A linkage shut-off natural gas ball valve and a preparation method thereof

Abstract

The application discloses a linkage shutdown type natural gas ball valve and a preparation method thereof, relates to the technical field of valves, and comprises a valve body, a ball body, a sleeve pipe and a linkage shutdown device; locking end heads are arranged at both ends of the valve body, the sleeve pipe is sleeved outside the locking end heads and is connected through thread cooperation; the locking end head is provided with a taper portion, a plurality of slits are formed in the taper portion in the axial direction, and the slits divide the taper portion into a plurality of petal bodies which can move in the radial direction; and the sleeve pipe is internally provided with a conical cavity.When the sleeve pipe is screwed, the conical cavity extrudes the taper portion so as to make the taper portion contract in the radial direction and tightly embrace the pipeline.The linkage shutdown device is connected to a valve rod and is used for automatically driving the valve rod to rotate and shut down the ball valve when detecting abnormal flow or pressure fluctuation.The application realizes convenient installation of the pipeline through the quick connection structure of the locking end head and the sleeve pipe, and the linkage shutdown device and the opening degree indicator are arranged, so that the automatic shutdown capacity and the operation safety of the ball valve are improved.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a linkage shut-off type natural gas ball valve and its manufacturing method. Background Technology

[0002] In medium-pressure natural gas transmission systems, ball valves serve as critical shut-off and control devices, and their performance directly impacts the safety and operational efficiency of the transmission system. The connection method between the valve and the natural gas pipeline directly affects the ease of pipeline installation and the long-term safety and reliability of operation.

[0003] Chinese Patent CN111442108B discloses a medium-pressure ball valve for natural gas. Its structure includes a valve, an inlet, a gas guide pipe, a valve body, and an outlet. The valve is movably engaged at the upper end of the valve body. The inlet is welded to the rear end of the gas guide pipe, and the outlet is installed at the front end of the gas guide pipe. The valve body is fixedly connected to the gas guide pipe. A clockwise rotation of a rotating rod drives a push rod to rotate synchronously along a sliding groove on the base plate, thereby discharging natural gas from the ball. When the rotating rod rotates 90°, the push rod pushes an exhaust plate connected to the base plate to block the two openings on the ball. The rotating rod then drives a linkage disc to rotate, causing the linkage disc to rotate and close the ball, effectively preventing residual natural gas from remaining inside the ball during rotational closure.

[0004] Currently, there are two main methods for connecting natural gas valves and pipelines: bolted flange connections, which require a large number of fasteners and involve complex and time-consuming installation procedures; and on-site welding connections, which have high requirements for the construction environment and whose welding quality is greatly affected by the operator's skill level. More importantly, both of these connection methods lack effective protective structures at the interface. With the increase in service time, the sealing gaskets of bolted flange connections are prone to aging and failure, and the welds of welded connections may develop defects, leading to natural gas leaks at the interface and posing a significant safety hazard.

[0005] Furthermore, existing ball valves typically require manual operation or rely on external electric actuators to close, and cannot automatically respond and shut off when pipeline flow is abnormal, which can easily lead to safety accidents. At the same time, most ball valves lack intuitive opening degree indicators, making it difficult for operators to quickly determine whether the valve is open or closed, causing inconvenience for daily inspections and emergency response.

[0006] Therefore, how to simplify the connection process between natural gas valves and pipelines, improve the reliability and convenience of interface connections, and at the same time realize the automatic linkage shut-off and opening degree indication functions of ball valves are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention is proposed.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a linkage shut-off type natural gas ball valve, comprising:

[0009] The valve body has locking ends at both ends;

[0010] A sphere is rotatably disposed inside the valve body;

[0011] The sleeve is fitted onto the outside of the locking end, and the sleeve and the locking end are connected by a threaded connection;

[0012] The locking end has a tapered portion, and the tapered portion has multiple slits opened along the axial direction, the slits dividing the tapered portion into multiple radially movable lobes;

[0013] The sleeve has a conical cavity inside, and the inner conical surface of the conical cavity matches the outer conical surface of the cone of the locking end.

[0014] When the sleeve is tightened relative to the locking end, the inner conical surface of the conical cavity presses against the outer conical surface of the cone, forcing the cone to retract radially to hold the pipe inserted into the locking end.

[0015] It also includes a linkage shut-off device, which is connected to the valve stem and is used to drive the valve stem to rotate to shut off the ball when a preset trigger condition is detected.

[0016] As a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, the linkage shut-off device is a flow linkage switch, which triggers shut-off when the natural gas flow exceeds a set threshold.

[0017] As a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, it further includes a valve opening indicator, which is disposed on the valve body or gland flange and is used to display the open or closed state of the ball.

[0018] As a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, the outer wall of the locking end is provided with an external thread section, and the sleeve is provided with an internal thread section, wherein the internal thread section and the thread section cooperate.

[0019] As a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, wherein: the locking end has a pipe insertion hole along the axis for inserting an external pipe, and the pipe insertion hole extends to the bottom of the external thread section.

[0020] As a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, the plurality of slits are evenly distributed along the axial direction of the cone.

[0021] In a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, there is an angle difference between the inner conical surface of the conical cavity and the outer conical surface of the cone portion of the locking end, and the angle between the inner conical surface of the conical cavity and the central axis is smaller than the angle between the outer conical surface of the cone portion and the central axis.

[0022] As a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, the valve body has a Haver-type structure, which is formed by the first valve body half shell and the second valve body half shell joining together along the enclosing surface, and the first valve body half shell and the second valve body half shell are fixedly connected by fasteners; an enclosing sealing groove is provided at the enclosing part of the first valve body half shell and the second valve body half shell, and a sealing element is embedded in the enclosing sealing groove.

[0023] As a preferred embodiment of the linkage shut-off natural gas ball valve of the present invention, the valve body is provided with two valve seats and two butterfly springs, the two valve seats are respectively located on both sides of the ball, and each butterfly spring abuts against the corresponding valve seat and the valve body;

[0024] The butterfly spring is a butterfly spring sealing ring formed by injecting rubber material into multiple butterfly spring plates for protection;

[0025] The valve body is also equipped with a vent pipe.

