Valve seat assembly and assembly method thereof

Abstract

The present invention belongs to the field of hydraulic valves, and specifically relates to a valve seat assembly and an assembly method thereof, wherein the valve seat assembly is composed of a valve seat, a lip seal ring, a sealing ring, a retaining ring, a retaining ring, a four-open ring, an inner liner ring, and a fastener; the lip seal ring, the retaining ring, and the retaining ring are sequentially installed on the valve seat, and the lip seal ring, the retaining ring, the retaining ring, and the valve seat are inserted into a mounting hole provided in the valve body together, and the retaining ring, the retaining ring, and the four-open ring are abutted together in sequence, and the other end of the four-open ring is abutted against the valve body, and the inner liner ring is installed in the four-open ring via the fastener. The valve seat assembly can protect the lip seal ring, reduce the travel distance of the lip seal ring, reduce the probability of the lip seal ring being damaged during use of a low-temperature top-mounted ball valve, and increase the service life of the low-temperature top-mounted ball valve.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic valves, and in particular relates to a valve seat assembly and an assembly method thereof. Background Art

[0002] The prior art cryogenic top-mounted ball valve includes a valve body 1, a ball 2, a valve seat 3, a lip seal 4 and a sealing ring 5. The outer periphery of the valve seat 3 is installed with a lip seal 4, which is used to seal between the valve seat 3 and the valve body 1. In the actual production and manufacturing process of the cryogenic top-mounted ball valve, due to the particularity of the top-mounted ball valve, when the ball 2 is installed into the valve cavity from the top, the valve seat 3 must be pulled a certain distance to both ends, which will cause the travel distance of the lip seal 4 installed on the valve seat 3 to be too long. During long-term use, the lip seal 4 will be damaged and cause leakage. Therefore, how to protect the lip seal on the valve seat to reduce the probability of the lip seal being damaged during the use of the cryogenic top-mounted ball valve has become a problem that urgently needs to be solved. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a valve seat assembly and an assembly method thereof, wherein the valve seat assembly can protect the lip sealing ring, reduce the travel distance of the lip sealing ring, reduce the probability of the lip sealing ring being damaged during the use of the low-temperature top-mounted ball valve, and increase the service life of the low-temperature top-mounted ball valve.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A valve seat assembly is used for a low-temperature top-entry ball valve. The valve seat assembly consists of a valve seat, a lip seal ring, a seal ring, a retaining ring, a retaining ring, a four-open ring, an inner liner ring and fasteners.

[0006] In which, the sealing ring is provided at one end of the valve seat, and the sealing ring is in sealing contact with the ball, and the lip sealing ring, the retaining ring and the retaining ring are installed in sequence at the other end of the valve seat. When the lip sealing ring, the retaining ring, the retaining ring and the valve seat are inserted into the mounting hole opened in the valve body, the retaining ring, the retaining ring and the four-open ring are abutted together in sequence, the other end of the four-open ring is abutted against the valve body, and the inner lining ring is installed in the four-open ring through the fastener.

[0007] Preferably, the valve seat includes a sealing section, a positioning section and an installation section arranged in sequence, the sealing ring is provided at one end of the sealing section, the tail of the installation section is provided with an assembly slope, the lip sealing ring, the retaining ring and the retaining ring are installed on the installation section in sequence, and the positioning section is inserted into the installation hole of the valve body.

[0008] Preferably, the cross-section of the retaining ring is an L-shaped cross-section having a short side and a long side, the short side is arranged on the outer periphery of the mounting section, and the long side is located between the mounting section and the inner liner ring; when the valve seat is installed in the valve body, a first gap is provided between the lip sealing ring and the retaining ring along the axial direction of the valve seat, and a second gap is provided between the end face of the mounting section and the long side along the axial direction of the valve seat, and the first gap is larger than the second gap.

[0009] Preferably, the inner liner ring is provided with a retaining hole and an operating hole which are connected in a radial direction, and the fastener is located in the retaining hole.

[0010] Preferably, an assembly groove is provided in the valve seat.

