Sand-prevention fracturing flat gate valve

Abstract

The utility model relates to the technical field of petroleum or natural gas drilling equipment, in particular to a sand-prevention fracturing flat gate valve which comprises a valve body, a valve plate, a pair of channel openings, a sand blocking ring and an elastic piece, a valve cavity is formed in the valve body, the valve plate is movably arranged in the valve cavity, annular valve seats are arranged in the valve cavity in pairs, the annular valve seats abut against the two sides of the valve plate, and the sand blocking ring abuts against the elastic piece. The elastic piece is arranged at the end, away from the annular valve seat, of the sand blocking ring, so that the end, close to the valve plate, of the annular valve seat abuts against the side face of the valve plate all the time, and sealing is formed; according to the flat gate valve, injection liquid containing sand or impurities is effectively prevented from entering the interior of the valve body or the sealing face where the annular valve seat is attached to the valve plate along a gap between the annular valve seat and the valve plate, the possibility that sand grains or impurities are deposited and deposited in the valve body is reduced, abrasion of the sand grains or the impurities to the sealing gasket is reduced, and normal use of the flat gate valve is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of oil or natural gas drilling equipment, in particular to a sand-proof fracturing flat gate valve. Background Art

[0002] At present, in the field of shale gas drilling and production, hydraulic sand fracturing is widely used at home and abroad, and the hydraulic sand fracturing process is recognized as an effective production increase measure. In the fracturing operation of shale gas formations, the fracturing flat gate valve is a key component for controlling pressure, flow and direction.

[0003] The conventionally designed fracturing flat gate valve has a certain gap between the valve seat and the gate plate. When the flat gate valve is closed, the valve body bears the pressure at the pressure inlet end, and uses the pressure difference between the pressure inlet end of the valve body and the pressure at the isolation end to achieve free fitting of the valve plate and the valve seat to form a seal; when the valve plate is movably set in the valve body, it will cause wear between the valve seat and the valve plate, causing the gap between the valve seat and the valve plate to become larger, resulting in the fluid containing sand or impurities flowing through the flat gate valve. The fluid containing sand or impurities will flow along the gap between the valve seat and the gate plate and enter the interior of the flat gate valve body or the gap between the valve seat and the valve body. Over time, with the sedimentation and accumulation of sand particles and the wear of the sand particles on the sealing ring, the flat gate valve will eventually fail to open and close or the seal will fail. If an emergency occurs, the flat gate valve needs to be closed immediately, but it cannot be closed due to a large amount of sedimentation, which will cause a safety accident. Utility Model Content

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the utility model provides a sand-proof fracturing flat gate valve, which solves the technical problem that sand-containing fluid enters the interior of the flat gate valve along the gap between the valve seat and the gate plate, causing wear on the sealing gasket of the flat gate valve, resulting in the flat gate valve being unable to open and close in place or the sealing failing.

[0005] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0006] A sand fracturing anti-flat gate valve comprises: a valve body, a valve plate and a pair of flow channel openings, a sand blocking ring and an elastic member, a valve body is provided with a valve cavity, the valve plate is movably arranged in the valve cavity, the valve plate moves linearly in the valve cavity to realize the switching of the flow channel open and closed states, annular valve seats are arranged in pairs in the valve cavity, a pair of the annular valve seats abut against two sides of the valve plate, a first annular receiving cavity is provided on the inner wall of the annular valve seat away from one end of the valve plate, the sand blocking ring is arranged in the first annular receiving cavity, the elastic member abuts on the side of the sand blocking ring away from the annular valve seat until the sand blocking ring axially abuts against the annular valve seat, a second annular receiving cavity is provided on the inner wall of the valve cavity opposite to the first annular receiving cavity, the elastic member is arranged in the second annular receiving cavity and abuts against the end of the second annular receiving cavity, and the sand blocking ring extends axially into the second annular receiving cavity away from one end of the annular valve seat.

[0007] Based on the above structure, the principle of the sand-proof fracturing flat gate valve is as follows: the annular valve seat is arranged at the end of the sand-blocking ring away from the annular valve seat, so that the end of the annular valve seat close to the valve plate always contacts the side of the valve plate to form a seal, thereby preventing the sand or impurities from flowing through the valve body. The sand or impurities enter the interior of the valve body or the fitting sealing surface of the annular valve seat and the valve plate through the gap between the annular valve seat and the valve plate, causing damage to the flat gate valve.

