CN212360844U

CN212360844U - Two-end lengthened gate valve

Info

Publication number: CN212360844U
Application number: CN202020887863.6U
Authority: CN
Inventors: 陈孝凌; 陈圣如
Original assignee: Zhejiang Xinghe Valve Co ltd
Current assignee: Zhejiang Xinghe Valve Co ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-01-15
Anticipated expiration: 2030-05-22

Abstract

The utility model discloses a gate valve with two lengthened ends, which comprises a valve body, a valve cover, a valve rod, a hand wheel, a flashboard and a valve seat, wherein a flow passing cavity is arranged in the valve body; the first lengthening pipe, the second lengthening pipe and the valve body are of an integrated structure; the lower part of the flashboard is provided with a first sealing surface and a second sealing surface; the valve seat comprises a first sealing seat and a second sealing seat, the first sealing seat is inserted into the first flow channel, a first limiting ring is arranged on the periphery of the first sealing seat, a first channel is arranged on the first sealing seat, and a first sealing inclined surface is arranged at one end, facing the flashboard, of the first sealing seat; the second seal seat is inserted into the second flow channel, a second limiting ring is arranged on the periphery of the second seal seat, a second channel is arranged on the second seal seat, and a second seal inclined surface is arranged at one end, facing the flashboard, of the second seal seat. The utility model discloses can improve the bulk strength of gate valve, the dismouting is very convenient moreover.

Description

Two-end lengthened gate valve

Technical Field

The utility model relates to the technical field of valves, especially, relate to a both ends extension formula gate valve.

Background

The valve is a control part in a fluid conveying system, has the functions of stopping, regulating, guiding, preventing counter flow, stabilizing pressure, shunting or overflowing and relieving pressure and the like, is one of valves, and has the opening and closing part as a flashboard which moves in the direction perpendicular to the fluid direction and can only be fully opened and fully closed but cannot be regulated and throttled. The gate plate of the wedge gate valve can be made into a whole, namely a rigid gate plate; the gate plate can also be made into a gate plate capable of generating micro deformation so as to improve the manufacturability of the gate plate and compensate the deviation of the angle of the sealing surface in the processing process, and the gate plate is called an elastic gate plate. The existing gate valve with two lengthened ends is characterized in that the two ends of the gate valve are lengthened through welding pipelines at the two ends of the traditional gate valve, so that the requirements on certain specific working conditions are met, the gate valve is not high in strength at a welding part, cracks are easy to appear, production safety is influenced, and after the two ends of the gate valve are lengthened, the difficulty of whole disassembly and assembly is increased, if: the valve seat can only extend into the inner cavity of the gate valve from the upper port of the gate valve to carry out installation operation on the valve seat. Therefore, there is a need in the market for a gate valve with two ends elongated to have high strength and easy assembly and disassembly to solve the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a both ends extension formula gate valve, the utility model discloses can not only improve the bulk strength of gate valve, the dismouting is very convenient moreover.

In order to achieve the above object, the utility model provides a following technical scheme: the gate valve with two lengthened ends comprises a valve body, a valve cover, a valve rod, a hand wheel, a gate plate and a valve seat, wherein an overflowing cavity is arranged in the valve body, a first lengthening pipe and a second lengthening pipe are arranged at two ends of the valve body, a first flow passage communicated with the overflowing cavity is arranged in the first lengthening pipe, a second flow passage communicated with the overflowing cavity is arranged in the second lengthening pipe, the valve cover is arranged at the upper end of the valve body, the valve rod penetrates through the valve cover and extends into the overflowing cavity in the valve body to be connected with the gate plate, and the valve seat is arranged in the valve body and used for forming sealing fit with the gate; the first lengthening pipe, the second lengthening pipe and the valve body are of an integrated structure; a first sealing surface and a second sealing surface are symmetrically arranged on two sides of the lower part of the flashboard, and the first sealing surface and the second sealing surface are gradually close to each other from top to bottom; the valve seat comprises a first sealing seat and a second sealing seat, one end of the first sealing seat, which is back to the flashboard, is inserted into the first flow channel, a first limiting ring which is used for abutting against the inner wall of the overflowing cavity is arranged on the peripheral side of the first sealing seat, a first channel which is communicated with the first flow channel and the overflowing cavity is arranged on the first sealing seat, and a first sealing inclined plane which is in sealing fit with the first sealing surface is arranged at one end, which faces the flashboard, of the first sealing seat; one end of the second sealing seat, which faces away from the flashboard, is inserted into the second flow channel, the periphery of the second sealing seat is provided with a second limiting ring used for abutting against the inner wall of the overflowing cavity, a second channel communicated with the second flow channel and the overflowing cavity is arranged on the second sealing seat, and one end of the second sealing seat, which faces towards the flashboard, is provided with a second sealing inclined surface in sealing fit with the second sealing surface.

