CN209743629U - Knife gate valve - Google Patents

Abstract

The utility model relates to a knife gate valve, which comprises a valve body, a flashboard, a valve rod, a valve cover and a bracket, the knife gate valve also comprises a valve seat assembly for realizing the bidirectional sealing of the valve, the valve seat assembly comprises a valve seat, a valve seat sealing ring and a valve seat supporting ring which are arranged on the valve seat, and a first screw for connecting the valve seat with the valve body, the valve seat sealing ring has certain elasticity, is contacted with the flashboard to play a sealing role, the valve seat supporting ring has certain hardness, when the valve seat sealing ring is compressed, the valve seat supporting ring is contacted with the flashboard, thereby not only playing a role of sealing, but also playing a role of supporting, and simultaneously cleaning attachments on the surface of the flashboard, the first screw is divided into a set screw and a fixing screw, the two screws are uniformly and alternately arranged on the same circumference, and therefore the valve seat can be fixed, and the magnitude of interference of the valve seat sealing ring can be adjusted.

Description

Knife gate valve

Technical Field

The utility model relates to a gate valve, more specifically say, relate to a two-way seal plate valve.

Background

At present, the most common knife gate valve has the advantages that the valve seat is sealed in a one-way and can only bear one-way pressure, the sealing function cannot be achieved when media flow reversely, in addition, the valve seat sealing ring is only provided with one sealing ring, and the sealing effect is poor; the valve adopts an open valve cover, and the flashboard is exposed outside after being lifted and is easy to be corroded by atmosphere or attached by dirt; the position of the valve rod is only sealed by packing, so that the leakage phenomenon of the position of the valve rod can occur after long-time use. In addition, the existing knife gate valve generally adopts a T-shaped groove structure for connecting the valve rod and the flashboard, the valve body and the valve cover are installed after the valve rod and the flashboard are installed, and the installation is very inconvenient in large caliber.

SUMMERY OF THE UTILITY MODEL

To the above-mentioned defect of current knife gate valve, the utility model aims at providing a two-way seal knife gate valve that sealing performance is good, for realizing the utility model discloses an aim, the utility model discloses a following technical scheme:

The utility model provides a knife gate valve, this knife gate valve includes the valve body, the flashboard, the valve rod, valve gap and support, this knife gate valve is still including being used for realizing the two-way sealed disk seat subassembly of valve, this disk seat subassembly includes the disk seat and installs disk seat sealing washer and the disk seat lock ring on this disk seat, and the first screw of being connected this disk seat and valve body, this disk seat sealing washer has certain elasticity, contact with this flashboard, play sealed effect, this disk seat lock ring has certain hardness, after the disk seat sealing washer is compressed, this disk seat lock ring and this flashboard contact, both can play sealed effect, can play supporting role again, can also clear up the deposit on this flashboard surface simultaneously.

furthermore, the first screw is divided into a set screw used for pushing the valve seat to the flashboard after being screwed down and a fixing screw used for fixing the valve seat in the valve body after being screwed down, the set screw and the fixing screw are uniformly and alternately arranged on the same circumference, the valve seat can be fixed, and the interference of a sealing ring of the valve seat can be adjusted, so that the sealing performance is adjusted.

Further, this disk seat subassembly still includes disk seat O type circle, this disk seat O type circle and this valve body contact for seal the gap between this disk seat and this valve body.

Further, the valve seat O-shaped ring is installed in the U-shaped groove of the valve seat and made of rubber materials.

Further, the valve seat sealing ring is arranged in a dovetail groove of the valve seat and made of rubber materials.

Furthermore, the valve seat support ring is arranged in a U-shaped groove of the valve seat and is made of polytetrafluoroethylene materials.

Further, this flashboard has the hole that runs through its thickness, and the head of this valve rod has the open shelves that are used for placing this flashboard, and this flashboard links together through the round pin hub connection mode with this valve rod.

Further, the pin shaft connecting method is realized through a pin shaft connecting assembly, the pin shaft connecting assembly comprises a pin shaft, a pressing plate and a second screw, the pin shaft penetrates through a hole of the flashboard to be connected to the opening of the head of the valve rod, the pressing plate is used for pressing the opening end of the pin shaft to prevent the pin shaft from falling off from the head of the valve rod, and the second screw is used for fixing the pressing plate on the head of the valve rod.