[0008] Furthermore, in a sand fracturing flat gate valve in the present application, a guide hole is provided on the valve plate, and the size of the guide hole is adapted to the inner diameter of the annular valve seat. As a preferred embodiment of the present application, the guide hole in a sand fracturing flat gate valve in the present application is used to switch the open and closed states of the valve plate. When the valve plate is in the open state, the guide hole corresponds to the inner hole of the annular valve seat, and a pair of convection ports are connected, so that the fluid can flow from one convection port to another convection port. When the valve plate is closed, the guide hole is completely offset from the inner hole of the annular valve seat.

[0009] Furthermore, in a sand-proof fracturing flat gate valve in the present application, a sealing assembly is provided on the side of the annular valve seat away from the valve plate, and the sealing assembly includes a first annular seal, the first annular seal is arranged between the axial fitting surface of the annular valve seat and the valve body, and the first annular seal is arranged radially outside the inner through hole of the annular valve seat. As a preferred embodiment of the present application, the first annular seal in a sand-proof fracturing flat gate valve in the present application is the first seal between the valve body and the annular valve seat, and is used to seal the gap between the valve body and the annular valve seat, to block sand or impurities, so that sand or impurities cannot enter the interior of the valve body, and to protect the flat gate valve.

[0010] Furthermore, in a sand-proof fracturing flat gate valve in the present application, the sealing assembly includes a second annular seal, the second annular seal is embedded in the outer side surface of the annular valve seat, the second annular seal is arranged at the end of the annular valve seat away from the valve plate, and corresponding to the second annular seal, an annular notch is arranged on the outer side surface of the annular valve seat, and the annular notch is used to accommodate the second annular seal. As a preferred embodiment of the present application, the second annular seal in a sand-proof fracturing flat gate valve in the present application forms a second seal between the valve body and the annular valve seat, and works together with the first annular seal to prevent sand or impurities from entering the interior of the valve body, thereby protecting the flat gate valve.

[0011] Furthermore, in the present application, a sand-proof fracturing flat gate valve has a clearance between the sand blocking ring and the inner walls of the second annular receiving chamber and the first annular receiving chamber, which is smaller than the minimum mesh size of the fracturing sand. As a preferred embodiment of the present application, the present application has a sand-proof fracturing flat gate valve, in which the minimum mesh size of the fracturing sand is smaller than the clearance between the axial fitting surface of the valve body and the annular valve seat, so as to prevent sand or impurities from entering through the clearance between the fitting surface of the valve body and the annular valve seat, thereby avoiding the wear of the sealing component by sand or impurities, which may lead to the failure of the sealing component.

[0012] Furthermore, a sand fracturing flat gate valve in the present application also includes: a connecting rod, the connecting rod includes: an upper rod and a lower rod, the upper rod is connected to the upper end of the valve plate, the lower rod is connected to the lower end of the valve plate, and also includes: a valve cover, the valve cover includes: an upper valve cover and a lower valve cover, the upper valve cover and the lower valve cover are respectively sleeved on the upper rod and the lower rod, and the upper valve cover and the lower valve cover are respectively sealed and installed on the upper and lower ends of the valve body. As a preferred embodiment of the present application, the upper valve cover and the lower valve cover in a sand fracturing flat gate valve in the present application are respectively installed on the upper and lower ends of the valve body using bolts.

[0013] Furthermore, a sand fracturing flat gate valve in the present application also includes: a combined seal, the combined seal includes: a gland, a group of annular sealing rings, an annular cavity is provided on the inner wall of the connection between the valve cover and the connecting rod, a group of annular sealing rings are axially stacked in the annular cavity, the gland is sleeved on the connecting rod, the gland is installed in the annular cavity and is threadedly connected to the valve cover, the gland abuts against the outer end of a group of annular sealing rings, and the gland is used to axially compress a group of axially stacked annular sealing rings. As a preferred embodiment of the present application, the gland in a sand fracturing flat gate valve of the present application is threadedly connected to the valve cover and is used to axially compress a group of axially stacked annular sealing rings, and the combined seal is used to prevent the fluid in the valve body from flowing out of the gap between the valve cover and the connecting rod.