Preferably, a first notch for externally connecting a pipeline is formed in the position, located at the outer end of the first flow passage, of the first lengthened pipe, a first mounting hole for inserting the first sealing seat is formed in the position, located at the inner end of the first flow passage, of the valve body, the diameter of the first flow passage is smaller than that of the first notch, the diameter of the first flow passage is larger than that of the first mounting hole, and a first step is formed between the first mounting hole and the first flow passage; the position of the second lengthened pipe, which is located at the outer end of the second flow channel, is provided with a second notch for externally connecting a pipeline, the position of the valve body, which is located at the inner end of the second flow channel, is provided with a second mounting hole for inserting a second sealing seat, the diameter of the second flow channel is smaller than that of the second notch, the diameter of the second flow channel is larger than that of the second mounting hole, and a second step is formed between the second mounting hole and the second flow channel.

Preferably, an end surface of the first sealing seat facing away from the gate plate is flush with the surface of the first step, and an end surface of the second sealing seat facing away from the gate plate is flush with the surface of the second step.

Preferably, a first mounting groove which is inconsistent with the first limiting ring and a second mounting groove which is inconsistent with the second limiting ring are formed in the inner wall of the overflowing cavity, the depth of the first mounting groove is larger than the diameter of the first limiting ring, and the depth of the second mounting groove is larger than the diameter of the second limiting ring.

Preferably, a conical hole is formed in the valve body at the bottom end of the overflowing cavity.

Preferably, an arc-shaped convex part protruding downwards is arranged at the position, below the conical hole, of the valve body.

Preferably, the flashboard is provided with a clamping block, and the valve rod is provided with a clamping groove matched with the clamping block.

Preferably, flashboard upper portion is equipped with the mesocarp with valve rod bottom looks adaptation, the fixture block sets up on the lateral wall of mesocarp.

Preferably, the valve cover is provided with a packing cavity coaxial with the valve rod, the packing cavity is internally provided with a sealing packing coated on the periphery of the valve rod, the upper end face of the sealing packing is provided with a packing gland, the upper end face of the packing gland is provided with a packing pressure plate, and the packing pressure plate is in locking connection with the valve cover through a bolt and applies extrusion force towards the sealing packing to the packing gland.

Preferably, a wound gasket is clamped between the lower end face of the valve cover and the upper end face of the valve seat.

The utility model discloses a technological effect and advantage:

1. the utility model discloses a first extension pipe, second extension pipe and valve body formula structure as an organic whole, for traditional welded structure the utility model has the advantages of intensity is high, can prevent that low temperature or high-pressure environment from leading to the local cracked condition of valve body to take place, improves the production security. And simultaneously, the utility model discloses a first seal receptacle and second seal receptacle are pegged graft respectively in first runner and second runner inner, and first spacing ring on the first seal receptacle supports to constitute spacingly overflowing the intracavity wall, and the second spacing ring on the second seal receptacle supports to constitute spacingly, and the dismouting is very convenient overflowing the intracavity wall to the second seal receptacle. The first sealing surface and the second sealing surface on the flashboard are symmetrically arranged and are gradually close to each other from top to bottom, so that a shape with a large top is formed, the first sealing seat is provided with a first sealing inclined surface which forms sealing fit with the first sealing surface on the flashboard, the second sealing seat is provided with a second sealing inclined surface which forms sealing fit with the second sealing surface on the flashboard, a space with a large top and a small bottom is formed between the first sealing inclined surface and the second sealing surface, the flashboard moves downwards and is matched with the first sealing inclined surface on the first sealing seat and the second sealing inclined surface on the second sealing seat to complete the closing of the valve, and the farther the flashboard goes downwards, the extrusion force between the first sealing surface on the flashboard and the first sealing inclined surface on the first sealing seat and the extrusion force between the second sealing surface on the flashboard and the second sealing inclined surface on the second sealing seat are gradually increased, thereby improving the sealing effect when the valve is closed.

