed between the mounting groove and the mounting portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of the valve seat of a fixed ball valve in the prior art;

[0031] Figure 2 It is a schematic structural diagram of the fixed ball valve provided in the present invention;

[0032] Figure 3 For Figure 2 an enlarged schematic view of the valve seat in

[0033] Figure 4 For Figure 2 an enlarged schematic view of the position A shown in

[0034] Figure 5 For Figure 4 an enlarged schematic view of the position B shown in

[0035] Figure 6 For Figure 4 an enlarged schematic view of the position C shown in

[0036] Description of the reference numerals:

[0037] 1 - housing; 11 - valve body; 12 - valve cover; 2 - valve ball; 3 - valve seat; 31 - self-sealing portion; 32 - mounting portion; 33 - limiting unit; 34 - deformation portion; 35 - anti-cut chamfer; 4 - relief groove; 5 - support mechanism; 6 - mounting groove; 7 - strengthened sealing unit; 8 - retaining ring; 9 - screw; 10 - support plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0041] Embodiment 1

[0042] As Figure 2 shown, the present invention discloses a fixed ball valve, which includes a housing 1 and a valve ball 2. The housing 1 is composed of a valve body 11 and a valve cover 12 covering it; a valve seat 3 is installed in the housing 1, and the valve seat 3 is a soft seal valve seat. As Figure 1 shown, the fixed ball valve in this embodiment is of a three-piece structure. The valve ball 2 is fixed in the valve by a support plate 10. Valve seats 3 are respectively installed on the valve covers 12 on both sides of the valve body 11 in the housing 1, and the valve ball 2 is arranged between the four valve seats 3. The valve body 11 and the valve cover 12 in this embodiment are both made of metal materials, and the valve seat 3 is made of plastic materials. The valve seat 3 can be made of materials such as PTFE (polytetrafluoroethylene), nylon, PEEK (polyether ether ketone, the English name is poly ether ether ketone), PCTFE (polychlorotrifluoroethylene), etc.

[0043] As Figure 3As shown, the valve seat 3 includes a self-sealing portion 31 and a mounting portion 32, and the mounting portion 32 is fixedly installed in the housing 1. In the three-piece structure fixed ball valve of this embodiment, the mounting portions 32 of the valve seat 3 are all fixed on the valve cover 12; wherein the self-sealing portion 31 is in interference fit with the valve ball 2, and the valve seat 3 is self-deformed under the extrusion of the valve ball 2. Through the self-deformation of the valve seat 3, it has a pre-tightening force that tightly seals against the valve ball 2; the valve seat 3 in this embodiment is a non-floating soft-sealing valve seat; there is no need to set floating units such as springs to apply a pre-tightening force to make the valve seat close to the valve ball. The pre-tightening force that makes the valve seat 3 tightly seal against the valve ball 2 can be provided through the self-deformation of the soft-sealing valve seat 3.

[0044] In order to allow the valve seat 3 to have elastic deformation and a yielding space under the action of the valve ball 2; see the appendix Figure 2 , at the corresponding position of the valve cover 12 and the self-sealing portion 31 in the housing 1, there is an annular anti-twist yielding groove 4 recessed away from the valve ball direction. A yielding space is formed in the yielding groove 4 to allow the self-sealing portion 31 to yield to the outside of the valve ball 2 (the outside refers to the direction away from the valve ball, that is, the side of the self-sealing portion facing away from the valve ball). During the rotation of the ball valve 2, a force will be applied to the valve seat 3, thereby causing the valve seat 3 to have a tendency to twist together with the valve ball 2. By setting an anti-twist yielding space to allow the self-sealing portion 31 in sealing contact with the valve ball 2 on the valve seat 3 to yield to the outside of the valve ball 2 after being stressed, it can not only ensure the sealing contact between the valve seat 3 and the valve ball 2 during the rotation of the valve ball 2 but also prevent the valve seat 3 from twisting with the valve ball 2; thus effectively reducing the failure of the valve seat caused by torsion.

