Dual-seal stop valve

Abstract

The invention relates to the technical field of valves, in particular to a dual-seal stop valve, a valve clack comprises a first clack body and a second clack body which are buckled with each other, a hard sealing layer is arranged on the first clack body, a graphite sealing ring is clamped between the second clack body and the first clack body, and a sealing layer is arranged on the second clack body. The hard sealing layer and the graphite sealing ring form a continuous sealing face, the channel is in sealing fit with the valve seat through the sealing face and is divided into an inlet flow channel and an outlet flow channel, the second petal body is arranged on the side, away from the valve seat, of the first petal body, and the surface of the valve seat is an inclined conical face. By means of the double-sealing structure, abrasion caused by long-time work is reduced, and effective and stable sealing fit is kept between the valve clack and the valve seat.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, in particular to a double-sealed stop valve. Background Art

[0002] The opening and closing part of the stop valve is a plug-shaped valve disc. The sealing surface is a flat surface or a sea cone surface. The valve disc moves linearly along the center line of the valve seat. The stop valve, also known as the gate valve, is a forced sealing valve. Therefore, when the valve is closed, pressure must be applied to the valve disc to force the sealing surface to prevent leakage.

[0003] Patent CN87213890U discloses a leak-free stop valve that uses a new stem sealing technology and improves the relevant parts of the main seal to increase the main seal pressure ratio. This solution effectively solves the problem of poor stem sealing of the stop valve.

[0004] However, this solution still has the following problems: the valve disc and valve seat of this stop valve will frequently contact and rub under long-term operation, the sealing surface will become uneven after severe wear, and the contact area between the valve disc and the valve seat will also be reduced. Even if the valve disc moves into place when the stop valve is subsequently closed, there will be a gap between the valve disc and the valve seat, which will eventually cause the stop valve to fail. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a double-sealed stop valve. The present invention reduces the wear caused by long-term operation through a double-sealed structure, and the valve disc and the valve seat maintain an effective and stable sealing fit.

[0006] The technical solution adopted by the present invention is as follows: a double-seal stop valve, including a valve body, a valve seat, a valve disc, a valve stem, a valve cover and a driving mechanism, the valve body is provided with a channel for medium circulation, the valve seat is arranged inside the valve body, the valve cover is connected to one end of the valve body, one end of the valve stem is connected to the driving mechanism, and the other end passes through the valve cover and is connected to the valve disc, the valve disc includes a first flap body and a second flap body that are buckled into each other, the first flap body is provided with a hard sealing layer, a graphite sealing ring is sandwiched between the second flap body and the first flap body, the hard sealing layer and the graphite sealing ring form a continuous sealing surface, the channel is separated into an inlet flow channel and an outlet flow channel by sealing with the valve seat through the sealing surface, the second flap body is arranged on the side of the first flap body away from the valve seat, and the surface of the valve seat is an inclined conical surface, and a buffer ring groove for medium inflow is also provided in the middle of the hard sealing layer.

[0007] The cache ring groove is connected to the inlet flow channel through a plurality of flow holes, and the plurality of flow holes are evenly distributed around the axis of the first petal body. The inner diameter of the flow hole is smaller than the inner diameter of the cache ring groove in the longitudinal section.

[0008] The second petal body is sleeved on the outside of the valve stem and is slidingly connected to the valve stem. An extrusion assembly is also provided between the second petal body and the valve stem. The extrusion assembly includes a first elastic member, a sleeve and an end cover detachably connected to the sleeve. The end cover is sleeved on the outside of the valve stem. The inner edge of the second petal body is provided with an installation cavity for installing the first elastic member. The first elastic member is also sleeved on the outside of the valve stem. A boss is raised on the outer wall of the valve stem. One end of the first elastic member abuts the boss and the other end abuts the second petal body. The sleeve is sleeved on one end of the second petal body with a mounting cavity, and the sleeve is used to separate the mounting cavity and the outlet flow channel. The second petal body extrude the graphite sealing ring toward the first petal body through the first elastic member.