[0014] Furthermore, in a sand fracturing flat gate valve in the present application, an indicator is provided on the lower rod, and the indicator is arranged on the outside of the lower rod. A lower valve cover is provided below the lower valve cover, and the indicator is inside the lower valve cover. A groove is provided on the side wall of the lower valve cover, and the groove extends in the vertical direction. The groove is directly opposite to the moving trajectory of the indicator, and the outside of the groove corresponds to the moving trajectory of the indicator, and a stroke mark is provided, and the stroke mark is arranged on the outside of the groove. As a preferred embodiment of the present application, the indicator in a sand fracturing flat gate valve in the present application will drive the indicator to move up and down with the up and down movement of the lower rod during the opening and closing process of the flat gate valve, and the position of the indicator relative to the stroke mark can be seen through the groove, so as to determine the opening and closing state of the flat gate valve.

[0015] Furthermore, a sand fracturing flat gate valve in the present application also includes: a switch mechanism, the switch mechanism includes: a rotating seat, a nut sleeve, a ball screw, and a handwheel, the rotating seat is installed on the upper valve cover, the nut sleeve is rotatably arranged in the rotating seat, the ball screw is fixed to the outer end of the upper rod, the nut sleeve is sleeved on the ball screw, the nut sleeve is threadedly connected to the ball screw, and the handwheel is installed at the upper end of the nut sleeve. As a preferred embodiment of the present application, a sand fracturing flat gate valve in the present application, rotating the handwheel can drive the nut sleeve to rotate in the rotating seat, because the nut sleeve is sleeved on the ball screw, and the nut sleeve is threadedly connected to the ball screw, therefore, the rotation of the nut sleeve can drive the ball screw to move axially, so as to drive the upper rod and the valve plate to move.

[0016] It can be seen from the above technical solution that the utility model has the following beneficial effects:

[0017] The closure of the valve body by the closure member is effected by the elastic member which is arranged at the end of the sand blocking ring away from the annular valve seat, so that the end of the annular valve seat close to the valve plate is always in contact with the side surface of the valve plate to form a seal, thereby effectively preventing the injection liquid containing sand or impurities from entering the interior of the valve body or the sealing surface where the annular valve seat and the valve plate fit along the gap between the annular valve seat and the valve plate, thereby reducing the possibility of sedimentation and accumulation of sand or impurities in the valve body, reducing the wear of the sealing gasket by sand or impurities, and ensuring the normal use of the closure member. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the cross-sectional structure of a sand-proof fracturing flat gate valve in an embodiment of the present application;

[0019] Figure 2 for Figure 1 A partial enlarged view of the area A in the middle circle;

[0020] Figure 3 for Figure 1 A partial enlarged view of the area in the middle circle B.

[0021] In the figure: 1-valve body; 10-valve cavity; 11-second annular receiving cavity; 12-indicator; 13-lower valve cover; 131-groove; 15-switch mechanism; 151-rotating seat; 1510-annular limiting cavity; 152-nut sleeve; 1521-annular convex portion; 153-thrust bearing; 154-ball screw; 155-handwheel; 2-valve plate; 20-guide hole; 3-annular valve seat; 30-annular notch; 31-first annular receiving cavity; 32-sealing assembly; 321-first annular sealing member; 322-second annular sealing member; 4-convection channel opening; 5-sand blocking ring; 6-elastic member; 70-annular cavity; 71-upper valve cover; 72-lower valve cover; 8-combined seal; 81-pressure cover; 82-annular sealing ring; 9-connecting rod; 91-upper rod; 92-lower rod. DETAILED DESCRIPTION Example

[0022] like Figure 1 As shown, a sand fracturing flat gate valve comprises: a valve body 1, a valve plate 2 and a pair of flow channel openings 4, a sand blocking ring 5, and an elastic member 6. A valve cavity 10 is provided in the valve body 1, and the valve plate 2 is movably arranged in the valve cavity 10. The valve plate 2 moves linearly in the valve cavity 10 to realize the switching of the flow channel open and closed states. An annular valve seat 3 is provided in pairs in the valve cavity 10. A pair of the annular valve seats 3 abuts against both sides of the valve plate 2. The inner wall of the annular valve seat 3 away from one end of the valve plate 2 is provided with a first annular receiving cavity 3. 1, the sand blocking ring 5 is arranged in the first annular receiving chamber 31, the elastic member 6 abuts against the side of the sand blocking ring 5 away from the annular valve seat 3 until the sand blocking ring 5 axially abuts against the annular valve seat 3, the inner wall of the valve chamber 10 is provided with a second annular receiving chamber 11 arranged opposite to the first annular receiving chamber 31, the elastic member 6 is arranged in the second annular receiving chamber 11 and abuts against the end of the second annular receiving chamber 11, and the end of the sand blocking ring 5 away from the annular valve seat 3 axially extends into the second annular receiving chamber 11.

