Balanced type double-cylinder valve

Abstract

The invention belongs to the technical field of valves, and particularly discloses a balanced type double-cylinder valve which comprises a valve body, a valve seat is arranged in the valve body, a first cavity is formed in the valve body, and the valve seat is arranged in the valve body; the executing mechanism is arranged on the valve body, a valve rod is arranged at a port of the executing mechanism, a valve element capable of being connected with the valve seat in a sealed mode is arranged at the free end of the valve rod, a piston is arranged in the valve element and the valve rod, and a second cavity is formed between the piston and the valve body; and the balance pipe assembly is arranged on the valve body, and the first cavity and the second cavity are communicated through the balance pipe assembly. By adopting a balanced sealing mode, the sealing force during valve sealing can be reduced, meanwhile, by adopting a double-cylinder driving mode, the size and the size of an executing mechanism can be reduced, on-site arrangement is facilitated, meanwhile, the positions of a limiting piece and an inductive switch are changed, and the sealing performance of the valve is improved. The situation that the inductive switch cannot accurately sense the position of the limiting piece is effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of valves, and in particular to a balanced double-cylinder valve. Background Art

[0002] A programmable valve is a regulating valve that controls the position of the valve by controlling the electrical signal of the actuator. Its working principle is similar to that of an ordinary regulating valve, but the programmable valve uses high-precision electronic components and computer control technology, and can perform automatic control according to preset conditions to achieve more intelligent and precise regulation.

[0003] Traditional program-controlled valves such as Figure 1 As shown, it is usually an unbalanced structure. When the on-site medium pressure is higher than 1.5Mpa and the valve diameter is higher than DN150, in order to ensure the normal opening of the valve, the actuator configuration will be quite large, resulting in a larger outer diameter of the actuator. Since the distance between the programmable valves is close, the actuator is too large, which will cause the on-site valves to be arranged farther apart, thereby increasing the user's pipeline layout cost. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a balanced double-cylinder valve for solving the problems of the prior art that the actuator of the program-controlled valve is relatively large and the pipeline layout is inconvenient.

[0005] To achieve the above objectives and other related objectives, the present invention provides a balanced double-cylinder valve, comprising:

[0006] A valve body, wherein a valve seat is arranged in the valve body, a first cavity is arranged on the valve body, and a valve seat is arranged in the valve body;

[0007] an actuator, arranged on the valve body, the actuator comprising a valve stem, a valve core capable of being sealed and connected to a valve seat is arranged at a free end of the valve stem, a piston is arranged on the valve stem, the piston is located at a side of the valve core away from the valve seat and is located in the valve body, and a second cavity is formed between the piston and the valve body;

[0008] A balance pipe assembly is arranged on the valve body, and the balance pipe assembly is connected with the first cavity and the second cavity.

[0009] Optionally, the balancing pipe assembly includes a first ferrule, a second ferrule and a connecting pipe arranged on the valve body, the valve body is provided with a first channel connected to the first cavity, the first channel is connected to the first ferrule, the valve body is provided with a second channel connected to the second cavity, the second channel is connected to the second cavity, and both ends of the connecting pipe are respectively connected to the first ferrule and the second ferrule.

[0010] Optionally, the actuator includes a cylinder body, an end cover is provided at one end of the cylinder body away from the valve body, a middle cylinder cover is provided inside the cylinder body, a first driving plug and a second driving plug are respectively provided on both sides of the middle cylinder cover, and the second driving plug abuts against the valve stem at one end close to the cylinder cover.

[0011] Optionally, a third cavity, a fourth cavity, a fifth cavity and a sixth cavity are provided in the cylinder body from bottom to top, the third cavity is arranged between the second driving plug and the valve body, the fourth cavity is arranged between the middle cylinder cover and the second driving plug, the fifth cavity is arranged between the middle cylinder cover and the first driving plug, and the sixth cavity is arranged between the first driving plug and the end cover.

[0012] Optionally, a first air inlet and outlet is provided on the end cover, and the port of the first air inlet and outlet faces the sixth cavity; a second air inlet and outlet is provided on the middle cylinder cover, and the port of the second air inlet and outlet faces the fourth cavity; a third air inlet and outlet is provided on the middle cylinder cover, and the port of the third air inlet and outlet faces the fifth cavity; a fourth air inlet and outlet is provided on the valve body, and the port of the fourth air inlet and outlet faces the third cavity.

