WO2016121709A1

WO2016121709A1 - Lined butterfly valve

Info

Publication number: WO2016121709A1
Application number: PCT/JP2016/052061
Authority: WO
Inventors: 明平 ▲邱▼; 博明仲川
Original assignee: 株式会社キッツ
Priority date: 2015-01-27
Filing date: 2016-01-26
Publication date: 2016-08-04
Also published as: CN107208810A; CN107208810B; JPWO2016121709A1; JP6738741B2

Abstract

　Provided is a lined butterfly valve that is corrosion resistant to fluids, that simultaneously improves top and bottom sealing properties and shaft sealing properties so as to reliably prevent leaks, and that is capable of maintaining said sealing properties even if a disc moves to the secondary side due to fluid pressure.　A disc (12), which is covered by a lining (32), is provided inside a cylindrical body (11) covered by a seat liner (20) and is able to open and close via a stem (13). The expansion of the diameter of a shaft sealing portion (18) of the stem (13) is prevented by sandwiching said shaft sealing portion (18) between a ring body (22) and the stem (13); and the sealing properties of top and bottom seal portions (19) are maintained as a result of the seat liner (20), which is positioned at top and bottom boss surfaces (37) of the disc (12), being pressed via the ring body (22) due to the spring force of a spring (44) provided inside a shaft installation part (27) of the body (11).

Description

Lining type butterfly valve

The present invention relates to a lining-type butterfly valve in which a resin lining is applied to the inner surface of a valve body and a valve box, and more particularly, to a butterfly valve with improved sealing performance near the top and bottom of the valve body and the shaft seal portion of the valve stem.

Conventionally, when a highly corrosive fluid is used in a plant for the chemical industry, or as a butterfly valve used for food-related flow paths, etc., the metal core of the valve body is covered with a resin lining layer, A so-called butterfly valve with a lining structure in which a resin sheet ring is mounted on the inner peripheral surface of a valve box is known. In this lining-type butterfly valve, the valve body lining layer and the resin sheet ring are made of a resin material such as PTFE and PFA, and since other materials do not touch the fluid, a severe corrosive fluid such as chlorine gas or hydrochloric acid is used. Suitable for chemical fluids, chemicals, foods, solvents, etc.

In this type of lining-type butterfly valve, a plurality of seal structures are provided stepwise in the vicinity thereof in order to prevent external leakage of fluid from the top and bottom sides of the valve body and from the vicinity of the shaft seal portion of the valve stem. The top and bottom side seal structure is called a so-called top and bottom seal and is provided as a primary seal. In the top and bottom seal, the resin sheet ring mounted on the inner periphery of the valve box is sealed by pressing to the top and bottom of the valve body, that is, the peripheral surface of the upper and lower valve stem insertion holes, respectively, from the upstream side to the downstream side. Fluid leakage through the fluid is prevented, and fluid leakage from around the valve stem connected to the valve body is prevented at the position closest to the valve body.
The seal structure of the shaft seal portion of the valve stem is called a so-called shaft seal, and is provided as a secondary seal concentrically with the valve stem at a position outside the butterfly valve in the axial direction of the valve stem. In the shaft seal, fluid leakage from around the valve stem is prevented, and fluid leakage (so-called back leakage) from between the valve box and the resin sheet ring is prevented.
Further, a seal member such as an O-ring may be disposed as a tertiary seal at an axially outward position of the valve stem from the secondary seal, thereby further preventing fluid leakage around the valve stem. .

For example, the butterfly valves disclosed in

Patent Documents

1 and 2 are disclosed as such a plurality of seal structures. In Patent Document 1, the resin sheet ring is held by a support provided on the inner peripheral side, and the diameter of the valve body is larger than that of the resin sheet ring. As a result, the resin sheet ring is compressed and the top and bottom seal functions. On the other hand, the ring-shaped member that is the seal member is stopped by the washer held by the shoulder formed in the body hole, so that the ring-shaped member rotates the shaft. The seal is functioning.
In Patent Document 2, the top and bottom seal functions by a cushion provided between the body and the resin sheet ring, and the shaft seal functions by a clamp device provided on the secondary side in the axial direction of the top and bottom seal portion. It has become.
Thus, in these valves, the top and bottom seals, which are primary seals, and the first shaft seals to the valve stems, which are secondary seals, are provided with independent structures. And a seal.

On the other hand, in the butterfly valves of Patent Documents 3 to 5, the top and bottom seals are provided with a structure using a pressing force by a spring.
In the butterfly valve of Patent Document 3, the cylindrical plug is elastically springed to the boss part side by a spring, thereby providing a top-and-bottom seal that is a primary seal between the resin sheet ring and the valve body, and the cylindrical plug and the resin A shaft seal as a secondary seal is provided by an O-ring provided between the seat ring and the seat ring.
In the butterfly valve of Patent Document 4, the presser ring is pressed by the disc spring, and the top seal and the shaft seal function by the seal ring pressed by the presser ring.
In Patent Document 5, an elastic body, which is a seal member, is pressed in the axial direction via a bearing member pressed by a spring, and the top seal and the shaft seal function by this elastic body.

Further, in the butterfly valve 1 shown in FIG. 9 as a comparative example, a metal core 2 is covered with a resin lining layer 3 to provide a disc-like valve body 4, and a resin is provided on the inner peripheral surface of the valve box 9. A seat ring 5 is attached. Further, the resin lining layer 3 is extended in the axial direction along the valve stem 6 attached to the valve body 4 to form a valve stem covering portion 7, and the resin sheet ring 5 is formed on the outer peripheral surface of the valve stem covering portion 7. However, the extended covering portion 8 extending along the valve stem 6 is arranged to ensure sealing performance.

By the way, in the butterfly valve, when a fluid pressure is applied from the primary side with the valve closed, it is known that the valve body slightly moves to the secondary side due to the fluid pressure. For example, in a butterfly valve with a nominal diameter of 100A, when a water pressure of 1.0 MPa is applied from the primary side with the valve closed, the valve body moves about 0.2 mm to the secondary side.