Furthermore, the distance between the two walls of the opening is larger than the thickness of the flashboard, so that the flashboard can move to the upstream or the downstream of the valve in parallel along the pin shaft after the flashboard is placed into the opening, and the lifting and the descending of the valve rod are not influenced.

Further, the valve stem has a triple sealing structure: an upper seal, a valve rod O-shaped ring seal and a packing seal, wherein the upper seal is realized by matching the external shape of the upper end of the valve rod head with the internal shape of the valve cover (4) close to the bracket end, so that the valve rod head is contacted with the internal surface of the valve cover close to the bracket end after the valve rod is lifted and forms a sealing fit,

The valve rod O-shaped ring seal is positioned between the upper seal and the packing seal and is used for sealing a gap between the valve cover and the valve rod,

The packing seal is realized by packing encapsulated in the gap, a packing pressing sleeve for pressing the packing and a packing pressing plate for pressing the packing pressing sleeve.

the valve stem O-ring is made of a resilient material, such as rubber.

Further, the shutter is a parallel type shutter, and guide plates are installed at both sides thereof, and are used for preventing the shutter from rotating together with the valve rod when lifting and closing the shutter.

Further, the guide plate is divided into two symmetrical parts, and fixed to both sides of the gate valve by connecting parts (e.g., a screw and a nut), respectively.

further, the valve rod is a threaded valve rod, and a gear operation actuator or an electric actuator can be installed. In another preferred embodiment of the present invention, the valve rod is a non-threaded valve rod connected to a straight stroke cylinder.

Furthermore, the valve cover is a closed valve cover, so that the flashboard cannot be exposed to the outside after being lifted, the flashboard is prevented from being corroded by the external atmosphere or dirt is prevented from being attached to the flashboard,

Furthermore, the periphery of the valve cover is provided with a rib plate, so that the strength of the valve cover is improved.

Compared with the prior art, the utility model discloses a banister valve has realized following beneficial effect:

(1) the valve seal of the flashboard adopts a valve seat seal ring and a valve seat support ring for sealing, and double sealing is realized. The valve seat sealing ring is made of elastic materials, and plays a good sealing role in normal use of the flashboard. However, in the opening and closing processes of the gate plate, sliding friction is generated between the gate plate and the valve seat sealing ring, so that the valve seat sealing ring made of elastic material is too soft and is easy to flatten, and the sealing effect is lost, and at the moment, the valve seat supporting ring made of material with certain hardness can play the sealing and supporting effects at the same time. The valve seat sealing ring and the valve seat supporting ring are combined for sealing, and the soft and hard combination is favorable for sealing and can provide enough supporting force. In addition, the valve seat support ring can prevent the valve seat sealing ring from losing elasticity due to over compression, and prevent the valve seat sealing ring 72 from being in contact with the metal material of the valve seat 71 after the valve plate 2 flattens the valve seat sealing ring, so that the valve plate 3 is scratched.

(2) the valve seat assembly is installed inside the valve body, and the valve seat is fixed by using a fixing screw and a fastening screw, and the magnitude of interference of the valve seat sealing ring is adjusted. When the set screw is tightened, the valve seat is pushed to the gate plate to increase the pressure applied to the gate plate by the valve seat sealing ring, and when the fixing screw is tightened, the valve seat is fixed in the valve body. Two kinds of screws are evenly and alternately arranged along the same circumference, the combination can realize the effect of fixing the valve seat assembly, can adjust the interference magnitude of the valve seat sealing ring, realizes that the valve seat assembly is replaceable, and is convenient to maintain.

(3) The groove for installing the valve seat sealing ring on the valve seat is a dovetail groove with a large inner opening and a small inner opening, and the valve seat sealing ring is prevented from being blown out by medium pressure after being integrally vulcanized.

