CN107208810A - Lined Butterfly Valve - Google Patents

Abstract

Provided is a butterfly valve of a liner type having corrosion resistance against a fluid, capable of improving both natural sealing performance and shaft sealing performance to reliably prevent leakage, and capable of maintaining the sealing performance even when a valve disc moves to the secondary side by fluid pressure. A valve disk (12) covered by a liner portion (32) is openably and closably provided in a cylindrical valve body (11) covered by a valve seat liner (20) via a valve stem (13). The shaft seal portion (18) of the valve rod (13) is clamped between the ring body (22) and the valve rod (13), so that the diameter of the shaft seal portion (18) is prevented from expanding, and the valve seat lining (20) positioned on the raised platform surface (37) of the heaven and earth of the valve disc (12) is pressed through the ring body (22) by the rebound force of a spring (44) arranged in the shaft mounting portion (27) of the valve body (11), so that the sealing performance of the heaven and earth seal portion (19) is maintained.

Description

Lined Butterfly Valve

technical field

The present invention relates to a liner type butterfly valve with a resin lining on the inner peripheral surface of a valve body and a valve box, and in particular to a butterfly valve with improved airtightness near the air and earth side of the valve body and the shaft sealing portion of the valve rod.

Background technique

Conventionally, as butterfly valves used in facilities for the chemical industry where highly corrosive fluids flow, or in food-related flow paths, etc., it is known that a metal core of the valve body is A butterfly valve with a so-called liner structure is covered with a resin liner layer and a resin seat ring is mounted on the inner peripheral surface of the valve box. The body lining layer and resin valve seat ring of this lined butterfly valve are made of resin materials such as PTFE or PFA. Other than these materials, they are not in contact with fluids, so they are suitable for severe corrosive fluids, chemical fluids such as chlorine or hydrochloric acid, chemicals, etc. Liquids, food, solvents, etc.

In such a liner type butterfly valve, in order to prevent external leakage of fluid from the air side of the valve body or the vicinity of the shaft seal portion of the valve rod, a plurality of seal structures are provided in stages near it. The airtight structure on the air-earth side is called a so-called air-to-earth seal, and is provided as a primary airtight seal. In the air-to-earth seal, the resin valve seat ring assembled on the inner periphery of the valve box is pressed and sealed by the air and earth of the valve body, that is, the surrounding surfaces of the valve rod insertion holes on the upper and lower sides, preventing leakage from the upstream side to the downstream side. Fluid leakage through, and prevents fluid leakage from around the valve stem connected to the valve body at the position closest to the valve body.

The sealing structure of the shaft seal part of the valve rod is called a so-called shaft seal, and it is provided as a secondary seal concentrically with the valve rod at a position outward in the axial direction of the valve rod from the primary seal of the butterfly valve. In the shaft seal, fluid leakage from around the valve stem is prevented, and fluid leakage from between the valve box and the resin seat ring (so-called backside leakage) is prevented.

Furthermore, a sealing member such as an O-ring may be disposed as a tertiary seal at a position outward in the axial direction of the valve rod from the secondary seal, thereby further preventing fluid leakage from around the valve rod.

As a structure provided with such a plurality of sealing structures, for example, the butterfly valves of Patent Documents 1 and 2 are disclosed. In Patent Document 1, the resin valve seat 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 valve seat ring. As a result, the resin valve seat ring is compressed to perform the air-to-earth seal function. On the other hand, the ring as the sealing member is fixed with a gasket, thereby enabling the shaft seal to function through the wheel. The gasket is formed on the valve. Shoulder hold on body hole.

In Patent Document 2, the air-to-earth seal functions through the gasket provided between the valve body and the resin valve seat ring, and the shaft seal functions through the clamping device provided on the secondary side in the axial direction of the air-to-earth seal. .

In this way, in these valves, the sky-earth seal as the primary seal and the first shaft seal to the valve rod as the secondary seal are provided in separate structures, and the sky-earth seal and the shaft seal are provided at each sealing location.

On the other hand, in the butterfly valves of Patent Documents 3 to 5, the structure utilizes the pressing force by the spring for air and earth sealing.

In the butterfly valve of Patent Document 3, the cylindrical plug is rebounded to the side of the boss by the spring, thereby implementing a world seal as a primary seal between the resin valve seat ring and the valve body. The O-ring between the plug and the resin seat ring is provided with a shaft seal as a secondary seal.

In the butterfly valve of Patent Document 4, the pressing ring is pressed by the coil spring, and the space seal and the shaft seal function through the seal ring pressed by the pressing ring.