JP-A-52-90815 Japanese Patent No. 3863563 JP-A-61-119881 Japanese Utility Model Publication No. 58-56463 Japanese Patent No. 2920364

In the butterfly valves of

Patent Documents

1 and 2, the top and bottom seals and the shaft seals are both provided independently of the springs. In Patent Document 1, the diameter of the valve body is larger than the resin sheet ring inner diameter. Then, the top and bottom seals each function by a cushion provided between the body and the resin sheet ring. Because of this structure, when the sealing performance decreases due to deterioration of the lining resin due to temperature change or aging, the top and bottom seals can be recovered by using the spring's resilience against this deterioration in sealing performance. I can't. As a result, it is difficult to maintain the top seal and the shaft seal.

On the other hand, in the butterfly valves of Patent Documents 3 to 5, the top and bottom seals using springs can recover the top and bottom seals by the spring force of the springs, but each has the following problems.
The butterfly valve of Patent Document 3 has a structure in which an O-ring is used for a secondary seal, and when a rubber-based material is used as the O-ring, it cannot be used for corrosive fluids such as chlorine. Therefore, a secondary seal cannot be secured, leading to a limited use of the valve.
In the butterfly valve in Patent Document 4, the pressing force of the disc spring is divided into the top seal direction and the shaft seal direction by the tapered surfaces provided on the presser ring and the seal ring. If the force is increased, the sealing property on the other side becomes weak, and the sealing force of both cannot be effectively increased. In addition, it is necessary to make an adjustment that keeps the top seal and the shaft seal in a well-balanced manner, which makes it difficult to adjust.
Also in Patent Document 5, since the pressing force of the spring is divided into the primary seal and the secondary seal using the tapered surface of the elastic body, there is a problem similar to that of Patent Document 4.

Further, in the butterfly valve 1 of FIG. 9 shown as Patent Documents 1 to 5 and a comparative example, for example, fluid pressure is applied to the butterfly valve 1 of FIG. 9 from the primary side in the fully closed state, as shown in the figure. When the body 4 moves to the secondary side, the resin lining layer 3 also moves to the secondary side. In this case, the top / bottom side of the resin lining layer 3 is shifted to the secondary side with respect to the resin sheet ring 5, and the adhesion thereof becomes worse, and the top / bottom of the valve body 4 formed by the resin lining layer 3 and the resin sheet ring 5. The sealing performance with the valve box 9 around the valve stem 6 on the side, that is, the top-to-bottom sealing performance, is lowered, and so-called primary leakage may occur.
Further, in FIG. 9, the valve stem 6 moves to the secondary side along with the movement of the valve body 4, so that the adhesion between the valve stem covering portion 7 and the extension covering portion 8 is also deteriorated. Further, the sealing performance between the valve stem 6 and the valve box 9, that is, the shaft sealing performance of the valve stem 6, which is formed by the extended covering portion 8, may be deteriorated, and so-called secondary leakage may occur.

The present invention was developed in order to solve the conventional problems, and the object of the present invention is a lining-type butterfly valve having corrosion resistance against fluids, which simultaneously improves the top seal and the shaft seal. It is an object of the present invention to provide a butterfly valve capable of reliably preventing leakage and maintaining these sealing properties even when a disc moves to the secondary side due to fluid pressure.

In order to achieve the above object, an invention according to claim 1 is a butterfly valve in which a disc covered with a lining portion is provided in a cylindrical body covered with a seat liner so as to be openable and closable via a stem. By sandwiching the seal part between the ring body and the stem, the shaft seal part is prevented from expanding in diameter, and the elastic boss of the spring provided in the shaft mounting part of the body allows the top boss of the disc through the ring body. This is a lining-type butterfly valve that maintains the sealing performance of the top-and-bottom seal portion by pressing a seat liner located on the surface.

The invention according to claim 2 is the lining type butterfly valve in which the top and bottom seal portion strongly presses the position in the vicinity of the outer periphery of the seal boss surface of the top and bottom of the disc.

The invention according to claim 3 is the lining type butterfly valve in which the ring body presses the seat liner through the annular flange of the sealing bush provided at the shaft seal portion.

The invention according to claim 4 is a lining-type butterfly valve in which a tapered surface that is inclined downward toward the outer diameter is provided on the bottom surface of the annular flange.

According to a fifth aspect of the present invention, a thick seal portion is provided on an inner periphery of a cylindrical lining portion extended on a seat liner, and the thick seal portion is provided on an outer periphery of a shaft cylinder lining portion extended on a lining portion of a disc. This is a pressed lining-type butterfly valve.

The invention according to claim 6 is a lining-type butterfly valve in which a tapered surface portion having a cross-sectional mountain shape is formed on a thick seal portion.

The invention according to claim 7 is a lining type in which a cylindrical portion formed on a sealing bush is interposed between the cylindrical lining portion and the ring body, and the diameter of the cylindrical lining portion is prevented by the ring body via the cylindrical portion. It is a butterfly valve.

The invention according to claim 8 is a lining-type butterfly valve in which an O-ring inserted in a cylindrical portion of a sealing bush is in sliding contact with a cylindrical lining portion of a seat liner.

The invention according to claim 9 is a lining-type butterfly valve in which a stem and a disc are formed separately.

In the invention according to claim 10, when the flow passage opening and the flange portion of the short cylindrical body are covered with a sheet liner, the disc and the stem are slightly moved to the secondary side by the fluid pressure when fully closed. This is a lining-type butterfly valve in which a movement space in which the liner can follow and move is provided at the edge position on the flow path side of the flange portion.

According to an eleventh aspect of the present invention, the lining portion includes a boss surface that covers the upper and lower boss portions of the disc, and a shaft cylinder lining portion that covers the outer periphery of the stem from the boss surface, and the seat liner includes the flange portion. Extending the flow path part up and down the seal surface that seals the boss surface and the cylindrical lining part that seal-connects from the seal surface to the outer periphery of the shaft cylinder lining part, and to the secondary side of the disc Following the movement, the sealing performance of the top seal between the boss surface and the seal surface and the shaft seal between the shaft lining portion and the cylindrical lining portion is maintained by the movement of the flow path portion of the seat liner by the moving space. A lining-type butterfly valve.

The invention according to claim 12 is the lining-type butterfly valve in which the moving space is a tapered surface formed by cutting out the edge of the flow passage opening of the body to the end surface side of the body.