2. The utility model discloses a form first step between first mounting hole and the first flow channel, first step can play the choked effect, weakens the washing effect in the clearance of medium between to first seal receptacle outer wall and the first mounting hole inner wall to avoid the clearance between first seal receptacle outer wall and the first mounting hole inner wall to take place to leak, the second step has the same effect.

3. The utility model discloses a terminal surface and the first step surface looks parallel and level of first seal receptacle dorsad flashboard, a terminal surface and the second step surface looks parallel and level of second seal receptacle dorsad flashboard can reduce the inside unevenness face of valve body, have the effect of improving the torrent, and then weaken washing away of each sealed face, can not only improve the life of valve, can also reduce the impulsive noise.

4. The utility model discloses first mounting groove on the inner wall is used for inconsistent with first spacing ring, and the degree of depth of first mounting groove is greater than the diameter of first spacing ring, can adapt to the first spacing ring of different specifications, reduces first spacing ring machining accuracy requirement, makes things convenient for its processing, and the second mounting groove has the advantage the same with first mounting groove.

5. The utility model discloses the design of conical hole provides extra bottom space for installing first seal receptacle and second seal receptacle in the valve body, can avoid owing to flow over the less big problem of the installation degree of difficulty of chamber bottom space when installing first seal receptacle and second seal receptacle to the installation of first seal receptacle and second seal receptacle has been made things convenient for greatly.

6. The utility model discloses the position that lies in the bell mouth below on the valve body has the arc convex part of downward arch, and this arc convex part can compensate the bell mouth and arouse the defect of valve body bottom attenuation, has guaranteed the bulk strength of valve body through the thickness at this position of increase.

7. The utility model discloses a fixture block on the flashboard agrees with mutually with the draw-in groove on the valve rod and realizes being connected of the two, has the swift laborsaving advantage of dismouting.

8. The utility model discloses offer on flashboard upper portion with the mesotrough of valve rod bottom looks adaptation, the fixture block sets up on the lateral wall of mesotrough, can make flashboard and valve rod keep on a straight line to guarantee that the power of valve rod to flashboard can stabilize the transmission, avoid the too big production of flashboard local stress to damage.

9. The utility model discloses a bolt locking pressure packing board makes pressure packing board exert the extrusion force towards gland packing to realize gland packing's fixed mounting, guarantee the leakproofness between valve gap and the valve rod, avoid the clearance between the two to produce the dielectric leakage.

10. The utility model discloses a press from both sides between terminal surface and the disk seat up end under the valve gap and establish the wound form packing ring and strengthen the leakproofness between the two, avoid the inside medium of valve body to leak from the clearance between terminal surface and the disk seat up end under the valve gap.

Drawings

Fig. 1 is a schematic overall structure diagram of the present invention;

fig. 2 is an enlarged schematic view of a portion a in fig. 1.