[0026] A method for manufacturing a linked shut-off natural gas ball valve, wherein the valve body, valve seat, ball, support seat, sleeve, valve stem, and gland flange of the linked shut-off natural gas ball valve are made of low-expansion austenitic stainless steel. The low-expansion austenitic stainless steel contains the following components by mass percentage: Ni 16.0–20.0 wt%, Cr 13.0–14.0 wt%, Mo 1.4–2.6 wt%, Nb 0.6–0.8 wt%, Si 0.8–1.2 wt%, C ≤ 0.05 wt%, Mn ≤ 1.0 wt%, with the balance being aluminum (Fe). The method includes the following steps:

[0027] S1: Valve body processing: Low expansion austenitic stainless steel pipe is selected, and after die forging and normalizing, it is machined according to the structural design. Locking ends are formed at both ends of the valve body. A tapered part and multiple slits along the axial direction are machined on the locking ends, and a vent pipe is welded on the valve body.

[0028] S2: Valve seat machining: Low expansion austenitic stainless steel tubing is selected, and after die forging and normalizing, it is machined according to the structural design, and the sealing surface of the valve seat is precision ground.

[0029] S3: Sphere machining: Low-expansion austenitic stainless steel bars are selected and after forging, normalizing, rough turning, precision turning, quenching and tempering, the surface of the sphere is precision ground, and through holes and keyways are machined into the sphere.

[0030] S4: Support base machining: Low expansion austenitic stainless steel bars are selected, machined according to the structural design, and the support surface of the support base is precision ground.

[0031] S5: Sleeve processing: Select expanded austenitic stainless steel bars and process conical cavities and internal thread sections according to the structural design;

[0032] S6: Valve stem and gland flange processing: Select low expansion austenitic stainless steel bars and machine them according to the structural design to produce valve stems and gland flanges.

[0033] S7: Processing of butterfly springs: Stack butterfly spring sheets in a mold and inject rubber material. After vulcanization and molding, the springs are trimmed to obtain butterfly springs.

[0034] S8: Seal processing: Make a mold according to the size and shape of the seal, put the rubber raw material into the mold, and after vulcanization and molding, trim and process to obtain the seal;

[0035] S9: Component Assembly: Install the butterfly spring and valve seat inside the valve body, and make the valve seat abut against the butterfly spring; connect the valve stem (180) to the ball, place the support seat against the bottom of the ball, and install the assembled valve stem, ball, and support seat into the valve body; embed the seal into the sealing groove of the valve body enclosure, close the valve body and lock it with fasteners; put the gland flange on the valve stem and fix it to the upper end of the valve body; put the sleeve on the outside of the locking end and connect it with the external thread section of the locking end through the internal thread section;

[0036] S10: Install the linkage shut-off device on the upper end of the valve stem and connect the linkage shut-off device to the valve stem drive; install the valve opening indicator on the upper surface of the valve body gland flange.

[0037] The beneficial effects of this invention are:

[0038] 1. Introduce alloying elements into the material: Ni 16.0–20.0 wt%, Cr 13.0–14.0 wt%, Mo 1.4–2.6 wt%, Nb 0.6–0.8 wt%, Si 0.8–1.2 wt%, C ≤ 0.05 wt%, Mn ≤ 1.0 wt%. The combined effect of Cr, Mo, and other alloying elements improves the wear resistance and corrosion resistance of stainless steel. Ni and Nb alloying elements stabilize austenite and reduce the coefficient of thermal expansion of stainless steel; C ≤ 0.05 wt% avoids sensitized intergranular corrosion and improves the corrosion resistance of processed stainless steel.

[0039] 2. By adopting a threaded fit structure between the locking end and the sleeve, and setting a cone with multiple slits on the locking end and a conical cavity inside the sleeve, when the sleeve is tightened relative to the locking end, the inner conical surface of the conical cavity presses against the outer conical surface of the cone, forcing the cone to contract radially, thereby gripping the pipe inserted into the locking end. This achieves a quick and reliable connection between the valve and the pipe. At the same time, a multi-protection structure of valve body, seal, and sleeve is formed at the interface, which significantly improves the sealing reliability and construction convenience of the interface.

[0040] 3. By setting up a linkage shut-off device and a valve opening indicator, the linkage shut-off device is installed on the upper end of the valve stem and connected to its transmission. When the natural gas flow exceeds the set threshold, it will automatically trigger the shut-off, realizing the automatic protection function of the valve and avoiding accidents caused by abnormal flow. The valve opening indicator is installed on the upper surface of the gland flange and displays the opening and closing status of the ball in linkage with the valve stem, which is convenient for on-site inspection and remote monitoring, and improves the safety and intelligence level of the natural gas transmission system. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the external appearance of the linkage shut-off natural gas ball valve in this invention;

[0043] Figure 2 This is a partial cross-sectional view and a schematic diagram of the disassembled sleeve structure of the linkage shut-off natural gas ball valve in this invention.

[0044] Figure 3 This is a schematic cross-sectional view of the linkage shut-off natural gas ball valve in this invention.

[0045] Figure 4 This is a schematic cross-sectional view of the valve body of the linkage shut-off natural gas ball valve in this invention.

[0046] Figure 5 This is a partial cross-sectional view of the valve seat of the linkage shut-off natural gas ball valve in this invention.

[0047] Figure 6 This is a schematic cross-sectional view of the valve seat of the linked shut-off natural gas ball valve in this invention.

[0048] Figure 7 This is a schematic diagram of the ball structure of the linkage shut-off natural gas ball valve in this invention;

[0049] Figure 8 This is a partial cross-sectional view of the support structure of the linkage shut-off natural gas ball valve in this invention.

[0050] Figure 9 This is a schematic cross-sectional view of the sleeve structure of the linkage shut-off natural gas ball valve in this invention.

[0051] Figure 10 This is a schematic diagram of the stem structure of the linkage shut-off natural gas ball valve in this invention;

[0052] Figure 11 This is a partial cross-sectional view of the gland flange of the linked shut-off natural gas ball valve in this invention.