The invention according to claim 13 is the lining-type butterfly valve in which the moving space is a stepped surface formed by cutting out the edge of the flow passage opening of the body into a stepped shape.

The invention according to claim 14 is the lining type butterfly valve in which the moving space is a tapered tapered space provided at a connection portion between the flow path portion and the flange end portion of the seat liner.

According to the first aspect of the present invention, the cylindrical body covered with the sheet liner and the disc covered with the lining portion have corrosion resistance against the fluid, and the top and bottom of the disc via the ring body by the elastic force of the spring. By pressing the seat liner located on the boss surface of the boss, the sealability of the top-and-bottom seal part is maintained, so that the top-and-bottom seal part, which is the primary seal, is improved. The shaft sealability can be improved by sandwiching the shaft seal portion to prevent the shaft seal portion from expanding. In this case, these top-to-bottom sealing properties and shaft sealing properties do not adversely affect each other, and both are retained and leakage is reliably prevented. In addition, since the ring body can be shared for securing the top-to-bottom seal and the shaft seal, the increase in the number of parts can be suppressed and the internal structure can be simplified. Since the top-to-bottom sealing property is maintained by utilizing the spring force of the spring, the sealing property can be recovered even when the resin as the lining material is deteriorated due to a temperature change or a secular change. At the time of assembling, the top and bottom sealability and the shaft sealability can be improved to a predetermined sealing force by mounting the ring body, so that it is not necessary to adjust each sealing force and the ring body can be easily assembled.

According to the second aspect of the invention, by pressing strongly in the vicinity of the outer periphery of the seal boss surface of the disk top and bottom, the sliding resistance of the contact portion between the seal boss surface and the seat liner is reduced, and the valve opening / closing operation torque is reduced. The top and bottom sealability can be improved while preventing the rise, and this top and bottom sealability can be maintained using a spring.

According to the invention of claim 3, the sheet is different from the case where the metal ring body directly presses the resin sheet liner by transmitting the pressing force of the spring from the ring body to the sheet liner via the annular flange. The local deformation of the liner is prevented, and the seat liner is maintained while the sheet liner is prevented from being damaged.

According to the invention of claim 4, the taper surface securely presses the vicinity of the outer periphery of the seal boss surface of the disk top and bottom to ensure the top and bottom sealability.

According to the invention which concerns on Claim 5, by pressing the thick seal part of the resin-made cylindrical lining part on the outer periphery of the resin-made cylindrical cylinder lining part, a frictional resistance is reduced and the valve opening / closing operation torque is increased. The shaft sealability can be secured while suppressing the above.

According to the invention of claim 6, it becomes easier to disperse the stress accompanying the pressing with the shaft cylinder lining part than the tapered surface part having a mountain-shaped cross section, and the local deformation of the thick seal part can be suppressed and the creep phenomenon can be reduced. . For this reason, a shaft seal is maintained and leakage is reliably prevented.

According to the seventh aspect of the invention, it is possible to maintain the shaft sealing performance by pressing the cylindrical lining portion against the outer periphery of the shaft cylinder lining portion using the elastic force of the cylindrical portion of the sealing bush.

According to the eighth aspect of the present invention, since the ceiling bush used for the top and bottom seal can be used for preventing the diameter of the tertiary seal portion from being expanded by the O-ring while adopting the top and bottom seal structure using the spring, the parts can be shared by the sealing bush. The shaft sealing performance can be maintained by improving the tertiary sealing performance while achieving the above-mentioned.

According to the ninth aspect of the present invention, the sealability of the shaft seal portion can be ensured simply by inserting the stem into the disc after incorporating the lined disc into the cylindrical body covered with the sheet liner. For this reason, the whole assembly work becomes easy, and the top and bottom sealability and the shaft sealability can be ensured while making the disc compact by separating the stem.

According to the invention of claim 10, even when the disc moves to the secondary side due to fluid pressure when the valve is closed, the seat liner can follow and move through the moving space, and the seat liner and the lining portion By preventing primary leakage between the two and maintaining the top-to-bottom seal, and maintaining the shaft seal by preventing secondary leakage, it is possible to reliably close highly corrosive fluids, chemical fluids such as chlorine gas, and fluids such as chemicals. . Moreover, since it is only necessary to provide a moving space for the sheet liner, it is excellent in workability and formability, and can be manufactured while suppressing the complexity of the sheet liner, the lining portion, and the body shape. And since the thickness of a sheet liner and disc lining can be ensured, the fluid permeation resistance can also be maintained.

According to the invention of claim 11, the boss surface that moves to the secondary side together with the disc, the shaft cylinder lining, as the flow path portion of the sheet liner moves by the moving space following the movement of the disc to the secondary side. The sealing surface can be maintained by causing the sealing surface and the cylindrical lining portion to follow the portion. This prevents the primary leakage between the boss surface and the sealing surface and maintains the vertical seal between the body and the disc, and prevents the secondary leakage between the shaft lining and the cylindrical lining. It is possible to reliably prevent fluid leakage by maintaining the shaft sealing performance with the disc.

According to the invention of claim 12, the flow path portion of the seat liner can be deformed without being constrained, and the flow path portion is smoothly deformed along the tapered surface when the disc and the stem move to the secondary side. Thus, the sheet liner can be followed, and stress concentration at the contact portion of the sheet liner with the body can be prevented. The taper surface allows the moving space to be easily formed on the body, which eliminates the need to process the sheet liner, improves formability, and eliminates the need to reduce the thickness of the sheet liner, and thus resists the passage of chlorine and other fluids. Sex can also be maintained.

According to the thirteenth aspect of the present invention, the stepped portion surface can be formed by simple processing without requiring high accuracy on the body side, and the flow path portion of the sheet liner is formed between the disk and the stem through the stepped portion surface. It can be reliably deformed to follow the side movement. Thereby, since it is not necessary to process the sheet liner, the moldability is good, and it is not necessary to reduce the thickness of the sheet liner, so that the permeation resistance to a fluid such as chlorine can be maintained.

According to the fourteenth aspect of the present invention, since the taper space can be provided simultaneously with the molding process of the sheet liner without processing the body, an increase in the number of work steps for forming the taper space can be suppressed. The flow path portion of the seat liner can be reliably deformed so as to follow the secondary side movement of the disc and the stem via the taper space.

