KR0161615B1 - Metal seat device of a valve - Google Patents

Abstract

The present invention reduces the opening and closing rotational force of the valve, and the end portion of the disk with high fluid pressure in the butterfly valve of large diameter and non-uniform clearance between the sheets due to the eccentricity of the rotary opening and closing member in the closed position of the valve using the metal sheet. Automatically compensates for gaps caused by bending to prevent fluid leakage, and in case of slight fluid leakage between metal sheets, multi-stage pressure reduction between sheet contact surfaces The present invention relates to a valve seat device which minimizes the amount of leakage and prevents leakage regardless of the fluid pressure directions on the upstream and downstream sides of the valve.

The present invention is a valve for controlling the flow of fluid in accordance with the opening and closing of the rotary opening and closing member, the sheet is formed on the sheet surface formed on the inner circumferential surface of the valve body in close contact with the sheet is strongly adhered to, The slight leakage is in close contact with the mating sheet by tightening the inner surface of the sheet member by the sheet member 300 which minimizes the leakage of the fluid by the multi-stage reducing action of the sheet protrusion and the decompression groove, and the tightening force that is wound around the inner circumferential surface of the sheet member. The sheet device of the valve, characterized in that it has an elastic tension bar (500,510) to maintain the.

Description

Metal sheet device of valve

1 is a side cross-sectional view of a valve schematically showing a state in which the present invention is applied.

2 is an enlarged cross-sectional view of portion A in FIG.

3 is an enlarged cross-sectional view taken along the line B-B in FIG.

4 and 5 are side cross-sectional views showing the disk being off the center or the fluid pressure is acting on one side.

Figure 6 is a schematic side cross-sectional view showing a state in which the present invention is applied to the ball valve.

7 is an enlarged cross-sectional view of part C in FIG.

* Explanation of symbols for the main parts of the drawings

100: valve body 120: floating interval

131,132: pressure reducing groove 135: pressure balance part

136: equilibrium interval 140: through hole

200: rotation opening and closing member 210: disk

220: mating sheet surface 300: sheet member

305: sheet surface 306: sheet inner peripheral surface

310: seat jaw 320: spring portion

321,322,323: Seating protrusion 330: Sealing surface

360: seal 400: support ring

410: support jaw 420: limit jaw

500, 510: elastic tension bar 520: adjustment screw

610: fixing nut 620: adjusting nut

700: sealing member

The present invention relates to a metal sheet device of the valve, and more particularly, in the metal sheet device of the valve used at a high temperature, by opening and closing the valve without contacting the disc and the sheet, the opening and closing power of the valve is significantly reduced, relative to the metal sheet The fluid leakage on the sheet surface is sealed by multi-stage pressure reduction, and the non-uniform gap between the sheets due to the eccentricity of the rotary opening and closing member at the valve closing position and the deviation from the closing center position is caused. The large diameter butterfly valve automatically compensates for gaps caused by bending of the disc member due to high fluid pressure, which minimizes fluid leakage between the sheet surface and the mating sheet surface. Sealing function independent of the direction of fluid pressure upstream and downstream of the valve. It relates to a probe of the sheet unit.

To open and close a valve with a rotary opening and closing member, the rotating friction force (bearing torque) generated between the rotating shaft and the bushing of the rotary opening and closing member, the fluid resistance force (dynamic torque) acting on the rotary opening and closing member, the end of the valve closing stroke or the beginning of the opening stroke The rotational force exceeding the frictional force (sheeting torque) between the sheet surface and the mating sheet surface should be applied to the axis of rotation of the valve.

In the conventional valve, the opening and closing rotation force in the middle stroke of opening and closing the valve requires a rotational force higher than the dynamic torque and the bearing torque, and the rotational force in the vicinity of the closed position requires the rotational torque to overcome the bearing torque and the seating torque. Increasing the capacity of the electric actuator to open and close the valve has become a major factor.