In the figure: 1. a valve body; 2. a valve cover; 3. a valve stem; 4. a hand wheel; 5. a shutter plate; 6. a first seal seat; 7. a second seal seat; 8. a valve seat; 9. a flow-through chamber; 10. a first elongated tube; 11. a second elongated tube; 12. a first flow passage; 13. a second flow passage; 14. a first notch; 15. a second notch; 16. a packing cavity; 17. sealing and filling; 18. a packing gland; 19. a packing press plate; 20. a bolt; 21. a first mounting hole; 22. a first step; 23. a first limit ring; 24. a first mounting groove; 25. a first channel; 26. a second mounting hole; 27. a second step; 28. a second stop collar; 29. a second mounting groove; 30. a second channel; 31. a first sealing surface; 32. a second sealing surface; 33. a first sealing bevel; 34. a second sealing bevel; 35. a clamping block; 36. a card slot; 37. a middle groove; 38. a tapered hole; 39. an arc-shaped convex part; 40. a wrap-around gasket.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example (b): the gate valve with the two ends being lengthened as shown in fig. 1 and fig. 2 comprises a valve body 1, a valve cover 2, a valve rod 3, a hand wheel 4, a gate plate 5 and a valve seat 8, wherein a flow passing cavity 9 is arranged in the valve body 1, a first lengthening pipe 10 and a second lengthening pipe 11 are arranged at two ends of the valve body 1, a first flow passage 12 communicated with the flow passing cavity 9 is arranged in the first lengthening pipe 10, a second flow passage 13 communicated with the flow passing cavity 9 is arranged in the second lengthening pipe 11, the valve cover 2 is installed at the upper end of the valve body 1, the valve rod 3 penetrates through the valve cover 2 and extends into the flow passing cavity 9 in the valve body 1 to be connected with the gate plate 5, and the valve seat 8 is arranged in the valve body 1 to form a sealing fit; the first elongated tube 10, the second elongated tube 11 and the valve body 1 are of an integrated structure, compared with a traditional welding structure, the novel welding structure has the advantage of high strength, the situation that the valve body 1 is partially broken due to a low-temperature or high-pressure environment can be prevented, and the production safety is improved; a first sealing surface 31 and a second sealing surface 32 are symmetrically arranged on two sides of the lower part of the gate plate 5, the first sealing surface 31 and the second sealing surface 32 are gradually close to each other from top to bottom, and a space with a large top and a small bottom is formed between the first sealing surface 31 and the second sealing surface 32; the valve seat 8 comprises a first sealing seat 6 and a second sealing seat 7, one end of the first sealing seat 6, which is back to the flashboard 5, is inserted into the first flow channel 12, a first limiting ring 23 used for abutting against the inner wall of the overflowing cavity 9 is arranged on the peripheral side of the first sealing seat 6, a first channel 25 communicating the first flow channel 12 with the overflowing cavity 9 is arranged on the first sealing seat 6, and a first sealing inclined plane 33 which is in sealing fit with the first sealing surface 31 is arranged at one end of the first sealing seat 6, which faces the flashboard 5; one end of the second sealing seat 7, which is back to the flashboard 5, is inserted into the second flow passage 13, the periphery of the second sealing seat 7 is provided with a second limiting ring 28 which is used for abutting against the inner wall of the overflowing cavity 9, the second sealing seat 7 is provided with a second passage 30 which communicates the second flow passage 13 and the overflowing cavity 9, one end of the second sealing seat 7, which faces the flashboard 5, is provided with a second sealing inclined surface 34 which forms sealing fit with the second sealing surface 32, the flashboard 5 moves downwards and is matched with the first sealing inclined surface 33 on the first sealing seat 6 and the second sealing inclined surface 34 on the second sealing seat 7 to complete the closing of the valve, and the more the gate plate 5 goes down, the extrusion force between the first sealing surface 31 on the gate plate 5 and the first sealing inclined surface 33 on the first sealing seat 6 and the extrusion force between the second sealing surface 32 on the gate plate 5 and the second sealing inclined surface 34 on the second sealing seat 7 are gradually increased, so that the sealing effect when the valve is closed is improved.