[0009] The sleeve includes a left sleeve and a right sleeve symmetrically spliced ​​along the axis, and the left sleeve and the right sleeve are both detachably connected to the end cover. A sealing assembly is also provided between the sleeve and the valve stem, and the sealing assembly includes a sealing filler and a C-shaped sealing ring. The outer wall of the second petal body is convex with a thickened layer, and the inner wall of the sleeve is recessed with a notch for the thickened layer to extend into. The edge of the thickened layer is provided with an arc-shaped extrusion portion, and the inner wall of the sleeve is provided with an arc-shaped yielding portion. The inner diameter of the sealing filler is smaller than the inner diameter of the notch. The sealing filler is extruded from both sides by the arc-shaped extrusion portion and the arc-shaped yielding portion to bend and deform. The C-shaped sealing ring is deformed by the extrusion of the thickened layer, forming a two-way tight abutment between the C-shaped sealing ring, the sealing filler and the sleeve.

[0010] The second petal body is externally mounted on the valve stem and is slidably connected to the valve stem. A movable gap is formed between the first petal body and the second petal body. A discharge hole is passed through the second petal body. The movable gap is connected to the outlet flow channel through the discharge hole.

[0011] The valve stem is connected to the first petal body through a fastener. A buckle plate for blocking the fastener is provided at one end of the first petal body close to the inlet flow channel. A convex edge and a concave edge are respectively provided on both sides of the buckle plate. The convex edge is embedded in the first petal body to form a snap connection, and the concave edge is snap-connected to the first petal body through an elastic cylinder.

[0012] The valve cover is provided with a limit assembly, which includes a limit slider, a toggle block, a cover plate and a second elastic member. The limit slider is slidably connected to the valve cover, the toggle block is threadedly connected to the limit slider, and the toggle block extends to the outside of the valve cover and is provided with an operating part. The cover plate is sleeved on the outside of the toggle block, and the cover plate is detachably connected to the valve cover through a fastening member. The second elastic member is arranged between the limit slider and the cover plate. The limit slider is squeezed toward the valve stem by the second elastic member. The side wall of the valve stem is recessed with a limit groove adapted to the limit slider. When the valve stem drives the valve disc to move to a position that seals with the valve seat, the limit slider slides into the limit groove to form a snap-fit ​​fit.

[0013] The end of the limit slider is arc-shaped, the inner wall of the limit groove is inner arc-shaped, an extrusion ring is extended from the end of the limit slider that abuts the second elastic member, and a fixing ring is extended from the cover plate for the second elastic member to be covered, and the extrusion ring is also covered on the outside of the fixing ring.

[0014] The valve stem is also provided with a medium flow channel connected to the inlet flow channel, the other end of the medium flow channel is connected to the limit groove, the limit slider and the toggle block are respectively provided with a first through hole and a second through hole connected to each other, and the toggle block is also externally connected to a pressure detection device connected to the second through hole. When the limit slider is engaged with the limit groove, the first through hole is connected to the medium flow channel.