In the conventional method of mounting a metal sheet on a valve body, the sheet is sandwiched between the valve body and a support wheel for fixing the sheet, and a seal ring or a gasket is installed so that there is no leakage therebetween. The method of fixing a support wheel firmly with many bolts is used.

In addition, the conventional metal sheet is formed so as to be in line contact with the part in contact with the mating sheet instead of the surface contact, which is the contact area of the valve becomes large, the contact area of the valve In the opening and closing operation, the seating torque is greatly increased, and since the sheet material is metal, there is no elasticity like the elastomer material such as rubber, so that the contact surface does not come into close contact with the mating sheet over the entire circumference of the sheet, causing leakage at the sheet site. Therefore, the line contact sheet is adopted.

In addition, in a valve equipped with a conventional metal sheet, the flow of the fluid is sealed regardless of the upstream or downstream direction, and the sheet is bent by the upstream fluid pressure applied to the sheet surface in addition to applying the sealing force by the spring elastic force stored in the sheet. The sheet surface is formed so that the sheet surface is brought into close contact with the mating sheet surface, and the adhesion force acting on the sheet varies according to the elastic force of the metal sheet, the sheet area subjected to the fluid pressure, and the fluid pressure, so that the countercurrent pressure from the downstream direction is applied. In this case, there is a problem that the leakage amount is increased than when the fluid pressure is applied in the upstream direction.

Other causes of leakage in the valve include the eccentricity of the rotary opening and closing member and the rotating shaft, the rotational opening and closing member being disengaged from the center position of the valve closing position, and the disc with insufficient rigidity as in the case of large diameter butterfly valves. When the end of the disc is perpendicular to the axis of rotation, the disc ends bend more than the disc of the axis of rotation, so that there is a gap between the sheet faces due to the deformation of the circumference of the disc relative sheet surface. There are gaps due to the difference in thermal expansion between the valve body, the rotary opening and closing member, and the sheet material according to the temperature of.

In order to minimize the leakage between the valve seats, valves using metal sheets are manufactured with high eccentricity between the rotating shaft and the counterpart sheet, forming process density of the sheet, and assembling precision in the manufacturing process.However, fluid leakage cannot be completely eliminated. As a result, international standards allow leakage below a certain amount.

However, in order to secure the precision, the manufacturing cost is high, and there is no method for correcting the manufacturing error of the valve and the leakage occurring during use.

The valve metal sheet device of the present invention,

In a valve that regulates the flow of fluid in accordance with opening and closing of the rotary opening and closing member, an annular metal sheet made of an elastic material mounted on the inner circumferential side of the valve body with support wheels A sheet surface which seals and separates the upstream and downstream sides of the valve in contact with the mating sheet surface provided on the outer circumference of the rotary opening and closing member when the valve is closed; A sealing surface formed on the outer circumferential side of the metal sheet to prevent fluid leakage between the metal sheet and the valve body and the support wheel; A spring portion for imparting bending elasticity to a connection portion between the sheet surface and the sealing surface; A sheet inner circumferential surface formed on an inner circumference of the sheet surface to expand the metal sheet in an annular shape and apply an annular force for bringing the sheet surface into close contact with the mating sheet surface; A sheet member comprising a sheet jaw formed by bending an end portion of the sheet surface to an outer circumferential side thereof; The valve body and the support wheel have sheet gaps and sealing surfaces having a predetermined distance between the sealing surface, the inner circumferential side of the valve body and the support wheels so that the sealing surface of the sheet member can move in the circumferential radial direction of the valve body. A floating gap that forms a predetermined space between the outer peripheral string portion and the valve body inner peripheral edge; A plurality of seal grooves for attaching a seal to each inner wall of the valve body and the support wheel to which the sealing surface is fitted to prevent fluid leakage in the seat gap between the sealing surface and the valve body and the support wheel when the valve is closed; A pressure balance portion that forms a space between the sheet inner circumference and the support wheel to introduce an upstream pressure to balance the inner circumferential pressure of the sheet; A limiting jaw formed in the support wheel to contact the inner circumference of the support wheel so as to restrict the sheet surface from bending to the inner circumferential side of the sheet, the seat surface of the sheet member and the rotary opening and closing member In order to adjust the sealing force with the mating sheet, one or more rolls of two or more sets of elastic materials are wound around the inner circumferential surface of the sheet, and one end of each rod is fixed to the outside of the valve body, and the length of the rods winding the inner circumferential surface of the sheet is adjusted. Also, on the other end of each rod, an adjustment screw and a nut are formed on the valve body so as to attach a means for pulling the rods from the outside of the valve body, and the valve body through which the rod penetrates is provided with a leakage preventing means. The rods wound around the inner surface of the sheet are fixed to the valve body so that the rods are balanced in the direction of the pulling force of the sheet member. Direction is composed of a resilient tension rod (彈性 張力 棒) arranged symmetrically. Further, in order to further minimize the amount of leakage between the sheet surface of the sheet member and the relative sheet surface of the rotary opening and closing member, the sheet surface is formed with several circumferential protrusions (sheeting protrusions) and grooves (reduction grooves).