As shown in fig. 1 and fig. 2, a first notch 14 for externally connecting a pipeline is formed in a position of the first elongated tube 10 at an outer end of the first flow channel 12, a first mounting hole 21 for inserting the first sealing seat 6 is formed in a position of the valve body 1 at an inner end of the first flow channel 12, the first sealing seat 6 is in interference fit with the first mounting hole 21, the first notch 14, the first flow channel 12 and the first mounting hole 21 are coaxially arranged, a diameter of the first flow channel 12 is smaller than that of the first notch 14, a diameter of the first flow channel 12 is larger than that of the first mounting hole 21, and a first step 22 is formed between the first mounting hole 21 and the first flow channel 12; the position of the second extension tube 11 at the outer end of the second flow channel 13 is provided with a second notch 15 for externally connecting a pipeline, the position of the valve body 1 at the inner end of the second flow channel 13 is provided with a second mounting hole 26 for inserting the second sealing seat 7, the second sealing seat 7 is in interference fit with the second mounting hole 26, the second notch 15, the second flow channel 13 and the second mounting hole 26 are coaxially arranged, the diameter of the second flow channel 13 is smaller than that of the second notch 15, the diameter of the second flow channel 13 is larger than that of the second mounting hole 26, and a second step 27 is formed between the second mounting hole 26 and the second flow channel 13. The first step 22 can play a role in blocking flow, and weakens the scouring effect of the medium on the gap between the outer wall of the first seal holder 6 and the inner wall of the first mounting hole 21, so that the leakage of the gap between the outer wall of the first seal holder 6 and the inner wall of the first mounting hole 21 is avoided, and the second step 27 has the same function.

As shown in fig. 2, an end surface of the first seal holder 6 facing away from the shutter 5 is flush with a surface of the first step 22, and an end surface of the second seal holder 7 facing away from the shutter 5 is flush with a surface of the second step 27. This structure can reduce the inside unevenness face of valve body 1, has the effect of improving the torrent, and then weakens washing away of each sealed face, can not only improve the life of valve, can also reduce the impulsive noise.

As shown in fig. 2, a first mounting groove 24 abutting against the first stop collar 23 and a second mounting groove 29 abutting against the second stop collar 28 are formed on the inner wall of the flow-through cavity 9, the depth of the first mounting groove 24 is greater than the diameter of the first stop collar 23, and the depth of the second mounting groove 29 is greater than the diameter of the second stop collar 28. This kind of design of first mounting groove 24 can the first spacing ring 23 of different specifications of adaptation, reduces first spacing ring 23 machining accuracy requirement, makes things convenient for its processing, and second mounting groove 29 has the same advantage with first mounting groove 24.

As shown in fig. 2, a tapered hole 38 is provided at a position of the valve body 1 at the bottom end of the flow passing chamber 9, the tapered hole 38 provides an additional bottom space for installing the first seal seat 6 and the second seal seat 7, and the problem of large installation difficulty due to a small bottom space of the flow passing chamber 9 when installing the first seal seat 6 and the second seal seat 7 can be avoided, so that the installation of the first seal seat 6 and the second seal seat 7 is greatly facilitated.

As shown in fig. 2, a portion of the valve body 1 below the tapered hole 38 is provided with an arc-shaped protrusion 39 protruding downward, the arc-shaped protrusion 39 is integrated with the valve body 1, the arc-shaped protrusion 39 can make up for the defect that the bottom of the valve body 1 becomes thinner due to the tapered hole 38, and the overall strength of the valve body 1 is ensured by increasing the thickness of the portion.

As shown in fig. 2, a latch 35 is disposed on the shutter 5, and a catch 36 engaged with the latch 35 is disposed on the valve rod 3. The clamping block 35 on the flashboard 5 is matched with the clamping groove 36 on the valve rod 3 to realize the connection of the two, so that the valve has the advantages of quick and labor-saving disassembly and assembly.

As shown in fig. 2, the upper portion of the gate plate 5 is provided with a middle groove 37 matched with the bottom end of the valve rod 3, and the fixture block 35 is arranged on the side wall of the middle groove 37, so that the gate plate 5 and the valve rod 3 can be kept on the same straight line, the force from the valve rod 3 to the gate plate 5 can be stably transmitted, and the gate plate 5 is prevented from being damaged due to excessive local stress.