[0015] The beneficial effects of the present invention are as follows: the present invention has a double sealing structure, that is, the hard sealing layer on the first flap body and the valve seat form a hard sealing fit, and the graphite sealing ring clamped between the second flap body and the first flap body and the valve seat form an elastic sealing fit. The hard seal and the elastic seal form a double seal with better sealing effect. The graphite sealing ring can reduce the wear caused by friction and elastically compensate for the sealing fit. The conical surface of the valve seat increases the fitting area with the sealing surface. During the closing process of the valve flap, the medium will flow into the cache ring groove in the middle of the hard sealing layer, reducing the resistance and friction brought by the medium, helping the hard sealing layer to fit the valve seat faster and tighter, reducing the wear caused by long-term work, and the valve flap and the valve seat maintain an effective and stable sealing fit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0017] Figure 1 This is a structural schematic diagram of a double-sealed stop valve of the present invention; Figure 2 It is a partial schematic diagram of the valve body portion of the present invention; Figure 3 for Figure 2 A partial enlarged schematic diagram of point A in the middle; Figure 4 for Figure 2 A partial enlarged schematic diagram of point B in the middle; Figure 5 for Figure 2 A partial enlarged schematic diagram of point C in the middle; Figure 6 It is a partial schematic diagram of the valve stem portion of the present invention; Figure 7 for Figure 6 A partial enlarged schematic diagram of point D in the middle; In the figure, 1-valve body, 2-valve seat, 3-valve disc, 4-valve stem, 5-valve cover, 6-driving mechanism, 7-first disc body, 8-second disc body, 9-hard sealing layer, 10-graphite sealing ring, 11-inlet flow channel, 12-outlet flow channel, 13-buffer ring groove, 14-flow hole, 15-first elastic member, 16-sleeve, 17-end cover, 18-installation cavity, 19-boss, 20-sealing packing, 21-C-type sealing ring, 22-thickening layer, 23-notch, 24- Arc-shaped extrusion portion, 25-arc-shaped yield portion, 26-active gap, 27-discharge hole, 28-fastener, 29-gusset plate, 30-convex edge, 31-concave edge, 32-elastic cylinder, 33-limiting slider, 34-toggle block, 35-cover plate, 36-second elastic member, 37-operating portion, 38-fastening connector, 39-limiting groove, 40-extrusion ring, 41-fixing ring, 42-medium flow channel, 43-first through hole, 44-second through hole, 45-pressure detection device. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0019] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. Subsequent embodiments will not explain this one by one.

[0020] The terms "upper," "lower," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side" used herein are merely references to the directions or positions in the accompanying drawings. These terms are intended to illustrate and facilitate understanding of the present invention and are not intended to limit the scope of protection of the present invention.

[0021] like Figures 1 to 7The figure shows an embodiment of the present invention, a double-sealed stop valve, comprising a valve body 1, a valve seat 2, a valve disc 3, a valve stem 4, a valve cover 5 and a drive mechanism 6. The valve body 1 is provided with a channel for medium circulation, the valve seat 2 is arranged inside the valve body 1, the valve cover 5 is connected to one end of the valve body 1, one end of the valve stem 4 is connected to the drive mechanism 6, and the other end passes through the valve cover 5 and is connected to the valve disc 3. The valve disc 3 includes a first flap body 7 and a second flap body 8 that are buckled into each other. The first flap body 7 is provided with a hard sealing layer 9, and a graphite sealing ring 10 is sandwiched between the second flap body 8 and the first flap body 7. The hard sealing layer 9 and the graphite sealing ring 10 form a continuous sealing surface. The channel is sealed with the valve seat 2 by the sealing surface and is divided into an inlet flow channel 11 and an outlet flow channel 12. The second flap body 8 is arranged on the side of the first flap body 7 away from the valve seat 2, and the surface of the valve seat 2 is an inclined conical surface. A buffer ring groove 13 for medium inflow is also provided in the middle of the hard sealing layer 9.

[0022] The beneficial effects of such a setting are as follows: the present invention has a double sealing structure, that is, the hard sealing layer on the first flap body and the valve seat form a hard sealing fit, and the graphite sealing ring clamped between the second flap body and the first flap body and the valve seat form an elastic sealing fit. The hard seal and the elastic seal form a double seal with better sealing effect. The graphite sealing ring can reduce the wear caused by friction and elastically compensate for the sealing fit. The conical surface of the valve seat increases the fitting area with the sealing surface. During the closing process of the valve flap, the medium will flow into the cache ring groove in the middle of the hard sealing layer, reducing the resistance and friction brought by the medium, helping the hard sealing layer to fit the valve seat faster and tighter, reducing the wear caused by long-term work, and the valve flap and the valve seat maintain an effective and stable sealing fit.

[0023] It is further provided that the cache ring groove 13 is connected to the inlet flow channel 11 through a plurality of flow holes 14, and the plurality of flow holes 14 are evenly distributed around the axis of the first petal body 7, and the inner diameter of the flow hole 14 is smaller than the inner diameter of the cache ring groove 13 in the longitudinal section.