(4) The valve rod and the flashboard are connected through a pin shaft, one end of the pin shaft is closed, the other end of the pin shaft is open, the open end of the pin shaft is pressed by a pressing plate, the pin shaft is prevented from being separated from the head of the valve rod, the pressing plate is fixed on the head of the valve rod through a second screw, and the connecting mode is convenient to install and disassemble. And a certain gap is reserved at the matching part of the valve rod head and the flashboard, so that the flashboard moves towards the upstream or the downstream of the valve in parallel under the action of medium pressure, and the valve rod is prevented from being bent and deformed.

(5) Install the deflector on the flashboard, the deflector both ends are supported at valve body and valve gap inner wall, prevent that the flashboard from following the valve rod rotation.

(6) The position of the valve rod is sealed by three combinations of sealing on the valve rod, sealing by an O-shaped ring and sealing by packing so as to prevent the valve rod from leaking outwards.

drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the embodiments will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and that other drawings can be obtained by those skilled in the art without inventive step.

Fig. 1a and 1b are the overall design structure diagram of the knife gate valve of the present invention, wherein fig. 1a is a side sectional view of the knife gate valve when viewed from the side, and fig. 1b is a half sectional view of the knife gate valve when viewed from the front.

FIG. 2 is a structure of a valve seat assembly of the knife gate valve at I of FIG. 1a, on an enlarged scale of 8: 1. The structures shown in the upper and lower views of fig. 2 correspond to the structures of the valve seat assembly at a and b in fig. 1b, respectively. The upper view of fig. 2 shows a set screw of the valve seat assembly for adjusting the interference of the valve seat seal, and the lower view of fig. 2 shows a set screw of the valve seat assembly for fixing the valve seat in the valve body.

FIG. 3 is a view of the knife gate valve configuration at II of FIG. 1a, at an enlarged scale of 6:1, showing the pin connection of the gate plate to the valve stem.

FIG. 4 is a view of the knife gate valve configuration at III of FIG. 1a, on a 4:1 scale, showing the triple seal configuration of the valve stem.

FIG. 5 is a cross-sectional view taken along A-A of FIG. 1b, at an enlarged scale of 3:1, showing the arrangement of the guide plates.

Detailed Description

In order to make the technical means, creation features, achievement purposes and effects of the present invention easy to understand and understand, the present invention is further explained below with reference to the accompanying drawings.

The meaning of the reference numbers in the drawings of the utility model is as follows: 1-valve body, 2-gate plate, 3-valve stem, 4-valve bonnet, 5-bracket, 6-valve stem protective sleeve, 7-valve seat assembly, 71-valve seat, 72-valve seat seal, 73-valve seat support ring, 74-valve seat O-ring, 75 a-set screw, 75 b-set screw, 8-pin shaft connection assembly, 81-pin shaft, 82-pressure plate, 83-second screw, 34-valve stem head, 9-valve stem O-ring, 10-gap, 101-packing, 102-packing press sleeve, 103-packing pressure plate, 104-third screw, 111-guide plate, 112-guide plate, 22-full thread stud, 23-nut, 24-spring washer, 25-full thread stud, 26-nut, 27-full thread stud, 28-nut, 29-full thread stud, 30-nut, 31-middle washer, 32-fourth screw, 33-nut.

The utility model provides a "dovetail" is the little groove of the big opening of the inside.

As shown in fig. 1a, in the embodiment shown in the figure, the knife gate valve comprises a valve body 1, a gate plate 2, a valve rod 3, a valve cover 4, a bracket 5 and a valve rod protective sleeve 6. The valve rod 3 can be a threaded valve rod and can be provided with a gear operation actuator or an electric actuator. The 3 valve rod can also be a non-thread valve rod and can be connected with a straight stroke cylinder. The valve cover 4 is a closed valve cover, so that the flashboard cannot be exposed to the outside after being lifted, and the flashboard 3 is prevented from being corroded by the external atmosphere or dirt from being attached. The periphery of the valve cover 4 is provided with a rib plate to increase the strength of the valve cover. The shape and the material of the valve cover 4 may be determined according to actual conditions.