[0011] Preferably, a threaded section is provided on the outer peripheral surface of the sealing section.

[0012] Preferably, the four-open ring is formed by splicing four sub-open rings, and a threaded hole is radially opened in the middle of each sub-open ring.

[0013] A method for assembling a valve seat assembly, the method being used to install the valve seat assembly into a cryogenic top-mounted ball valve, the ball valve comprising at least the valve body, the valve seat assembly, the ball, a spring seat, and a nut, the valve body being sequentially provided with a first groove, a second groove, and a third groove for mounting the valve seat assembly, wherein the method comprises the following steps:

[0014] Step S1: first assembling the spring seat into the first groove, then placing the fastener into the retaining hole on the inner liner, and then assembling the inner liner into the third groove;

[0015] Step S2: sequentially installing the lip seal, the retaining ring, and the retaining ring on the mounting section, such that one side of the lip seal abuts against the positioning section and a gap is reserved between the other side and the retaining ring; then inserting the positioning section into the second groove until the side surface of the sealing section contacts the first groove, such that the retaining ring and the retaining ring are located at a first predetermined position on the mounting section;

[0016] Step S3: Keeping the valve seat and the valve body relatively fixed, screwing the nut into the threaded section on the sealing section until the nut presses against the spring seat;

[0017] Step S4: After the ball is installed into a predetermined position of the valve cavity from the top of the valve body, the valve seat is released. Under the action of the preload force of the spring seat, the valve seat, the lip seal ring, the retaining ring and the retaining ring move axially together, so that the sealing ring is in sealing contact with the ball;

[0018] Step S5: Assembling the four-open ring into the gap between the retaining ring and the second groove, so that one side of the four-open ring abuts against the retaining ring and the other side of the four-open ring abuts against the second groove, and the four-open ring pushes the retaining ring to move axially, so that the retaining ring and the retaining ring are located at the second predetermined position on the mounting section;

[0019] Step S6: After pushing the inner lining ring out of the third groove into the interior of the four-open ring, adjust the inner lining ring so that the retaining hole is aligned with the threaded hole on the four-open ring, and then screw the fastener into the threaded hole to complete the assembly positioning of the four-open ring.

[0020] Preferably, step S3 also includes: first inserting the working section of the semi-open ring into the assembly groove, then inserting the valve seat fixing support into the semi-open ring, and using the valve seat fixing support to apply a radial pre-tightening force to the semi-open ring, so that the valve seat, the semi-open ring and the valve seat fixing support are relatively fixed, and then keeping the valve seat fixing support stationary so that the position of the valve seat and the valve body is relatively fixed.

[0021] Preferably, step S4 also includes: driving the semi-open ring and the valve seat fixing support to move axially, so that the spring seat pushes the valve seat, the lip sealing ring, the retaining ring and the retaining ring to move axially together until the sealing ring is in sealing contact with the ball, and then removing the semi-open ring and the valve seat fixing support.

[0022] Compared with the prior art, the valve seat assembly and assembly method provided by the present invention have the following beneficial technical effects:

[0023] 1. The present invention sequentially installs a lip seal ring, a retaining ring and a baffle ring on the valve seat, and when inserted into the mounting hole opened in the valve body, the retaining ring, the retaining ring and the four-open ring abut against each other in sequence, the other end of the four-open ring abuts against the valve body, and the inner liner ring is installed in the four-open ring through fasteners. This valve seat structure can reduce the travel distance of the lip seal ring, reduce the probability of the lip seal ring being damaged during the use of the low-temperature top-mounted ball valve, and improve the service life of the low-temperature top-mounted ball valve.

[0024] 2. The present invention sets the first gap between the lip sealing ring and the retaining ring along the axial direction of the valve seat to be larger than the second gap between the end face and the long side of the mounting section along the axial direction of the valve seat. This ensures that during the entire working process of the valve seat, the mounting section of the valve seat will first contact the long side of the retaining ring, so that the lip sealing ring will not abut against the retaining ring, thereby avoiding damage to the lip sealing ring under the squeezing of the valve seat and the retaining ring.