[0023] Based on the above structure, the principle of the anti-sand fracturing flat gate valve is as follows: the annular valve seat 3 always makes the end of the annular valve seat 3 close to the valve plate 2 contact the side of the valve plate 2 through the elastic member 6 arranged at the end of the sand blocking ring 5 away from the annular valve seat 3, forming a seal to prevent the sand or impurities from entering the valve body 1 or the fitting sealing surface of the annular valve seat 3 and the valve plate 2 from the gap between the annular valve seat 3 and the valve plate 2 when the fluid containing sand or impurities flows through the valve body 1, causing damage to the flat gate valve. In this embodiment, the elastic member 6 is a wave spring.

[0024] In this embodiment, the valve plate 2 is provided with a guide hole 20, and the size of the guide hole 20 is adapted to the inner diameter of the annular valve seat 3. The guide hole 20 is used to switch the open and closed states of the valve plate 2. When the valve plate 2 is in the open state, the guide hole 20 corresponds to the inner hole of the annular valve seat 3, and a pair of convection ports 4 are connected, and the fluid can flow from one convection port 4 to another convection port 4. When the valve plate 2 is closed, the guide hole 20 is completely staggered with the inner hole of the annular valve seat 3.

[0025] like Figure 2 As shown, in this embodiment, a sealing assembly 32 is provided on the side of the annular valve seat 3 away from the valve plate 2, and the sealing assembly 32 includes a first annular seal 321, which is arranged between the axial fitting surface of the annular valve seat 3 and the valve body 1, and the first annular seal 321 is arranged radially outside the inner through hole of the annular valve seat 3. The first annular seal 321 is the first seal between the valve body 1 and the annular valve seat 3, and is used to seal the gap between the valve body 1 and the annular valve seat 3, block sand or impurities, and prevent sand or impurities from entering the interior of the valve body 1, so as to protect the flat gate valve. The first annular seal 321 adopts an O-ring.

[0026] In this embodiment, the sealing assembly 32 further includes a second annular seal 322, which is embedded in the outer side surface of the annular valve seat 3. The second annular seal 322 is arranged at one end of the annular valve seat 3 away from the valve plate 2. Corresponding to the second annular seal 322, an annular notch 30 is provided on the outer side surface of the annular valve seat 3, and the annular notch 30 is used to accommodate the second annular seal 322. The second annular seal 322 forms a second seal between the valve body 1 and the annular valve seat 3, and works together with the first annular seal 321 to prevent sand or impurities from entering the interior of the valve body 1, thereby protecting the flat gate valve. The second annular seal 322 adopts a Y-shaped sealing ring, which is a one-way acting sealing member. When installed, the lip portion of the Y-shaped sealing ring faces the valve plate 2.

[0027] In this embodiment, the matching clearance between the sand blocking ring 5 and the inner walls of the second annular receiving chamber 11 and the first annular receiving chamber 31 is smaller than the minimum mesh size of the fracturing sand. The minimum mesh size of the fracturing sand is smaller than the gap between the axial fitting surfaces of the valve body 1 and the annular valve seat 3, preventing sand or impurities from entering from the gap between the axial fitting surfaces of the valve body 1 and the annular valve seat 3, and avoiding the wear of the sealing component 32 by sand or impurities, which leads to the failure of the sealing component 32.

[0028] In this embodiment, it also includes: a connecting rod 9, the connecting rod 9 includes: an upper rod 91 and a lower rod 92, the upper rod 91 is connected to the upper end of the valve plate 2, and the lower rod 92 is connected to the lower end of the valve plate 2, and also includes: a valve cover, the valve cover includes: an upper valve cover 71 and a lower valve cover 72, the upper valve cover 71 and the lower valve cover 72 are respectively sleeved on the upper rod 91 and the lower rod 92, the upper valve cover 71 and the lower valve cover 72 are respectively sealed and installed on the upper and lower ends of the valve body 1, and the upper valve cover 71 and the lower valve cover 72 are respectively installed on the upper and lower ends of the valve body 1 using bolts.

[0029] In this embodiment, a grease injection port is provided on the valve cover, and a grease injection valve is provided at the grease injection port. The grease injection valve is used to inject grease between the valve cover and the connecting rod 9 for lubrication.