[0053] Explanation of reference numerals in the attached drawings: 100, valve body; 1001, valve body flow channel; 101, first valve body half-shell; 102, second valve body half-shell; 103, enclosing sealing groove; 104, bolt countersunk hole; 105, bolt through hole; 106, screw hole; 107, spring retainer groove; 110, locking end; 111, cone; 112, slit; 113, external thread section; 114, pipe insertion hole; 120, sleeve; 121, conical cavity; 122. Internal thread section; 130, valve seat; 131, valve seat flow channel; 140, butterfly spring; 150, ball; 151, ball through hole; 152, keyway; 160, vent pipe; 170, support seat; 180, valve stem; 181, lock head; 182, stem body; 183, flange; 1831, flange sealing groove; 184, stem key; 185, stem body sealing groove; 190, gland flange; 191, valve stem through hole; 192, flange countersunk hole. Detailed Implementation

[0054] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0055] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0056] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0057] Example 1:

[0058] Reference Figures 1-11As shown, this is the first embodiment of the present invention. This embodiment provides a linkage shut-off type natural gas ball valve, which includes: a valve body 100, two valve seats 130, a ball 150, a support seat 170, a sleeve 120, a valve stem 180, a gland flange 190, a butterfly spring 140, and a sealing element, which is sleeved on the outside of the locking end 110. The sleeve 120 is connected to the locking end 110 by a threaded connection. The sleeve 120 has a conical cavity 121 inside, and the inner conical surface of the conical cavity 121 mates with the outer conical surface of the cone portion 111 of the locking end 110. When the sleeve 120 is tightened relative to the locking end 110, the inner conical surface of the conical cavity 121 presses against the outer conical surface of the cone portion 111, forcing the cone portion 111 to radially retract, so as to tightly hold the pipe inserted into the locking end 110. This embodiment also includes a linkage shut-off device and a valve opening indicator. The linkage shut-off device is installed at the upper end of the valve stem 180 and is connected to the valve stem 180 in a driving connection. The valve opening indicator is installed on the upper surface of the gland flange 190.

[0059] like Figures 1 to 4 As shown, the valve body 100 is the main load-bearing component of the entire ball valve, and its interior forms a cavity to accommodate the ball 150, valve seat 130, and support seat 170. The ball 150 is rotatably positioned in the center of the cavity. Two valve seats 130 are respectively located on the left and right sides of the ball 150, and the sealing surfaces of both valve seats 130 are spherical arc surfaces, respectively fitting against the left and right outer spherical surfaces of the ball 150 to form the main sealing structure. The support seat 170 is located at the bottom of the cavity, directly below the ball 150. The supporting surface of the support seat 170 is a spherical arc surface, fitting against the lower outer spherical surface of the ball 150, used to support the ball 150 from below, ensuring the stability of the ball 150 during rotation, and distributing part of the weight of the ball 150, reducing the stress on the valve stem 180. The internal valve body flow channel 1001 of the valve body 100 adopts a smooth transition design to reduce natural gas flow resistance. The wall thickness of valve body 100 is designed according to medium pressure conditions to ensure that it will not deform under medium pressure.

[0060] In this embodiment, the valve body 100 adopts a Haver-type structure, which is divided into a first valve body half-shell 101 and a second valve body half-shell 102, and the valve body 100 is formed by the first valve body half-shell 101 and the second valve body half-shell 102 joining together along the enclosing surface. The Haver-type structure of the valve body 100 facilitates the assembly and maintenance of the internal components of the ball valve.

[0061] In one embodiment, a protrusion is provided on the first valve body half-shell 101, and a groove is provided on the second valve body half-shell 102 to mate with the protrusion; the protrusion and groove are positioned in conjunction. In another embodiment, a groove is provided on the first valve body half-shell 101, and a protrusion is provided on the second valve body half-shell 102. Both arrangements can achieve precise positioning, and those skilled in the art can choose according to actual needs.

[0062] The first valve body half-shell 101 has several bolt countersunk holes 104 and bolt through holes 105 on its circumference, and the second valve body half-shell 102 has several screw holes 106 corresponding to the bolt through holes 105 on its circumference. During assembly, the bolts pass through the bolt countersunk holes 104 and bolt through holes 105 of the first valve body half-shell 101 and are screwed into the screw holes 106 of the second valve body half-shell 102 to lock and fix the first valve body half-shell 101 and the second valve body half-shell 102.

[0063] Furthermore, a sealing groove 103 is provided at the junction of the first valve body half shell 101 and the second valve body half shell 102, and a sealing element is embedded in the sealing groove 103 to ensure the sealing performance of the valve body 100 after it is closed.

[0064] In one embodiment, the valve body 100 has two spring slots 107 inside, located on the left and right sides of the valve body 100 respectively, and positioned on the side of the two valve seats 130 away from the ball 150. Each spring slot 107 contains a butterfly spring 140. The butterfly spring 140 is a sealing ring formed by injecting a protective adhesive onto multiple butterfly spring discs. The butterfly spring 140 abuts against the valve seat 130 and the valve body 100, applying a continuous preload to the valve seat 130 to ensure that the sealing surface of the valve seat 130 remains in close contact with the ball 150 under different operating conditions.

[0065] Furthermore, two locking ends 110 are symmetrically arranged at both ends of the valve body 100. The outer wall of the locking end 110 is provided with an external thread section 113, and the sleeve tube 120 is provided with an internal thread section 122, which cooperates with the thread section.

[0066] The angle between the outer conical surface of the cone 111 and the central axis of the valve body flow channel 1001 is 22°. A pipe insertion hole 114 is provided inside the locking end 110 along the axial direction, extending to the bottom of the external thread section 113. The diameter of the pipe insertion hole 114 is designed according to the outer diameter of the external natural gas pipeline for insertion into the external natural gas pipeline. Six slits 112 are evenly distributed axially on the outer conical surface of the cone 111. The width of each slit 112 is 6 mm, and the multiple slits 112 divide the cone 111 into multiple radially movable flaps. Utilizing the elasticity of the material, the cone 111 can be radially tightened and expanded.

