CN113883294B

CN113883294B - Gate valve

Info

Publication number: CN113883294B
Application number: CN202111286664.5A
Authority: CN
Inventors: 陆诗雨; 李晓慧; 郑志刚
Original assignee: Xifulong Valve Group Co Ltd
Current assignee: Xifulong Valve Group Co Ltd
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2023-11-10
Anticipated expiration: 2041-11-02
Also published as: CN113883294A

Abstract

The invention relates to a gate valve comprising: valve body, valve gap, valve rod, first valve plate, second valve plate, switching component can make first valve plate switch between a plurality of working positions through rotatory valve rod, when first valve plate is in first working position, the valve plate can block fluid pipeline, forward rotatory valve rod can make the valve plate upwards move to second working position, make fluid pipeline intercommunication, continue forward rotatory valve rod, can make first valve plate continue upwards to move to third working position, make first valve plate and switching component be connected, when first valve plate is in third working position, through controlling the switching component rotation, can switch the position of first valve plate and second valve plate, thereby make second valve plate and valve rod be connected. The invention has the advantages that: through setting up first valve plate and second valve plate, after the first valve plate appears wearing and tearing and makes the gate valve produce revealing, can replace first valve plate with the second valve plate that sets up in advance in the gate valve to extension gate valve's life.

Description

Gate valve

Technical Field

The invention relates to the field of pipeline valves, in particular to a gate valve.

Background

The existing gate valve drives the valve rod nut to rotate by the hand wheel to lift the valve rod and descend the valve rod, so that the practical gate valve is opened and closed, and the gate valve is widely applied to the industrial fields of electric power, petroleum, chemical industry, metallurgy, mining, sewage treatment and the like, and the existing gate valve has the following problems when in use:

1. because the structural characteristics of the gate valve lead the valve plate and the valve seat of the gate valve to be tightly matched, the valve plate and the valve seat can generate great friction when the gate valve is opened and closed, the valve plate is easy to wear, and in the opening and closing process of the gate valve, the medium speed flowing through the valve plate is high, the sealing surface of the valve plate can be damaged, the gate valve can leak, and the service life of the gate valve is influenced;

2. when the gate valve is maintained, the gate valve is required to be detached from the pipeline and then maintained in the current maintenance method, so that the process is complicated, and the work of the whole system is influenced; a large amount of medium flows out of the pipeline to pollute the working environment;

the present invention has been designed to solve the above problems.

Disclosure of Invention

Based on this, it is necessary to provide a gate valve against the above-mentioned problems.

The invention discloses a gate valve, which comprises: the valve body is provided with a fluid pipeline and a middle cavity, and the middle cavity is communicated with the fluid pipeline through a communication opening; the valve cover is covered at the upper end of the valve body to seal the upper side of the middle cavity; the valve rod is in threaded connection with the valve cover and extends into the middle cavity; the first valve plate is rotatably connected to the lower end of the valve rod and can penetrate through the communication opening to extend into the fluid pipeline to block the fluid pipeline; the switching component is arranged in the middle cavity; the second valve plate is connected to the switching assembly, the first valve plate can be switched among a first working position, a second working position and a third working position by rotating the valve rod, when the first valve plate is positioned at the first working position, the first valve plate can block the fluid pipeline, the valve rod is rotated in the forward direction, the first valve plate can be moved upwards to the second working position, the fluid pipeline is communicated, the valve rod is rotated in the forward direction continuously, the first valve plate can be moved upwards continuously to the third working position, the first valve plate is connected with the switching assembly, and when the first valve plate is positioned at the third working position, the switching assembly rotates, the positions of the first valve plate and the second valve plate can be switched, so that the second valve plate is connected with the valve rod.