[0013] Optionally, one end of the valve stem away from the valve core passes through the first drive plug, the middle cylinder cover and the second drive plug and is arranged on the end cover, and a fixing component is provided on the end cover, and the fixing component is used to fix the valve stem.

[0014] Optionally, the fixing assembly includes a support sleeve and a locking piece, the support sleeve is detachably connected to the end cover, the locking piece passes through the support sleeve and is detachably connected to the end cover, and the valve stem passes through the support sleeve and is slidably connected to the support sleeve.

[0015] Optionally, there is a floating gap between the support sleeve and the end cover.

[0016] Optionally, a protective shell is provided on the end cover, a limit piece is provided at one end of the valve stem passing through the support sleeve, the limit piece is arranged along the axial direction of the valve stem, the limit piece is provided with a shielding portion, and an induction switch is provided on the protective shell, the induction switch is arranged along the radial direction of the valve stem, and the height of the shielding portion is greater than the diameter of the induction end of the induction switch.

[0017] Optionally, a sealing assembly is provided between the piston and the inner wall of the valve body.

[0018] As described above, the balanced double-cylinder valve proposed by the present invention has the following beneficial effects:

[0019] Compared with the prior art, the present invention forms a first cavity and a second cavity inside the valve body, and sets a balancing pipe assembly so that the medium pressure can enter the valve body. The medium generates pressure on the valve core, thereby reducing the pressure required for the valve to seal. The thrust on the valve stem is smaller. Accordingly, under the premise of meeting the sealing force, the actuator can be made smaller, thereby facilitating the arrangement of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is a schematic diagram of the structure of the prior art;

[0021] Figure 2 Shown is a schematic structural diagram of an embodiment of the present invention;

[0022] Figure 3 Shown is an enlarged view of point A in the present invention;

[0023] Figure 4 Shown is an enlarged view of point B in the present invention;

[0024] Figure 5 Shown is an enlarged view of point C in the present invention;

[0025] Figure 6 Shown is a schematic diagram of the actuator in the present invention.

[0026] Description of reference numerals:

[0027] Valve body 1, first cavity 101, second cavity 102, fourth inlet and outlet 103, valve seat 2, valve stem 3, piston 4, first sealing ring 401, first grease groove 402, second sealing ring 403, PTFE guide belt 404, first channel 5, first ferrule 6, connecting pipe 7, second ferrule 8, second channel 9, cylinder body 10, third cavity 1001, fourth cavity 1002, fifth cavity 1003, sixth cavity 1004, middle cylinder cover 11, second inlet and outlet Air port 1101, third air inlet and outlet 1102, first drive plug 12, connecting sleeve 13, positioning bearing 1301, second drive plug 14, end cover 15, first air inlet and outlet 1501, supporting sleeve 16, third sealing ring 1601, second grease groove 1602, fourth sealing ring 1603, sliding bearing 1604, floating gap 17, locking piece 18, protective shell 19, limit piece 20, shielding part 2001, sensing switch 21, sensing end 2101. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] It should be noted that the diagram provided in the present embodiment only illustrates the basic concept of the present invention in a schematic manner, so the diagram only shows the components related to the present invention rather than drawing according to the number, shape and size of the components during actual implementation. The type, quantity and ratio of each component during actual implementation can be a random change, and the component layout type may also be more complicated. The structure, ratio, size, etc. illustrated in the drawings of the present specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that the present invention can implement, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effect that the present invention can produce and the purpose that can be achieved. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of narration, and are not used to limit the scope of the present invention. The change or adjustment of its relative relationship should also be regarded as the scope of the present invention without substantially changing the technical content.

[0030] Before describing the present application, the prior art is described. Figure 1 As shown, in order to ensure the sealing of the valve, the volume and size of the actuator are quite large to provide the corresponding sealing force. During on-site installation and arrangement, it is often impossible to install it normally due to environmental restrictions.

[0031] like Figure 1-Figure 6 As shown, the present invention proposes a balanced double-cylinder valve.