[0067] In one embodiment, the valve body 100 is also provided with a vent pipe 160, which is a double vent pipe 160 structure, used to connect to the vent valve to discharge natural gas in the pipeline during maintenance or emergency.

[0068] In one embodiment, such as Figure 5 and Figure 6As shown, valve seats 130 are a pair of symmetrically arranged annular components, respectively located on both sides of the ball 150. A valve seat flow channel 131 is formed in the middle of the valve seat 130, the size of which is consistent with the valve body flow channel 1001 of the valve body 100 to ensure smooth media flow. The sealing surface of the valve seat 130 is a spherical arc surface, which matches the outer spherical surface of the ball 150. The sealing surface is precision ground, with a surface roughness of no more than 0.8μm, ensuring a tight fit between the sealing surface and the ball 150, enhancing wear resistance and sealing performance. A valve seat 130 sealing groove is provided along the outer edge of the sealing surface of the valve seat 130, and a sealing element is embedded in the valve seat 130 sealing groove to enhance the valve's sealing performance.

[0069] In one embodiment, such as Figure 7 As shown, the ball 150 is forged from a high-strength alloy material. The ball 150 has a through-hole 151 with the same dimensions as the valve seat flow channel 131. The inner wall of the through-hole 151 is polished to further reduce natural gas flow resistance. A keyway 152 is formed on the upper end face of the ball 150 for connection with the valve stem 180. The outer spherical surface of the ball 150 is precision ground to a surface roughness of no more than 0.8 μm, ensuring a tight fit between the ball 150 and the sealing surface of the valve seat 130, as well as the sealing element.

[0070] In one embodiment, such as Figure 8 As shown, the support seat 170 is annular, disposed inside the valve body 100 and located below the ball 150. The support surface of the support seat 170 is a spherical arc surface, which matches the outer spherical surface of the ball 150. The support surface is precision ground to a surface roughness of no more than 1.6μm, ensuring a tight fit and wear resistance between the support surface and the ball 150. The support seat 170 is used to support the ball 150 from below, ensuring the stable rotation of the ball 150 inside the valve body 100, and distributing part of the weight of the ball 150, thus reducing the stress on the valve stem 180.

[0071] In one embodiment, such as Figure 9 As shown, the sleeve 120 and the locking end 110 are configured as a pair, and the sleeves 120 at both ends of the valve body 100 have identical structures. The sleeve 120 has an internal thread section 122 and a conical cavity 121 inside. The internal thread section 122 has an internal thread that matches the external thread of the external thread section 113 of the locking end 110, for fastening the sleeve 120 and the locking end 110.

[0072] The inner conical surface of the conical cavity 121 matches the outer conical surface of the cone portion 111 of the locking end 110. The angle between the inner conical surface of the conical cavity 121 and the central axis is 20°, which is 2° smaller than the angle between the outer conical surface of the cone portion 111 and the central axis (22°). This ensures a transition zone is formed when the sleeve 120 mates with the locking end 110, preventing stress concentration and ensuring a uniform distribution of the compressive force. The surface roughness of the inner conical surface of the conical cavity 121 is no greater than 3.2 μm.

[0073] In one embodiment, such as Figure 10 As shown, the valve stem 180 includes a locking head 181, a stem body 182, a flange 183, and a stem key 184. The locking head 181 is located at the upper end of the valve stem 180 and has a square design for easy engagement with operating tools such as wrenches to apply rotational torque. The stem body 182 is cylindrical, and the portion of the stem body 182 that contacts the valve body 100 has multiple stem body sealing grooves 185. Sealing elements are embedded in the stem body sealing grooves 185 to prevent media leakage along the valve stem 180. The flange 183 has a circular structure and is located in the middle of the stem body 182. The upper surface of the flange 183 has a flange sealing groove 1831, which contains a sealing element for sealing between the flange 183 and the gland flange 190.

[0074] A key 184 is located at the lower end of the valve stem 180, and the key 184 has a square design. The key 184 is embedded in the keyway 152 on the upper surface of the ball 150, thereby fixing the valve stem 180 and the ball 150 circumferentially. By rotating the valve stem 180, the ball 150 is driven to rotate synchronously, realizing the opening and closing of the valve.

[0075] Furthermore, this embodiment also includes a linkage shut-off device and a valve opening indicator. The linkage shut-off device is installed on the upper end of the valve stem 180 and is drively connected to the valve stem 180. The linkage shut-off device is a flow-linked switch. When the flow rate in the natural gas pipeline exceeds a set threshold, the linkage shut-off device is automatically triggered and drives the valve stem 180 to rotate, causing the ball 150 to rotate to the shut-off position, thereby achieving automatic valve closure. The valve opening indicator is installed on the upper surface of the gland flange 190 and is used to display the open or closed state of the ball 150. The opening indicator can be a mechanical pointer type or an electronic sensor type. Its pointer is linked to the valve stem 180. When the valve stem 180 rotates, the pointer rotates synchronously. The operator can intuitively determine whether the valve is currently in an open or closed state by observing the opening indicator.

[0076] In one embodiment, such as Figure 11As shown, the gland flange 190 is fitted over the valve stem 180 and fixed to the upper end of the valve body 100. The upper part of the gland flange 190 has a valve stem through hole 191 for the valve stem 180 to pass through; the diameter of the valve stem through hole 191 matches the stem body 182 of the valve stem 180. The lower part of the gland flange 190 has a flange countersunk hole 192, used to protect the upper port of the valve body 100. Specifically, the upper port of the hole for assembling the valve stem 180, formed when the first valve body half-shell 101 and the second valve body half-shell 102 are closed, is secured by the flange countersunk hole 192, providing protection and sealing.

[0077] In this application, the seals are made of rubber material with good elasticity and resistance to natural gas corrosion; in this embodiment, fluororubber material is preferred. All seals adopt an embedded structure, that is, they are embedded into corresponding grooves to improve sealing reliability.

[0078] Specifically, the seal is embedded in the following locations: within the enclosing sealing groove 103 at the junction of the first valve body half shell 101 and the second valve body half shell 102 of the valve body 100; within the valve seat 130 sealing groove at the outer edge of the sealing surface of the valve seat 130; within the stem sealing groove 185 of the stem body 182 of the valve stem 180; and within the flange sealing groove 1831 of the valve stem 180 flange 183.

