KR100343511B1 - A gate valve - Google Patents

Abstract

The present invention relates to a gate valve which is connected between the fluid pipe to block and open and close the flow of the fluid, the object of which is to provide a valve seat that is tightly sealed with the knife plate when the gate valve fluid is blocked, if necessary By preventing expansion and contraction of the friction between the valve seat and the knife plate, to prevent the fluid leakage due to seat wear, as well as to improve the operability of the valve for fluid blocking because there is no friction.

Therefore, in order to achieve the above object, the present invention is pinned to the lower portion of the movable rod 20 installed to move as the drive means 10 in the upper bonnet 30 of the gate valve 1, the valve body 50 The valve seat is coupled as a guide ring 110 to one side of the body 50 to seal the gate valve 1 in close contact with the knife plate 40 moving up and down through the gasket 52 and the guider 58 installed in the). Expansion and contraction as air (A) is supplied through the guide ring 110 and the backup ring 120 via a backup ring 120 is fixed between the valve body 50 and the guide ring 110 (100). Provide a gate valve installed so far.

Description

Gate valve {A GATE VALVE}

The present invention relates to a gate valve which is connected between the fluid pipe to block and open and close the flow of the fluid, the object of which is to provide a valve seat that is tightly sealed with the knife plate when the gate valve fluid is blocked, if necessary By preventing the friction between the valve seat and the knife plate by expanding and contracting, it prevents fluid leakage due to seat wear, and also improves the operability of the valve for fluid shutoff without friction, thereby extending the life of the valve. KNIFE GATE VALVE.

Generally known KNIFE GATE VALVE is a valve that is connected between the pipe (pipe) and the pipe to block or open or close the flow of fluid flowing through the pipe as a knife plate moving up and down within the valve. The characteristic is that the flow of fluid is blocked by the lowering of the knife plate. On the contrary, when the knife plate is raised, the fluid flows, and the flow of high-viscosity fluid, such as a mixture of fluid and other substances or a jelly-like fluid Used to control.

This general gate valve 1 is shown in FIGS. 1 and 2.

That is, as shown in FIGS. 1 and 2, the conventional gate valve 1 has a bonnet 30 in which a moving rod 20 to which a driving means 10 such as an adjusting handle 10 is connected is installed through a sleeve 22. And a valve body in which a knife plate 40 fixed with a pin 42 at a lower portion of the movable rod 20 moving upward and downward to the lower side of the bonnet 30 is seated through a gasket 52. Comprising a large (50), the central opening (54) portion of the body 50 is formed with a processing surface 56 for smooth transfer of fluid, the body 50 on both sides of the processing surface 56 The guide ring 70 and the sub-ring 80 for fixing the valve seat 60 for the valve sealing when the fluid is shut off is made of a configuration that is bolted.

In addition, as shown in Fig. 4, the driving means 10 is a steering wheel 10a (Fig. 4a) that is usually used, but in order to avoid the manual operation of the operator depending on the nature of the fluid and the position used. A cylinder 10b (FIG. 4B) or a motor 10c (FIG. 4C) is used. In this case, in the case of the cylinder 10b, a sleeve 22 installed in the bonnet 30 to move the movable rod 20 is provided. The rod portion is connected to the occupational knife plate 40 without necessity, and thus the movable rod 20 is a screw bar that is joined with the sleeve 22 in the case of the adjusting handle and the motor.

That is, in the conventional knife gate valve 1 as described above, when the operator turns the driving means 10, for example, the adjusting handle 10a, the sleeve 22 of the bonnet 30 rotates to form a screw rod 20. And the knife plate 40 connected to the lower side thereof are lowered while being supported by the gasket 52 and the guider 58 sequentially installed at the center portion of the body 50, and eventually the knife plate 40 The flow rate of the fluid tube is determined according to the width of the body opening 54 to be opened according to the falling width of the. When the knife plate 40 is completely lowered, the knife plate 40 is in close contact with the valve seat 60. The fluid flow is interrupted, and the knife plate 40 is supported as a stepping stone 90 formed at approximately 120 degree intervals on the machining surface 56 of the opening 54 portion of the body 50 shown in FIG.