[0032] In an exemplary embodiment, a balanced dual-cylinder valve comprises:

[0033] A valve body 1, a valve seat 2 is arranged in the valve body 1, a first cavity 101 is arranged on the valve body 1, and a valve seat 2 is arranged in the valve body 1;

[0034] an actuator, arranged on the valve body 1, comprising a valve stem 3, a valve core capable of being sealed and connected to the valve seat 2 being provided at a free end of the valve stem 3, a piston 4 being provided on the valve stem 3, the piston 4 being located at a side of the valve core away from the valve seat 2 and located in the valve body 1, and a second cavity 102 being formed between the piston 4 and the valve body 1;

[0035] The balancing pipe assembly is arranged on the valve body 1 , and the balancing pipe assembly connects the first cavity 101 and the second cavity 102 .

[0036] In this embodiment, by forming the first cavity and the second cavity inside the valve body 1 and by providing a balancing pipe assembly, the medium pressure can enter the valve body 1, and the medium exerts pressure on the valve core, thereby reducing the pressure required for the valve to seal, and the thrust on the valve stem 3 is smaller. Accordingly, under the premise of satisfying the sealing force, the actuator can be made smaller, thereby facilitating the arrangement of the valve.

[0037] In an exemplary embodiment, the balancing pipe assembly includes a first ferrule 6, a second ferrule 8 and a connecting pipe 7 arranged on the valve body 1, the valve body 1 is provided with a first channel 5 connected to the first cavity 101, the first channel 5 is connected to the first ferrule 6, the valve body 1 is provided with a second channel 9 connected to the second cavity 102, the second channel 9 is connected to the second cavity 102, and both ends of the connecting pipe 7 are respectively connected to the first ferrule 6 and the second ferrule 8.

[0038] In this embodiment, Figure 3 As shown, by providing the first ferrule 6, the second ferrule 8 and the connecting pipe 7, the first cavity 101 and the second cavity 102 can be effectively connected. After the medium input end of the valve body 1 enters the first cavity 101, the medium will enter the second cavity 102 through the balance pipe assembly due to the pressure. At this time, the pressure in the second cavity 102 is the same as the pressure in the first cavity 101. The medium in the second cavity 102 will generate a downward pressure on the piston 4. The piston 4 transmits the force to the valve stem 3 and finally to the valve core. Therefore, compared with the valve in the prior art, when the valve core is sealed with the valve seat 2, the lifting force of the medium on the valve core is reduced, thereby being able to reduce the volume of the actuator accordingly.

[0039] Exemplarily, the first ferrule 6 and the second ferrule 8 in this embodiment both adopt double-ended ferrule joints, which have stable connections and high sealing properties.

[0040] It is worth mentioning that Figure 5 As shown, a sealing assembly is provided between the piston 4 and the inner wall of the valve body 1 to prevent the medium in the second cavity 102 from entering the medium output end of the valve body 1 and causing valve leakage. The sealing assembly includes a first sealing ring 401, a first grease groove 402 and a second sealing ring 403 arranged in sequence from bottom to top. Two sealing assemblies are provided, and a polytetrafluoroethylene guide belt 404 is provided between the sealing assemblies. The polytetrafluoroethylene guide belt 404 can guide the piston 4 and reduce the friction between the piston 4 and the valve body 1.

[0041] In an exemplary embodiment, the actuator includes a cylinder body 10, an end cover 15 is provided at one end of the cylinder body 10 away from the valve body 1, a middle cylinder cover 11 is provided inside the cylinder body 10, a first driving plug 12 and a second driving plug 14 are provided on both sides of the middle cylinder cover 11, and the second driving plug 14 is abutted against the valve stem 3 at one end close to the cylinder cover.

[0042] In this embodiment, a middle cylinder cover 11 is provided inside the cylinder body 10, so that two large cavities are formed inside the cylinder body 10, and a first driving plug 12 and a second driving plug 14 are respectively provided in the two large cavities, and an air inlet and outlet assembly is provided corresponding to each driving plug to realize dual-cylinder power supply. While improving the driving force, the size of each driving plug can be reduced accordingly, which is conducive to reducing the size of the driving mechanism.