In Patent Document 5, an elastic body as a sealing member is pushed in the axial direction via a bearing member pressed by a spring, and the space seal and the shaft seal function through the elastic body.

In addition, in the butterfly valve 1 shown in FIG. A resin valve seat ring 5 is assembled on the peripheral surface. Further, the resin lining layer 3 is extended in the axial direction along the valve rod 6 assembled on the valve body 4 to form a valve rod covering part 7, and the resin valve seat ring 5 is arranged on the outer peripheral surface of the valve rod covering part 7 along the The extension covering part 8 is extended by the valve rod 6, thereby ensuring the sealing performance.

In addition, in the butterfly valve, it is known that when fluid pressure is applied from the primary side in the valve-closed state, the valve body is slightly moved toward the secondary side by the fluid pressure. For example, in a butterfly valve with a nominal diameter of 100A, when a hydraulic pressure of 1.0 MPa is applied from the primary side in the valve-closed state, the valve body moves about 0.2 mm toward the secondary side.

Patent Document 1: Japanese Patent Application Laid-Open No. 52-90815.

Patent Document 2: Japanese Patent No. 3863563.

Patent Document 3: Japanese Patent Application Laid-Open No. 61-119881.

Patent Document 4: Japanese Publication No. 58-56463.

Patent Document 5: Japanese Patent No. 2920364.

In the butterfly valves of Patent Documents 1 and 2, both the air-to-earth seal and the shaft seal are installed independently of the spring. In Patent Document 1, the diameter of the valve body is larger than the inner diameter of the resin valve seat ring. In Patent Document 2, With the help of the gasket between the valve body and the resin valve seat ring, the heaven and earth seal functions respectively. Due to such a structure, when the airtightness decreases due to deterioration due to temperature change or aging of the lining resin, the airtight seal cannot be recovered by the rebound force of the spring against the airtightness degradation. Therefore, it is difficult to maintain airtightness and shaft tightness.

On the other hand, in the butterfly valves of Patent Documents 3 to 5, the space-to-ground seal by the spring can be restored by the rebound force of the spring, but each has the following problems.

The butterfly valve of Patent Document 3 has a structure using an O-ring for secondary sealing, and when a rubber-like material is used as the O-ring, it cannot be used for corrosive fluids such as chlorine. Therefore, secondary sealing cannot be ensured, and the use of the valve is limited.

In the butterfly valve of Patent Document 4, the pressing force of the coil spring is decomposed by the tapered surface on the pressing ring and the sealing ring in the direction of air-to-earth sealing and the direction of shaft sealing. Therefore, if the sealing force on one side is strengthened, Then the sealing performance on the other side becomes weak, and the sealing force of both sides cannot be effectively improved. In addition, it is also necessary to perform an adjustment to maintain these spacer seals and shaft seals in a well-balanced manner, and this adjustment also becomes difficult.

Also in Patent Document 5, the pressing force of the spring is divided into the primary seal and the secondary seal by the taper force of the elastic body, so it has the same problem as Patent Document 4.

In addition, in Patent Documents 1 to 5 and the butterfly valve 1 shown in FIG. 9 as a comparative example, when fluid pressure is applied from the primary side to the butterfly valve 1 in FIG. 9 in a fully closed state, as shown in the figure, When the valve body 4 moves to the secondary side as shown, the resin lining layer 3 also moves to the secondary side. In this case, the upper and lower sides of the resin lining layer 3 are biased toward the secondary side with respect to the resin valve seat ring 5 , and the adhesiveness is deteriorated. The airtightness of the periphery of the side valve rod 6 and the valve box 9, that is, the airtightness is lowered, and so-called primary leakage may occur.

Furthermore, in FIG. 9 , as the valve body 4 moves, the valve rod 6 moves to the secondary side, whereby the adhesiveness between the valve rod covering portion 7 and the extended covering portion 8 also deteriorates, and these valve rod covering portions 7 The sealability between the valve rod 6 and the valve box 9 achieved by the extended covering portion 8 , that is, the shaft sealability of the valve rod 6 is lowered, and so-called secondary leakage may occur.

Contents of the invention

The present invention was developed to solve the conventional problems, and its object is to provide a butterfly valve which is a liner-type butterfly valve having corrosion resistance to fluids and which can simultaneously improve airtightness and shaft sealing. On the other hand, leakage is reliably prevented, and the sealing performance can be maintained even when the valve disc moves to the secondary side due to fluid pressure.