[0079] The specific working principle of valve opening and closing is as follows:

[0080] When the valve needs to be opened, the locking head 181 of the valve stem 180 is rotated by the operating tool. The valve stem 180 drives the ball 150 to rotate 90° through the lever key 184, so that the ball through hole 151 of the ball 150 is aligned with the valve body flow channel 1001 of the valve body 100 and the valve seat flow channel 131 of the valve seat 130. Natural gas medium can then flow from one end of the valve to the other end, realizing the conduction of the medium.

[0081] When the valve needs to be closed, the locking head 181 of the valve stem 180 is rotated in the reverse direction. The valve stem 180 drives the ball 150 to rotate 90° in the reverse direction, so that the ball through hole 151 of the ball 150 is perpendicular to the valve body flow channel 1001 of the valve body 100 and the valve seat flow channel 131 of the valve seat 130. The solid part of the ball 150 blocks the medium flow channel, thereby achieving the cut-off of the medium.

[0082] Furthermore, when the natural gas flow rate in the pipeline abnormally increases beyond a set threshold, the linkage shut-off device is automatically triggered, driving the valve stem 180 to rotate to the shut-off position, thus achieving automatic shut-off. The valve opening indicator moves in tandem with the valve stem 180, displaying the opening and closing status of the ball 150 in real time, facilitating on-site inspection.

[0083] During valve opening and closing, the butterfly spring 140 always abuts against the valve seat 130 and the valve body 100, applying a continuous preload to the valve seat 130 to ensure that the sealing surface of the valve seat 130 is tightly fitted with the outer spherical surface of the ball 150. Simultaneously, the seals embedded in the grooves provide auxiliary sealing at the valve body 100 enclosure, between the valve seat 130 and the ball 150, and between the valve stem 180 and the valve body 100, ensuring the overall sealing performance of the valve.

[0084] During the construction and installation of natural gas pipelines, firstly, the sleeve 120 is removed from the locking end 110 of the valve body 100 and fitted onto the natural gas pipeline to be connected. Secondly, sealing rubber or sealant is wrapped around the end of the natural gas pipeline, and the end of the natural gas pipeline with the sealing rubber or sealant is inserted into the pipeline insertion hole 114 of the locking end 110 of the valve body 100 until the bottom of the pipeline insertion hole 114 is reached.

[0085] Then, slide the sleeve 120 along the natural gas pipeline to the locking end 110 of the valve body 100, and tighten it by engaging the internal thread section 122 of the sleeve 120 with the external thread section 113 of the locking end 110.

[0086] During the tightening process, the inner conical surface of the conical cavity 121 of the sleeve 120 gradually presses against the outer conical surface of the cone 111 of the locking end 110, forcing the cone 111 to retract radially along the slit 112, thereby gripping the inserted natural gas pipeline and achieving a tight connection between the valve and the natural gas pipeline.

[0087] The connection interface between the sleeve 120 and the locking end 110 is protected by multiple layers of valve body 100, sealing material, and sleeve 120, which avoids the problems of complex procedures, unstable quality, and easy leakage of the interface caused by the existing natural gas valve using bolts or welding processes, and improves the sealing performance and construction convenience of the interface.

[0088] The manufacturing method for the interlocking shut-off natural gas ball valve is as follows: The materials used for machining the valve body 100, valve seat 130, ball 150, support seat 170, sleeve 120, valve stem 180, and gland flange 190 are composed of the following by mass percentage: Ni 16.2wt%, Cr 14.0wt%, Mo 1.43wt%, Nb 0.61wt%, Si 0.8wt%, C 0.05wt%, Mn 1.0wt%, with the balance being aluminum (Fe). The material formula is batched, smelted, and prepared into the required low-expansion austenitic stainless steel profile.

[0089] The valve body 100 is machined using low-expansion austenitic stainless steel tubing prepared according to the specified formula. The stainless steel tubing is heated to 1110℃ for die forging, followed by normalizing at 810℃ for 3 hours, and then air-cooled to room temperature. The valve body 100 is machined according to the structural design, including turning, cutting, and welding. The valve body flow channel 1001, the embedded groove, the conical surface of the locking end 110, and the threads are precision-machined using specialized tools to ensure smooth surfaces and accurate dimensions. The angle between the outer conical surface of the locking end 110's conical portion 111 and the central axis of the valve body flow channel 1001 is machined to 22°, and the surface roughness is controlled to 3.2μm. The pipe insertion hole 114 inside the locking end 110, along the axial direction, is machined to a diameter of Φ370mm, extending to the bottom of the external thread section 113. Six slits 112 are evenly opened along the axial direction on the outer conical surface of the tapered portion 111 of the locking end 110, and the width of the slits 112 is 6mm. Holes are bored above the valve body flow channels 1001 at both ends of the valve body 100, and vent pipes 160 are welded to them respectively.

[0090] For valve seat 130, low-expansion austenitic stainless steel tubing was selected as the raw material. The stainless steel tubing was heated to 1110℃ for die forging, followed by normalizing at 810℃ for 3 hours, and then air-cooled to room temperature. Machining was performed according to the valve seat 130's structural design, including precision boring, burring, cutting, and precision grinding. The valve seat 130's shape, valve body flow channel 1001, and insert groove were precision-bored using specialized tools to ensure smooth surfaces and accurate dimensions. The sealing surface of valve seat 130, after precision boring, was precision-ground to a surface roughness of 0.8μm.

[0091] To process sphere 150, low-expansion austenitic stainless steel bars were prepared using the selected formula as raw material. The casting mold was preheated to 500℃, and molten metal was poured into the mold. After cooling to room temperature, the bars were demolded to obtain high-strength alloy bars. The cast alloy bars were forged at 1120℃, followed by normalizing at 860℃ for 2 hours, and then air-cooled. The normalized sphere 150 blank was rough-machined to remove surface oxide scale and excess material, and then finish-machined to ensure the basic dimensional accuracy of the sphere 150. After finish machining, heat treatment was performed: quenching at 820℃ for 1 hour, followed by oil cooling, and tempering at 500℃ for 3 hours to improve the hardness and wear resistance of the sphere 150. Finally, the surface of the sphere 150 is precision ground to a surface roughness of 0.8μm, and then the sphere through hole 151 and keyway 152 on the sphere 150 are machined according to the design structure.