As shown in fig. 1, a packing cavity 16 coaxial with the valve rod 3 is arranged on the valve cap 2, a sealing packing 17 covering the periphery of the valve rod 3 is arranged in the packing cavity 16, a packing gland 18 is arranged on the upper end surface of the sealing packing 17, a packing pressure plate 19 is arranged on the upper end surface of the packing gland 18, and the packing pressure plate 19 is in locking connection with the valve cap 2 through a bolt 20 and applies extrusion force towards the sealing packing 17 to the packing gland 18, so that the fixed installation of the sealing packing 17 is realized, the sealing performance between the valve cap 2 and the valve rod 3 is ensured, and the medium leakage generated in the gap between the valve cap 2 and the valve rod.

As shown in fig. 1, a wound gasket 40 is interposed between the lower end surface of the valve cover 2 and the upper end surface of the valve seat 8, so as to enhance the sealing performance therebetween and prevent the medium inside the valve body 1 from leaking from the gap between the lower end surface of the valve cover 2 and the upper end surface of the valve seat 8.

The working principle is as follows: the utility model discloses a first extension pipe 10,

second extension pipe

11 and 1 formula structure as an organic whole of valve body, for traditional welded structure the utility model has the advantages of intensity is high, can prevent that low temperature or high-pressure environment from leading to the condition emergence of 1 local fracture of valve body, improves the production security. And simultaneously, the utility model discloses a first seal receptacle 6 and second seal receptacle 7 are pegged graft respectively in first flow channel 12 and second flow channel 13 the inner, and first spacing ring 23 on the first seal receptacle 6 supports to overflowing that the chamber 9 inner wall constitutes spacingly to first seal receptacle 6, and second spacing ring 28 on the second seal receptacle 7 supports to overflowing that the chamber 9 inner wall constitutes spacingly to second seal receptacle 7, and the dismouting is very convenient. The first sealing surface 31 and the second sealing surface 32 on the gate plate 5 are symmetrically arranged and the first sealing surface 31 and the second sealing surface 32 are gradually close from top to bottom, so as to form a shape with a large top and a small bottom, a first sealing inclined surface 33 which forms sealing fit with the first sealing surface 31 on the gate plate 5 is arranged on the first sealing seat 6, a second sealing inclined surface 34 which forms sealing fit with the second sealing surface 32 on the gate plate 5 is arranged on the second sealing seat 7, a space with a large top and a small bottom is arranged between the first sealing inclined surface 33 and the second sealing surface 32, the gate plate 5 moves downwards and is matched with the first sealing inclined surface 33 on the first sealing seat 6 and the second sealing inclined surface 34 on the second sealing seat 7 to complete the closing of the valve, and the pressing force between the first sealing surface 31 on the gate plate 5 and the first sealing inclined surface 33 on the first sealing seat 6 and the pressing force between the second sealing surface 32 on the gate plate 5 and the second sealing inclined surface 34 on the second sealing seat 7 are gradually increased as the gate plate 5 goes downwards, thereby improving the sealing effect when the valve is closed.

Claims

1. The gate valve with the two lengthened ends comprises a valve body (1), a valve cover (2), a valve rod (3), a hand wheel (4), a gate plate (5) and a valve seat (8), wherein a flow passing cavity (9) is formed in the valve body (1), a first lengthening pipe (10) and a second lengthening pipe (11) are arranged at the two ends of the valve body (1), a first flow passage (12) communicated with the flow passing cavity (9) is formed in the first lengthening pipe (10), a second flow passage (13) communicated with the flow passing cavity (9) is formed in the second lengthening pipe (11), the valve cover (2) is installed at the upper end of the valve body (1), the valve rod (3) penetrates through the valve cover (2) and extends into the flow passing cavity (9) in the valve body (1) to be connected with the gate plate (5), and the valve seat (8) is arranged in the valve body (1) and used for forming sealing fit with the gate; the method is characterized in that: the first lengthening pipe (10), the second lengthening pipe (11) and the valve body (1) are of an integrated structure; a first sealing surface (31) and a second sealing surface (32) are symmetrically arranged on two sides of the lower portion of the gate plate (5), and the first sealing surface (31) and the second sealing surface (32) are gradually close to each other from top to bottom; the valve seat (8) comprises a first sealing seat (6) and a second sealing seat (7), one end, back to the flashboard (5), of the first sealing seat (6) is inserted into the first runner (12), a first limiting ring (23) used for abutting against the inner wall of the overflowing cavity (9) is arranged on the peripheral side of the first sealing seat (6), a first channel (25) communicating the first runner (12) with the overflowing cavity (9) is arranged on the first sealing seat (6), and a first sealing inclined plane (33) in sealing fit with the first sealing surface (31) is arranged at one end, facing the flashboard (5), of the first sealing seat (6); one end of the second sealing seat (7) back to the flashboard (5) is inserted into the second flow channel (13), the peripheral side of the second sealing seat (7) is provided with a second limiting ring (28) used for abutting against the inner wall of the overflowing cavity (9), a second channel (30) communicated with the second flow channel (13) and the overflowing cavity (9) is arranged on the second sealing seat (7), and one end of the second sealing seat (7) facing the flashboard (5) is provided with a second sealing inclined surface (34) in sealing fit with the second sealing surface (32).