[0024] The beneficial effects of this setting are as follows: the flow hole allows the medium in the buffer ring groove to flow back to the inlet flow channel, preventing the medium from accumulating in the buffer ring groove and affecting the normal opening and closing of the valve disc; the inner diameter of the flow hole is smaller, which helps the medium to flow back slowly when the valve disc is fully closed, preventing the medium from entering the flow hole and the buffer ring groove at the same flow rate at the same time during the closing process of the valve disc, thereby avoiding failure of the function of the buffer ring groove.

[0025] It is further provided that the second petal body 8 is sleeved on the outside of the valve stem 4 and is slidingly connected to the valve stem 4. An extrusion assembly is also provided between the second petal body 8 and the valve stem 4. The extrusion assembly includes a first elastic member 15, a sleeve 16 and an end cover 17 detachably connected to the sleeve 16. The end cover 17 is sleeved on the outside of the valve stem 4. The inner edge of the second petal body 8 is provided with a mounting cavity 18 for installing the first elastic member 15. The first elastic member 15 is also sleeved on the outside of the valve stem 4. A boss 19 is raised on the outer wall of the valve stem 4. One end of the first elastic member 15 abuts against the boss 19 and the other end abuts against the second petal body 8. The sleeve 16 is sleeved on one end of the second petal body 8 with the mounting cavity 18, and the sleeve 16 is used to separate the mounting cavity 18 from the outlet flow channel 12. The second petal body 8 squeezes the graphite sealing ring 10 toward the first petal body 7 through the first elastic member 15.

[0026] The beneficial effects of this arrangement are as follows: the first elastic member adopts a spring of the existing technology. When the valve disc is fully closed, the second disc body moves toward the first valve disc under the push of the elastic force of the first elastic member and further squeezes the graphite sealing ring, causing the graphite sealing ring to deform toward the valve seat and press against the valve seat, further improving the sealing effect of the elastic seal, and then through the connection and cooperation of the sleeve and the end cover, the outlet flow channel and the installation cavity are separated, protecting the first elastic member from being affected by the medium, and the extrusion assembly is convenient for disassembly and assembly.

[0027] It is further provided that the sleeve 16 includes a left sleeve and a right sleeve symmetrically spliced ​​along the axis, and the left sleeve and the right sleeve are both detachably connected to the end cover 17. A sealing assembly is also provided between the sleeve 16 and the valve stem 4, and the sealing assembly includes a sealing filler 20 and a C-type sealing ring 21. The outer wall of the second petal 8 is convex with a thickened layer 22, and the inner wall of the sleeve 16 is recessed with a notch 23 for the thickened layer 22 to extend into. The edge of the thickened layer 22 is provided with an arc-shaped extrusion portion 24, and the inner wall of the sleeve 16 is provided with an arc-shaped yielding portion 25. The inner diameter of the sealing filler 20 is smaller than the inner diameter of the notch 23. The sealing filler 20 is squeezed from both sides by the arc-shaped extrusion portion 24 and the arc-shaped yielding portion 25 to bend and deform it, and the C-type sealing ring 21 is deformed by the extrusion of the thickened layer 22, forming a two-way tight resistance between the C-type sealing ring 21 and the sealing filler 20 and the sleeve 16.

[0028] The beneficial effects of this arrangement are as follows: the split sleeve is easy to disassemble and assemble, and the sealing between the sleeve and the second petal body is increased by the sealing assembly. The second petal body moves under the push of the first elastic member, and the thickened layer of the outer wall of the second petal body also moves accordingly, squeezing the C-shaped sealing ring and the sealing filler at the same time. The sealing filler is squeezed and deformed to extend between the arc-shaped extrusion part and the arc-shaped yielding part, filling the gap between the two, greatly increasing the sealing performance. After being squeezed and deformed, the C-shaped sealing ring firmly presses the end of the sealing filler away from the arc-shaped extrusion part to prevent the sealing filler from sliding out and detaching from the sleeve after being squeezed and deformed, thereby ensuring both sealing performance and stable installation.

[0029] It is further provided that the second flap body 8 is sleeved on the outside of the valve stem 4 and is slidingly connected to the valve stem 4, and a movable gap 26 is formed between the first flap body 7 and the second flap body 8, and a discharge hole 27 is penetrated on the second flap body 8, and the movable gap 26 is connected to the outlet flow channel 12 through the discharge hole 27.