In one embodiment, the switching component comprises a shaft rod, a rotary sleeve, a clamping jaw piece, a first clamping jaw arm and a second clamping jaw arm, the shaft rod is fixedly arranged in the middle cavity, a first flow channel is arranged in the middle of the shaft rod, the fluid pipeline is communicated with the first flow channel through a one-way valve, the middle cavity can be communicated with the first flow channel through a stop valve, a driving cavity is formed in the valve cover, the driving cavity is semi-cylindrical, the rotary sleeve is sleeved on the shaft rod, a first torsion spring is arranged between the rotary sleeve and the shaft rod, a driving valve is arranged on the rotary sleeve, the driving valve is positioned in the driving cavity and divides the driving cavity into a first containing cavity and a second containing cavity, the first containing cavity is communicated with the first flow channel through the second flow channel, the clamping jaw piece is rotationally arranged on the shaft rod, a ratchet wheel is arranged on the rotary sleeve, the clamping jaw piece is abutted to the ratchet wheel, the first torsion spring can rotate relative to the rotary sleeve, the first clamping jaw arm can be matched with the first clamping jaw piece, the first clamping jaw piece can be matched with the first valve plate, and the first clamping jaw piece can be rotated to the first valve plate, and the first clamping jaw piece can be matched with the first valve plate through the first position, and the first clamping jaw can be rotated by the first valve plate.

In one embodiment, the one-way valve is composed of a first elastic piece and a valve ball, so that liquid can enter the first containing cavity from the fluid pipeline in a one-way.

In one embodiment, the stop valve is composed of a valve core and a second elastic piece, a first pushing inclined plane is arranged on the first valve plate, and when the first valve plate moves from the second working position to the third working position, the first pushing inclined plane can push the valve core to move so as to open the stop valve, so that liquid can enter the middle cavity from the first containing cavity.

In one embodiment, a second pushing inclined plane is arranged on the second valve plate, and the second pushing inclined plane is matched with the first pushing inclined plane to form an annular inclined plane.

In one embodiment, the lower end of the valve rod is provided with a T-shaped connecting protrusion, a first T-shaped groove is formed in the first valve plate, the T-shaped connecting protrusion can extend into the first T-shaped groove, so that the valve rod is connected with the first valve plate, the second valve plate is provided with a second T-shaped groove, and when the first valve plate and the second valve plate are in position exchange, the T-shaped connecting protrusion can extend into the second T-shaped groove, so that the valve rod is connected with the second valve plate.

In one embodiment, the first valve plate is fixedly provided with a first connecting block, the second valve plate is fixedly provided with a second connecting block, the clamping jaw piece is provided with a first connecting groove and a second connecting groove along the vertical direction respectively, the second connecting block is connected to the second connecting groove, and when the first valve plate moves to a third working position, the first connecting block can extend into the first connecting groove, so that the first valve plate and the second valve plate can be driven to rotate simultaneously when the rotating sleeve rotates.

In one embodiment, a second torsion spring is arranged at the hinge joint of the first claw arm and the clamping jaw piece, so that the first claw arm and the clamping jaw piece can clamp the first valve plate, and a third torsion spring is arranged at the hinge joint of the second claw arm and the clamping jaw piece, so that the second claw arm and the clamping jaw piece can clamp the second valve plate.

In one embodiment, the first valve plate can divide the fluid pipeline into a liquid inlet pipe and a liquid outlet pipe, and the first flow channel is communicated with the liquid inlet pipe.

In one embodiment, a side cover plate is arranged on the side wall of the valve body, which is positioned in the middle cavity.

The invention has the advantages that:

1. by arranging the first valve plate and the second valve plate, after the first valve plate is worn to cause leakage of the gate valve, the first valve plate can be replaced by the second valve plate which is arranged in the gate valve in advance, so that the service life of the gate valve is prolonged;

2. by arranging the side cover plate, after the second valve plate is replaced, the side cover plate can be opened by closing the gate valve, the worn first valve plate is taken out, and a new valve plate is replaced for standby, so that the operation is simple and convenient;

3. the clamping jaw piece and the clamping jaw arm are arranged to clamp the valve plate, and the valve plate is forcibly removed when the valve plate is replaced, so that the operation is simple and convenient;

4. after the valve plate rises in place, the valve core is touched to enable a medium in the first containing cavity to enter the middle cavity, so that the rotating sleeve is enabled to rotate under the action of the torsion spring to drive the clamping jaw piece to rotate, the positions of the first valve plate and the second valve plate are changed, after the second valve plate closes the fluid pipeline again, the medium enters the first containing cavity through the one-way valve to push the rotating sleeve to rotate, and the torsion spring stores force again for the next replacement; the replacement mode is simple and quick, can be completed by only rotating the valve rod, and is simple to operate.