[0043] For example, Figure 6 As shown, a third cavity 1001, a fourth cavity 1002, a fifth cavity 1003 and a sixth cavity 1004 are sequentially provided in the cylinder body 10 from bottom to top. The third cavity 1001 is arranged between the second driving plug 14 and the valve body 1, the fourth cavity 1002 is arranged between the middle cylinder head 11 and the second driving plug 14, the fifth cavity 1003 is arranged between the middle cylinder head 11 and the first driving plug 12, and the sixth cavity 1004 is arranged between the first driving plug 12 and the end cover 15.

[0044] Exemplarily, a first air inlet and outlet 1501 is provided on the end cover 15, and the port of the first air inlet and outlet 1501 faces the sixth cavity 1004; a second air inlet and outlet 1101 is provided on the middle cylinder cover 11, and the port of the second air inlet and outlet 1101 faces the fourth cavity 1002; a third air inlet and outlet 1102 is provided on the middle cylinder cover 11, and the port of the third air inlet and outlet 1102 faces the fifth cavity 1003; a fourth air inlet and outlet 103 is provided on the valve body 1, and the port of the fourth air inlet and outlet 103 faces the third cavity 1001.

[0045] It is worth noting that when the first air inlet and outlet 1501 and the second air inlet and outlet 1101 are inletting air, the third air inlet and outlet 1102 and the fourth air inlet and outlet 103 are exhausted, and the pressurized gas enters the sixth cavity 1004 and the fourth cavity 1002, and the pressurized gas in the third cavity 1001 and the fifth cavity 1003 is discharged synchronously, and the first driving plug 12 moves from the sixth cavity 1004 to the fifth cavity 1003, and the second driving plug 14 moves from the fourth cavity 1002 to the third cavity 1001. At this time, the first driving plug 12 and the second driving plug 14 move downward, pushing the valve stem 3 downward, and the valve is closed; when the third inlet and outlet 1501 and the second air inlet and outlet 1101 are inletting air, the pressure gas enters the sixth cavity 1004 and the fourth cavity 1002, and the pressure gas in the third cavity 1001 and the fifth cavity 1003 is discharged synchronously, and the first driving plug 12 moves from the sixth cavity 1004 to the fifth cavity 1003, and the second driving plug 14 moves from the fourth cavity 1002 to the third cavity 1001. When air is taken in by the air outlet 1102 and the fourth air inlet and outlet 103, the pressurized gas enters the fifth cavity 1003 and the third cavity 1001, and the pressurized gas in the fourth cavity 1002 and the sixth cavity 1004 is discharged synchronously, and the first driving plug 12 moves from the fifth cavity 1003 to the sixth cavity 1004, and the second driving plug 14 moves from the third cavity 1001 to the fourth cavity 1002. At this time, the first driving plug 12 and the second driving plug 14 move upward, and the driving force on the valve stem 3 disappears. The pressure of the medium at the bottom lifts the valve stem 3, and the upper end surface of the valve stem 3 is always in contact with the lower end surface of the second driving plug 14.

[0046] It should also be noted that, in this embodiment, the first drive plug 12 and the second drive plug 14 are fixedly connected together by a connecting sleeve 13, the connecting sleeve 13 is slidably connected to the middle cylinder cover 11, and a positioning bearing 1301 is provided between the connecting sleeve 13 and the middle cylinder cover 11 to support the connecting sleeve 13.

[0047] It should also be noted that in this embodiment, while providing the same thrust, the use of a double-cylinder structure can reduce the diameter of the cylinder body 10 by half, reduce the outer diameter of the entire actuator, make the structure more compact, and reduce the on-site installation space, shortening the user's on-site pipeline layout distance and reducing costs.

[0048] In an exemplary embodiment, one end of the valve stem 3 away from the valve core passes through the first drive plug 12 , the middle cylinder cover 11 and the second drive plug 14 and is arranged on the end cover 15 . The end cover 15 is provided with a fixing assembly for fixing the valve stem 3 .

[0049] In this embodiment, the valve stem 3 is set so that the valve stem 3 can move upward or downward synchronously with the first drive plug 12 and the second drive plug 14, and the fixing component is set so that the valve stem 3 can be installed on the end cover 15 and can move up and down.