[0030] like Figure 3 As shown, in this embodiment, it also includes: a combined seal 8, which includes: a gland 81, a group of annular sealing rings 82, an annular cavity 70 is provided on the inner wall of the connection between the valve cover and the connecting rod 9, a group of annular sealing rings 82 are axially stacked and arranged in the annular cavity 70, the gland 81 is sleeved on the connecting rod 9, the gland 81 is installed in the annular cavity 70, and is threadedly connected to the valve cover, the gland 81 abuts against the outer end of a group of annular sealing rings 82, and the gland 81 is used to axially compress a group of axially stacked annular sealing rings 82. The gland 81 is threadedly connected to the valve cover and is used to axially compress a group of axially stacked annular sealing rings 82. The combined seal 8 is used to prevent the fluid in the valve body 1 from flowing out from the gap between the valve cover and the connecting rod 9. A group of annular sealing rings 82 consists of 4 annular sealing rings 82.

[0031] In this embodiment, the lower rod 92 is provided with an indicator 12, and the indicator 12 is arranged on the outer side of the lower rod 92. A lower valve cover 13 is provided below the lower valve cover 72. The indicator 12 is inside the lower valve cover 13. A groove 131 is provided on the side wall of the lower valve cover 13. The groove 131 extends in the vertical direction. The groove 131 is directly opposite to the moving track of the indicator 12. The outer side of the groove 131 corresponds to the moving track of the indicator 12 and is provided with a stroke mark. The stroke mark is arranged on the outer side of the groove 131. During the opening and closing process of the flat gate valve, the indicator 12 will move up and down with the up and down movement of the lower rod 92. The position of the indicator 12 relative to the stroke mark can be seen through the groove 131, so as to determine the opening and closing state of the flat gate valve.

[0032] In this embodiment, the indicator 12 extends out of the slot 131 .

[0033] In this embodiment, the switch mechanism 15 is also included, and the switch mechanism 15 includes a rotating seat 151, a nut sleeve 152, a ball screw 154, and a hand wheel 155. The rotating seat 151 is installed on the upper valve cover 71, and the nut sleeve 152 is rotatably arranged in the rotating seat 151. The ball screw 154 is fixed to the outer end of the upper rod 91. The nut sleeve 152 is sleeved on the ball screw 154, and the nut sleeve 152 is threadedly connected to the ball screw 154. The hand wheel 155 is installed on the upper end of the nut sleeve 152. Rotating the hand wheel 155 can drive the nut sleeve 152 to rotate in the rotating seat 151. Since the nut sleeve 152 is sleeved on the ball screw 154, and the nut sleeve 152 is threadedly connected to the ball screw 154, the rotation of the nut sleeve 152 can drive the ball screw 154 to move axially, so as to drive the upper rod 91 and the valve plate 2 to move.

[0034] In this embodiment, the rotating seat 151 is provided with an annular limiting cavity 1510 with an opening at the lower end, and an annular protrusion 1521 extends from the outer side of the nut sleeve 152, and the annular protrusion 1521 is arranged in the annular limiting cavity 1510. The switch mechanism 15 also includes: a pair of thrust bearings 153 arranged on the inner side of the annular limiting cavity 1510, and the thrust bearing 153 is sleeved on the outer side of the nut sleeve 152, and the annular protrusion 1521 is arranged between the pair of thrust bearings 153.

[0035] In this embodiment, the thrust bearing 153 is used to improve the rotation stability of the nut sleeve 152 , and the annular limiting cavity 1510 is used to limit the nut sleeve 152 and the thrust bearing 153 .

[0036] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanation here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A sand fracturing flat gate valve, comprising: A valve body (1), a valve plate (2) and a pair of flow channel openings (4), characterized in that: it includes: a sand blocking ring (5), an elastic member (6), a valve cavity (10) is provided in the valve body (1), the valve plate (2) is movably arranged in the valve cavity (10), the valve plate (2) moves linearly in the valve cavity (10) to realize the switching of the flow channel open and closed states, annular valve seats (3) are provided in pairs in the valve cavity (10), a pair of the annular valve seats (3) abut against two sides of the valve plate (2), and a first annular receiving cavity (31) is provided on the inner wall of the annular valve seat (3) away from the valve plate (2). The sand blocking ring (5) is arranged in the first annular receiving chamber (31); the elastic member (6) abuts against the side of the sand blocking ring (5) away from the annular valve seat (3) until the sand blocking ring (5) axially abuts against the annular valve seat (3); the inner wall of the valve chamber (10) is provided with a second annular receiving chamber (11) arranged opposite to the first annular receiving chamber (31); the elastic member (6) is arranged in the second annular receiving chamber (11) and abuts against the end of the second annular receiving chamber (11); and the end of the sand blocking ring (5) away from the annular valve seat (3) axially extends into the second annular receiving chamber (11).