Realize the utility model discloses what valve seal function was that valve seat subassembly 7 has double seal structure. As shown in fig. 2, the valve seat assembly 7 includes a valve seat 71, a valve seat seal ring 72, a valve seat support ring 73, a valve seat O-ring 74, and a first screw 75. The valve seat 71 is located in a gap formed by the valve seat convex portion and the shutter 2, a front end surface of the valve seat 71 faces the shutter 2, and a rear end surface of the valve seat 71 faces the convex portion. The front end surface of the valve seat 71 has a dovetail groove and a U-shaped groove for mounting the valve seat seal ring 72 and the valve seat support ring 73, respectively. The valve seat 7 has a U-shaped groove on the side for mounting a valve seat O-ring 74. The rear end surface of the valve seat 71 is connected to the valve body 1 by a first screw 75. The valve seat sealing ring 72 is made of an elastic material (e.g., a rubber material), has certain elasticity and compressibility, and can be integrally molded in a dovetail groove of the valve seat 71 by vulcanization or separately molded and installed in the dovetail groove of the valve seat 71. The dovetail design prevents the media pressure from blowing the seat seal 72 out. The valve seat sealing ring 72 is in contact with the gate plate 2, and plays a good sealing role. The seat support ring 73 is made of a material having a certain hardness (e.g., polytetrafluoroethylene). After valve seat sealing washer 72 is compressed, valve seat support ring 73 and flashboard 2 contact both can play sealed effect, can play the supporting role again, can also clear up the attachment on flashboard 2 surface simultaneously. In addition, during the opening and closing processes of the gate plate 2, sliding friction is generated between the gate plate 2 and the valve seat sealing ring 72, the valve seat sealing ring 72 is easily flattened and loses the sealing effect if the material is too soft, and at the moment, the valve seat supporting ring 73 made of a certain hardness material can play a sealing effect. Therefore, the valve seat sealing ring 72 and the valve seat support ring 73 are combined for sealing, and the combination of hardness and softness is favorable for sealing and can provide enough support force. The valve seat O-ring 74 may be made of an elastic material (e.g., rubber) that contacts the valve body 1 for sealing a gap between the valve seat 71 and the valve body 1.

the first screws 75 are classified into set screws 75a (shown in the upper drawing of fig. 2) for pushing the valve seat toward the shutter 2 after being tightened, and set screws 75b (shown in the lower drawing of fig. 2) for fixing the valve seat 71 inside the valve body 1 after being tightened. The set screw 75a is installed in a threaded hole of the valve body 1, and when the set screw is tightened, a force that presses the valve seat assembly 7 against the shutter 2 is provided, the valve seat 71 is pushed toward the shutter 2, and the force that the valve seat seal 72 exerts on the shutter 2 is increased, thereby providing sealing. The threaded end of the fixing screw 75b is screwed with the threaded hole of the valve seat 71, the other end of the fixing screw is installed in the counter bore of the valve body 1, and the valve seat assembly is fixed inside the valve body when the fixing screw 75b is screwed down. The set screws 75a and the set screws 75b are arranged alternately and uniformly on the same circumference. The fixing screw 75b and the set screw 75a act simultaneously, so that the valve seat assembly can be fixed, and the interference of the valve seat sealing ring can be adjusted, thereby adjusting the sealing performance.

The valve seat components 7 are symmetrically distributed on two sides of the flashboard 2, when the flashboard 2 is placed downwards to the bottom of the valve body 1, the valve seat sealing rings 72 are fully matched with the flashboard 2, a certain pre-tightening force is provided for sealing the flashboard 2, and the flashboard 2 can move towards the upstream or the downstream of the valve in parallel. When the medium acting force pushes the gate plate 3 to the valve seat on the upstream or downstream of the valve, the valve seat support ring 73 is in contact with the gate plate 2 to support the gate plate 2 and assist sealing, and the gate plate 3 is prevented from being scratched due to the fact that the gate plate 2 is in contact with the metal material of the valve seat 71 after flattening the valve seat seal ring 72.