Referring to the operation and effect of the metal sheet device of the present invention.

In a valve having a known rotation opening and closing member, the sheet member is fixed to the valve body or the rotation opening and closing member by using an annular fixing ring, but the sheet member of the present invention seals the sealing surface of the sheet member to prevent leakage. Insert a ring with a predetermined side gap between the valve body equipped with the ring and the support wheel, respectively, and form a predetermined space between the outer peripheral end of the seal ring surface and the inner circumference of the valve body so that the sheet member is circumferentially radiated from the valve body. Engage with the valve body in a floating position that can move in an upward direction.

On the other hand, in order to make the elastic tension bar wound around the sheet inner circumference of the sheet member into an initial state of operation, the screws of each elastic tension rod arranged and symmetrically disposed on the valve body in the valve closed position are adjusted to rotate the sheet surface of the sheet member. The center of the sheet member is adjusted to coincide with the center of rotation of the rotational opening and closing member with a predetermined gap between the sheet surface and the relative sheet surface so that the relative sheet surface of the opening member does not contact.

As described above, the sheet member has a clearance with the mating sheet surface and is not floating on the valve body but is a floating high definition state capable of moving in the circumferential direction of the valve. When the center of the sheet member coincides with the center of the sheet member, the seating torque does not work because the sheet surface and the counterpart sheet surface do not contact each other while the valve is opened and closed. If the rotary opening and closing member is eccentric, the contact area between the relative sheet surface of the rotary opening and closing member and the sheet surface of the sheet member is increased due to the eccentricity in the conventional rotary valve, but the seating torque is greatly increased. Even if the rotational opening / closing member is eccentric, the portion of the eccentric sheet surface which is eccentric during valve opening / closing is pushed against the sheet surface by pushing the sheet member in a floating fixed state which can be easily moved in any direction on the valve circumference. Since the center is moved to coincide with the eccentric axis of the rotational opening and closing member, the seating torque between the sheet surface and the counter seat surface due to the eccentricity is minimized than that of the conventional valve.

When the rotary opening and closing part of the valve pulls up each of the elastic tension rods wound around the inner periphery of the sheet, the elastic tension rods are wound around the sheet surface, so that the sheet surface is contracted in the circumferential direction. (C) occurs, and the sheet surface closely adheres to the mating sheet surface, thereby sealing the flow of fluid upstream and downstream of the valve.

Further, when the rotary opening and closing member of the valve is in the closed position, the upstream pressure of the fluid flowing into the equilibrium interval formed between the seat jaw and the restriction jaw is transmitted to the sheet inner circumferential surface through the pressure balance portion of the sheet circumferential portion so as to face the sheet surface. Since it pushes against a sheet surface, the sealing force of a sheet is improved.

Referring to the action of the seating protrusion and the decompression groove formed on the sheet surface as follows.