[0045] In this embodiment, there is no spring for applying pressure to the valve seat. Due to the absence of a spring, during the rotation of the valve ball 2, especially when the edge of the valve ball 2 rotates to contact the valve seat 3, the valve seat 3 only receives a unidirectional force from the valve ball 2 and will not receive an additional extrusion force from the spring that is opposite to the force of the valve ball. Therefore, the external extrusion force on the soft-sealing valve seat is reduced, reducing the damage and failure of the valve seat 3. In this embodiment, a yielding space is also provided, which can prevent the valve seat 3 from twisting with the valve ball 2 during the rotation of the valve ball 2. Therefore, the deformation and damage of the valve seat 3 are further reduced, and the service life of the valve seat 3 is improved.

[0046] See the appendix Figure 3-4 , in this embodiment, in order to prevent the valve seat 3 from disengaging from the anti-twist yielding groove 4, a limiting unit 33 for preventing it from disengaging from the yielding groove 4 is also provided on the side of the self-sealing portion 32 facing away from the valve ball 2 (that is, the side away from the valve ball); thus, the self-sealing portion 32 at the end of the valve seat 3 can be prevented from falling off from the yielding groove 4.

[0047] See the appendix Figure 6 , on the inner side of the self-sealing portion 32 in contact with the valve ball 2 in this embodiment, an anti-cut chamfer 35 is also provided to prevent the valve port of the valve ball 2 from cutting off the valve seat 3 during the opening and closing process.

[0048] See the appendix Figure 4 In this embodiment, a support mechanism 5 is further provided inside the valve cover 12 and is oriented towards the valve ball 2. The support mechanism 5 provides a supporting force for the valve seat 3 to make it close to the valve ball 2; a deformation portion 34 that is supported on the support mechanism and is adapted to the shape of the support mechanism 5 is further provided on the valve seat 3, wherein the deformation portion 34 is transitionally connected to the self-sealing portion 31 and the mounting portion 32. By providing this support mechanism, a supporting effect on the valve seat in the direction of the valve ball is achieved, avoiding the problem that the valve seat cannot provide sufficient pre-tightening force due to insufficient stiffness, and thus avoiding the problem of insufficient sealing between the valve seat and the valve ball.

[0049] See the appendix Figure 4 In this embodiment, the support mechanism 5 includes a plurality of annular protrusions provided on the inner wall of the valve cover 12 and extending towards the valve ball 2; the deformation portion 34 is an annular groove clamped on the annular protrusions. An annular mounting groove 6 adapted for the mounting portion 32 to be inserted into is provided on the valve cover 12, and the mounting groove 6 and the relief groove 4 are respectively arranged on both sides of the annular protrusion. As Figure 3 shown, the axial cross-section of the valve seat 3 is in a hooked shape (where the axial direction refers to the direction parallel to the axial direction of the valve stem).

[0050] Among them, see the appendix Figure 5 Between the mounting groove 6 and the mounting portion 32, a strengthened sealing unit 7 for improving the sealing between the two is further provided. The strengthened sealing unit 7 in this embodiment includes a plurality of grooves provided on the mounting groove 6, and the grooves are in contact with the surface of the mounting portion 32. The grooves in this embodiment are triangular grooves, and the openings of the triangular grooves gradually decrease in the direction away from the mounting portion 32. Of course, the grooves are not limited to being provided as triangular grooves, nor are they limited to being provided on the inner wall of the mounting groove 6. The grooves can be provided on the surface of the mounting portion 32 in contact with the mounting groove 6, or on the inner wall surface of the mounting groove 6 in contact with the mounting portion 32.

[0051] As an alternative embodiment, the strengthened sealing unit 7 may further include a plurality of protrusions. The protrusions can be provided on the surface of the mounting portion 32 in contact with the mounting groove 6, and at this time the protrusions are embedded in the mounting groove 6; or the protrusions can also be provided on the inner wall surface of the mounting groove 6 in contact with the mounting portion 32, and at this time the protrusions are embedded in the mounting portion 32.