It is a center longitudinal cross-sectional view which shows embodiment of the lining type butterfly valve of this invention. It is a center longitudinal cross-sectional view of the lining type butterfly valve of FIG. It is a principal part expanded sectional view of FIG. It is a partially expanded sectional view which shows the thickness seal | sticker part vicinity. It is a partially expanded sectional view which shows sealing bush vicinity. It is a principal part expanded sectional view which shows the state which the disk of FIG. 3 moved to the secondary side. It is a principal part expanded sectional view which shows 2nd Embodiment of the lining type butterfly valve of this invention. It is a principal part expanded sectional view which shows 3rd Embodiment of the lining type butterfly valve of this invention. It is a principal part expanded sectional view which shows the conventional rose fly valve.

DESCRIPTION OF SYMBOLS 10 Valve main body 11 Body 12 Disc 13 Stem 15 Flow path port 16 Flange part 18 Shaft seal part 19 Top and bottom seal part 20 Seat liner 22 Ring body 23 Sealing bush 23a Cylindrical part 23b Annular collar part 24 O-ring 26 Tapered surface 27 Shaft part 30 Flow path portion 31 Seal surface 32 Lining portion 33 Shaft cylinder lining portion 34 Cylindrical lining portion 36 Boss portion 37 Boss surface 40 Tapered surface (moving space)
42 Thick seal part 43 Tapered surface part 44 Spring 51 Step surface (moving space)
61 Taper space (moving space)

Hereinafter, an embodiment of a lining-type butterfly valve according to the present invention will be described in detail with reference to the drawings. 1 and 2 show an embodiment of the butterfly valve of the present invention, and FIG. 3 shows an enlarged cross-sectional view of the main part of FIG.

1 and 2, a butterfly valve (hereinafter referred to as a valve body 10) is used, for example, in a chemical industry plant, a food-related pipeline, and the like, and has a cylindrical body 11, a disc 12, an upper stem 13a, It has a stem 13 composed of a lower stem 13b and is provided with a diameter of a nominal diameter of 100A. As will be described later, in the valve body 1, a cylindrical lining portion 34 of the seat liner 20, a shaft cylinder lining portion 33 of the lining portion 32, a shaft seal portion 18 having the sealing bush 23, a boss surface 37 of the lining portion 32, a seat A top and bottom seal portion 19 having a seal surface 31 of the liner 20 is provided.

The body 11 is formed into a cylindrical shape by cast iron such as ductile cast iron and has an upper body 11a and a lower body 11b, which are detachably fixed by bolts 14. The body 11 is provided with a flow path port 15 and a flange portion 16, which are covered with a sheet liner 20. A shaft mounting portion 27 having a shaft mounting hole 21 is provided on the shaft mounting side of the stem 13 of the upper body 11a and the lower body 11b, and the upper stem 13a and the lower stem 13b are mounted on the shaft mounting portion 27, respectively. A ring body 22, a sealing bush 23, an O-ring 24, and a bearing 25 are mounted on the mounting side of the disc 12 of the shaft mounting portion 27, followed by a spring 44 formed of a coil spring.

The sheet liner 20 is made of a resin material. In the present embodiment, the sheet liner 20 is provided with a thickness of, for example, about 3 mm using a fluororesin such as PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), thereby providing high corrosion resistance and heat resistance. It is possible to demonstrate the sex. In the seat liner 20, a flow path portion 30 that is movable in the flow path direction is formed on the flow path port 15 side, and the flow path portion 30 extends from the flange portion 16 so that the inner periphery side is sealed. A surface 31 is provided, and a cylindrical lining 34 that can be sealed from the sealing surface 31 to the outer periphery of a shaft cylinder lining 33 described later extends in the axial direction of the upper and lower shaft mounting holes 21.

3 and 4, the cylindrical lining portion 34 is formed of a cylindrical portion, and is integrally extended on the side of the seat liner 20 where the stem 13 is inserted. The cylindrical lining portion 34 has an annular wall thickness on the inner periphery thereof. A seal portion 42 is formed.

The thick seal portion 42 is provided so as to protrude to a size capable of pressing the outer periphery of the shaft tube lining portion 33. The thick seal portion 42 is formed with a tapered surface portion 43 having a mountain-shaped cross section, and the taper angle of the tapered surface portion 43 is set in a range of 8 ° to 15 °, for example. When the stem 13 is inserted into the shaft tube lining 33 in a state where the thick seal portion 42 is in contact with the outer periphery of the shaft tube lining 33, the thick seal portion 42 is pressed and adhered to the outer diameter side of the shaft tube lining 33. Thus, the shaft seal state of the shaft seal portion 18 is obtained.

1 to 3, the disc 12 is formed separately from the stem 13 and is rotatably provided in the body 11 via the stem 13. A cored bar 35 is provided on the center side of the disc 12, and the cored bar 35 is formed in a disk shape using, for example, a stainless alloy as a material. Similarly, the lining portion 32 made of a resin material such as a fluororesin such as PFA is coated with a thickness of 3 mm, for example.

The lining portion 32 includes a boss surface 37 covering a boss portion 36 formed on a peripheral surface of a stem insertion hole 12 a formed above and below the disc 12 on the top and bottom sides of the disc 12, and an outer periphery of the stem 13 from the boss surface 37. And a shaft cylinder lining portion 33 comprising a shaft cylinder portion on the shaft seal side extending so as to be covered, and through the through holes 35a formed at appropriate positions of the core metal 35, By integrally covering the outer periphery, detachment from the core bar 35 is prevented.

A square hole portion 38 is formed on the top side of the stem insertion hole 12a of the disc 12, and the connection side of the upper stem 13a and the lower stem 13b is inserted and fitted from the square hole portion 38. The upper stem 13a and the lower stem 13b are connected to each other. Accordingly, the disc 12 covered with the lining portion 32 is pivotally mounted on the body 11 covered with the sheet liner 20. Thus, assembly is facilitated by providing the stem 13 and the disc 12 in a separate structure.

A cylindrical bearing 25 is provided on the outer peripheral side of the stem 13 of the shaft mounting hole 21, and a metal cylindrical ring body 22 is sandwiched between the bearing 25 and the seat liner 20 positioned below. Provided.