In order to close and block the high pressure fluid, the pulling force of the elastic tension bar that applies adhesion to the sheet surface in contact with the mating sheet surface must be increased, but several seating protrusions and pressure reducing grooves are formed on the sheet surface. Since each seating protrusion is in line contact with the mating seat surface, the torsional force of the elastic tension beam is concentrated on the seating protrusions of a narrow width, so that the sealing force increases, and several consecutive sheet protrusions Since the pressure reducing groove serves as a multi-stage pressure reducing step for lowering the fluid leakage between the mating sheet surface and the sheet surface in steps, the amount of leakage of the fluid is extremely reduced.

The present invention is characterized in that the metal sheet is fixedly fixed to the valve body, but the opening / closing operation of the valve rotates the rotary switch in a state where the sheet surface does not contact the mating sheet surface in the closed stroke section of the valve. After the rotating member stops at the closed position of the valve, the elastic tension bar wound on the inner circumferential surface of the sheet is pulled from the outside of the valve and the sheet surface is firmly adhered to the mating sheet surface to block the flow of fluid. Since the torque does not work, the valve can be opened and closed by a low output valve manipulator with a rotational force of more than the maximum bearing torque, and the wear and tear of the sheet due to the long-term repeated opening and closing of the valve is significantly reduced. Elasticity that presses the inner circumferential surface of the sheet even when the elastic force of the sheet decreases due to repeated thermal stress By adjusting the output rod tensile force may be a valve for long periods of time.

According to another aspect of the present invention, a sheet formed by several seating protrusions and pressure reducing grooves in line contact with a mating sheet surface on the sheet surface is subjected to a multi-stage pressure-closing action against fluid leakage on the upstream and downstream sides of the valve, thereby allowing the valve to flow up and down. The fluid leakage between the sheets due to the pressure difference between them is minimized than that of the conventional metal sheet having one line contact.

Another feature of the present invention is to pull the elastic tension rod wound around the inner circumferential surface of the sheet to close the sheet to the mating sheet to block the flow of the fluid, thus having the same sealing function regardless of the direction of fluid pressure upstream and downstream.

Another feature of the present invention is that the elastic metal sheet is fixed to the groove of the valve body, so that the disc center of the butterfly valve is eccentric with respect to the rotation axis of the valve closing member, or deviates from the center of the closed position, or of the large diameter valve. Even when the end of the disk is bent under fluid pressure, the elastic tension rod pulls the inner circumferential surface of the sheet in the circumferential direction to pull the valve in order to close the valve. As it is deformed and compressed, the sealing function is enhanced.

This feature allows a large amount of bending of the disc cross section in the butterfly valve, providing a cost-effective way to design the disc.

An additional feature of the present invention is to easily adjust the amount of leakage of the sheet by adjusting the tension force of the elastic tension bar that presses the sheet surface from the outside of the valve to control the amount of leakage in the sheet of the valve installed in the pipeline without removing the valve from the pipeline. Can be.

In addition, if the seat device of the present invention is adjusted to the elastic tension bar so that the sheet and the relative sheet is in close contact in the valve closing stroke section, that is, if the sealing operation stroke of the present invention is omitted, the seating torque during the opening and closing stroke of the valve acts It is not necessary to relax the elastic tension bar before and after opening and closing the valve by using a separate device, so the 1/4 turn valve opening and closing operation used in the conventional 90 degree rotation valve can be used without any additional device. Except for becoming similar to this conventional valve, the various features of the invention retain the same effect.

Hereinafter, the configuration of an embodiment of the present invention based on the accompanying drawings.

1 is a side cross-sectional view of a butterfly valve schematically showing a state in which the present invention is applied, and a cylindrical flow path 110 is formed in the valve body 100, and a rotation opening and closing member 200 is formed in the flow path. On the outer periphery of one end of the disk 210 formed in the rotary opening and closing member 200, a mating sheet surface 220 as a sealing surface for blocking the flow path is formed, wherein the disk is from the upper and lower parts of the valve body, respectively. It is fixed by the pin 250 in the state in which the drive shaft 230 and the driven shaft 240 are penetrated, and can be arbitrarily rotated about the shaft, and the drive shaft 230 is external to the valve body. It protrudes to make it possible to attach the valve open / close actuator.