[0050] Exemplarily, the fixing assembly includes a support sleeve 16 and a locking member 18, the support sleeve 16 is detachably connected to the end cover 15, the locking member 18 passes through the support sleeve 16 and is detachably connected to the end cover 15, and the valve stem 3 passes through the support sleeve 16 and is slidably connected to the support sleeve 16. In this embodiment, there are multiple locking members 18, which are arranged along the circumference of the support sleeve 16 to facilitate fixing the support sleeve 16 to the end cover 15.

[0051] Exemplarily, the fixing assembly also includes a sliding sealing assembly arranged between the valve stem 3 and the support sleeve 16, and the sliding sealing assembly includes a third sealing ring 1601, a second grease groove 1602, a fourth sealing ring 1603 and a sliding bearing 1604 arranged in sequence from top to bottom, which can effectively ensure that the valve stem 3 can move freely following the first driving plug 12 and the second driving plug 14.

[0052] For example, Figure 4 As shown, there is a floating gap 17 between the support sleeve 16 and the end cover 15. In this embodiment, the valve stem 3 adopts an integral structure. During the processing or assembly of related matching parts, coaxiality errors will inevitably occur, which increases the difficulty of valve assembly and affects the valve leakage level. A floating connection seal is adopted between the end cover 15 and the valve stem 3. The floating gap 17 is 0.2-0.4mm, which ensures that the end cover 15 and the valve stem 3 can be automatically aligned when assembled, reduces the difficulty of assembly, and avoids the misalignment of the valve stem 3 during the installation process. The service life of the valve. In this embodiment, a floating connection can also be used when the valve core is connected to the valve stem 3, which can effectively ensure the contact surface between the valve core and the soft valve seat 2 and ensure the leakage level of the valve.

[0053] In an exemplary embodiment, a protective shell 19 is provided on the end cover 15, and a limit member 20 is provided at one end of the valve stem 3 passing through the support sleeve 16. The limit member 20 is arranged along the axial direction of the valve stem 3, and the limit member 20 is provided with a shielding portion 2001. An induction switch 21 is provided on the protective shell 19, and the induction switch 21 is arranged along the radial direction of the valve stem 3. The height of the shielding portion 2001 is greater than the diameter of the induction end 2101 of the induction switch 21.

[0054] In this embodiment, since the limiter 20 is arranged along the axial direction of the valve stem 3, and the induction switch 21 is arranged along the radial direction of the valve stem 3, when the valve stem 3 is opened, the induction switch 21 senses the limiter 20, and then controls the actuator to stop the air inlet and outlet.

[0055] In the prior art, the limit member 20 and the sensing switch 21 are both arranged along the radial direction of the valve stem 3, wherein the limit member 20 is arranged on the valve stem 3, and the sensing switch 21 is arranged on the protective shell 19. When the valve stem 3 rotates during the driving process, when the valve is opened, the sensing switch 21 cannot sense the limit member 20, and cannot accurately transmit the valve opening position to the control center, which may easily cause safety hazards. In the present embodiment, the limit member 20 adopts a cylindrical structure. The program-controlled valve generally requires a limited opening position. When the valve is opened, the limit member 20 and the center of the induction switch 21 are at the same horizontal position, and the distance is maintained at a sensing distance of 2.5 to 3 mm. The shielding portion 2001 of the limit member 20 is 1 to 1.5 mm longer than the sensing end 2101 of the sensing switch 21. During the long-term switching process of the valve, even if the push rod position rotates, since the sensing switch 21 is a cylinder, its axial direction is collinear with the axial direction of the valve stem 3, thereby effectively maintaining the distance from the sensing switch 21 unchanged. At the same time, even if the soft valve seat 2 has a slight wear during long-term use, the shielding portion 2001 of the limit member 20 is 1 to 1.5 mm longer than the sensing end 2101 of the sensing switch 21, thereby ensuring that the limit member 20 is always within the sensing range of the sensing switch 21 when the valve is opened, thereby ensuring that the valve switching information is ready to be transmitted to the control center.

[0056] Illustratively, in this embodiment, the limiting member 20 is connected to the top of the valve stem 3 by threads.

[0057] Illustratively, the limit member 20 in this embodiment is mainly used to limit the open position of the valve. If the closed position is required, the valve is in the closed position when the sensing switch 21 is aligned with the limit position. If both the closed position and the open position are to be controlled, two sensing switches 21 are respectively installed at the open and closed positions of the valve to meet the user's various production safety control needs.