[0025] 3. When assembling the lip seal, the retaining ring and the retaining ring, the side of the sealing section is firstly used to contact the first groove to ensure that the retaining ring and the retaining ring are installed to the first predetermined position (such as the attached Figure 4 ), then use the spring seat preload force to make the valve seat, lip seal, retaining ring and retaining ring move axially together until they are in sealing contact with the ball, and then use the four-open ring to push the retaining ring to move axially so that the retaining ring and retaining ring are located at the second predetermined position on the installation section (as shown in the attached figure). Figure 6 ), thereby simply and conveniently ensuring that the first gap between the lip seal ring and the retaining ring along the axial direction of the valve seat is larger than the second gap between the end face and the long side of the mounting section along the axial direction of the valve seat.

[0026] 4. The present invention opens an assembly groove on the valve seat, and cooperates with the semi-open ring and the valve seat fixing support to simply and conveniently maintain the relative fixed position of the valve seat and the valve body, thereby facilitating the assembly of the nut to a predetermined position. Subsequently, by driving the semi-open ring and the valve seat fixing support to move axially, the spring seat pushes the valve seat, lip sealing ring, retaining ring and retaining ring to move axially together until the sealing ring is in sealing contact with the ball. On the one hand, it can ensure that there is sufficient sealing pre-tightening force between the sealing ring and the ball, and on the other hand, it ensures that the lip sealing ring can be smoothly installed in place. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram of a valve seat assembly in the prior art;

[0028] Figure 2 Schematic diagram of the structure of the valve seat assembly of the present invention;

[0029] Figure 3 This is a schematic structural diagram of the present invention in a first assembly state;

[0030] Figure 4 It is a structural schematic diagram of the second assembly state of the present invention;

[0031] Figure 5 This is a schematic structural diagram of the present invention in a third assembly state;

[0032] Figure 6 It is a structural schematic diagram of the fourth assembly state of the present invention.

[0033] The meanings of the symbols in the figure are as follows:

[0034] 1. Valve body; 2. Ball; 3. Valve seat; 4. Lip seal; 5. Sealing ring; 6. Retaining ring; 7. Retaining ring; 8. Four-open ring; 9. Inner liner; 10. Fastener; 11. First groove; 12. Second groove; 13. Third groove; 14. Spring seat; 15. Nut; 16. Assembly groove; 17. Half-open ring; 18. Valve seat retaining support;

[0035] 111. Retention hole; 112. Operation hole; 113. Sealing section; 114. Positioning section; 115. Installation section; 116. Assembly slope; 117. Short side; 118. Long side; 119. First gap; 120. Second gap. DETAILED DESCRIPTION

[0036] 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 with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0037] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some 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 shall fall within the scope of protection of the present invention.

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein may be combined with each other.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0040] In the description of the present invention, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art. Such terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0041] See attached Figure 1 -Attached Figure 6As shown, the present invention provides a valve seat assembly, which is applied to a low-temperature top-mounted ball valve. The valve seat assembly consists of a valve seat 3, a lip seal 4, a sealing ring 5, a retaining ring 6, a retaining ring 7, a four-open ring 8, an inner liner 9, and a fastener 10. A sealing ring 5 is provided at one end of the valve seat 3, which is in sealing contact with the ball 2. The lip seal 4, retaining ring 6, and retaining ring 7 are sequentially mounted on the other end of the valve seat 3. When the lip seal 4, retaining ring 6, retaining ring 7, and valve seat 3 are inserted into the mounting hole provided in the valve body 1, the retaining ring 6, retaining ring 7, and four-open ring 8 abut against each other in sequence. The other end of the four-open ring 8 abuts against the valve body 1, and the inner liner 9 is mounted on the four-open ring 8 via the fastener 10.

[0042] Preferably, an assembly groove 16 is provided in the valve seat 3, and the valve seat 3 includes a sealing section 113, a positioning section 114 and an installation section 115 arranged in sequence, a sealing ring 5 is provided at one end of the sealing section 113, a threaded section is provided on the outer peripheral surface of the sealing section 113, an assembly slope 116 is provided at the tail of the installation section 115, a lip sealing ring 4, a retaining ring 6 and a retaining ring 7 are installed on the installation section 115 in sequence, and the positioning section 114 is inserted into the installation hole of the valve body 1.