2. The gate valve of claim 1, wherein: a first notch (14) for externally connecting a pipeline is formed in the position, located at the outer end of the first flow channel (12), of the first lengthened pipe (10), a first mounting hole (21) for inserting the first sealing seat (6) is formed in the position, located at the inner end of the first flow channel (12), of the valve body (1), the diameter of the first flow channel (12) is smaller than that of the first notch (14), the diameter of the first flow channel (12) is larger than that of the first mounting hole (21), and a first step (22) is formed between the first mounting hole (21) and the first flow channel (12); the position of the second lengthened pipe (11) at the outer end of the second flow channel (13) is provided with a second notch (15) for externally connecting a pipeline, the position of the valve body (1) at the inner end of the second flow channel (13) is provided with a second mounting hole (26) for inserting a second sealing seat (7), the diameter of the second flow channel (13) is smaller than that of the second notch (15), the diameter of the second flow channel (13) is larger than that of the second mounting hole (26), and a second step (27) is formed between the second mounting hole (26) and the second flow channel (13).

3. The gate valve with two ends lengthened according to claim 2, wherein: one end face of the first sealing seat (6) back to the flashboard (5) is flush with the surface of the first step (22), and one end face of the second sealing seat (7) back to the flashboard (5) is flush with the surface of the second step (27).

4. The gate valve of claim 1, wherein: the inner wall of the overflowing cavity (9) is provided with a first mounting groove (24) which is abutted against the first limiting ring (23) and a second mounting groove (29) which is abutted against the second limiting ring (28), the depth of the first mounting groove (24) is larger than the diameter of the first limiting ring (23), and the depth of the second mounting groove (29) is larger than the diameter of the second limiting ring (28).

5. The gate valve of claim 1, wherein: the part of the valve body (1) at the bottom end of the overflowing cavity (9) is provided with a conical hole (38).

6. The gate valve of claim 5, wherein: an arc convex part (39) protruding downwards is arranged at the position, below the conical hole (38), of the valve body (1).

7. The gate valve of claim 1, wherein: and a clamping block (35) is arranged on the flashboard (5), and a clamping groove (36) matched with the clamping block (35) is arranged on the valve rod (3).

8. The gate valve of claim 7, wherein: flashboard (5) upper portion is equipped with well groove (37) with valve rod (3) bottom looks adaptation, fixture block (35) set up on the lateral wall of well groove (37).

9. The gate valve of claim 1, wherein: the valve cap is characterized in that a packing cavity (16) coaxial with the valve rod (3) is formed in the valve cap (2), a sealing packing (17) coated on the periphery of the valve rod (3) is arranged in the packing cavity (16), a packing gland (18) is arranged on the upper end face of the sealing packing (17), a packing pressing plate (19) is arranged on the upper end face of the packing gland (18), and the packing pressing plate (19) is in locking connection with the valve cap (2) through a bolt (20) and applies extrusion force towards the sealing packing (17) to the packing gland (18).

10. The gate valve of claim 1, wherein: a winding washer (40) is clamped between the lower end face of the valve cover (2) and the upper end face of the valve seat (8).