[0058] To sum up, the present invention adopts a balanced sealing method to reduce the sealing force when the valve is sealed, and adopts a dual-cylinder driving method to reduce the volume and size of the actuator, which is beneficial to the on-site layout. At the same time, it changes the position of the limit member and the sensing switch, effectively avoiding the induction switch from being unable to accurately sense the position of the limit member.

[0059] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A balanced double-cylinder valve, characterized in that: include: A valve body, wherein a valve seat is arranged in the valve body, a first cavity is arranged on the valve body, and a valve seat is arranged in the valve body; an actuator, arranged on the valve body, the actuator comprising a valve stem, a valve core capable of being sealed and connected to a valve seat is arranged at a free end of the valve stem, a piston is arranged on the valve stem, the piston is located at a side of the valve core away from the valve seat and is located in the valve body, and a second cavity is formed between the piston and the valve body; A balance pipe assembly is arranged on the valve body, and the balance pipe assembly is connected with the first cavity and the second cavity.

2. The balanced double-cylinder valve according to claim 1, characterized in that: The balancing pipe assembly includes a first ferrule, a second ferrule and a connecting pipe arranged on the valve body, the valve body is provided with a first channel connected to the first cavity, the first channel is connected to the first ferrule, the valve body is provided with a second channel connected to the second cavity, the second channel is connected to the second cavity, and both ends of the connecting pipe are respectively connected to the first ferrule and the second ferrule.

3. The balanced double-cylinder valve according to claim 2, characterized in that: The actuator also includes a cylinder body, an end cover is provided at one end of the cylinder body away from the valve body, a middle cylinder cover is provided in the cylinder body, a first driving plug and a second driving plug are respectively provided on both sides of the middle cylinder cover, and the second driving plug is abutted against the valve stem at one end close to the cylinder cover.

4. The balanced double-cylinder valve according to claim 3, characterized in that: The cylinder body is provided with a third cavity, a fourth cavity, a fifth cavity and a sixth cavity from bottom to top in sequence, the third cavity is arranged between the second driving plug and the valve body, the fourth cavity is arranged between the middle cylinder cover and the second driving plug, the fifth cavity is arranged between the middle cylinder cover and the first driving plug, and the sixth cavity is arranged between the first driving plug and the end cover.

5. The balanced double-cylinder valve according to claim 4, characterized in that: The end cover is provided with a first air inlet and outlet, and the port of the first air inlet and outlet faces the sixth cavity. The middle cylinder cover is provided with a second air inlet and outlet, and the port of the second air inlet and outlet faces the fourth cavity. The middle cylinder cover is provided with a third air inlet and outlet, and the port of the third air inlet and outlet faces the fifth cavity. The valve body is provided with a fourth air inlet and outlet, and the port of the fourth air inlet and outlet faces the third cavity.

6. The balanced double-cylinder valve according to claim 3, characterized in that: One end of the valve stem away from the valve core passes through the first driving plug, the middle cylinder cover and the second driving plug and is arranged on the end cover. The end cover is provided with a fixing component, and the fixing component is used to fix the valve stem.

7. The balanced double-cylinder valve according to claim 6, characterized in that: The fixing assembly includes a support sleeve and a locking piece. The support sleeve is detachably connected to the end cover. The locking piece passes through the support sleeve and is detachably connected to the end cover. The valve stem passes through the support sleeve and is slidably connected to the support sleeve.

8. The balanced double-cylinder valve according to claim 7, characterized in that: A floating gap is provided between the support sleeve and the end cover.

9. The balanced double-cylinder valve according to claim 7, characterized in that: A protective shell is provided on the end cover, a limit piece is provided at one end of the valve stem passing through the support sleeve, the limit piece is arranged along the axial direction of the valve stem, the limit piece is provided with a shielding portion, an induction switch is provided on the protective shell, the induction switch is arranged along the radial direction of the valve stem, and the height of the shielding portion is greater than the diameter of the induction end of the induction switch.

10. The balanced double-cylinder valve according to claim 1, characterized in that: A sealing assembly is provided between the piston and the inner wall of the valve body.

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