[0043] Preferably, the cross-section of the retaining ring 7 is an L-shaped cross-section having a short side 117 and a long side 118. The short side 117 is arranged on the periphery of the mounting section 115, and the long side 118 is located between the mounting section 115 and the inner liner 9. When the valve seat 3 is installed in the valve body 1, a first gap 119 is defined between the lip seal 4 and the retaining ring 6 along the axial direction of the valve seat 3. A second gap 120 is defined between the end surface of the mounting section 115 and the long side 118 along the axial direction of the valve seat 3. The first gap 119 is larger than the second gap 120.

[0044] Preferably, a connecting retaining hole 111 and an operating hole 112 are respectively opened on the inner liner 9 along the radial direction, and the fastener 10 is located in the retaining hole 111. The four-open ring 8 is spliced ​​by four sub-open rings, and a threaded hole is opened in the middle of each sub-open ring along the radial direction.

[0045] In the above embodiment, by installing the lip sealing ring, retaining ring and retaining ring on the valve seat in sequence, and when inserted into the mounting hole opened in the valve body, the retaining ring, retaining ring and four-open ring are abutted together in sequence, the other end of the four-open ring is abutted against the valve body, and the inner lining ring is installed in the four-open ring through fasteners. The valve seat structure can reduce the travel distance of the lip sealing ring, reduce the probability of the lip sealing ring being damaged during the use of the low-temperature top-mounted ball valve, and improve the service life of the low-temperature top-mounted ball valve.

[0046] Secondly, the first gap between the lip sealing ring and the retaining ring along the axial direction of the valve seat is set to be larger than the second gap between the end face and the long side of the mounting section along the axial direction of the valve seat. This ensures that during the entire working process of the valve seat, the mounting section of the valve seat will first contact the long side of the retaining ring, so that the lip sealing ring will not abut against the retaining ring, thereby avoiding damage to the lip sealing ring under the squeezing of the valve seat and the retaining ring.

[0047] The present invention also provides a method for assembling a valve seat assembly, which is used to install the valve seat assembly into a low-temperature top-mounted ball valve. The ball valve includes at least a valve body 1, a valve seat assembly, a ball 2, a spring seat 14, and a nut 15. The valve body 1 is sequentially provided with a first groove 11, a second groove 12, and a third groove 13 for mounting the valve seat assembly. The method comprises the following steps:

[0048] Step S1: First, assemble the spring seat 14 into the first groove 11, then put the fastener 10 into the retaining hole 111 on the inner liner 9, and then assemble the inner liner 9 into the third groove 13. At this time, the positions of the inner liner 9 and the spring seat 14 are as shown in the attached figure. Figure 3 As shown in .

[0049] Step S2: Install the lip seal 4, the retaining ring 6 and the retaining ring 7 on the installation section 115 in sequence, so that one side of the lip seal 4 abuts against the positioning section 114, and a gap is reserved between the other side and the retaining ring 6. Then, insert the positioning section 114 into the second groove 12 until the side of the sealing section 113 contacts the first groove 11, so that the retaining ring 6 and the retaining ring 7 are located at the first predetermined position on the installation section 115. The first predetermined position is as shown in the attached figure. Figure 4 As shown in .

[0050] Step S3 : while keeping the valve seat 3 and the valve body 1 relatively fixed, screw the nut 15 into the threaded section on the sealing section 113 until the nut 15 presses the spring seat 14 .

[0051] Step S4: After the ball 2 is loaded into the predetermined position of the valve cavity from the top of the valve body 1, the valve seat 3 is released. Under the action of the preload force of the spring seat 14, the valve seat 3, the lip seal 4, the retaining ring 6 and the retaining ring 7 move axially together, so that the sealing ring 5 is in sealing contact with the ball 2. At this time, the lip seal 4, the retaining ring 6 and the retaining ring 7 move to the adjacent Figure 5 The location in the.