The ring body 22 is provided with a diameter capable of strongly pressing the position near the outer periphery of the top seal boss surface 37 of the disc 12 from above with a stainless steel material. The elastic force of the spring 44 of FIG. 1 is provided so that transmission is possible.

In FIG. 1, a bearing member 70 is disposed in the shaft mounting hole 21 of the upper body 11 a while being locked by a holding ring 71, and the spring 44 is supported by the bearing member 70 in a state in which the spring 44 can be springed downward. The On the other hand, a top member 72 is disposed in the shaft mounting hole 21 of the lower body 11 b in a state of being locked by a holding ring 71, and a bearing member 73 is overlaid on the top member 72. The spring 44 is supported in a state in which it can be repelled upward. By these bearing

members

70 and 73 and the top member 72, the upper and

lower springs

44 and 44 are respectively ejected in the direction of the disk 12. Dustproof and waterproof O-

rings

74 and 75 are mounted on the inner and outer peripheries of the bearing member 70 and the top member 72, respectively.

The bearing 25 is disposed between the spring 44 of the shaft mounting hole 21 and the ring body 22, and the upper stem 13 a and the lower stem 13 b are rotatable by the bearing 25 in the vicinity of the tertiary seal (near the O-ring 24). And it is supported in an aligned state. The bearing 25 is provided in a two-layer structure in which a resin multi-layer bearing 25b with a back metal is mounted on the inner periphery of a metal bearing bush 25a such as stainless steel.

The bearing bush 25a is provided on the outer diameter to which the spring 44 comes into contact and the elastic force is applied, and when the elastic force is applied, the end face side comes into contact with the ring body 22 and presses the ring body 22 toward the disk 12 side. Provided possible. In this case, the end surface of the bearing bush 25a on the disk 12 side may be in contact with the end surface of the sealing bush 23, but it is not necessary to apply a pressing force from the bearing bush 25a to the sealing bush 23.

In the present embodiment, a slight gap (not shown) is provided between the lower surface of the bearing bush 25a and the upper surface of the sealing bush 23, and the sealing bush 23 is disposed so as not to be pressed by the bearing 25. . A structure in which the ring body 22 is directly pressed by the spring 44 without using the bearing 25 may be used.

The sealing bush 23 is formed of a bowl-shaped member, is molded from a resin material such as PTFE (polytetrafluoroethylene) containing carbon fiber, and is a seal portion between the ring body 22 of the shaft mounting hole 21, the lining portion 32, and the seat liner 20. It is provided as. In FIG. 3, a cylindrical portion 23 a is formed in the sealing bush 23, and a flange portion 23 b including an annular flange portion is formed on the lower side of the cylindrical portion 23 a so as to be bent in the outer peripheral direction. The end surface 22a of the ring body 22 is brought into contact with the flange portion 23b, so that the ring body 22 presses the seat liner 20 via the flange portion 23b.

According to this structure, even if the valve is severely used, the sealing performance of the top seal portion 19 and the shaft seal portion 18 is reduced, and even if fluid enters between the seat liner 20 and the sealing bush 23. Since the flange portion 23b of the resin sealing bush 23 is strongly pressed by the resin sheet liner 20 by the ring body 22, this pressed portion prevents leakage called so-called back leakage. Therefore, the metal ring body 22 does not come into contact with the corrosive fluid, and the elasticity of the spring 44 is increased so that the seat liner 20 is pressed through the ring body 22 and the top-to-bottom seal can be recovered.

Here, as shown in FIG. 5, the bottom surface of the flange portion 23b is provided with a tapered surface 26 that is inclined downward toward the outer diameter at an angle θ, whereby the sealing bush 23 of FIG. When attached, the vicinity of the outer diameter portion of the bottom surface of the buttocks may be brought into contact with the seat liner 20 in FIG.

Although not shown, when the fluid is not corrosive, an annular flange portion of the ring body 22 is formed so that the lower side of the ring body 22 is bent in the inner circumferential direction, and the seat liner 20 is directly attached to the ring body 22. A structure for pressing may be used. In this case, the sealing bush 23 does not require the flange portion 23b, and the cylindrical portion 23a may be disposed above the annular flange portion of the ring body 22.

The sealing bush 23 is mounted so that the cylindrical portion 23a is interposed between the cylindrical lining portion 34 and the ring body 22, and the ring body 22 prevents the diameter of the cylindrical lining portion 34 from being increased via the cylindrical portion 23a. The

With such a configuration, in the valve main body 10 shown in FIG. 1, the spring 44 provided in the shaft mounting portion 27 of the body 11 is positioned on the top boss surface 37 of the disk 12 via the ring body 22 by elastic force. By pressing the sheet liner 20 to be held, the sealing property of the top-and-bottom seal portion 19 that is a primary seal is maintained.

At the same time, the shaft seal part 18 having the tubular lining 34, the shaft cylinder lining 33, and the sealing bush 23 of the stem 13 is sandwiched between the ring body 22 and the stem 13, thereby increasing the diameter of the shaft seal part 18. The shaft seal portion 18 which is the sliding contact portion functions as a secondary seal.

Further, in FIG. 3, a holding portion 23c is provided above the cylindrical portion 23a of the sealing bush 23, and an O-ring 24 is inserted into the holding portion 23c. As a result, the O-ring 24 is mounted above the shaft seal portion 18 (secondary seal), and the O-ring 24 comes into sliding contact with the shaft tube lining portion 33, and these shaft tube lining portions 33 (the upper stem 13a and the lower stem). 13b) and the slidable contact portion formed by the O-ring 24 function as a tertiary seal. The holding portion 23 c is provided at a height at which the gap X can be formed between the holding portion 23 c and the cylindrical lining portion 34.
Although FIG. 3 shows the vicinity of the upper side of the disc 12 in the valve body 10, the lower side of the disc 12 is provided in the same structure as the upper side.

In the above embodiment, the ring body 22 is made of stainless steel. However, the ring body 22 may be made of a metal material other than this, or when the ring body 22 is pressed by the bearing 25 (the outer periphery of the disk 12). A material other than a metal material may be used as long as it can be pressed strongly.