At this time, although the valve seat 60 is not shown in the figure, a metal sheet formed integrally with the body 50 may be used. Such a metal seat requires additional work such as processing when manufacturing a valve, and thus wear rate is Although it is small but has a high cost and makes it difficult to seal completely, rubber valve seats 60 made of rubber or Teflon are used. The valve seat 60 having such elasticity is separately provided. It is fixed to the body 50 as the guide ring 70 of the, and this role of the valve seat 60 is important for preventing the fluid leakage of the valve (1) to perform the sealing of the knife plate (40).

However, in the conventional knife gate valve 1, in particular, the valve seat 60 as described above, as shown in Fig. 3, the end portion 40a of the knife plate 40 lowered by the operation of the drive means 10. ) Is lowered in contact with the valve seat (60), on the contrary, friction is generated by repeated contact with the upward contact when opening the valve, and eventually wears the valve seat (60) easily, which causes the It causes fluid leakage.

In addition, the fluid leakage of the valve, as well as frequent replacement of the valve seat 60 by the valve wear is required, which increases the cost of maintenance and repair of the valve (1).

In addition, the knife plate 40 is lowered and raised while in close contact with the valve seat 60, which prevents the smooth movement of the knife plate 40, which not only makes it difficult to operate the valve 1 quickly, When using the cylinder (10b) or the drive motor (10c), there are a number of problems, such as the load is badly generated to increase the capacity of each part more than necessary.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and its object is to maintain the valve sealing state by completely lowering and then expanding the knife plate when operating a valve to block the flow of fluid. When opening the valve, the valve seat is contracted to completely remove the friction with the knife plate, thereby providing a gate valve to prevent the leakage caused by fluid leakage and component replacement due to wear of the valve seat.

In addition, another object of the present invention, there is no friction between the knife plate and the valve seat for the fluid shut-off of the gate valve to improve the operability of the drive means for the movement of the knife gate, and at the same time use a smaller capacity drive means It is possible to reduce the price of the entire valve, and to provide a gate valve that improves valve operability by quicker operation.

1 is a partial cutaway perspective view of a typical knife gate valve

2 is a side structural view showing a knife gate valve

3 is a sectional view showing main parts of a valve seat of a conventional knife gate valve.

4 (a)-(c) are perspective views of main parts showing driving means for operating a knife gate valve;

5 is a sectional view showing main parts of a valve seat as a first embodiment of a knife gate valve according to the present invention;

6 is a sectional view showing the main parts of a valve seat according to another second embodiment of the valve seat of the first embodiment of the present invention;

7A and 7B are schematic cross-sectional views showing a valve seat operating state as a first embodiment of a gate valve of the present invention;

Fig. 8 is a sectional view showing the main parts of a valve seat as a third embodiment of the knife gate valve of the present invention.

9 is a sectional view showing the principal parts of a valve seat according to another fourth embodiment of the valve seat of a third embodiment of the present invention;

10A and 10B are sectional views showing the main parts of fifth and sixth embodiments of the gate valve of the present invention.

Explanation of symbols on the main parts of the drawings

1 .... gate valve 10 ... driving means

20 .... Lee Dong Bong 30 ... Bonnet

40 ... knife plate 50 ... valve body

100,100 ', 200,200', 300,300 '.... Valve seat

110,210,310 .... guide ring

110a, 120a, 210c, 220a, 320a .... Air passage

120,120 ', 220,220', 320,320 '.... Backup ring

130,230,330 .... connector 140,240,340 ... control valve

As a technical configuration for achieving the above object, the present invention, the pin is connected to the lower portion of the movable rod installed to move as a drive means in the upper bonnet of the gate valve, the knife plate which moves up and down through the gasket and guider installed in the valve body In the valve seat is in close contact with the valve seat coupled as a guide ring to one side of the body to seal the gate valve,

The valve seat is provided by a gate valve which is installed to expand and contract as air supplied through the guide ring and the backup ring via a backup ring fixed between the valve body and the at least one guide ring.

In addition, the pin is connected to the lower portion of the movable rod installed to move as a driving means in the upper bonnet of the gate valve, in close contact with the knife plate that moves up and down through the gasket and guider installed on the valve body to guide the gate valve to one side of the body to seal. In a valve seat coupled as

The valve seat is composed of a rubber seat fixed to expand and contract as air supplied through the guide ring and the backup ring through a backup ring between the valve body and the guide ring, and the body and the backup ring and the guide ring are the valve. By providing a gate valve for fixing the seat in a tapered shape.