[0052] Step S5: Assemble the four-open ring 8 into the gap between the retaining ring 7 and the second groove 12, so that one side of the four-open ring 8 abuts against the retaining ring 7, and the other side of the four-open ring 8 abuts against the second groove 12, and the four-open ring 8 pushes the retaining ring 7 to move axially, so that the retaining ring 6 and the retaining ring 7 are located at the second predetermined position on the installation section 115. The second predetermined position is as shown in the attached figure. Figure 6 As shown in .

[0053] Step S6: After pushing the inner lining ring 9 from the third groove 13 to the inside of the four-open ring 8, adjust the inner lining ring 9 so that the retaining hole 111 is aligned with the threaded hole on the four-open ring 8, and then screw the fastener 10 into the threaded hole to complete the assembly positioning of the four-open ring 8. The final assembly state is as shown in the attached figure. Figure 6 shown.

[0054] Preferably, step S3 also includes: first inserting the working section of the semi-open ring 17 into the assembly groove 16, then inserting the valve seat fixing support 18 into the semi-open ring 17, and using the valve seat fixing support 18 to apply a radial pre-tightening force to the semi-open ring 17, so that the valve seat 3, the semi-open ring 17 and the valve seat fixing support 18 are relatively fixed, keeping the valve seat fixing support 18 stationary, so that the position of the valve seat 3 and the valve body 1 is relatively fixed.

[0055] Preferably, step S4 also includes: driving the semi-open ring 17 and the valve seat fixing support 18 to move axially, so that the spring seat 14 pushes the valve seat 3, the lip sealing ring 4, the retaining ring 6 and the retaining ring 7 to move axially together, until the sealing ring 5 is in sealing contact with the ball 2, and then removing the semi-open ring 17 and the valve seat fixing support 18.

[0056] In the above embodiment, when assembling the lip seal, the retaining ring and the retaining ring, firstly, the side of the sealing section is in contact with the first groove to ensure that the retaining ring and the retaining ring are installed to the first predetermined position (such as the attached Figure 4 ), then use the spring seat preload force to make the valve seat, lip seal, retaining ring and retaining ring move axially together until they are in sealing contact with the ball, and then use the four-open ring to push the retaining ring to move axially so that the retaining ring and retaining ring are located at the second predetermined position on the installation section (as shown in the attached figure). Figure 6 ), thereby simply and conveniently ensuring that the first gap between the lip seal ring and the retaining ring along the axial direction of the valve seat is larger than the second gap between the end face and the long side of the mounting section along the axial direction of the valve seat.

[0057] Secondly, an assembly groove is opened on the valve seat, and the combination of the semi-open ring and the valve seat fixing support can simply and conveniently keep the position of the valve seat and the valve body relatively fixed, thereby facilitating the assembly of the nut to the predetermined position. Subsequently, by driving the semi-open ring and the valve seat fixing support to move axially, the spring seat pushes the valve seat, lip seal ring, retaining ring and retaining ring to move axially together until the seal ring is in sealing contact with the ball. On the one hand, it can ensure that there is sufficient sealing pre-tightening force between the seal ring and the ball, and on the other hand, it ensures that the lip seal ring can be smoothly installed in place.

[0058] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A valve seat assembly, characterized in that: The valve seat assembly is applied to a low-temperature top-mounted ball valve, and the valve seat assembly consists of a valve seat, a lip seal ring, a seal ring, a retaining ring, a retaining ring, a four-open ring, an inner lining ring and fasteners; Wherein, one end of the valve seat is provided with the sealing ring, and the sealing ring is in sealing contact with the ball, and the other end of the valve seat is sequentially installed with the lip sealing ring, the retaining ring and the retaining ring, when the lip sealing ring, the retaining ring, the retaining ring and the valve seat are inserted into the mounting hole provided in the valve body, the retaining ring, the retaining ring and the four-open ring are abutted together in sequence, the other end of the four-open ring is abutted against the valve body, and the inner lining ring is installed in the four-open ring through the fastener; The valve seat includes a sealing section, a positioning section and an installation section arranged in sequence. The sealing ring is provided at one end of the sealing section. The tail of the installation section is provided with an assembly slope. The lip sealing ring, the retaining ring and the retaining ring are installed on the installation section in sequence. The positioning section is inserted into the installation hole of the valve body. The cross-section of the retaining ring is an L-shaped cross-section with a short side and a long side, the short side is arranged on the outer periphery of the mounting section, and the long side is located between the mounting section and the inner liner ring; when the valve seat is installed in the valve body, a first gap is provided between the lip sealing ring and the retaining ring along the axial direction of the valve seat, and a second gap is provided between the end face of the mounting section and the long side along the axial direction of the valve seat, and the first gap is larger than the second gap.