In addition, the bushing 260 is configured between each of the shafts and the valve body to which they are fitted to reduce the rotational friction force of the driving shaft and the driven shaft.

In addition, at the point where the inner circumferential surface of the valve body, that is, the position of the relative sheet surface 220 of the disk, is in contact with the relative sheet surface, the sheet member 300 is formed to prevent leakage of the fluid.

The present invention relates to a sheet device, which is in close contact with the mating sheet surface 220 of the disc to the sheet member 300 fitted between the valve body 100 and the support wheel 400 as shown in FIG. Forming a sheet surface 305 to be bent, and providing bending elasticity to the sealing surface 330 and the sheet surface 305 in contact with the seal 360 for preventing leakage of fluid between the sheet, the valve body and the support wheel. It consists of a spring part 320 for this purpose, and puts the pressure balance part 135 between the sheet inner peripheral part and the annular ring so that the pressure of the back surface of the sheet may be equal to the upstream pressure P1.

In addition, the seal 360 is inserted into the valve body 100 and the support wheel 400, respectively, but the seat gaps 136 and 137 are disposed between the sealing surface 330 and the valve body support wheel, and the sheet member 300 has a floating interval ( The support wheel is fixed with a predetermined force so as to be able to flow in the circumferential radial direction of the valve within 120, and a gasket 370 is inserted to prevent leakage between the support wheel and the valve body.

In addition, two or more sets of elastic tension bars 500 and 510 made of an elastic material are disposed symmetrically on the circumference of the valve body, and each elastic tension bar is wound once or several times on the sheet inner circumferential surface 306, wherein the elastic tension bars 500 and 510 are used. Silver sheet jaw 310 to the sheet so as not to deviate from the state wound around the sheet inner peripheral surface 306, the support ring is limited to prevent excessive bending of the sheet surface by the pressure applied to the support jaw 410 and the sheet inner peripheral surface The jaw 420 is configured so that both ends of the elastic tension rods are exposed to the outside of the valve through the through holes 140 formed in the valve body 100, respectively, and one end of the jaw 420 is fixedly fixed by the fixing nut 610. The other end is coupled to the adjustment nut 620 to adjust the degree and the balance position of the elastic tension rod is wound around the inner circumference of the sheet by the adjustment nut, the end of the adjustment screw known linear motion It is a combination of means so as to pull on the elastic tension rods.

At this time, the sealing member 700 is configured at the end of the through-hole through which the elastic tension bar penetrates to prevent the fluid from leaking through the gap of the valve body through which the elastic tension bar penetrates.

As another means for minimizing fluid leakage between the sheet surface and the counter sheet, a number of seating protrusions 321, 322, 323 and decompression grooves 131, 132 are formed in the seat surface 305 between the seating protrusions. .

Referring to the operation and effects of the present invention having the above configuration is as follows.

First, the annular sheet 300 fitted to the floating interval 120 of the valve body 100 is held in an annular shape by the elastic memory of the spring portion 320 applied during the sheet forming process.

In addition, by adjusting the adjustment nut 620 of each elastic tension bar (500,510) consisting of two or more sets so that the sheet surface 305 is not in contact with the mating sheet surface 220 during the closing stroke of the valve.

In this state, as shown in FIG. 2, when the fluid flows between the flow path 110 of the valve body 100 from the upstream side 130 to the downstream side 138, both sides of the sealing surface 330 sandwiched between the floating intervals 120 are provided. The fluid flowing through the sheet gaps 136 and 137 is blocked by the seal 360, but the sealing surface of the sheet is not press-fixed and fixed to the support wheel 400, thereby allowing flow.