[0092] The support base 170 is machined using low-expansion austenitic stainless steel bars prepared according to the selected formula. The support surface of the support base 170 is machined according to the structural design. The surface roughness is controlled to 1.6μm after boring and precision grinding.

[0093] For the sleeve tube 120, low-expansion austenitic stainless steel bars are prepared using the selected formula as raw materials. The inner conical cavity 121 is machined according to the structural design of the sleeve tube 120. The angle between the inner conical surface of the conical cavity 121 and the central axis is machined to 20°. The surface roughness of the inner conical surface is controlled to 3.2μm. Then, the internal thread section 122 of the sleeve tube 120 is tapped.

[0094] For machining the valve stem 180 and the gland flange 190, low-expansion austenitic stainless steel bars prepared by the scheme are selected as raw materials, and boring, cutting and polishing are carried out according to the structural design of the valve stem 180 and the gland flange 190.

[0095] Process the butterfly spring 140. Make a mold according to the size of the spring slot 107. Select the appropriate butterfly spring 140 pieces and quantity according to the tension. Stack the spring pieces in the mold, inject rubber material, and vulcanize and form at a temperature of 160℃ and a pressure of 10MPa for 25 minutes. Trim and process the formed butterfly spring 140 to remove burrs and flash.

[0096] For processing the seals, molds are made according to the dimensions and shapes of the seals in each part. Fluororubber raw materials are placed in the molds and vulcanized at 165℃ and 10MPa for 25 minutes. The molded seals are then trimmed to remove burrs and flash. The fluororubber seals also undergo a second vulcanization process in a high-temperature oven at 240℃ for 4 hours.

[0097] Assemble the components by installing the butterfly spring 140 and valve seat 130 onto the valve body 100, ensuring the butterfly spring 140 is correctly positioned and abuts against the valve seat 130 and valve body 100. Embed the seal into the stem sealing groove 185 of the valve stem 180 and the flange sealing groove 1831 of the flange 183. Embed the key 184 of the valve stem 180 into the keyway 152 of the ball 150. Place the support surface of the support base 170 against the bottom of the ball 150. Push the assembled valve stem 180, ball 150, and support base 170 into the second valve body half-shell 102. Adjust the position of the ball 150 so that the ball through hole 151 of the ball 150 is aligned with the valve body flow channel 1001 of the valve body 100 and the valve seat flow channel 131 of the valve seat 130. Embed the seal into the sealing groove 103 of the first valve body half-shell 101, close the second valve body half-shell 102 with the first valve body half-shell 101, insert the bolts through the through holes 104 on the circumference of the first valve body half-shell 101, connect them to the threaded holes 106 of the second valve body half-shell 102, and tighten the bolts with a torque of 30 N·m. Slide the gland flange 190 over the valve stem 180 and securely fasten it around the valve stem 180 mounting hole on the valve body 100. Finally, install the linkage shut-off device on the upper end of the valve stem 180, making it drive-connected to the valve stem 180; install the valve opening indicator on the upper surface of the gland flange 190. Finally, perform debugging to ensure that the ball valve operates flexibly and has good sealing performance.

[0098] Example 2:

[0099] Please see Figures 1 to 11 This embodiment provides a linkage shut-off natural gas ball valve, whose structure is basically the same as that of Embodiment 1, except that some materials, dimensions, and process parameters are different. The following mainly describes the differences from Embodiment 1, and the same parts will not be repeated.

[0100] The manufacturing method for the interlocking shut-off natural gas ball valve is as follows: The materials used for machining the valve body 100, valve seat 130, ball 150, support seat 170, sleeve 120, valve stem 180, and gland flange 190 are composed of the following by mass percentage: Ni 18.5wt%, Cr 13.5wt%, Mo 2.60wt%, Nb 0.74wt%, Si 1.0wt%, C 0.03wt%, Mn 0.6wt%, with the balance being aluminum (Fe). The material formula is batched, smelted, and prepared into the required low-expansion austenitic stainless steel profile.

[0101] In this embodiment, the valve body 100 uses low-expansion austenitic stainless steel tubing prepared according to the specified formula as raw material. The stainless steel tubing is heated to 1200℃ for die forging, followed by normalizing treatment at 900℃ for 2 hours, and then air-cooled to room temperature. The angle between the outer conical surface of the cone 111 and the central axis of the valve body flow channel 1001 is 11°. The pipe insertion hole 114 inside the locking end 110 has a diameter of Φ160mm and is used to insert a DN150 natural gas pipeline. Four slits 112 are evenly spaced axially on the outer conical surface of the cone 111, each slit 112 being 4mm wide. The vent pipe 160 welded to the valve body 100 is DN32.

[0102] In this embodiment, the valve seat 130 is formed by die forging low-expansion austenitic stainless steel tubing prepared according to the specified formula. The stainless steel tubing is heated to 1200℃ for die forging, and then normalized at 900℃ for 2 hours, followed by air cooling to room temperature. The sealing surface of the valve seat 130 is precision ground to a surface roughness of 0.8μm.

[0103] In this embodiment, sphere 150 is manufactured using low-expansion austenitic stainless steel bars prepared according to the specified formula as raw materials through a forging process. The casting mold is preheated to 420°C. The forging temperature is 1200°C, followed by normalizing treatment at 900°C for 1 hour. After precision machining, heat treatment is performed: quenching at 820°C for 1 hour, and tempering at 550°C for 2 hours. The outer spherical surface of sphere 150 is precision ground to a surface roughness of 0.8 μm.

[0104] In this embodiment, the support base 170 is made from low-expansion austenitic stainless steel bars prepared according to the specified formula. The support surface is precision ground to a surface roughness of 1.6 μm.