2. The valve seat assembly according to claim 1, wherein: The inner lining ring is provided with a retaining hole and an operating hole which are connected in a radial direction, and the fastener is located in the retaining hole.

3. The valve seat assembly according to claim 2, wherein: An assembly groove is provided in the valve seat.

4. The valve seat assembly according to claim 3, wherein: A threaded section is provided on the outer peripheral surface of the sealing section.

5. The valve seat assembly according to claim 4, wherein: The four-open ring is formed by splicing four sub-open rings, and a threaded hole is radially opened in the middle of each sub-open ring.

6. A method for assembling the valve seat assembly according to claim 5, wherein the method is used to install the valve seat assembly into a cryogenic top-mounted ball valve, wherein the ball valve comprises at least the valve body, the valve seat assembly, the ball, a spring seat, and a nut, wherein the valve body is sequentially provided with a first groove, a second groove, and a third groove for mounting the valve seat assembly, wherein: The assembly method comprises the following steps: Step S1: first assembling the spring seat into the first groove, then placing the fastener into the retaining hole on the inner liner, and then assembling the inner liner into the third groove; Step S2: sequentially installing the lip seal, the retaining ring, and the retaining ring on the mounting section, such that one side of the lip seal abuts against the positioning section and a gap is reserved between the other side and the retaining ring; then inserting the positioning section into the second groove until the side surface of the sealing section contacts the first groove, such that the retaining ring and the retaining ring are located at a first predetermined position on the mounting section; Step S3: Keeping the valve seat and the valve body relatively fixed, screwing the nut into the threaded section on the sealing section until the nut presses against the spring seat; Step S4: After the ball is installed into a predetermined position of the valve cavity from the top of the valve body, the valve seat is released. Under the action of the preload force of the spring seat, the valve seat, the lip seal ring, the retaining ring and the retaining ring move axially together, so that the sealing ring is in sealing contact with the ball; Step S5: Assembling the four-open ring into the gap between the retaining ring and the second groove, so that one side of the four-open ring abuts against the retaining ring and the other side of the four-open ring abuts against the second groove, and the four-open ring pushes the retaining ring to move axially, so that the retaining ring and the retaining ring are located at the second predetermined position on the mounting section; Step S6: After pushing the inner lining ring out of the third groove into the interior of the four-open ring, adjust the inner lining ring so that the retaining hole is aligned with the threaded hole on the four-open ring, and then screw the fastener into the threaded hole to complete the assembly positioning of the four-open ring.

7. The assembly method according to claim 6, wherein: The step S3 also includes: first inserting the working section of the semi-open ring into the assembly groove, then inserting the valve seat fixing support into the semi-open ring, and using the valve seat fixing support to apply a radial pre-tightening force to the semi-open ring, so that the valve seat, the semi-open ring and the valve seat fixing support are relatively fixed, and then keeping the valve seat fixing support stationary so that the position of the valve seat and the valve body is relatively fixed.

8. The assembly method according to claim 7, wherein: The step S4 also includes: driving the semi-open ring and the valve seat fixing support to move axially, so that the spring seat pushes the valve seat, the lip sealing ring, the retaining ring and the retaining ring to move axially together until the sealing ring is in sealing contact with the ball, and then removing the semi-open ring and the valve seat fixing support.

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