[0030] The beneficial effects of this arrangement are as follows: the second petal body moves relative to the first petal body, and a movable gap is generated between the two. When the second petal body moves toward the first petal body, the medium and gas in the movable gap are discharged to the outlet flow channel through the discharge hole. The principle of compression discharge is adopted to effectively avoid the second petal body being unable to move toward the first petal body due to the accumulation of medium or gas in the movable gap, thereby ensuring smooth movement of the second petal body. During the opening process of the valve disc, the medium will also flow into the movable gap through the discharge hole to help the second petal body move away from the first petal body, loosening the squeeze on the graphite sealing ring, and making the valve disc opening easier and more labor-saving.

[0031] It is further provided that the valve stem 4 is connected to the first petal body 7 through a fastener 28, and a buckle plate 29 for blocking the fastener 28 is provided at one end of the first petal body 7 close to the inlet flow channel 11, and a convex edge 30 and a concave edge 31 are respectively provided on both sides of the buckle plate 29, the convex edge 30 is embedded in the first petal body 7 to form a snap connection, and the concave edge 31 is snap-connected with the first petal body 7 through an elastic cylinder 32.

[0032] The beneficial effects of this arrangement are as follows: the first petal body is fixedly connected to the valve stem through a fastener, and a buckle plate is fastened on the outside of the fastener to prevent the fastener from loosening. One side of the buckle plate uses an arc-shaped convex edge to engage with the first petal body, and the other side uses an arc-shaped concave edge for the elastic cylinder to cooperate with and engage. The elastic characteristics of the elastic cylinder help the buckle plate to be embedded in and fixed on the first petal body.

[0033] It is further provided that the valve cover 5 is provided with a limit assembly, which includes a limit slider 33, a toggle block 34, a cover plate 35 and a second elastic member 36. The limit slider 33 is slidably connected to the valve cover 5, the toggle block 34 is threadedly connected to the limit slider 33, and the toggle block 34 extends to the outside of the valve cover 5 and is provided with an operating portion 37. The cover plate 35 is sleeved on the outside of the toggle block 34, and the cover plate 35 is detachably connected to the valve cover 5 through a fastening member 38. The second elastic member 36 is arranged between the limit slider 33 and the cover plate 35. The limit slider 33 is squeezed toward the valve stem 4 by the second elastic member 36. The side wall of the valve stem 4 is recessed with a limit groove 39 adapted to the limit slider 33. When the valve stem 4 drives the valve disc 3 to move to a position that is sealed with the valve seat 2, the limit slider 33 slides into the limit groove 39 to form a snap-fit ​​fit.

[0034] The beneficial effects of such a setting are as follows: the limit assembly provided on the valve cover can lock the valve stem when the valve is closed in place to prevent the valve stem from being accidentally touched to open the valve, that is, the limit slider forms a snap fit with the limit groove of the valve stem, and the limit slider is squeezed toward the valve stem through the second elastic member, and automatically slides into the limit groove to form a lock when the valve stem is rotated into place. The second elastic member also adopts the spring of the existing technology. The limit slider is also connected to a toggle block, and the toggle block extends to the outside of the valve cover and is provided with an operating part. The lifting operating part can drive the limit slider away from the limit groove for unlocking the valve stem. The limit assembly has the advantages of effective locking and convenient operation through the combination of automatic locking and manual unlocking.

[0035] It is further configured that the end of the limiting slider 33 is arc-shaped, the inner wall of the limiting groove 39 is inner arc-shaped, an extrusion ring 40 is extended from the end of the limiting slider 33 that abuts the second elastic member 36, and the cover plate 35 is extended with a fixing ring 41 for the outer sleeve of the second elastic member 36, and the extrusion ring 40 is also outermost on the outside of the fixing ring 41.