In order to achieve the above object, the invention related to technical solution 1 is a lined butterfly valve, which is a butterfly valve in which a valve disc is freely opened and closed via a valve stem in a cylindrical valve body. Covered by the valve seat lining, the valve disc is covered by the lining part, and the shaft sealing part of the valve stem is sandwiched between the ring body and the valve stem, thereby preventing the diameter expansion of the shaft sealing part, and the The rebound force of the spring in the shaft mounting part pushes the valve seat lining on the boss surface of the valve disc through the ring body, thereby maintaining the airtightness of the sealing part of the valve disc.

The invention related to Claim 2 is a liner type butterfly valve, in which the spacer sealing part strongly presses the position near the outer periphery of the spacer sealing boss surface of the valve disc.

The invention related to claim 3 is a liner type butterfly valve in which the ring body presses the valve seat liner via the ring-shaped flange portion of the seal bush provided at the shaft seal portion.

The invention related to claim 4 is a liner type butterfly valve in which a tapered surface inclined downward toward the outer diameter is provided on the bottom surface of the annular flange portion.

The invention related to claim 5 is a liner type butterfly valve, in which a thick seal is provided on the inner periphery of a cylindrical liner, and the thick seal is pressed against the outer periphery of the liner of the shaft cylinder. The shaped lining part is extended on the valve seat lining, and the shaft cylinder lining part is extended on the lining part of the valve disc.

The invention related to claim 6 is a liner type butterfly valve in which a tapered portion having a mountain-shaped cross-section is formed on the thick-walled sealing portion.

The invention related to claim 7 is a liner-type butterfly valve in which a cylindrical portion formed on a sealing bush is sandwiched between a cylindrical liner portion and a ring body, and the ring body prevents the cylindrical liner from The expansion of the part.

The invention related to claim 8 is a liner type butterfly valve in which an O-ring inserted in a cylindrical portion of a seal bush is brought into sliding contact with a cylindrical liner portion of a seat liner.

The invention related to claim 9 is a liner type butterfly valve in which a valve stem and a valve disc are formed separately.

The invention related to claim 10 is a lined butterfly valve in which the flow path port and the flange portion of the short cylindrical valve body are covered with a valve seat lining, and at the edge portion of the flange portion on the flow path side, , There is a movement space where the valve seat liner can follow the movement when the fluid depresses the valve disc and the valve stem moves slightly to the secondary side when the fluid is fully closed.

The invention related to claim 11 is a liner type butterfly valve, wherein the liner portion includes a boss surface covering the upper and lower boss portions of the valve disc, and a sleeve lining portion covering the outer periphery of the valve stem from the boss surface, And the valve seat lining extends up and down with a sealing surface extending from the flange part in the flow path part and sealingly connected with the boss surface, and a cylindrical lining part sealingly connected with the outer periphery of the shaft cylinder lining part from the sealing surface, and By following the movement of the valve disc to the secondary side, the movement of the flow path of the valve seat lining from the moving space maintains the air-to-earth seal between the boss surface and the sealing surface, and the shaft between the shaft cylinder lining and the cylindrical lining. Hermetic tightness.

The invention related to claim 12 is a liner type butterfly valve in which the movement space is a tapered surface formed by notching the edge of the flow path opening of the valve body on the end surface side of the valve body.

The invention related to claim 13 is a liner type butterfly valve, in which the movement space is a step surface formed by notching the edge of the flow path opening of the valve body in a step shape.

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

According to the invention related to claim 1, the cylindrical valve body covered by the valve seat liner and the valve disc covered by the liner are corrosion-resistant to the fluid, and the valve located on the valve disc is pushed through the ring body by the rebound force of the spring. The valve seat lining on the boss surface of the sky and earth maintains the airtightness of the air and earth sealing part, thereby improving the air and earth airtightness as a primary seal, and at the same time, sandwiching the shaft sealing part of the valve stem between the ring body and the valve stem By preventing the diameter expansion of the shaft seal portion, the shaft seal performance can be improved. In this case, the earth-tightness and the shaft-tightness do not adversely affect each other, and both can be maintained to reliably prevent leakage. In addition, since the ring body can be used in common to ensure air-tightness and shaft-tightness, it is also advantageous to simplify the internal structure by suppressing an increase in the number of parts. The airtightness of the space is maintained by the rebound force of the spring, so even if the resin used as the lining material deteriorates due to temperature changes or aging, the airtightness can be restored. During assembly, the airtightness and shaft sealing performance can be improved to a predetermined sealing force by means of the assembly of the ring body, so there is no need to adjust the sealing forces, and the ring body is easy to install.

According to the invention related to claim 2, the vicinity of the outer periphery of the sealing boss surface of the valve disc is strongly pushed, thereby reducing the sliding resistance of the contact portion between the sealing boss surface and the valve seat lining, and can prevent the valve from opening. The airtightness can be improved while the closing operation torque is increased, and the airtightness can be maintained by using a spring.