In addition, since the fluid on the upstream side flows into the pressure balance part 135 of the sheet member through the balance gap 136, which is a gap between the seat jaw 310 and the limiting jaw 420 formed in the support wheel, the inside of the sheet face. The pressure of the same as the pressure of the flow path there is no pressure difference, the elastic tension bar (500,510) is pulled in the radial direction while the sheet inner peripheral surface is wound, but the gap between the sheet surface 305 and the relative sheet surface 220 does not contact Since the force pulling the elastic tension bar by adjusting with the adjustment nut 620 is in an equilibrium state, the sheet member 300 is maintained in a floating state.

That is, the sheet in the floating fixed state is to be in a state that can be easily moved in any direction on the circumference in the state inserted into the floating interval 120.

In describing the closing operation of the valve, when the disk 210 is rotated to the closed position, the seating torque is at a predetermined distance from the counterpart seat, so that the seating torque is not applied in the closing stroke section, and thus the rotational force required to close the valve is described above. It is sufficient to exceed one maximum bearing torque.

Next, in the state where the disk is in the closed position, the fluid is introduced into the pressure balance unit 135 through the equilibrium interval 136 and is equal to the upstream pressure P1, and the fluid flows between the gap between the sheet surface and the counter sheet surface. Since the pressure drops, the sheet inner circumferential surface 306 is pressurized due to this pressure difference, and the sheet surface is bent toward the mating sheet surface by the pressure difference, but the sheet jaw ( Since the sheet 310 is in contact, excessive bending of the sheet is limited.

The pressure acting on the sheet inner circumferential surface 306 serves to reduce the force that the elastic tension bar presses the sheet.

When the valve reaches the closed position, the rotation of the drive shaft 230 is stopped, and when the adjustment screws 520 of each of the elastic tension bars 500 and 510 are pulled out, the circumferential diameter of the elastic tension rods surrounding the inner circumference of the sheet is reduced, and the sheet inner peripheral surface is reduced. A ring force that strongly winds up 306 is generated so that the sheet surface 305 is in close contact with the mating sheet 220.

In FIG. 2, when the downstream pressure P2 is higher than the upstream pressure P1, that is, when the reverse pressure is applied, the downstream pressure P2 is applied to the sheet surface side near the spring portion 320 to be interposed between the sheets. The sheet is bent to the right of FIG. 2 with respect to the spring part 320 by acting as a force to be opened from the relative seat, but the support jaw 410 formed in the support wheel prevents it.

Therefore, the action of pressing the sheet inner circumferential surface 306 by the upstream pressure P1 described above and the sealing force of the sheet surface 305 by the elastic tension bar are the same.

In addition, when opening the valve, first loosen the adjustment screw 520 of the elastic tension bar (500,510) to release the adhesion between the sheet surface and the mating sheet surface, and then rotate the disk, so that friction contact rotation between the sheet surface and the mating sheet surface In this case, the wear of the sheet is significantly reduced.

In the case where the center of the disk 210 is eccentric in one direction as shown in FIGS. 4 and 5, when the disk is partially in contact with the sheet, the sheet is immobilized, so that the center of the sheet is reduced even by a small force that pushes the sheet. The sheet is moved to the center of the sheet, and even when the disk is bent in one direction due to the high pressure of the fluid, the sheet has an accurate sealing action because the elastic tension rod compresses the sheet inner circumferential surface 306 along the outer circumferential diameter of the deformed disk. It has the function of compensating for the leakage due to the error in the valve manufacturing process or the wear during use.In the case of large valves, the allowable bending amount of the disk is increased to reduce the thickness of the disk or to reduce the thickness of the disk reinforcement material. Enable production.

The operation and effects of the several seating protrusions 321, 322, 323 and the decompression grooves 131, 132, 133 formed on the sheet surface 305 as another means for minimizing the fluid leakage between the sheet surface and the mating sheet will be described as follows. .