Further, although the coil spring is used as the spring 44, the present invention is not limited to this, and for example, a disc spring may be used as the spring.

Next, the procedure for assembling the valve body will be described. When assembling the valve body 1, the upper and lower sides are similarly assembled.
In FIG. 1 and FIG. 2, first, the disc 12 covered with the lining portion 32 is incorporated inside the sheet liner 20. At that time, the upper and lower shaft cylinder lining portions 33 of the disk 12 are respectively inserted into the cylindrical lining portions 34 of the seat liner 20.

Next, the sealing bush 23 having the O-ring 24 attached to the holding portion 23c is attached to the outer periphery of the cylindrical lining portion 34. At this time, the flange portion 23b is fitted into the outer peripheral side of the cylindrical lining portion 34, and the upper O-ring 24 is assembled so as to contact the outer periphery of the shaft cylindrical lining portion 33 in FIG.

The ring body 22 is mounted on the outer periphery of the sealing bush 23 while keeping the bottom surface in contact with the top surface of the flange 23b. Thereby, the metal ring body 22 holds the cylindrical portion 23a and the holding portion 23c of the sealing bush 23 from the outer peripheral side, and the diameter expansion of the thick seal portion 42 of the cylindrical lining portion 34 is prevented.

In this state, the upper stem 13a and the lower stem 13b are respectively inserted into the shaft lining portion 33 and connected to the stem insertion hole 12a. Thereby, a predetermined pressing force is applied to the thick seal portion 42 in the radial direction, and the secondary seal and the tertiary seal can function.

On the other hand, the bearing 25, the spring 44, the bearing

members

70 and 73, and the top member 72 are mounted at the corresponding positions in the shaft mounting holes 21 of the upper body 11a and the lower body 11b, respectively. Each retaining ring 71 is prevented from coming out.

Finally, the above-described sheet liner 20 with the disc 12, the sealing bush 23, and the ring body 22 mounted between the upper body 11a and the lower body 11b is arranged, and the bolts 14 are tightened in a state in which the sheet liner 20 is sandwiched. The assembly of the valve body 10 is completed.

In FIG. 6, when fluid pressure is applied to the assembled valve body 10 from the primary side when fully closed, the disc 12 and the stem 13 slightly move to the secondary side by this fluid pressure. When a fluid pressure of 0.0 MPa is applied, the disc 12 moves to the secondary side by about 0.2 mm. The valve body 10 has a moving space 40 in which the seat liner 20 can follow and move when the disc 12 is moved, as shown in FIG. It is provided in the part position.

By the movement of the flow path portion 30 of the sheet liner 20 following the movement of the disc 12 to the secondary side by the moving space 40, the top and bottom seals of the boss surface 37 and the seal surface 31, the shaft cylinder lining portion 33 and the cylindrical shape are obtained. The sealability of the shaft sealability with the lining portion 34 is maintained.

The moving space 40 is provided by a tapered surface formed by cutting the edge portion of the flow passage port 15 of the body 11 toward the end surface of the body 11, and the flow passage portion 30 can be deformed within the range of the moving space 40. It has become. Therefore, the taper surface 40 can maintain the top and bottom seals and the shaft seal by the flow path portion 30 following the disc 12 and moving to the secondary side, and the lateral movement dimension in FIG. Is provided at a predetermined angle. In the present embodiment, the moving space 40 in which the disc moves laterally with a maximum width of 0.2 mm is provided at an angle that can be secured between the body 11 and the seat liner 20 by the fluid pressure of 1.0 MPa as described above. It is done. When the lateral movement dimension of the flow path portion 30 is too large, care must be taken because the flow path portion 30 may move too much and negatively affect the seal on the valve blade side of the disc 12.

Furthermore, it is also possible to set the amount of movement of the flow path portion 30 by adjusting the angle of the tapered surface 40, and by finely adjusting the amount of movement with a very small amount, the valve body 10 to which a different bore diameter or fluid pressure is applied. Accordingly, the amount of movement of the flow path portion 30 can be set to maintain the top seal and the shaft seal.

The taper surface 40 is formed along the flow path port 15 of the body 11, and the outer diameter of the taper surface 40 is arranged at a connection portion with an external pipe (not shown) connected to the valve body 10. It is set to equal or less. Accordingly, the taper surface 40 does not reach the seal surface 41a of the gasket 41 in the flow path direction, and the flange portion of the seat liner 20 is affected even when fluid pressure is applied to the seal surface 41a of the gasket 41. Since it does not deform | transform, the sealing performance with external piping by the gasket 41 can be maintained.

In this case, in FIG. 2, the right side is the upstream side and the left side is the downstream side. However, in the case of the valve body 1 having a symmetric structure as shown in the figure, the left side may be the upstream side and the right side may be the downstream side.
The moving space 40 described above is not necessarily formed in the body 11 and may be formed in the sheet liner 20. As described above, the moving space 40 may be provided in one or both of the seat liner 20 and the body 11, and in any case, the moving space 40 is formed in various shapes other than the tapered surface. It can also be provided.

Next, the operation of the above embodiment of the lining type butterfly valve of the present invention will be described.
In FIG. 3, in the fully closed valve body (nominal diameter 100A) 10, the seat liner 20 positioned on the top boss surface 37 of the disk 12 is pressed through the ring body 22 by the elastic force of the spring 44. In addition, it is possible to maintain the top-to-bottom sealability, which is a primary seal by the top-and-bottom seal portion 19 having the boss surface 37 and the seal surface 31, and even if the seat liner 20 and the lining portion 32 are deteriorated, the spring 44 is elastic. Sealing ability can be recovered with force.

In this case, the elastic force of the spring 44 is transmitted as a pressing force to the outer peripheral side of the boss surface 37 on the top and bottom seal side of the disc 12 via the ring body 22. For this reason, the sealing performance of a predetermined top-and-bottom seal can be obtained because the boss surface 37 and the seal surface 31 can be intensively brought into contact while suppressing an increase in operating torque.