According to the invention related to claim 3, the pressing force of the spring is transmitted from the ring body to the seat lining through the annular flange, thereby preventing The local deformation of the seat liner prevents damage to the seat liner and maintains airtightness.

According to the invention related to claim 4 , the tapered surface reliably and strongly presses the vicinity of the outer periphery of the sealing boss surface of the space of the valve disc to ensure space-to-ground sealing.

According to the invention of claim 5, the thick seal portion of the resin cylindrical liner is pressed against the outer periphery of the resin shaft liner, thereby reducing the frictional resistance and suppressing the opening and closing torque of the valve. rise and ensure shaft sealing.

According to the invention related to claim 6, the taper portion with a mountain-shaped cross section can easily disperse the stress accompanying the pressing against the barrel lining portion, and can also suppress local deformation of the thick seal portion and reduce the creep phenomenon. . Therefore, the shaft sealing performance is maintained to reliably prevent leakage.

According to the invention of claim 7 , the cylindrical lining portion can be pressed against the outer periphery of the shaft cylinder lining portion by the elastic force of the cylindrical portion of the seal bush, thereby maintaining the shaft sealing performance.

According to the invention related to claim 8, the space-to-ground seal structure using the spring is adopted, and the seal bush used in the space-to-ground seal can be used to prevent the diameter expansion of the tertiary sealing portion by the O-ring, so the seal bush can Realize the common use of parts, and improve the tertiary sealing performance while maintaining the shaft sealing performance.

According to the invention related to claim 9, after the valve disc with the liner is installed in the cylindrical valve body covered with the seat liner, the sealability of the shaft sealing portion can be ensured only by inserting the valve stem into the valve disc. Therefore, the overall assembly work becomes easy, and the valve disc can be made compact by separating the valve stem, and the air-tightness and the shaft-tightness can be ensured.

According to the invention related to claim 10, even when the valve disc moves to the secondary side under the action of fluid pressure when the valve is closed, the valve seat liner can follow the movement through the movement space, and it is possible to prevent the gap between the valve seat liner and the lining portion. Maintain air-to-earth sealability by preventing primary leakage, and maintain shaft sealability by preventing secondary leakage, thereby being able to reliably seal fluids such as highly corrosive fluids, chemical fluids such as chlorine gas, and liquid medicine. In addition, only a moving space for the seat liner is required, so the processability and formability are also good, and it is possible to manufacture the seat liner, the liner portion, and the shape of the valve body while suppressing the complexity of the valve body shape. In addition, since the thickness of the seat lining and the valve disc lining can be ensured, the permeation resistance of the fluid can also be maintained.

According to the invention related to claim 11, the flow path portion of the valve seat lining moves through the movement space following the movement of the valve disc to the secondary side, whereby the sealing surface and the cylindrical lining portion can move toward the secondary side with the valve disc relative to each other. The boss surface and the barrel liner that move on the secondary side follow and maintain a sealed state. Therefore, it is possible to prevent the primary leakage between the boss surface and the sealing surface and maintain the airtightness of the valve body and the valve disc, and prevent the secondary leakage between the shaft cylinder lining part and the cylindrical lining part to maintain the airtightness of the valve body and the valve disc. Excellent shaft sealing can reliably prevent fluid leakage.

According to the invention of claim 12, the flow path portion of the seat liner can be deformed without restricting it, and the flow path portion can be smoothly deformed along the tapered surface when the valve disc and the valve stem move to the secondary side. The seat liner follows, and it is also possible to prevent stress concentration at the contact portion of the seat liner with the valve body. The tapered surface can easily form a moving space on the valve body, so there is no need to process the seat liner, the formability is improved, and the thickness of the seat liner does not need to be thinned, so the resistance to fluids such as chlorine can also be maintained. Permeability.

According to the invention of claim 13, high precision is not required on the valve body side, and the stepped surface can be formed by simple processing, and the flow path of the valve seat lining can be reliably made to follow the valve disc through the stepped surface. and deformation of the way the secondary side of the stem moves. This eliminates the need to process the valve seat lining, so formability is improved, and it is not necessary to reduce the thickness of the valve seat lining, so the permeation resistance to fluids such as chlorine can also be maintained.

According to the invention related to claim 14, the taper space can be provided simultaneously with the forming process of the seat liner without processing the valve body, so that an increase in the number of work steps for forming the taper space can be suppressed. Through the taper space, the flow path portion of the seat liner can be reliably deformed so as to follow the secondary-side movement of the valve disc and the valve stem.