The lower side of the gate as shown in fig. 2 has a wedge chamfer to prevent scoring of the seat seal 72 when the gate is closed.

as shown in fig. 3, the shutter 2 and the valve stem 3 are connected together by a pin joint assembly 8. The shutter 2 has a circular hole through the thickness and, correspondingly, the head of the valve stem 3 has an open step. The pin connecting assembly 8 includes a cylindrical pin 81, a pressing plate 82, and a socket head cap screw (second screw) 83. The pin 81 is used to connect the shutter 2 to the opening of the head of the valve stem 3 through a circular hole through the thickness of the shutter 2. The pressing plate 82 is used to press the open end of the pin 81, to prevent the pin 81 from moving laterally along the circular hole of the shutter 2 and coming off (coming off) from the stem head 34, and to facilitate disassembly. Socket head cap screws 83 are used to secure pressure plate 82 to valve stem head 34. The width of the opening of the head of the valve stem 3 is slightly greater than the thickness of the shutter 2. When the gate plate 2 is placed in the open position, a certain gap exists between the two side walls of the gate plate 2 and the wall of the open position, so that the gate plate 2 can move towards the upstream or the downstream of the valve in parallel without influencing the lifting and descending of the valve rod.

As shown in fig. 4, the valve stem 3 has a triple seal structure: upper seal, O-shaped ring seal and packing seal. An O-ring seal is located between the upper seal and the packing seal. In the embodiment shown in fig. 4, the upper seal is achieved by: a convex cone surface of a convex cone angle shape is provided on the outer portion of the upper end of the valve head 34 (see fig. 3), and a concave cone surface of a concave cone angle shape is provided on the inner portion of the end of the valve cover 4 adjacent to the bracket 5 to be in contact with the upper end of the valve head 34 (see fig. 4), so that the upper end of the valve head 34 is shaped to match the inner shape of the end of the valve cover 4 adjacent to the bracket 5 after the valve stem 3 is lifted, thereby achieving sealing. In the embodiment shown in fig. 4, the valve stem O-ring 9 forming the valve stem O-ring seal is made of a material having a certain elasticity and compressibility, such as rubber. The valve stem O-ring 9 is mounted in a groove in the valve cap 4, which groove is located above the concave conical surface of the valve cap 4. Vertically above the recess is a circumferential gap 10 formed by the bonnet 4 and the valve stem 3. As shown in fig. 4, the packing structure includes: the packing 101, the packing pressing sleeve 102 and the packing pressing plate 103 are packaged in a circumferential gap 10 formed by the valve cover 4 and the valve rod 3. The packing pressing sleeve 102 press-seals the packing 101 in the circumferential gap 10 by inserting one end thereof into the circumferential gap 10, and the other end thereof is pressed with the packing pressing plate 103, and the packing pressing plate 103 is fixed to the extended rim of the bonnet 4 by the third screw 104. Thus, the packing seal can be adjusted online, and if the position of the valve rod 3 leaks, the third screw 104 can be adjusted to enable the packing 101 to be pressed downwards continuously to form a seal again.

As shown in fig. 5, the gate plate 2 of the knife gate valve of the present invention is a parallel gate plate, and guide plates 11 are installed on both sides of the gate plate 2. The guide plate 11 is composed of two mutually symmetrical parts: a guide plate 111 and a guide plate 112. As can be seen from the sectional view of fig. 5, the guide plates 111 and 112 have a cross section in the shape of a hat with a center protruded, respectively, and the shutter 2 has a hole penetrating the thickness thereof at a position where the guide plate 11 is installed, and the guide plates 111 and 112 are installed at both sides of the shutter 2 at the hat rims thereof, respectively, by means of fourth screws and nuts. The outer walls of the convex portions of the guide plate 111 and the guide plate 112 are supported on the inner walls of the valve body 1 and the bonnet 4, respectively. In this way, when lifting and closing the shutter 2, the guide plate 11 functions to prevent the shutter 2 from rotating together with the valve rod 3, while also preventing the valve rod 3 from rotating together with the actuator. The upper and lower ends of the protruding portions of the guide plates 111 and 112 are also provided with chamfers to prevent the shutter from being jammed when it is lifted or lowered.