In addition, the pin is connected to the lower portion of the movable rod installed to move as a driving means in the upper bonnet of the gate valve, in close contact with the knife plate that moves up and down through the gasket and guider installed on the valve body to guide the gate valve to one side of the body to seal. In a valve seat coupled as

The valve seat is fixed to expand and contract as air supplied through the guide ring and the backup ring through the backup ring to the inside of the first guide ring fixed to the valve body and the second guide ring fixed to the first guide ring. Consists of a rubber seat, the body, the backup ring and the second guide ring is provided by providing a gate valve for fixing the valve seat in a conical shape.

In addition, the pin is connected to the lower portion of the moving rod installed to move as a drive means in the upper bonnet of the gate valve, in close contact with the knife plate moving up and down through the gasket and the guider installed in the valve body to guide the gate valve to one side of the body to seal. In a valve seat coupled as

The valve seat is provided by providing a gate valve installed to expand and contract as air supplied through the backup ring via a backup ring fixed between the valve body and the at least one guide ring.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the same components as in the prior art will be denoted by the same reference numerals.

Fig. 5 is a sectional view showing the main parts of a valve seat as a first embodiment of a knife gate valve according to the present invention, and Fig. 6 is a sectional view showing the main parts of a valve seat as another second embodiment of a valve seat according to the first embodiment of the present invention. 7A and 7B are schematic cross-sectional views showing a valve seat operating state as a first embodiment of a gate valve of the present invention.

That is, Fig. 5 shows a valve seat 100 as a first embodiment of the gate valve of the present invention, which is provided as a drive means 10 in the upper bonnet 30 of the gate valve 1. A pin is connected to the lower portion of the movable rod 20 installed to move, and the gate valve 1 is sealed in close contact with the knife plate 40 which moves up and down through the gasket 52 and the guider 58 installed in the valve body 50. This prevents the fluid from leaking when the gate valve 1 is completely shut off.

At this time, the first valve seat 100, as shown in Figure 5, is fixed via the backup ring 120 between the valve body 50 and the guide ring 110 that is bolted to it, actually When assembling, the backing ring 120 is fixed to the outside while the valve seat 100 is wrapped on the body 50, and then bolts the guide ring 110 to the body 50 to the upper side. It is fixed.

Therefore, the valve seat 100 is formed of a rubber seat to be wrapped in the backup ring 120 as compared to the conventional valve seat 60 forms a body, in particular the body 50 and the backup ring 120 and the guide ring One side 110 is formed to be inclined to fix the valve seat 100 in a tapered shape, and the reason for fixing the valve seat 100 in a tapered shape is as described below. In order to secure the valve seat 100 more firmly by overcoming the force caused by the flow of the fluid at the time of expansion, and to facilitate the assembly.

In addition, the valve seat 100 has both ends 100a and 100b inserted into and fixed to the fixing grooves 122a and 122b asymmetrically formed on the upper and lower surfaces of the backup ring 120 to guide the ring 110 more firmly. It is fixed between the backup ring 120 and the body 50, the important thing is that the length of the valve seat 100 is appropriately formed so that a certain interval between the valve seat 100 and the front surface of the backup ring 120 (D) is formed.

That is, this gap D needs to be formed with a gap D in order to uniformly inflate the entire portion of the valve seat 100 that is ring-shaped during expansion of the valve seat 100 as air. This is because such a spacing (D) should be adjusted to the same as the expansion width (S) of the valve seat 100 described below.

Meanwhile, a fixing jaw 124 is integrally formed at the lower end of the backup ring 120. The fixing jaw 124 of the backup ring 120 is inserted into the fixing groove 50a formed at one side of the body 50. When the body 50 of the backup ring 120 is fixed, that is, as a reference when assembling the actual gate valve 1 facilitates the assembly operation,

At this time, it is important to properly form the thickness (T) of the fixing jaw 124 of the backup ring 120, which is in close contact with the expansion of the knife plate 40 for the fluid blocking of the gate valve (1) This is because the sealing state of the valve seat 100 to be adjusted as the fixing jaw 124 of the backup ring 120, which is the substantial expansion width (S) of the valve seat 100 in accordance with the projecting state of the backup ring 120 ) Is adjusted.