Drawings

FIG. 1 is a cross-sectional view of the gate valve of the present invention in a closed state;

FIG. 2 is a cross-sectional view taken along the direction A-A in FIG. 1 in accordance with the present invention;

FIG. 3 is a cross-sectional view taken along the direction B-B in FIG. 1 in accordance with the present invention;

FIG. 4 is a cross-sectional view of the invention in another operational state according to FIG. 3;

FIG. 5 is a cross-sectional view of the valve flap of the present invention after replacement;

fig. 6 is a sectional view of the gate valve of the present invention in an opened state.

Fig. 7 is a perspective view of a first valve plate of the present invention with a first connecting block hidden.

In the drawing, a valve body 1, a fluid pipe 11, a liquid inlet pipe 111, a liquid outlet pipe 112, a middle chamber 12, a communication opening 13, a side cover plate 14, a valve cover 2, a first containing chamber 211, a second containing chamber 212, a second flow passage 22, a valve rod 3, a T-shaped connecting projection 31, a first valve plate 4, a first pushing inclined surface 41, a first T-shaped groove 42, a first connecting block 43, a second valve plate 5, a second pushing inclined surface 51, a second T-shaped groove 52, a second connecting block 53, a shaft 61, a first flow passage 611, a rotating sleeve 62, a driving valve 621, a ratchet 622, a claw member 63, a pawl 631, a first connecting groove 632, a second connecting groove 633, a first claw arm 64, a second torsion spring 641, a second claw arm 65, a third torsion spring 651, a first elastic member 661, a valve ball 662, a second elastic member 671, a valve core 672, and a first torsion spring.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It will be understood that when an element is referred to as being "mounted" to another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or/and" as used herein includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1, the present invention discloses a gate valve, comprising: a valve body 1, a valve cover 2, a valve rod 3, a first valve plate 4 and a switching assembly, wherein the valve body 1 is provided with a fluid pipeline 11 and a middle cavity 12, and the middle cavity 12 is communicated with the fluid pipeline 11 through a communication opening 13; the valve cover 2 is covered at the upper end of the valve body 1 to seal the upper side of the middle cavity 12; the valve rod 3 is connected with the valve cover 2 in a threaded manner and extends into the middle cavity 12; a first valve plate 4 rotatably connected to the lower end of the valve stem 3, the first valve plate 4 being capable of penetrating the communication opening 13 into the fluid pipe 11 to block the fluid pipe 11; the switching assembly is arranged in the middle cavity 12; the second valve plate 5 is connected to the switching assembly,

by rotating the valve rod 3, the first valve plate 4 can be switched among a first working position, a second working position and a third working position, when the first valve plate 4 is in the first working position as shown in fig. 1, the first valve plate can block the fluid pipeline 11, when the valve rod 3 is rotated forward as shown in fig. 6, the first valve plate can be moved upwards to the second working position to enable the fluid pipeline to be communicated, when the valve rod 3 is rotated forward as shown in fig. 5, the first valve plate 4 can be moved upwards to the third working position to enable the first valve plate 4 to be connected with the switching assembly, when the first valve plate 4 is in the third working position, the switching assembly can be rotated automatically, so that the positions of the first valve plate 4 and the second valve plate 5 can be switched, and the second valve plate 5 is connected with the valve rod 3.

It should be noted that the valve cover 2 is composed of a first cover body and a second cover body, the first cover body is covered on the valve body 1, the second cover body is fixedly connected with the first cover body, and the valve rod 3 is in threaded connection with the second cover body.