Description of drawings

Fig. 1 is a central longitudinal sectional view showing an embodiment of a liner type butterfly valve according to the present invention.

Fig. 2 is a central longitudinal sectional view of the liner type butterfly valve of Fig. 1 .

Fig. 3 is an enlarged cross-sectional view of a main part of Fig. 2 .

Fig. 4 is a partially enlarged cross-sectional view showing the vicinity of a thick-walled sealing portion.

Fig. 5 is a partially enlarged cross-sectional view showing the vicinity of a seal bush.

6 is an enlarged cross-sectional view of main parts showing a state in which the valve disc of FIG. 3 has moved to the secondary side.

7 is an enlarged cross-sectional view of a main part showing a second embodiment of the liner type butterfly valve of the present invention.

Fig. 8 is an enlarged cross-sectional view of main parts showing a third embodiment of the liner type butterfly valve of the present invention.

Fig. 9 is an enlarged sectional view showing a main part of a conventional butterfly valve.

Explanation of reference signs

10 Valve body

11 valve body

12 Disc

13 Stem

15 flow intersection

16 Flange

18 Shaft seal part

19 Heaven and earth seal

20 seat liner

22 ring body

23 Sealing bushing

23a Cylindrical part

23b ring flange

24 O-rings

26 Cone

27 Shaft mounting

30 Flow path

31 sealing surface

32 Lining

33 Shaft liner

34 Cylindrical lining

36 Boss

37 Convex table

40 cones (movement space)

42 thick wall seal

43 cone face

44 springs

51 Step face (move space)

61 Cone space (move space).

detailed description

Hereinafter, embodiment of the liner type butterfly valve of this invention is demonstrated in detail based on drawing. 1 and 2 show an embodiment of a butterfly valve according to the present invention, and FIG. 3 shows an enlarged sectional view of a main part of FIG. 2 .

In Fig. 1 and Fig. 2, the butterfly valve (hereinafter referred to as the valve main body 10) is used, for example, in chemical industry facilities or food-related pipelines, etc., and has a cylindrical valve body 11, a valve disc 12, and an upper part The stem 13 constituted by the stem 13a and the lower stem 13b is provided with a nominal diameter of 100A. As will be described later, in the valve main body 10, there are provided a cylindrical lining portion 34 having the valve seat lining 20, a shaft cylinder lining portion 33 of the lining portion 32, a shaft sealing portion 18 of the sealing bush 23, and a cylindrical lining portion 34 having the lining portion 32. Boss surface 37, sealing surface 31 of valve seat liner 20, sealing part 19 of heaven and earth.

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

The valve seat liner 20 is made of a resin material. In the present embodiment, a fluororesin such as PFA (tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer) is used to have a thickness of about 3 mm. High corrosion resistance and heat resistance. In the valve seat liner 20, a flow path portion 30 movable in the flow path direction is formed on the flow path opening 15 side, and the flow path portion 30 is extended from the flange portion 16, and a sealing surface 31 is provided on the inner peripheral side. A cylindrical lining portion 34 capable of sealingly connecting with the outer periphery of a shaft cylinder lining portion 33 described later extends from the sealing surface 31 in the axial direction of the upper and lower shaft mounting holes 21 .

In FIG. 3 and FIG. 4 , the cylindrical liner 34 is composed of a cylindrical portion, and is integrally extended on the side of the valve seat liner 20 where the valve stem 13 is inserted, and a thick wall is formed in a ring shape on the inner periphery of the cylindrical liner 34 Sealing portion 42 .

The thick seal portion 42 protrudes to a size capable of pressing the outer periphery of the barrel lining portion 33 . A tapered portion 43 having a mountain-shaped cross section is formed on the thick seal portion 42 , and the taper angle of the tapered portion 43 is set within a range of, for example, 8° to 15°. The thick seal portion 42 is in contact with the outer circumference of the barrel lining portion 33 , and when the valve stem 13 is inserted into the barrel lining portion 33 , it is press-contacted by the outer diameter side of the barrel lining portion 33 and tightly contacted. The shaft sealing state of the shaft sealing point 18 can thus be obtained.

In FIGS. 1 to 3 , the valve disc 12 is formed separately from the valve stem 13 , and is rotatably provided in the valve body 11 via the valve stem 13 . A metal core 35 is provided on the center side of the valve disc 12, and the metal core 35 is formed into a disk shape by, for example, a stainless steel alloy. The lining portion 32 formed of a resin material such as a fluororesin such as PFA is covered with a thickness of, for example, 3 mm.