As a result, air passages 110a and 120a are integrally formed in the guide ring 110 and the backup ring 120, respectively, and a control valve is formed at the end of the passage 110a toward the outside of the guide ring 110. When the air (A) is supplied through the air pipe (130) by connecting the air pipe 130, the supply and discharge of air is adjusted as 140, the valve seat 100 is expanded to the control valve 140 Depending on the operation of) will maintain the expanded state or shrink.

Therefore, as shown in FIG. 7A, the gate valve 1 drives the moving means 10 to shut off the fluid and lowers the moving rod 20 so that the knife plate 40 has the body 50 processing surface 56. When descending to the bottom, the valve seat 100 primarily maintains the initial contracted state, and eventually the end portion 40a of the knife plate 40 descending and the valve seat 100 are frictionally spaced apart from each other. It doesn't work.

Next, as shown in FIG. 7B, at the time when the knife plate 40 finishes descending, the control valve 40 is opened to supply air A as an air compressor. When the valve seat 100 is rapidly inflated through the air passages 110a and 120a, the expanded valve seat 100 is in close contact with the surface of the end portion 40a of the knife plate 40. It is possible to prevent the wear of the valve seat 100 due to friction while at the same time maintaining the fluid blocking of the gate valve 1 completely, and at the same time, there is no load due to the rising and falling of the knife plate 40. This is to be improved.

At this time, the control valve 140 installed in the air pipe 130, as shown in Figure 4, that is, according to the drive means of the gate valve 1, that is, the operator directly manipulates the steering wheel (10a) In the case, a manual opening and closing valve for manual operation is installed, and in the case of a cylinder 10b or a driving motor 10c that does not require an operator as a driving means, the limit for detecting the timing of the operation of the cylinder and the driving motor is completed. As a switch (not shown), an electronic open / close valve such as a solenoid valve that operates by receiving a signal is installed.

6 shows a valve seat 100 'which is a second embodiment different from the first gate valve 1 of the present invention.

The second valve seat 100 ′ as described above has upper and lower surfaces of the backup ring 120 as opposed to the both ends 100a and 100b of the first valve seat 100 asymmetrically fixed to the backup ring 120. Both ends 100a 'and 100b' are inserted into and fixed to the symmetrical fixing grooves 122a 'and 122b'.

That is, compared to the first valve seat 100, there is a difficulty in processing the fixing groove (122b ') in the central portion of the backup ring 120, the valve seat 100' is fixed while being symmetrically wrapped in the backup ring Therefore, assembly is easy.

Next, FIG. 8 is a sectional view showing the main parts of a valve seat as a third embodiment of the knife gate valve of the present invention, and FIG. 9 is a sectional view showing main parts of a valve seat as a fourth embodiment of the valve seat according to a third embodiment of the present invention.

That is, as shown in FIGS. 8 and 9, the third and fourth valve seats 200 and 200 ′ of the present invention are characterized in that the first guide ring 210a and the first guide ring are fixed to the valve body 50. Air supplied through the first guide ring 210a and the backup ring 220 through the backup rings 220 and 220 'to the inside of the second guide ring 210b fixed to the first guide ring 210a. A) consists of a rubber sheet fixed to expand and contract.

That is, the third and fourth valve seats 200 and 200 ′ are fixed as the second guide ring 210b as compared with the first and second valve seats 100 and 100 ′. In the case of using the ring 210b, the number of parts is increased, but the valve installation work of the actual valve seats 200 and 200 'is quite simple.

In this case, the third and fourth valve seats 200 and 200 ′ are fixed in a conical shape as the body 50, the backup ring 220, and the second guide ring 210b, thereby providing the first and second valve seats. Compared to (100, 100 '), the expansion width (S) of the valve seats 200 and 200' can be adjusted more easily. As will be described in detail below, the backup rings 220 and 220 ' After the valve seats 200 and 200 'are fixed to the first guide ring 210a as the second guide ring 210b, the set first guide ring 210a is bolted to the body 50. This is easy.

Next, as shown in FIG. 8, both ends 200a and 200b of the third valve seat 200 are inserted into fixing grooves 222a and 222b symmetrically formed on the upper and lower surfaces of the backup ring 220. The first guide ring 210a and the body 50 are sequentially fixed as the second guide ring 210b while being fixed to the backup ring 220.