[0052] The valve seat 3 in this embodiment is fixedly connected to the valve cover 12 through a compression ring 8. A fastening compression ring 8 is provided inside the mounting portion 32 close to the valve ball 2. The compression ring 8 is fixed to the valve cover 12 by screws 9. Thus, the compression ring 8 presses and fixes the mounting portion 32 of the valve seat 3 in the mounting groove 6 of the valve cover 12.

[0053] As an alternative embodiment, when a fixed ball valve with a two-piece structure is adopted, the above-mentioned valve seats can be respectively arranged at the positions corresponding to the ball valve on the valve cover and the valve body on both sides of the ball valve. The structure of the valve seat and the valve seat installation and matching structure on the valve body are the same as the valve seat installation and matching structure on the valve cover in this embodiment.

[0054] The fixed ball valve of the present invention cancels the "metal valve seat + soft seal valve seat + O-ring + spring" structure in the prior art, and directly fixes the soft seal valve seat on the valve cover, with a simple structure and low cost; compared with the existing floating valve seat, the valve seat structure of the present invention has better elasticity and is not easily deformed during the opening and closing process, and can be applied to fixed ball valves with larger diameters.

[0055] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A fixed ball valve, which comprises: A housing, which is formed by covering a valve body with a valve cover. Inside the housing, valve seats are respectively installed on the valve body and / or the valve cover, and the valve seats are soft-sealing valve seats; A valve ball, which is arranged between the valve seats; It is characterized in that: The valve seat includes a self-sealing part and an installation part. The installation part is fixedly installed on the housing. The self-sealing part abuts against the valve ball and makes the valve seat have a pre-tightening force that tightly seals against the valve ball through its self-deformation; A support mechanism is further provided inside the housing. The support mechanism provides a supporting force for the valve seat to make it close to the valve ball; The valve seat further includes a deformation part supported by the support mechanism and adapted to it. The deformation part is connected between the self-sealing part and the installation part; The support mechanism includes several annular protrusions extending from the inner wall of the housing towards the direction close to the valve ball; The deformation part is an annular groove clamped on the annular protrusions; An annular retreat groove recessed away from the valve ball is provided at the position corresponding to the self-sealing part inside the housing; An annular installation groove suitable for the installation part to be inserted into is provided on the valve body and / or the valve cover. The installation groove and the retreat groove are respectively arranged on the axial two sides of the annular protrusion; A limiting unit for preventing it from detaching from the retreat groove is further provided on the side of the self-sealing part facing away from the valve ball.

2. The fixed ball valve according to claim 1, It is characterized in that: A retreat space allowing the self-sealing part to retreat towards the outside of the valve ball is formed in the retreat groove.

3. The fixed ball valve according to claim 1 or 2, It is characterized in that: The axial cross-section of the valve seat is in a hook shape.

4. The fixed ball valve according to claim 1 or 2, It is characterized in that: A strengthened sealing unit is further provided between the valve cover and the installation part.

5. The fixed ball valve according to claim 4, It is characterized in that: The strengthened sealing unit includes several grooves, and the grooves are provided on the side surface of the installation part in contact with the installation groove, or the grooves are provided on the side surface of the installation groove in contact with the installation part.

6. The fixed ball valve according to claim 5, It is characterized in that: The strengthened sealing unit includes several protrusions. The protrusions are provided on the side surface of the installation part in contact with the installation groove, and the protrusions are embedded in the installation groove; Or, the protrusions are provided on the side surface of the installation groove in contact with the installation part, and the protrusions are embedded in the installation part.

7. The fixed ball valve according to claim 1 or 2, It is characterized in that: A fastening compression ring is provided on the side of the installation part close to the valve ball, and the compression ring is fixed to the housing through a fixing member.

8. The fixed ball valve according to claim 7, It is characterized in that: Both the valve body and the valve cover are made of metal materials, and the valve seat is made of plastic materials.

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