Preferably, the switching assembly comprises a shaft 61, a rotating sleeve 62, a clamping jaw 63, a first clamping jaw 64 and a second clamping jaw 65, the shaft 61 is fixedly arranged in the middle cavity 12, as shown in fig. 2, a first runner 611 is arranged in the middle of the shaft 61, the first runner 611 is communicated with the fluid pipeline 11 through a one-way valve, the first runner 611 is communicated with the middle cavity 12 through a stop valve, a driving cavity is arranged in the valve cover 2, the driving cavity is semi-cylindrical, the rotating sleeve 62 is sleeved on the shaft 61, a first torsion spring is arranged between the rotating sleeve 62 and the shaft 61, a driving valve 621 is arranged on the rotating sleeve 62, the driving valve 621 is positioned in the driving cavity and divides the driving cavity into a first accommodating cavity 211 and a second accommodating cavity 212, the first accommodating cavity 211 is communicated with the first runner 611 through a second runner 22, the clamping jaw member 63 is rotatably arranged on the shaft 61, the rotating sleeve 62 is provided with a ratchet 622, the clamping jaw member 63 is provided with a pawl 631 abutting against the ratchet 622, so that the clamping jaw member 63 can rotate unidirectionally relative to the rotating sleeve 62, the first clamping jaw arm 64 and the second clamping jaw arm 65 are hinged to the clamping jaw member 63, the first clamping jaw arm 64 and the clamping jaw member 63 cooperate to clamp the first valve plate 4, the second clamping jaw arm 65 and the clamping jaw member 63 cooperate to clamp the second valve plate 5, when the first valve plate 4 moves to a third working position, the first valve plate 4 can open the stop valve, the first accommodating cavity 211 is communicated with the middle cavity 12, so that the rotating sleeve 62 rotates forward by 180 degrees under the action of the first torsion spring, and the positions of the first valve plate 4 and the second valve plate 5 are switched.

Preferably, the first valve plate 4 is capable of dividing the fluid conduit 11 into a liquid inlet pipe 111 and a liquid outlet pipe 112, and the first flow channel 611 is in communication with the liquid inlet pipe 111.

Preferably, the check valve is composed of the first elastic member 661 and the valve ball 662, so that the liquid can be unidirectionally introduced from the fluid pipe 11 into the first chamber 211.

Preferably, the stop valve is composed of a valve core 672 and a second elastic member 671, the first valve plate 4 is provided with a first pushing inclined plane 41, and when the first valve plate 4 moves from the second working position to the third working position, the first pushing inclined plane 41 can push the valve core 672 to move so as to open the stop valve, so that liquid can enter the middle cavity 12 from the first containing cavity 211.

It should be noted that, when the first torsion spring is in the deformed state, the stop valve is opened, the rotary sleeve 62 can rotate forward under the action of the first torsion spring, and when the stop valve is closed and the fluid pipeline 11 is in the stopped state, the medium pressure in the liquid inlet pipe 111 is higher, and the medium can enter the first containing cavity 211 through the one-way valve to push the rotary sleeve 62 to rotate reversely, so that the first torsion spring is deformed.

Preferably, a second pushing inclined plane 51 is disposed on the second valve plate 5, and the second pushing inclined plane cooperates with the first pushing inclined plane to form an annular inclined plane.

Preferably, the first pushing inclined surface 41 and the second pushing inclined surface 51 form an annular inclined surface, so that the stop valve is always in an open state during the rotation of the rotary sleeve 62.

Preferably, the lower end of the valve rod 3 is provided with a T-shaped connection protrusion 31, the first valve plate 4 is provided with a first T-shaped groove 42, the T-shaped connection protrusion 31 can extend into the first T-shaped groove 42, so that the valve rod 3 is connected with the first valve plate 4, the second valve plate 5 is provided with a second T-shaped groove 52, and when the first valve plate 4 and the second valve plate 5 are in position-changing, the T-shaped connection protrusion 31 can extend into the second T-shaped groove 52, so that the valve rod 3 is connected with the second valve plate 5.

The T-shaped connection protrusion 31 can rotate in the first T-shaped groove 42 and the second T-shaped groove 52.

Preferably, the first valve plate 4 is fixedly provided with a first connection block 43, the second valve plate 5 is fixedly provided with a second connection block 53, the clamping jaw member 63 is provided with a first connection groove 632 and a second connection groove 633 along a vertical direction, the second connection block 53 is connected to the second connection groove 633, when the first valve plate 4 moves to a third working position, the first connection block 43 can extend into the first connection groove 632, so that the first valve plate 4 and the second valve plate 5 can be simultaneously driven to rotate when the rotating sleeve rotates.