9, one end 200a 'of the fourth valve seat 200' is inserted into and fixed to a fixing groove 222a 'formed on the bottom surface of the backup ring 220', and the valve The other end 200b 'of the seat 200' is interposed between the backup ring 220 'and the second guide ring 210b to be fixed when the first guide ring 210a of the second guide ring 210b is fixed. .

That is, the fourth valve seat 200 ′ is weaker than the third valve seat 200 in the fixed state of the valve seat, but requires no processing and is extremely easy to assemble.

In this case, the third and fourth valves 200 and 200 ′ are front surfaces of the valve seats 200 and 200 ′ and the backup rings 220 and 220 ′ as shown in FIGS. 8 and 9. Similarly to the first and second valve seats 100 and 100 ′, a predetermined interval D is formed between the first and second valve seats 100 and 100 ′.

In addition, the lower end of the backup ring 220 is integrally formed with a fixing jaw 224 inserted into the fixing groove 50a formed at one side of the body 50, the thickness (T) of the fixing jaw 224 is It is formed to adjust the valve seat expansion width (S), and like the first and second valve seats (100, 100 '), the expansion width (S) is adjusted based on the fixing jaw (224), the backup ring It is a standard for fixing the body.

In addition, inside the first guide ring 210a and the backup ring 220, 220 'of the third and fourth valve seats 200 and 200', an air pipe is disposed outside the first guide ring 210a. When the air passage 210c to which the 230 is connected is integrally formed, when the air A is instantaneously supplied through the air valve 230, the valve seats 200 and 200 ′ are expanded to form a gate valve. (1) to maintain the sealing state when the fluid is blocked.

In addition, the air pipe 230 of the third and fourth valve seats 200 and 200 ′ is also connected to the air supply by resuming the control valve 240 to supply air after the knife plate 40 is lowered. The control valve 240 is a manual opening, a valve or an electronic opening that is manually operated according to the adjusting handle 10a or the cylinder 10b and the driving motor 10c as in the first and second valve seats 100 and 100 '. It is installed as one of the closing valves.

Next, FIGS. 10A and 10 show a fifth and sixth embodiment of the gate valve of the present invention, which is characterized by expanding and contracting the valve seats 300 and 300 '. The air A is supplied through the air passages 320a and 320a 'formed in the backup rings 320 and 320', which means that the gate valve of the first to fourth embodiments is connected to the backup ring and the guide ring. Compared to forming an air passage, the air passages 320a and 320a 'are formed only in the backup rings 320 and 320', thereby simplifying the process of manufacturing the valve.

In FIG. 10A, the valve seat 300 of the gate valve 1 according to the fifth embodiment is illustrated. The valve seat 300 includes a valve body 50, a backup ring 320, and one guide ring 310. The valve seat 300 is fixed in a tapered shape.

10B illustrates a valve seat 300 ′ of the gate valve 1 of the sixth embodiment, the valve seat 300 ′ having a first guide ring 310 a fixed to the valve body 50. The inside of the second guide ring 310b fixed to the first guide ring 310a is fixed in a conical shape via a backup ring 320 '.

Meanwhile, although the valve seats 300 and 300 ′ are fixed in a symmetrical shape, the valve seats 300 and 300 ′ of the fifth and sixth embodiments are also shown in the second and fourth embodiments. Likewise it can be installed asymmetrically.

In addition, the air passage 320a through which the air A supplied through the air pipe 330 connected to the outside is integrally formed through the backup rings 320 and 320 ', and the air pipe is integrally formed therethrough. 330 is connected to the air supply by restarting the control valve 340 to supply the air after the lowering of the knife plate 40.

Therefore, the air A pressurized through the air supply and the control valve 340 expands the valve seats 300 and 300 'which are rubber sheets through the air pipe 330 and the air passages 320a and 320a'. Or shrink to prevent friction between knife plates 40.

At this time, the control valve 340 is also a manual operation, a valve or an electronic opening which is manually operated according to the adjustment handle 10a or the cylinder 10b and the driving motor 10c, which are valve driving means, as in the first to fourth embodiments. It is installed as one of the closing valves.

In addition, the valve seats of the first to sixth embodiments are preferably formed of an elastic rubber having elasticity such as EPDM, BUNA-N, SILLICON, POLYURETHANE or VITON to facilitate expansion and contraction during air supply. At the ends of the air passages for supplying air to the valve seats, an O-ring 92 is provided to prevent leakage of air.