Since the several seating protrusions 321, 322, 323 formed on the sheet surface make linear contact with the mating sheet, the strong compressive force of the elastic tension beam wound around the inner circumference of the sheet is concentrated on the narrow seating protrusion. This increases the sealing capacity of the sheet.

In addition, there are empty portions 131 and 132, in which the counterpart sheet and the sheet protrusion do not come into contact with each other, which acts as a multistage decompression acting as a decompression groove that gradually lowers the pressure of the fluid leaking from the sheet. Will be

In detail, if there is a small gap between the first seating protrusion 321 and the counter seat surface 220 on the upstream side and the fluid leaks into the first decompression groove 131 on the downstream side, a narrow gap is formed. During this passage, the pressure of the fluid drops rapidly, which is much lower than the upstream pressure P1, and the fluid in the decompression groove 131 again opens another gap between the second seating protrusion 322 and the mating seat. When leaking through the second decompression groove 132 through the pressure drop as described above, the pressure in the second decompression groove is lower than the first decompression groove 131.

In this way, the pressure of the fluid leaking through the several seating protrusions and the decompression grooves is reduced in stages so that the fluid leakage in the sheet is minimized.

6 and 7 illustrate a state in which the present invention is applied to a ball valve. Unlike the disc of the butterfly valve, the ball valve has almost no bending phenomenon of the rotation opening / closing member 200. Ball valve will have the same effect.

Claims (2)

In a valve that regulates the flow of fluid in accordance with opening and closing of the rotary opening and closing member, an annular metal sheet of elastic material mounted on the support wheel 400 on the inner circumferential side of the valve body 100 is rotated when the valve is closed. A sheet surface 305 for sealing the upstream and downstream sides of the valve in contact with the mating sheet surface 220 provided on the outer periphery of the opening and closing member; A sealing surface 330 formed on the outer circumferential side of the metal sheet to prevent fluid leakage between the metal sheet and the valve body and the support wheel; A spring portion 320 which provides bending elasticity to a connection portion between the sheet surface and the sealing surface high; A sheet inner circumferential surface 306 formed in the inner circumferential portion of the sheet surface so as to expand the metal sheet in an annular shape and apply an annular force for bringing the sheet surface into close contact with the mating sheet surface; A sheet member 300 formed of a sheet jaw 310 formed by bending an end portion of the sheet surface to an outer circumferential side thereof; The valve body and the support wheel have sheet gaps 136 and 137 having a predetermined distance between the sealing surface and the inner circumferential side of the valve body and the support wheels so that the sealing surface of the sheet member can move in the circumferential radial direction of the valve body. A floating interval 120 forming a predetermined space between the peripheral end portion and the valve body inner circumference; Several seals 360 for preventing fluid leakage in the seat gap between the sealing surface and the valve body and the support wheel when the valve is closed; A pressure balance part 135 which forms a space between the sheet inner circumferential part and the support wheel to introduce an upstream pressure to balance the inner circumferential pressure of the sheet; The support wheel has a support jaw 410 on the inner side of the spring and a limiting jaw 420 on the seat jaw side, respectively, as a means of preventing bending of the sheet surface more than a predetermined amount, and two or more sets of elastic rods are formed on the sheet inner circumferential surface 306. One or several times of winding the one end of each rod is fixed to the outside of the valve body with a fixing nut 610, the means for adjusting the length of the rods wound around the sheet inner peripheral surface and also pull each rod from the outside of the valve body The other end of each rod constitutes an adjusting screw 520 and an adjusting nut 620 at the other end of the rod, and is installed in the valve fuselage. The seat is fixed to the seat device of the valve, characterized in that consisting of symmetrically arranged elastic tension bars (500,510). The method of claim 1, wherein the sheet surface 305 comprises a plurality of seating protrusions 321, 322, 323 formed in a columnar protrusion, and a pressure reducing groove 131, 132 formed of grooves between the seating protrusions. The sheet apparatus of the valve characterized by the above-mentioned.