Preferably, a second torsion spring 641 is disposed at the hinge joint of the first claw arm 64 and the clamping jaw member 63, so that the first claw arm 64 and the clamping jaw member 63 can clamp the first valve plate 4, and a third torsion spring 651 is disposed at the hinge joint of the second claw arm 65 and the clamping jaw member 63, so that the second claw arm 65 and the clamping jaw member 63 can clamp the second valve plate 5.

Preferably, a side cover 14 is disposed on the side wall of the valve body 1 located in the middle cavity 12.

The working mode of the invention is as follows: as shown in fig. 1, the first valve plate 4 is in the first working position, blocks the fluid pipeline 11, makes the medium in the liquid inlet pipe 111 keep a high-pressure state, opens the one-way valve through the first flow channel 611, enters the first containing cavity 211 through the second flow channel 22, pushes the driving valve 621 to rotate, and makes the first torsion spring in a deformed state.

As shown in fig. 6, the first valve plate 4 is moved up to the second working position by rotating the valve stem 3 in the forward direction, so that the fluid pipe 11 can be completely opened.

When the first valve plate 4 needs to be replaced, the valve rod 3 is continuously rotated in the forward direction, so that the first valve plate 4 moves from the second working position to the third working position, as shown in fig. 5, at this time, the first connecting block 43 of the first valve plate 4 stretches into the first connecting groove 632, and when the first pushing inclined surface 41 of the first valve plate 4 rises to the top, the valve core 672 of the stop valve is pushed, so that the stop valve is opened, and because the middle cavity 12 is communicated with the liquid outlet pipe 112 of the fluid pipeline 11, the medium in the first containing cavity 211 can enter the middle cavity 12 through the second flow channel 22 and the first flow channel 611, namely, as shown in fig. 4, the rotating sleeve 62 rotates in the forward direction under the action of the first torsion spring, and the ratchet 622 and the pawl 631 drive the clamping jaw 63 to rotate in the forward direction, so that the switching position of the first valve plate 4 and the second valve plate 5 can be realized, and the T-shaped connecting protrusion 31 is separated from the first T-shaped groove 42 in the rotation process, and then connected with the second T-shaped groove 52. The valve rod 3 is then reversely rotated to lower the second valve plate 5 to the first working position, the pressure in the liquid inlet pipe 111 rises due to the blocking of the fluid pipeline 11, the liquid enters the first containing cavity 211 through the check valve, the first flow channel 611 and the second flow channel 22, the rotating sleeve 62 is pushed to reversely rotate, and the rotating sleeve 62 is connected with the clamping jaw piece 63 through the ratchet wheel 622, so that the clamping jaw piece 63 is kept stationary when the rotating sleeve 62 reversely rotates, and the valve plate switching is completed.

By opening the side cover plate 14, the worn first valve plate 4 can be removed, replaced with a new valve plate, ready for the next replacement.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A gate valve, said gate valve comprising:

the valve body is provided with a fluid pipeline and a middle cavity, and the middle cavity is communicated with the fluid pipeline through a communication opening;

the valve cover is covered at the upper end of the valve body to seal the upper side of the middle cavity;

the valve rod is in threaded connection with the valve cover and extends into the middle cavity;

the first valve plate is rotatably connected to the lower end of the valve rod and can penetrate through the communication opening to extend into the fluid pipeline to block the fluid pipeline;

the switching component is arranged in the middle cavity;

a second valve plate connected to the switching assembly,

the first valve plate can be switched among a first working position, a second working position and a third working position by rotating the valve rod, when the first valve plate is in the first working position, the first valve plate can block the fluid pipeline, the valve rod can be rotated in the forward direction, the first valve plate can be moved upwards to the second working position, the fluid pipeline is communicated, the valve rod can be rotated in the forward direction continuously, the first valve plate can be moved upwards continuously to the third working position, the first valve plate is connected with the switching assembly, and when the first valve plate is in the third working position, the switching assembly rotates, the positions of the first valve plate and the second valve plate can be switched, so that the second valve plate is connected with the valve rod;