[0036] The beneficial effects of this arrangement are as follows: the end of the limit slider and the inner wall of the limit groove are both arc-shaped, which not only ensures firm locking but also facilitates the sliding of the limit slider. The extrusion ring of the limit slider and the fixing ring of the cover plate form a plug-in fit, and the second elastic part is installed in a closed environment to prevent the second elastic part from twisting and avoid interference.

[0037] It is further configured that the valve stem 4 is also provided with a medium flow channel 42 connected to the inlet flow channel 11, the other end of the medium flow channel 42 is connected to the limit groove 39, the limit slider 33 and the toggle block 34 are respectively provided with a first through hole 43 and a second through hole 44 connected to each other, and the toggle block 34 is also externally connected to a pressure detection device 45 connected to the second through hole 44. When the limit slider 33 is engaged with the limit groove 39, the first through hole 43 is connected to the medium flow channel 42.

[0038] The beneficial effects of such a setting are as follows: the external pressure detection device can detect the pressure of the inlet flow channel in real time through the medium flow channel, and cooperate with the limit assembly to manually unlock the valve stem to form a warning effect, avoid excessive pressure in the inlet flow channel, and open the valve disc in time to relieve pressure. The fastener uses the open-hole screw of the existing technology to be connected to the medium channel. There are also openings on the buckle plate for medium channel connection. The limit slider and the toggle block are also respectively provided with a first through hole and a second through hole for the medium channel to connect. The medium channel is combined with the limit assembly, and the medium channel is only connected for pressure detection when the valve disc is closed. The structure is sophisticated and the operation is stable.

[0039] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A double-sealed stop valve, comprising a valve body (1), a valve seat (2), a valve disc (3), a valve stem (4), a valve cover (5) and a drive mechanism (6), wherein a passage for medium circulation is provided inside the valve body (1), the valve seat (2) is arranged inside the valve body (1), the valve cover (5) is connected to one end of the valve body (1), one end of the valve stem (4) is connected to the drive mechanism (6), and the other end passes through the valve cover (5) and is connected to the valve disc (3), characterized in that: The valve flap (3) includes a first flap body (7) and a second flap body (8) that are interlocked with each other, a hard sealing layer (9) is provided on the first flap body (7), and a graphite sealing ring (10) is sandwiched between the second flap body (8) and the first flap body (7), the hard sealing layer (9) and the graphite sealing ring (10) form a continuous sealing surface, and the channel is sealed with the valve seat (2) through the sealing surface and is separated into an inlet flow channel (11) and an outlet flow channel (12), the second flap body (8) is arranged on the side of the first flap body (7) away from the valve seat (2), and the surface of the valve seat (2) is an inclined conical surface, and a buffer ring groove (13) for medium to flow into is also provided in the middle of the hard sealing layer (9).

2. A double seal stop valve according to claim 1, characterized in that: The buffer ring groove (13) is connected to the inlet flow channel (11) through a plurality of flow holes (14), and the plurality of flow holes (14) are evenly distributed around the axis of the first petal body (7), and the inner diameter of the flow hole (14) is smaller than the inner diameter of the buffer ring groove (13) in the longitudinal section.

3. A double seal stop valve according to claim 1, characterized in that: The second flap (8) is sheathed on the outside of the valve stem (4) and is slidably connected to the valve stem (4). An extrusion assembly is further provided between the second flap (8) and the valve stem (4). The extrusion assembly comprises a first elastic member (15), a sleeve (16), and an end cover (17) detachably connected to the sleeve (16). The end cover (17) is sheathed on the outside of the valve stem (4). An installation cavity (18) for installing the first elastic member (15) is provided on the inner edge of the second flap (8). The first elastic member (15) It is also sleeved on the outside of the valve stem (4), and the outer wall of the valve stem (4) is raised with a boss (19). One end of the first elastic member (15) is in contact with the boss (19) and the other end is in contact with the second flap body (8). The sleeve (16) is sleeved on one end of the second flap body (8) provided with a mounting cavity (18), and the sleeve (16) is used to separate the mounting cavity (18) from the outlet flow channel (12). The second flap body (8) squeezes the graphite sealing ring (10) toward the first flap body (7) through the first elastic member (15).