A shaft cylinder that is a secondary seal without adversely affecting the top-to-bottom sealability by sandwiching the shaft seal portion 18 between the ring body 22 and the stem 13 to prevent the diameter of the shaft seal portion 18 from expanding. The shaft sealing property by the lining part 33 and the cylindrical lining part 34 can also be ensured. As a result, it is possible to improve both of the sealing properties without reducing the sealing property of either the top-to-bottom sealing property or the shaft sealing property, and to suppress an increase in the number of parts.

Since the seal surface 31 and the cylindrical lining portion 34 of the seat liner 20 and the boss 37 and the shaft lining portion 33 of the lining portion 32 are each integrally formed of resin, they have excellent corrosion resistance against corrosive fluids such as chlorine. To maintain.

The sealability of each seal part will be described more specifically. In the top-and-bottom seal part 19, the ring body 22 disposed concentrically on the outer periphery of the upper stem 13 a and the lower stem 13 b is seated by the elastic force of the spring 44. The liner 20 is pressed to maintain the sealing performance. At that time, the top and bottom seal portion 19 is pressed strongly in the vicinity of the outer periphery of the top and bottom boss surface 37 of the disc 12, so that the disc 12 and the seat liner 20 are compared with the case where the entire boss surface 37 is pressed. The primary sealing performance can be maintained while reducing the sliding resistance, and the valve opening / closing operation torque is prevented from increasing.

In addition, the sealing bush 23 is provided in the shaft seal portion 18 and the sheet liner 20 is pressed via the flange 23b of the sealing bush 23, so that the end surface 22a of the ring body 22 directly presses the sheet liner 20. Accordingly, the resin sealing bush 23 is pressed, and the pressing force from the ring body 22 is transmitted to the seat retainer 20 side via the flange 23b to prevent stress concentration. For this reason, the local deformation | transformation of the sheet liner 20 can be prevented compared with the case where the metal ring bodies 22 press directly.

Furthermore, by strongly pressing the collar portion 23b and the seat liner by the ring body 22, these contact portions also function as seal portions, and this press portion functions as a portion that prevents the above-described leakage called back leakage.

Here, as shown in FIG. 5, a tapered surface 26 having an angle θ is provided on the bottom surface of the flange portion 23b so as to be inclined downward, and the vicinity of the outer periphery of the disk 12 is more concentrated on the outer diameter side of the tapered surface 26. The top and bottom sealability can be further enhanced by strongly pressing the ring.

On the other hand, in the shaft seal portion 18, the cylindrical lining portion 34 and the shaft lining portion 33 are in sliding contact, and at this time, the thick seal portion 42 on the inner periphery of the cylindrical lining portion 34 is the outer periphery of the shaft lining portion 33. It works by being pressed. Thereby, it becomes possible to obtain high sealing performance locally, and leakage between the tubular lining portion 34 and the shaft tubular lining portion 33 is prevented. Since the thick seal portion 42 is a resin integrally formed with the cylindrical lining portion 34, these secondary seals are in sliding contact with each other. Therefore, if a resin material having a small coefficient of friction such as a fluororesin is used as these materials, the friction resistance is compared with the case where the resin-made cylindrical lining 34 is directly pressed against the metal stem 13. The valve opening / closing operation torque can be prevented from increasing.

By forming the taper surface portion 43 having a mountain-shaped cross section in the thick seal portion 42, the boundary portion between the taper surface portion 43 and the cylindrical lining portion 34 spreads in the shape of a skirt, so that the pressure against the shaft tube lining portion 33 can be reduced. It becomes easy to disperse the accompanying stress. As a result, local deformation of the thick seal portion 43 is suppressed, and the creep phenomenon is also reduced to prevent the sealing performance from being reduced. When the stem 13 is attached to the disc 12, the stem 13 can be smoothly passed over the thick seal portion 42 and inserted into the disc 12. At the time of manufacturing the seat liner 20, the thick seal portion 42 protrudes inward of the cylindrical lining portion 34, but there is no possibility that the removal of the mold is obstructed by the cross-sectional mountain shape of the tapered surface portion 43.

In order to maintain the sealing performance of the secondary seal by sandwiching the shaft seal portion 18 as described above and preventing the thick seal portion 42 from being enlarged by the ring body 22, the ring body 22 is used as in the present embodiment. It may be arranged at a position facing the thick seal portion 42. In the present embodiment, in FIG. 4, the height of the disk side end portion 42 a of the thick seal portion 42 is set so as to substantially coincide with the height of the end surface 22 a of the ring body 22.

A cylindrical portion 23a is interposed between the cylindrical lining portion 34 and the ring body 22, and the diameter of the cylindrical lining portion 34 is prevented by the ring body 22 via the cylindrical portion 23a. The shaft sealing performance is further improved by reliably pressing the shaft 42 against the shaft cylinder lining portion 33 and further utilizing the elastic force of the resin cylindrical portion 23a.

On the tertiary seal side, the O-ring 24 inserted into the cylindrical portion 23a of the sealing bush 23 is in sliding contact with the cylindrical lining portion 34 of the seat liner 20, so that the O-ring 24 is connected to each of the upper stem 13a and the lower stem 13b. The outer periphery can be brought into sliding contact with a predetermined pressing force to ensure sealing performance, and tertiary leakage from around the stem 13 can be prevented. Furthermore, since the holding portion 23c is internally provided in the ring body 22, the ring body 22 is also used for preventing the diameter of the holding portion 23c from being increased, and the shaft sealability can be further improved while sharing parts.

In addition, the tertiary seal function around the stem 13 of the O-ring 24 can prevent tertiary leakage around the stem even when the disc 12 is moved to the secondary side due to fluid pressure, and the sealing bush 23 can share parts. The tertiary seal function is exhibited while preventing stress concentration.

In FIG. 3, when a fluid pressure of 1.0 MPa is applied from the primary side (right side in the figure) to the valve body (nominal diameter 100A) 10 when fully closed, the disc 12 and the stem 13 are about 0.2 mm 2 Move slightly to the next side (left side in the figure).

Here, the seat liner 20 has a sealing surface 31 that seals with a boss surface 37 that covers the boss portion 36 of the disk 12 to form a top-and-bottom seal, and a cylindrical lining portion 34 of the seat liner 20 has an outer periphery of the stem 13. Since the shaft seal is configured by sealing with the shaft cylinder lining portion 33 covering the surface, the flow path portion 30 of the seat liner 20 has a seal surface as the disc 12 and the stem 13 move to the secondary side. The force which moves to the secondary side with 31 and the cylindrical lining part 34 is added.