2. The anti-sand fracturing flat gate valve according to claim 1, characterized in that: The valve plate (2) is provided with a flow guide hole (20), and the size of the flow guide hole (20) is adapted to the inner diameter of the annular valve seat (3).

3. The anti-sand fracturing flat gate valve according to claim 1, characterized in that: A sealing assembly (32) is provided on a side of the annular valve seat (3) away from the valve plate (2), and the sealing assembly (32) comprises a first annular sealing member (321). The first annular sealing member (321) is arranged between the axially fitting surfaces of the annular valve seat (3) and the valve body (1), and the first annular sealing member (321) is arranged radially outside the inner through hole of the annular valve seat (3).

4. The anti-sand fracturing flat gate valve according to claim 3, characterized in that: The sealing assembly (32) further comprises a second annular seal (322), wherein the second annular seal (322) is embedded in the outer side surface of the annular valve seat (3), and the second annular seal (322) is arranged at an end of the annular valve seat (3) away from the valve plate (2). Corresponding to the second annular seal (322), an annular notch (30) is provided on the outer side surface of the annular valve seat (3), and the annular notch (30) is used to accommodate the second annular seal (322).

5. The anti-sand fracturing flat gate valve according to claim 1, characterized in that: The matching clearance between the sand blocking ring (5) and the inner walls of the second annular receiving chamber (11) and the first annular receiving chamber (31) is smaller than the minimum mesh size of the fracturing sand.

6. The anti-sand fracturing flat gate valve according to claim 1, characterized in that: Also includes: A connecting rod (9), the connecting rod (9) comprising: an upper rod (91) and a lower rod (92), the upper rod (91) being connected to the upper end of the valve plate (2), the lower rod (92) being connected to the lower end of the valve plate (2), and further comprising: a valve cover, the valve cover comprising: an upper valve cover (71) and a lower valve cover (72), the upper valve cover (71) and the lower valve cover (72) being respectively sleeved on the upper rod (91) and the lower rod (92), and the upper valve cover (71) and the lower valve cover (72) being respectively sealed and mounted on the upper and lower ends of the valve body (1).

7. The anti-sand fracturing flat gate valve according to claim 6, characterized in that: Also includes: A combined seal (8), the combined seal (8) comprising: a gland (81), a group of annular sealing rings (82), an annular cavity (70) being provided on the inner wall of the connection between the valve cover and the connecting rod (9), a group of annular sealing rings (82) being axially stacked and arranged in the annular cavity (70), the gland (81) being sleeved on the connecting rod (9), the gland (81) being installed in the annular cavity (70) and being threadedly connected to the valve cover, the gland (81) being in contact with the outer ends of the group of annular sealing rings (82), and the gland (81) being used to axially compress the group of axially stacked annular sealing rings (82).

8. The anti-sand fracturing flat gate valve according to claim 6, characterized in that: The lower rod (92) is provided with an indicator (12), and the indicator (12) is arranged on the outer side of the lower rod (92). A lower valve cover (13) is provided below the lower valve cover (72), and the indicator (12) is inside the lower valve cover (13). A groove (131) is provided on the side wall of the lower valve cover (13), and the groove (131) extends in the vertical direction. The groove (131) is directly opposite to the moving trajectory of the indicator (12), and the outer side of the groove (131) corresponds to the moving trajectory of the indicator (12), and a stroke mark is provided, and the stroke mark is arranged on the outer side of the groove (131).

9. The anti-sand fracturing flat gate valve according to claim 6, characterized in that: Also includes: A switch mechanism (15), the switch mechanism (15) comprising: a rotating seat (151), a nut sleeve (152), a ball screw (154), and a hand wheel (155), the rotating seat (151) being mounted on the upper valve cover (71), the nut sleeve (152) being rotatably arranged in the rotating seat (151), the ball screw (154) being fixed to the outer end of the upper rod (91), the nut sleeve (152) being sleeved on the ball screw (154), the nut sleeve (152) being threadedly connected to the ball screw (154), and the hand wheel (155) being mounted on the upper end of the nut sleeve (152).

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