The lining part 32 has a boss surface 37 that covers the boss part 36 formed on the peripheral surface of the valve stem insertion hole 12 a formed on the upper and lower sides of the valve disk 12 on the heaven and earth side of the valve disk 12 . The shaft cylinder lining part 33 is composed of the shaft cylinder part on the shaft sealing side that can cover the outer circumference of the valve rod 13 from the boss surface 37; The holes 35 a integrally cover the outer peripheries of the front and back surfaces of the metal core 35 , thereby preventing detachment from the metal core 35 .

A square hole 38 is formed on the heaven and earth side of the stem insertion hole 12a of the valve disc 12, and the connecting side of the upper stem 13a and the lower stem 13b is inserted and fitted from the square hole 38, and the upper stem 13a, The lower valve stem 13b, the valve disc 12 covered by the liner 32 are rotatably mounted on the valve body 11 covered with the seat liner 20 . Assembling becomes easy by making the valve rod 13 and the valve disc 12 into separate structures in this way.

A cylindrical bearing 25 is provided on the outer peripheral side of the valve stem 13 of the shaft mounting hole 21, and a metal cylindrical ring body 22 is sandwiched between the bearing 25 and the valve seat lining 20 located below. set up.

The ring body 22 is provided with a diameter such that the position near the outer periphery of the sealing boss surface 37 of the valve disc 12 can be strongly pressed from the upper side by a stainless steel material, and in a state where the valve disc 12 can rotate, the figure can be transmitted through the bearing 25. The rebound force of the spring 44 of 1 is set.

In FIG. 1 , in the shaft mounting hole 21 of the upper valve body 11 a, a bearing member 70 is arranged in a state locked by a retaining ring 71 , and the spring 44 is supported by the bearing member 70 in a state capable of rebounding downward. On the other hand, in the shaft mounting hole 21 of the lower valve body 11b, the stopper member 72 is arranged in a state of being locked by the retaining ring 71, the bearing member 73 is superimposed on the stopper member 72, and through the bearing member 73, The spring 44 is supported in a state capable of rebounding upward. By means of these bearing components 70, 73 and the stopper component 72, the upper and lower springs 44, 44 rebound towards the direction of the valve disc 12 respectively. On the inner and outer peripheries of the bearing member 70 or the stopper member 72, O-rings 74 and 75 for dustproof and waterproof are mounted, respectively.

The bearing 25 is arranged between the spring 44 of the shaft mounting hole 21 and the ring body 22. With the help of the bearing 25, the upper valve stem 13a and the lower valve stem 13b can be rotated freely in the vicinity of the three seals (near the O-ring 24). And it is supported in a self-aligning state. The bearing 25 has a two-layer structure in which a metal-backed resin multilayer bearing 25b is mounted on the inner periphery of a bearing bush 25a made of metal such as stainless steel.

The bearing bush 25a has an outer diameter on which the spring 44 abuts and exerts its repulsive force. When the repulsive force is applied, the end face side abuts the ring body 22 and is installed so as to push the ring body 22 toward the valve disc 12 side. In this case, the valve disc 12 side end surface of the bearing bush 25a may also be in contact with the end surface of the seal bush 23, but it is not necessary to apply a pressing force to the seal bush 23 from the bearing bush 25a.

In this embodiment, a slight gap (not shown) is provided between the lower surface of the bearing bush 25 a and the upper surface of the seal bush 23 , so that the seal bush 23 is not pressed by the bearing 25 . In addition, a structure in which the coil body 22 is directly pressed by the spring 44 without passing through the bearing 25 may also be adopted.

The sealing bush 23 is composed of a flange-shaped part, and is formed of resin materials such as PTFE (polytetrafluoroethylene) containing carbon fiber, and is used as a sealing part between the ring body 22 of the shaft mounting hole 21, the lining part 32 and the valve seat lining 20 set up. In FIG. 3, a cylindrical portion 23a is formed on the sealing bush 23, and a flange portion 23b is formed on the lower side of the cylindrical portion 23a. The protruding part is formed. The end surface 22a of the ring body 22 abuts on the flange portion 23b, whereby the ring body 22 presses the valve seat liner 20 via the flange portion 23b.

According to this structure, even if the sealing performance of the ground seal part 19 or the shaft seal part 18 is reduced due to severe use of the valve, etc., and fluid infiltrates between the seat liner 20 and the seal bush 23, the resin seal bush The flange portion 23b of the ring body 23 is also strongly pressed against the resin valve seat liner 20 by the ring body 22, so this pressed portion prevents leakage called so-called backside leakage. Therefore, the ring body 22 made of metal will not come into contact with corrosive fluid, the rebound force of the spring 44 will be increased, and the valve seat liner 20 will be pushed through the ring body 22 to restore the air-to-earth seal.