The basic principles, main features and advantages of the present invention have been shown and described above. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (10)

1. A knife gate valve comprises a valve body (1), a gate plate (2), a valve rod (3), a valve cover (4) and a support (5), and is characterized by further comprising a valve seat assembly (7) for realizing bidirectional sealing of the valve, wherein the valve seat assembly (7) comprises a valve seat (71), a valve seat sealing ring (72) and a valve seat supporting ring (73) which are arranged on the valve seat, and a first screw (75) for connecting the valve seat (71) and the valve body (1),

The valve seat sealing ring (72) has certain elasticity and compressibility, is in contact with the gate plate (2) and plays a role in sealing,

The valve seat supporting ring (73) has certain hardness, and after the valve seat sealing ring (72) is compressed, the valve seat supporting ring (73) is in contact with the flashboard (2), so that the sealing effect and the supporting effect can be achieved, and meanwhile, attachments on the surface of the flashboard (2) can be cleaned.

2. Knife gate valve according to claim 1, characterised in that the first screw (75) is divided into a set screw (75a) for pushing the valve seat (71) towards the shutter (2) after tightening and a fixing screw (75b) for fixing the valve seat (71) in the valve body (1) after tightening,

The set screws (75a) and the fixing screws (75b) are uniformly and alternately arranged on the same circumference, so that the valve seat (71) can be fixed, and the interference of the valve seat sealing ring (72) can be adjusted, thereby adjusting the sealing performance.

3. Knife gate valve according to claim 1, characterised in that the seat seal (72) is mounted in a dovetail groove of the valve seat (71) and is made of a rubber material.

4. Knife gate valve according to claim 1, characterised in that the seat support ring (73) is mounted in a U-shaped groove of the valve seat (71) made of teflon material.

5. Knife gate valve according to any of claims 1 to 4, characterised in that the shutter (2) has a hole through its thickness and the head (34) of the valve stem (3) has an open shelf for placing the shutter (2), the shutter (2) and the valve stem (3) being connected together by means of a pin connection.

6. knife gate valve according to claim 5, characterized in that the pin connection is realized by a pin connection assembly (8), the pin connection assembly (8) comprising a pin (81), a second screw (83) and a pressure plate (82), the pin (81) being adapted to pass through a hole of the gate (2) for connecting it to the open end of the valve stem head (34), the pressure plate (82) being adapted to press the open end of the pin (81) to prevent the pin (81) from coming out of the valve stem head (34), the second screw (83) being adapted to fix the pressure plate (82) to the valve stem head (34).

7. Knife gate valve according to claim 5, characterized in that the distance between the two walls of the opening is greater than the thickness of the shutter (2), so that when the shutter (2) is placed in the opening, the shutter (2) can move parallel to the pin (81) upstream or downstream of the valve without affecting the lifting and lowering of the stem (3).

8. a knife gate valve according to any of claims 1 to 4, characterised in that the valve stem (3) has a triple sealing structure: an upper seal, a valve rod O-shaped ring seal and a packing seal,

The upper sealing is realized by matching the external shape of the upper end of the valve rod head (34) with the internal shape of the end of the valve cover (4) close to the bracket, so that the head (34) of the valve rod is contacted with the internal surface of the end of the valve cover (4) close to the bracket after the valve rod (3) is lifted and forms sealing fit,

The valve rod O-shaped ring seal is positioned between the upper seal and the packing seal and is used for sealing a gap between the valve cover (4) and the valve rod (3),

The packing seal is realized by packing (101) packed in a gap (10) between the valve cover (4) and the valve rod (3), a packing pressing sleeve (102) for pressing the packing (101), and a packing pressing plate (103) for pressing the packing pressing sleeve (102).

9. Knife gate valve according to one of claims 1 to 4, characterised in that the gate (2) is a parallel gate, on both sides of which guide plates (11) are mounted, which guide plates (11) are used to prevent the gate (2) from rotating with the valve stem (3) when lifting and closing the gate.

10. A knife gate valve according to any of claims 1 to 4, characterised in that the valve stem (3) is a threaded valve stem, to which a gear-operated or electric actuator can be mounted, or

The valve rod (3) is a non-threaded valve rod and is connected with a straight-stroke cylinder.