4. A double seal stop valve according to claim 3, characterized in that: The sleeve (16) comprises a left sleeve body and a right sleeve body symmetrically connected along an axis, and the left sleeve body and the right sleeve body are both detachably connected to the end cover (17). A sealing assembly is also provided between the sleeve (16) and the valve stem (4), and the sealing assembly comprises a sealing filler (20) and a C-shaped sealing ring (21). The outer wall of the second petal (8) is convex with a thickening layer (22), and the inner wall of the sleeve (16) is recessed with a notch (23) for the thickening layer (22) to extend into. An arc-shaped extrusion portion (24) is provided on the edge, and an arc-shaped evacuation portion (25) is provided on the inner wall of the sleeve (16). The inner diameter of the sealing filler (20) is smaller than the inner diameter of the notch (23). The sealing filler (20) is squeezed from both sides by the arc-shaped extrusion portion (24) and the arc-shaped evacuation portion (25) to bend and deform. The C-shaped sealing ring (21) is squeezed by the thickening layer (22) to be deformed, forming a two-way tight contact between the C-shaped sealing ring (21), the sealing filler (20) and the sleeve (16).

5. The double seal stop valve according to claim 1, characterized in that: The second flap (8) is sheathed outside the valve stem (4) and is slidably connected to the valve stem (4). A movable gap (26) is formed between the first flap (7) and the second flap (8). A discharge hole (27) is passed through the second flap (8). The movable gap (26) is communicated with the outlet flow channel (12) through the discharge hole (27).

6. The double seal stop valve according to claim 1, characterized in that: The valve stem (4) is connected to the first flap body (7) via a fastener (28); a pinch plate (29) for blocking the fastener (28) is provided at one end of the first flap body (7) close to the inlet flow channel (11); a convex edge (30) and a concave edge (31) are provided on both sides of the pinch plate (29); the convex edge (30) is embedded in the first flap body (7) to form a snap connection; the concave edge (31) is snap-connected to the first flap body (7) via an elastic cylinder (32).

7. The double seal stop valve according to claim 1, characterized in that: The valve cover (5) is provided with a limit assembly, which includes a limit slider (33), a toggle block (34), a cover plate (35) and a second elastic member (36). The limit slider (33) is slidably connected to the valve cover (5), the toggle block (34) is threadedly connected to the limit slider (33), and the toggle block (34) extends to the outside of the valve cover (5) and is provided with an operating portion (37). The cover plate (35) is sheathed on the outside of the toggle block (34), and the cover plate (35) is fastened to the outside of the valve cover (5) by a fastening member (38). ) is detachably connected to the valve cover (5), the second elastic member (36) is arranged between the limiting slider (33) and the cover plate (35), the limiting slider (33) is squeezed toward the valve stem (4) through the second elastic member (36), and the side wall of the valve stem (4) is recessed with a limiting groove (39) adapted to the limiting slider (33), when the valve stem (4) drives the valve disc (3) to move to a position where it seals with the valve seat (2), the limiting slider (33) slides into the limiting groove (39) to form a snap-fit ​​fit.

8. The double-sealed stop valve according to claim 7, characterized in that: The end of the limiting slider (33) is in an arc shape, and the inner wall of the limiting groove (39) is in an inner arc shape. An extrusion ring (40) extends from the end of the limiting slider (33) that abuts the second elastic member (36). The cover plate (35) is extended with a fixing ring (41) for the outer sleeve of the second elastic member (36), and the extrusion ring (40) is also outer-sheathed on the outside of the fixing ring (41).

9. The double-sealed stop valve according to claim 7, characterized in that: The valve stem (4) is further provided with a medium flow channel (42) connected to the inlet flow channel (11); the other end of the medium flow channel (42) is connected to the limit groove (39); the limit slider (33) and the toggle block (34) are respectively provided with a first through hole (43) and a second through hole (44) connected to each other; the toggle block (34) is further externally connected to a pressure detection device (45) connected to the second through hole (44); when the limit slider (33) is engaged with the limit groove (39), the first through hole (43) is connected to the medium flow channel (42).

Images