Here, as shown in FIG. 5 , on the bottom surface of the flange portion 23b, a tapered surface 26 descending and inclined toward the outer diameter is provided at an angle θ, so that when the sealing bush 23 shown in FIG. , it is also possible to abut against the valve seat liner 20 near the outer diameter portion of the bottom surface of the flange portion in FIG. 5 .

In addition, although not shown in the figure, when the fluid is not corrosive, a structure in which the ring-shaped flange portion of the ring body 22 is formed so that the lower side of the ring body 22 is bent toward the inner peripheral direction may be used. , The seat liner 20 is directly pushed with the ring body 22 . In this case, the flange portion 23 b is not required for the seal bush 23 , and the cylindrical portion 23 a may be disposed above the annular flange portion of the ring body 22 .

The seal bush 23 is assembled so that the cylindrical portion 23 a is sandwiched between the cylindrical lining portion 34 and the ring body 22 , and the diameter expansion of the cylindrical lining portion 34 is prevented by the ring body 22 via the cylindrical portion 23 a.

With such a structure, in the valve main body 10 shown in FIG. 1 , the spring 44 disposed in the shaft mounting portion 27 of the valve body 11 uses the rebound force to push the boss surface 37 located at the top and bottom of the valve disc 12 through the ring body 22 . The upper valve seat liner 20, thereby maintaining the airtightness of the heaven and earth seal portion 19 as a primary seal.

And, the shaft sealing part 18 having the cylindrical lining part 34 of the valve stem 13, the shaft cylinder lining part 33 and the sealing bush 23 is clamped between the ring body 22 and the valve stem 13, thereby preventing the shaft sealing part 18 from being damaged. The shaft seal portion 18, which is the sliding contact portion, is expanded in diameter and functions as a secondary seal.

Furthermore, in FIG. 3 , a holding portion 23 c is provided above the cylindrical portion 23 a of the seal bush 23 , and an O-ring 24 is inserted into the holding portion 23 c. As a result, an O-ring 24 is installed above the shaft seal portion 18 (secondary seal), and the O-ring 24 is in sliding contact with the sleeve lining portion 33 , and these sleeve lining portions 33 (upper valve stem) 13a, the lower stem 13b) and the sliding contact portion of the O-ring 24 functions as a triple seal. The holding portion 23 c is set at a height capable of forming a gap X with the cylindrical lining portion 34 .

In FIG. 3 , the vicinity of the upper side of the valve disc 12 of the valve main body 10 is shown, but the lower side of the valve disc 12 also has the same structure as the upper side.

In addition, in the above-mentioned embodiment, the ring body 22 is provided with stainless steel, but it may also be provided with other metal materials, or as long as the ring body 22 side (near the outer periphery of the valve disc 12) can be moved when the bearing 25 is pressed. ) to push strongly, and materials other than metal materials may be used.

In addition, although a coil spring is used as the spring 44, it is not limited to this, For example, a valve coil spring may be used as a spring.

Next, the assembly procedure of the valve main body will be described. When assembling the valve main body 1, it is assumed that the upper and lower sides are assembled in the same manner.

In FIGS. 1 and 2 , first, the valve disc 12 covered by the liner portion 32 is installed inside the valve seat liner 20 . At this time, the upper and lower sleeve liner portions 33 of the valve disc 12 are respectively inserted into the cylindrical liner portions 34 of the valve seat liner 20 .

Next, the seal bush 23 with the O-ring 24 fitted on the holding portion 23 c is fitted to the outer periphery of the cylindrical liner portion 34 . At this time, the flange part 23b is fitted in the outer peripheral side of the cylindrical lining part 34, and it inserts so that the upper O-ring 24 may abut the outer periphery of the cylindrical lining part 33 in FIG.

On the outer periphery of the seal bush 23, the ring body 22 is fitted while bringing the bottom surface into abutment on the upper surface of the flange portion 23b. Thereby, the metal ring body 22 holds the cylindrical portion 23 a and the holding portion 23 c of the seal bush 23 from the outer peripheral side, and prevents the diameter expansion of the thick seal portion 42 of the cylindrical lining portion 34 .

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

On the other hand, in each shaft mounting hole 21 of the upper valve body 11a and the lower valve body 11b, the bearing 25, the spring 44, the bearing parts 70, 73, and the stopper parts 72 are assembled to corresponding positions respectively, and the bearing part 70 The stopper members 72 are respectively prevented from loosening by being locked by the retaining ring 71 .