Accordingly, the valve seats 100, 100 ', 200, 200', 300, and 300 'of the present invention prevent friction between the valve seat and the knife plate, as well as fluid leakage due to wear, and replacement of parts. Another cost reduction is achieved, and in particular, there is no friction to improve the operability of the valve (1).

Thus, according to the knife gate valve of the present invention, when operating the valve to block the flow of the fluid, and descends completely with the knife plate and then expands to maintain the valve sealing state, on the contrary, when opening the valve shrinks to friction with the knife plate By installing the valve seat completely removed, it is advantageous to prevent the leakage caused by fluid leakage and component replacement caused by the wear of the valve seat.

In addition, there is no friction between the knife plate and the valve seat for fluid shutoff of the gate valve, thereby improving the operability of the driving means for moving the knife gate, and at the same time, it is possible to use smaller driving means, thereby reducing the price of the entire valve. It is lowered, and there is an excellent effect of improving the valve operability by faster operation.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to know that those who have knowledge of this can easily know.

Claims (23)

It is pin-connected to the lower part of the moving rod 20 installed to move as the drive means 10 to the upper bonnet 30 of the gate valve 1, and through the gasket 52 and the guider 58 provided in the valve body 50. In the valve seat 100 which is in close contact with the knife plate 40 moving up and down and coupled as a guide ring 110 to one side of the body 50 to seal the gate valve 1, The valve seat 100 is air supplied through the guide ring 110 and the backup ring 120 via the backup ring 120 is fixed between the valve body 50 and the at least one guide ring 110. (A) Gate valve characterized in that it is installed to expand and contract According to claim 1, The air passage through which the air (A) supplied through the air pipe 130 connected to the outside of the guide ring 110 inside the guide ring 110 and the backup ring 120 is integrally connected Gate valve, characterized in that the through (110a) and 120a are formed integrally with each other 3. The gate valve of claim 2, wherein the air pipe 130 is connected to the air supply by resuming the control valve 140 to supply air after the knife plate 40 is lowered. 4. The control valve 140 according to claim 3, wherein the control valve 140 is one of a manual opening, a pedal, or an electronic opening and closing valve which is manually operated according to the adjustment handle 10a or the cylinder 10b and the driving motor 10c which are valve driving means. Gate valve characterized in that the installation It is pin-connected to the lower part of the moving rod 20 installed to move as the drive means 10 to the upper bonnet 30 of the gate valve 1, and through the gasket 52 and the guider 58 provided in the valve body 50. In the valve seat 100 which is in close contact with the knife plate 40 moving up and down and coupled as a guide ring 110 to one side of the body 50 to seal the gate valve 1, The valve seat 100 is inflated as air A supplied through the guide ring 110 and the backup ring 120 via the backup ring 120 between the valve body 50 and the guide ring 110. It consists of rubber sheets fixed to shrink The body 50, the backup ring 120 and the guide ring 110 is a gate valve, characterized in that for fixing the valve seat 100 in a tapered shape The valve seat 100 has both end portions 100a and 100b inserted into and fixed to the fixing grooves 122a and 122b formed asymmetrically on the upper and lower surfaces of the backup ring 120. Gate valve, characterized in that the gap (D) for expanding the valve seat of the air is formed between the 100 and the front of the backup ring 120 6. The valve seat (100 ') is fixed at both ends (100a') (100b ') in the fixing groove (122a', 122b ') formed symmetrically on the upper and lower surfaces of the backup ring (120). A gate valve is formed between the valve seat 100 and the front surface of the backup ring 120 to form an interval D for expanding the valve seat of air. The lower end of the backup ring 120 is integrally formed with a fixing jaw 124 to be inserted into the fixing groove (50a) formed on one side of the body 50, the thickness of the fixing jaw (124) (T) is a gate valve, characterized in that configured to adjust the valve seat expansion width (S) According to claim 5, The air passage through which the air (A) supplied through the air pipe 130 connected to the outside of the guide ring 110 inside the guide ring 110 and the backup ring 120 is integrally connected Gate valve, characterized in that the through (110a) and 120a are formed integrally with each other 10. The gate valve of claim 9, wherein the