At that time, since the body 11 is previously provided with a moving space 40 having a width of 0.2 mm at the edge portion of the flange portion 16 on the flow passage portion 15 side, the flow passage portion 30 of the seat liner 20 is shown in FIG. As shown in FIG. 6, it can be deformed within the range of the moving space 40 (maximum width 0.2 mm), and moves 0.2 mm to the secondary side following the movement of the disc 12 and the stem 13 to the secondary side. can do.

For this reason, each of the top seal by the boss | hub surface 37 and the sealing surface 31, and the shaft seal by the cylindrical lining part 34 and the axial cylinder lining part 33 which are formed in the orthogonal direction of the flow-path part 30 of the sheet liner 20 are each. It is possible to maintain the sealing performance. Thereby, the primary leak on the top seal side and the secondary leak on the shaft seal side can be prevented.

In addition, since the moving space is provided by the tapered surface 40 formed by notching the edge portion of the flow passage port 15 of the body 11 to the end surface side of the body 11, the flow passage portion 30 of the sheet liner 20 can be formed while preventing stress concentration. Since it can move, consumption of the sheet liner 20 can be suppressed.

Furthermore, by mounting the O-ring 24 on the inner periphery of the cylindrical portion 23a of the bowl-shaped member 23, it is possible to prevent tertiary leakage between the bowl-shaped member 23 and the shaft cylinder lining portion 33.

Next, in FIG. 7, 2nd Embodiment of the lining type butterfly valve of this invention is shown. In the following embodiments, the same parts as those in the above embodiments are denoted by the same reference numerals, and the description thereof is omitted.
In the valve body 50 in this embodiment, the edge of the flow passage port 15 of the body 11 is notched in a stepped shape to form a circumferential stepped surface 51, and the seatliner 20 is formed by the stepped surface 51. A moving space is provided that can be moved along.
In this case, since the stepped surface 51 can be formed by cutting out the flange portion 16 on the body 11 side at a predetermined depth, the stepped surface 51 can be formed by simple processing without requiring high accuracy. . At that time, by forming the stepped surface 51 as shallow as possible, stress concentration of the sheet liner 20 near the boundary of the stepped surface 51 can be avoided.

FIG. 8 shows a third embodiment of the lining-type butterfly valve of the present invention. In the valve main body 60 of this embodiment, a tapered space 61 is formed in a connection portion between the flow path portion 30 and the flange end portion of the seat liner 20 so that the tapered space 61 becomes a movement space. ing.
In this case, the taper space 61 can be formed at the time of molding on the sheet liner 20 side without processing the body 11, and more preferably, the taper space 61 is formed so that the sheet liner 20 is in close contact with the body 11. It is also possible to suppress the influence on the permeation resistance of the fluid.

Claims

A butterfly valve in which a disc covered with a lining part is provided in a cylindrical body covered with a seat liner so as to be opened and closed through a stem. By preventing the diameter of the shaft seal part from expanding and pressing the seat liner located on the top boss surface of the disc through the ring body by the spring force of the spring provided in the shaft mounting portion of the body. A lining-type butterfly valve characterized by maintaining the sealing performance of the top and bottom seal portion.
The lining-type butterfly valve according to claim 1, wherein the top and bottom seal portion strongly presses a position in the vicinity of the outer periphery of the seal boss surface of the top and bottom of the disc.
The lining-type butterfly valve according to claim 1 or 2, wherein the ring body presses the seat liner through an annular flange of a sealing bush provided at the shaft seal portion.
The lining-type butterfly valve according to claim 3, wherein a tapered surface that is inclined downward toward the outer diameter is provided on a bottom surface of the annular flange portion.
5. A thick seal portion is provided on an inner periphery of a cylindrical lining portion extending to the sheet liner, and the thick seal portion is pressed against an outer periphery of a shaft tube lining portion extending to a lining portion of a disc. A lining-type butterfly valve according to any one of the above.
The lining-type butterfly valve according to claim 5, wherein a taper surface portion having a mountain-shaped cross section is formed on the thick seal portion.
The cylindrical part formed in the said sealing bush between the said cylindrical lining part and the said ring body is interposed, The diameter expansion of the said cylindrical lining part was prevented by the said ring body via the said cylindrical part or. 6. The lining-type butterfly valve according to 6.
The lining-type butterfly valve according to any one of claims 3 to 7, wherein an O-ring inserted in a cylindrical portion of the sealing bush is in sliding contact with a cylindrical lining portion of the seat liner.
The lining-type butterfly valve according to any one of claims 1 to 8, wherein the stem and the disc are formed separately.
When the flow path opening and the flange portion of the short cylindrical body are covered with the seat liner, the seat liner follows when the disc and the stem move slightly to the secondary side by the fluid pressure when fully closed. The lining-type butterfly valve according to any one of claims 1 to 9, wherein a movable movement space is provided at an edge position on the flow path side of the flange portion.
The lining portion includes a boss surface covering the upper and lower boss portions of the disc and a shaft cylinder lining portion covering the outer periphery of the stem from the boss surface, and the sheet liner extends from the flange portion to the flow path. A seal surface that extends the portion and seal-connects to the boss surface, and a cylindrical lining portion that seal-connects from the seal surface to the outer periphery of the shaft cylinder lining portion, and extends to the secondary side of the disc. By the movement of the flow path portion of the seat liner by the movement space following the movement of the seal, the sealing performance between the top seal of the boss surface and the seal surface and the shaft seal of the shaft cylinder lining portion and the cylindrical lining portion The lining-type butterfly valve according to claim 10, wherein the lining-type butterfly valve is maintained.
The lining-type butterfly valve according to claim 10 or 11, wherein the moving space is a tapered surface formed by notching an edge portion of a body channel opening to an end surface side of the body.
The lining-type butterfly valve according to claim 10 or 11, wherein the moving space is a stepped surface formed by cutting out an edge of a flow passage opening of the body into a stepped shape.
The lining-type butterfly valve according to claim 10 or 11, wherein the moving space is a tapered space provided in a connection portion between the flow path portion and the flange end portion of the seat liner.