[0105] In this embodiment, the sleeve 120 is made from low-expansion austenitic stainless steel bars prepared according to the specified formula. The angle between the inner conical surface of the conical cavity 121 and the central axis is 10°, which is 1° smaller than the angle between the outer conical surface of the cone 111 and the central axis, which is 11°. The surface roughness of the inner conical surface is 3.2 μm.

[0106] In this embodiment, the valve stem 180 and the gland flange 190 are made from low-expansion austenitic stainless steel bars prepared according to the formula, and the rest of the structure is the same as in embodiment 1.

[0107] In this embodiment, the vulcanization molding process parameters for the disc spring 140 are: temperature 180℃, pressure 15MPa, and vulcanization time 10 minutes.

[0108] In this embodiment, the seal is made of nitrile rubber. The molding process parameters are: temperature 180℃, pressure 15MPa, and vulcanization time 10 minutes. The nitrile rubber seal does not require secondary vulcanization.

[0109] This embodiment also includes a linkage shut-off device and a valve opening indicator. Their installation position, connection method and working principle are exactly the same as those in Embodiment 1, and will not be repeated here.

[0110] The working principle of this embodiment is basically the same as that of embodiment 1. The only difference is the low-expansion austenitic stainless steel composition and the fact that when connecting the pipe, sealant is applied to the end of the natural gas pipe instead of wrapping the sealant. Then, the pipe end is inserted into the bottom of the pipe insertion hole 114 of the locking end 110, and the sleeve 120 is slid to the locking end 110 and tightened to achieve the connection.

[0111] Example 3:

[0112] Please see Figures 1 to 11 This embodiment provides a linkage shut-off natural gas ball valve, whose structure is basically the same as that of Embodiment 1, except that some materials, dimensions, and process parameters are different. The following mainly describes the differences from Embodiment 1, and the same parts will not be repeated.

[0113] The manufacturing method for the interlocking shut-off natural gas ball valve is as follows: The materials used for machining the valve body 100, valve seat 130, ball 150, support seat 170, sleeve 120, valve stem 180, and gland flange 190 are composed of the following by mass percentage: Ni 20.0wt%, Cr 13.0wt%, Mo 1.83wt%, Nb 0.8wt%, Si 1.2wt%, C 0.026wt%, Mn 0.8wt%, with the balance being aluminum (Fe). The material formula is batched, smelted, and prepared into the required low-expansion austenitic stainless steel profile.

[0114] The preparation method of the linkage shut-off natural gas ball valve in this embodiment is as follows:

[0115] The valve body 100 is machined using low-expansion austenitic stainless steel tubing prepared according to the selected formula. The stainless steel tubing is heated to 1200℃ for die forging, followed by normalizing at 900℃ for 2 hours, and then air-cooled to room temperature. The angle between the outer conical surface of the tapered portion 111 of the locking end 110 and the central axis of the valve body flow channel 1001 is machined to 11°. The pipe insertion hole 114 inside the locking end 110 along the axial direction is machined to a diameter of Φ160mm. Four slits 112, each 4mm wide, are evenly opened axially on the outer conical surface of the tapered portion 111 of the locking end 110. Vent pipes 160 are welded to both ends of the valve body 100.

[0116] For the valve seat 130, low-expansion austenitic stainless steel tubing was selected as the raw material. The stainless steel tubing was heated to 1200℃ for die forging, followed by normalizing treatment at 900℃ for 2 hours, and then air-cooled to room temperature. The sealing surface of the valve seat 130 was precision ground to a surface roughness of 0.8μm.

[0117] Sphere 150 was machined using low-expansion austenitic stainless steel bars prepared according to the selected formula. The casting mold was preheated to 420℃. The forging temperature was 1200℃, followed by normalizing at 900℃ for 1 hour. After precision turning, heat treatment was performed: quenching at 820℃ for 1 hour, and tempering at 550℃ for 2 hours. The surface roughness of sphere 150 was controlled to 0.8μm after precision grinding.

[0118] The support base is 170mm in size. Low-expansion austenitic stainless steel tubing is selected as the raw material and prepared according to the formula. The support surface is precision ground to control the surface roughness to 1.6μm.

[0119] For the processing of sleeve tube 120, low-expansion austenitic stainless steel tubes are selected as raw materials based on the chosen formula. The angle between the inner conical surface of the conical cavity 121 and the central axis is processed to 10°, and the surface roughness of the inner conical surface is controlled to 3.2μm.

[0120] The valve stem 180 and the gland flange 190 are processed using low-expansion austenitic stainless steel pipe prepared according to the formula, and the rest of the structure is the same as in Example 1.

[0121] The processing of the 140 disc spring involves a vulcanization temperature of 180℃, a pressure of 15MPa, and a vulcanization time of 10 minutes.

[0122] To process the sealing parts, the nitrile rubber raw material is placed into the mold and vulcanized at a temperature of 180℃ and a pressure of 15MPa for 10 minutes. The molded sealing parts are then trimmed to remove burrs and flash.

[0123] The component assembly steps are the same as those in Example 1. Similarly, after assembly, the linkage shut-off device is installed on the upper end of the valve stem 180, making it drively connected to the valve stem 180; the valve opening indicator is installed on the upper surface of the gland flange 190.

[0124] The difference between the pipe connection method in this embodiment and the pipe connection method in embodiment 1 is that: instead of wrapping the natural gas pipe end with sealant, sealant is applied to the end of the natural gas pipe, and then the end of the pipe is inserted into the bottom of the pipe insertion hole 114 of the locking end 110. Then, the sleeve 120 is slid to the locking end 110 and tightened to achieve the connection.

[0125] This embodiment also includes a linkage shut-off device and a valve opening indicator. Their installation position, connection method and working principle are exactly the same as those in Embodiment 1, and will not be repeated here.