air pipe 130 is connected to the air supply by resuming the control valve 140 to supply air after the knife plate 40 is lowered. The control valve 140 according to claim 10, wherein the control valve 140 is one of a manual opening, a pedal, or an electronic opening and closing valve which is manually operated according to the adjustment handle 10a or the cylinder 10b and the driving motor 10c which are valve driving means. Gate valve characterized in that the installation It is pin-connected to the lower part of the moving rod 20 installed to move as the drive means 10 to the upper bonnet 30 of the gate valve 1, and through the gasket 52 and the guider 58 provided in the valve body 50. In the valve seat 200 is in close contact with the knife plate 40 moving up and down is coupled as a guide ring 210 to one side of the body 50 to seal the gate valve (1), The valve seat 200 has a backup ring 220 inside the first guide ring 210a fixed to the valve body 50 and the second guide ring 210b fixed to the first guide ring 210a. It is composed of a rubber sheet fixed to expand and contract as air (A) supplied through the first guide ring 210a and the backup ring 220 through the interposition, The body 50, the backup ring 220 and the second guide ring 210b is a gate valve, characterized in that for fixing the valve seat 200 in a conical shape The valve seat 200 of claim 12, wherein both ends 200a and 200b of the valve seat 200 are inserted into and fixed to the fixing grooves 222a and 222b symmetrically formed on the upper and lower surfaces of the backup ring 220. Gate valve, characterized in that the gap (D) for expanding the valve seat of the air is formed between the 200 and the front of the backup ring 220 13. The valve seat 200 'of claim 12, wherein one end 200a' is inserted into and fixed to a fixing groove 222a 'formed on a bottom surface of the backup ring 220', and the valve seat 200 ' The other end of the (200b ') is interposed between the backup ring 220' and the second guide ring 210b is fixed, A gate valve is formed between the valve seat 200 ′ and the front surface of the backup ring 220 ′ with a gap D for the entire expansion of the valve seat of air. The method of claim 12, wherein the lower end of the backup ring 220 is integrally formed with a fixing jaw 224 inserted into the fixing groove 50a formed in one side of the body 50, the thickness of the fixing jaw 224 (T) is a gate valve, characterized in that configured to adjust the valve seat expansion width (S) The air A supplied to the first guide ring 210a and the backup ring 220 through the air pipe 230 connected to the outside of the first guide ring 210a is integrally formed. The gate valve, characterized in that the air passage (210c) (220a) leading to the respective through The gate valve of claim 16, wherein the air pipe 230 is connected to the air supply by resuming the control valve 240 to supply air after the knife plate 40 is lowered. 18. The method of claim 17, wherein the control valve 240 is a manual valve, a valve or an electronic opening, closing valve of the manual operation according to the control handle (10a) or the cylinder (10b) and the drive motor (10c) which is a valve drive means Gate valve, characterized in that installed in one It is pin-connected to the lower part of the moving rod 20 installed to move as the drive means 10 to the upper bonnet 30 of the gate valve 1, and through the gasket 52 and the guider 58 provided in the valve body 50. In the valve seat 300 which is in close contact with the knife plate 40 moving up and down and coupled as a guide ring 310 to one side of the body 50 to seal the gate valve 1, The valve seat 300 expands as air A supplied through the backup ring 320 via a backup ring 320 fixed between the valve body 50 and the at least one guide ring 310. Gate valve characterized in that it is installed to shrink 20. The air passage 320a of claim 19, wherein the air passage 320a through which the air A supplied through the air pipe 330 connected to the outside of the backup ring 320 is integrally formed is formed inside the backup ring 320. The air pipe 330 is connected to the air supply by restarting the control valve 340 to supply air after the lowering of the knife plate 40 21. The control valve 340 of claim 20, wherein the control valve 340 is manually operated according to an adjustment handle 10a or a cylinder 10b or a driving motor 10c, which are valve driving means. Gate valve, characterized in that installed in one The gate valve of claim 19, wherein the valve seat 300 is fixed in a tapered shape through the body 50, the backup ring 320, and the guide ring 310. 20. The valve seat 300 'of claim 19, wherein the valve seat 300' is provided with a first guide ring 310a fixed to the valve body 50 and a second guide ring 310b fixed to the first guide ring 310a. The gate valve is characterized in that the conical shape is fixed via the backup ring 320 '