the switching component comprises a shaft lever, a rotary sleeve, a clamping jaw piece, a first clamping jaw arm and a second clamping jaw arm, wherein the shaft lever is fixedly arranged in the middle cavity, a first flow passage is arranged in the middle of the shaft lever, a fluid pipeline is communicated with the first flow passage in a unidirectional way through a one-way valve, the middle cavity can be communicated with the first flow passage through a stop valve, a driving cavity is arranged in a valve cover, the driving cavity is semi-cylindrical, the rotary sleeve is sleeved on the shaft lever, a first torsion spring is arranged between the rotary sleeve and the shaft lever, a driving valve is arranged on the rotary sleeve and is positioned in the driving cavity and divides the driving cavity into a first containing cavity and a second containing cavity, the first containing cavity is communicated with the first flow passage through the second flow passage, the clamping jaw piece is rotatably arranged on the shaft rod, a ratchet wheel is arranged on the rotating sleeve, a pawl which is abutted to the ratchet wheel is arranged on the clamping jaw piece, the clamping jaw piece can rotate unidirectionally relative to the rotating sleeve, the first clamping jaw arm and the second clamping jaw arm are hinged to the clamping jaw piece, the first clamping jaw arm and the clamping jaw piece are matched to clamp the first valve plate, the second clamping jaw arm and the clamping jaw piece are matched to clamp the second valve plate, when the first valve plate moves to a third working position, the first valve plate can open the stop valve, the first containing cavity is communicated with the middle cavity, and therefore the rotating sleeve positively rotates 180 degrees under the action of the first torsion spring, and the positions of the first valve plate and the second valve plate are switched.

2. The gate valve of claim 1, wherein the one-way valve is comprised of a first resilient member and a valve ball to allow one-way passage of fluid from the fluid conduit into the first chamber.

3. The gate valve of claim 2, wherein the shut-off valve is comprised of a valve core and a second elastic member, and a first pushing ramp is provided on the first valve plate, and when the first valve plate moves from the second working position to the third working position, the first pushing ramp can push the valve core to move so as to open the shut-off valve, so that liquid can enter the middle cavity from the first containing cavity.

4. A gate valve as claimed in claim 3 wherein a second push ramp is provided on the second valve plate, the second push ramp cooperating with the first push ramp to form an annular ramp.

5. The gate valve of claim 4, wherein the lower end of the valve rod is provided with a T-shaped connection protrusion, the first valve plate is provided with a first T-shaped groove, the T-shaped connection protrusion can extend into the first T-shaped groove, thereby connecting the valve rod with the first valve plate, the second valve plate is provided with a second T-shaped groove, and when the first valve plate and the second valve plate are in position, the T-shaped connection protrusion can extend into the second T-shaped groove, thereby connecting the valve rod with the second valve plate.

6. The gate valve of claim 5, wherein a first connecting block is fixedly arranged on the first valve plate, a second connecting block is fixedly arranged on the second valve plate, a first connecting groove and a second connecting groove are respectively formed in the clamping jaw piece in the vertical direction, the second connecting block is connected to the second connecting groove, and when the first valve plate moves to a third working position, the first connecting block can extend into the first connecting groove, so that when the rotary sleeve rotates, the first valve plate and the second valve plate can be simultaneously driven to rotate.

7. The gate valve of claim 1, wherein a second torsion spring is provided at the hinge of the first jaw arm and the jaw member to enable the first jaw arm and the jaw member to clamp the first valve plate, and a third torsion spring is provided at the hinge of the second jaw arm and the jaw member to enable the second jaw arm and the jaw member to clamp the second valve plate.

8. The gate valve of claim 1, wherein the first valve plate is capable of separating the fluid conduit into a liquid inlet tube and a liquid outlet tube, the first flow passage being in communication with the liquid inlet tube.

9. The gate valve of claim 1, wherein a side cover plate is provided on a side wall of the valve body located in the middle chamber.