[0126] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0127] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0128] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A linked shut-off natural gas ball valve, characterized in that, include: The valve body (100) has locking ends (110) at both ends. A ball (150) is rotatably disposed inside the valve body (100); The sleeve (120) is sleeved on the outside of the locking end (110), and the sleeve (120) and the locking end (110) are connected by a threaded connection; The locking end (110) has a cone (111) with a plurality of slits (112) opened along the axial direction, the slits (112) dividing the cone (111) into a plurality of radially movable lobes; The sleeve (120) has a conical cavity (121) inside, and the inner conical surface of the conical cavity (121) matches the outer conical surface of the cone (111) of the locking end (110); When the sleeve (120) is tightened relative to the locking end (110), the inner conical surface of the conical cavity (121) presses against the outer conical surface of the cone (111), forcing the cone (111) to retract radially to hold the pipe inserted into the locking end (110). It also includes a linkage shut-off device, which is connected to the valve stem (180) and is used to drive the valve stem (180) to rotate to shut off the ball (150) when a preset trigger condition is detected.

2. The interlocking shut-off natural gas ball valve as described in claim 1, characterized in that: The linkage shutdown device is a flow linkage switch, which triggers shutdown when the natural gas flow exceeds a set threshold.

3. The interlocking shut-off natural gas ball valve as described in claim 2, characterized in that: It also includes a valve opening indicator, which is disposed on the valve body (100) or the gland flange (190) to indicate the open or closed state of the ball (150).

4. The interlocking shut-off natural gas ball valve as described in claim 3, characterized in that: The outer wall of the locking end (110) is provided with an external thread section (113), and the sleeve tube (120) is provided with an internal thread section (122), which cooperates with the thread section.

5. The interlocking shut-off natural gas ball valve as described in claim 4, characterized in that: The locking end (110) has a pipe insertion hole (114) for inserting an external pipe along the axis inside, and the pipe insertion hole (114) extends to the bottom of the external thread section (113).

6. The interlocking shut-off natural gas ball valve as described in claim 5, characterized in that: The multiple slits (112) are evenly distributed along the axial direction of the cone (111).

7. The interlocking shut-off natural gas ball valve as described in claim 6, characterized in that: There is an angle difference between the inner conical surface of the conical cavity (121) and the outer conical surface of the cone (111) of the locking end (110), and the angle between the inner conical surface of the conical cavity (121) and the central axis is smaller than the angle between the outer conical surface of the cone (111) and the central axis.

8. The interlocking shut-off natural gas ball valve as described in claim 7, characterized in that: The valve body (100) has a Haver-type structure, which is formed by the first valve body half shell (101) and the second valve body half shell (102) joining together along the enclosing surface. The first valve body half shell (101) and the second valve body half shell (102) are fixedly connected by fasteners. An enclosing sealing groove (103) is provided at the enclosing part of the first valve body half shell (101) and the second valve body half shell (102), and a sealing element is embedded in the enclosing sealing groove (103).

9. The interlocking shut-off natural gas ball valve as described in claim 8, characterized in that: The valve body (100) is provided with two valve seats (130) and two butterfly springs (140) inside. The two valve seats (130) are respectively located on both sides of the ball (150), and each butterfly spring (140) abuts against the corresponding valve seat (130) and the valve body (100). The butterfly spring (140) is a butterfly spring sealing ring formed by injecting rubber material into multiple butterfly spring sheets for protection; The valve body (100) is also provided with a vent pipe (160).

10. A method for preparing a linkage shut-off natural gas ball valve, as described in claims 1-9, wherein the valve body (100), valve seat (130), ball (150), support seat (170), sleeve (120), valve stem (180), and gland flange (190) of the linkage shut-off natural gas ball valve are made of low-expansion austenitic stainless steel, which contains the following components by mass percentage: Ni 16.0-20.0 wt%, Cr 13.0-14.0 wt%, Mo 1.4-2.6 wt%, Nb 0.6-0.8 wt%, Si 0.8-1.2 wt%, C ≤ 0.05 wt%, Mn ≤ 1.0 wt%, with the balance being aluminum (Fe); the method comprises the following steps: S1: Valve body (100) machining: Low expansion austenitic stainless steel pipe is selected, and after die forging and normalizing, it is machined according to the structural design. Locking ends (110) are formed at both ends of the valve body (100). A tapered part (111) and multiple slits (112) along the axial direction are machined on the locking ends (110), and a vent pipe (160) is welded on the valve body (100). S2: Valve seat (130) machining: Low expansion austenitic stainless steel tubing is selected, and after die forging and normalizing, it is machined according to the structural design, and the sealing surface of the valve seat (130) is precision ground. S3: Sphere (150) machining: After forging, normalizing, rough turning, fine turning, quenching and tempering, the surface of the sphere (150) is precision ground and the sphere through hole (151) and keyway (152) are machined. S4: Support base (170) machining: Select low expansion austenitic stainless steel bars, machine them according to the structural design, and perform precision grinding on the support surface of the support base (170). S5: Sleeve tube (120) processing: Select expanded austenitic stainless steel bar and process the conical cavity (121) and internal thread section (122) according to the structural design. S6: Valve stem (180) and gland flange (190) machining: Select low expansion austenitic stainless steel bars and machine them according to the structural design to produce valve stem (180) and gland flange (190). S7: Processing of butterfly spring (140): The butterfly spring sheet is stacked in the mold and the rubber material is injected. After vulcanization and molding, it is trimmed to obtain the butterfly spring (140). S8: Seal processing: Make a mold according to the size and shape of the seal, put the rubber raw material into the mold, and after vulcanization and molding, trim and process to obtain the seal; S9: Component Assembly: Install the butterfly spring (140) and valve seat (130) inside the valve body (100), and make the valve seat (130) abut against the butterfly spring (140); connect the valve stem (180) to the ball (150), place the support seat (170) against the bottom of the ball (150), and install the assembled valve stem (180), ball (150), and support seat (170) together into the valve body (100). Embed the seal into the sealing groove (103) at the enclosure of the valve body (100), close the valve body (100) and lock it with fasteners; put the gland flange (190) on the valve stem (180) and fix it to the upper end of the valve body (100); put the sleeve (120) on the outside of the locking end (110) and connect it with the external thread section (113) of the locking end (110) through the internal thread section (122); S10: Install the linkage shut-off device on the upper end of the valve stem (180) and make the linkage shut-off device drive-connected to the valve stem (180); install the valve opening indicator on the upper surface of the valve body (100) cover flange (190).

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