Finally, between the upper valve body 11a and the lower valve body 11b, the aforementioned valve seat liner 20 with the valve disc 12, the sealing bush 23, and the ring body 22 is arranged, and the bolt 14 is tightened in a sandwiched state. Integrating, the assembly of the valve main body 10 is completed.

In FIG. 6 , when fluid pressure is applied from the primary side when the assembled valve body 10 is fully closed, the valve disc 12 and the valve stem 13 are slightly moved toward the secondary side when the fluid pressure is applied. When the fluid pressure of 1.0MPa is exceeded, the valve disc 12 moves to the secondary side by about 0.2mm. In the valve main body 10, as shown in FIG. 3 , at the position of the edge portion of the flange portion 16 on the flow path portion 30 side, there is provided a movement space in which the valve seat liner 20 can follow the movement of the valve disc 12 as described above. 40.

By the movement of the flow path portion 30 of the valve seat liner 20 following the movement of the valve disc 12 to the secondary side by the movement space 40, the air-to-earth seal between the boss surface 37 and the sealing surface 31 and the shaft liner portion are maintained. 33 and the cylindrical liner part 34 for shaft sealing.

The movement space 40 is provided by a tapered surface formed by notching the edge of the flow path port 15 of the valve body 11 on the end surface side of the valve body 11 , and the flow path portion 30 is deformable within the movement space 40 . Therefore, the tapered surface 40 is set at a predetermined angle as follows: the flow path portion 30 can follow the movement of the valve disc 12 to the secondary side to maintain the air-to-earth seal and the shaft seal, and the lateral movement dimension in FIG. 3 is the maximum movement of the valve disc 12. distance. In the present embodiment, an angle is set at which the following movement space 40 can be ensured between the valve body 11 and the valve seat liner 20 : as described above, the valve disc can move with a maximum width of 0.2 mm in the lateral direction by a fluid pressure of 1.0 MPa. move up. When the lateral movement dimension of the flow path portion 30 is too large, the flow path portion 30 may move excessively and adversely affect the sealing of the valve blade side of the valve disc 12 , so caution is required.

Furthermore, it is also possible to adjust the angle of the tapered surface 40 to set the movement amount of the flow path portion 30. By finely adjusting the movement amount by a small amount, the flow path can be set according to the valve body 10 acting on different calibers and fluid pressures. The amount of movement of the portion 30 maintains airtightness and shaft tightness.

The tapered surface 40 is formed along the flow port 15 of the valve body 11, and its outer diameter is set to be equal to or less than the inner diameter of the gasket 41 shown in FIG. At the connection part of the external piping. Thus, the tapered surface 40 is not adjacent to the sealing surface 41a of the gasket 41 in the flow path direction, and even if fluid pressure is applied to the sealing surface 41a of the gasket 41, the flange portion of the seat liner 20 is not affected. Since the gasket 41 deforms, it is possible to maintain the sealability with the external piping by the gasket 41 .

In this case, in FIG. 2, the right side is defined as the upstream side, and the left side is defined as the downstream side. However, in the case of a valve body 1 having a bilaterally symmetrical structure as shown in the figure, the left side may be defined as the upstream side. , let the right side be the downstream side.

The aforementioned moving space 40 does not necessarily need to be formed on the valve body 11 , and may also be formed on the valve seat liner 20 . In this way, the movement space 40 may be provided on either or both of the seat liner 20 and the valve body 11, and in either case, the movement space 40 can be formed in various shapes other than the tapered surface.

Next, the operation of the above-mentioned embodiment of the liner type butterfly valve of the present invention will be described.

In FIG. 3 , in the fully closed valve body (nominal diameter 100A) 10, the rebound force of the spring 44 is used to push the valve seat lining 20 on the boss surface 37 of the valve disc 12 through the ring body 22, thereby This can maintain the air-to-earth seal performance as a primary seal brought about by the air-to-earth seal portion 19 having the boss surface 37 and the sealing surface 31, and even if deterioration occurs in the valve seat lining 20 or the lining portion 32, the spring can be used. The 44's rebound force restores the airtightness.

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 airtight side of the valve disc 12 via the ring body 22 . Therefore, while suppressing an increase in the operating torque, the boss surface 37 and the sealing surface 31 are brought into intensive close contact, whereby a predetermined air-to-earth sealing performance can be obtained.

The shaft seal part 18 is sandwiched between the ring body 22 and the valve stem 13 to prevent the diameter expansion of the shaft seal part 18, thereby ensuring a secondary seal without adversely affecting the airtightness. The shaft sealing performance brought by the shaft cylinder lining part 33 and the cylindrical lining part 34. Thereby, the airtightness of both can be improved without degrading either airtightness or shaft airtightness, and an increase in the number of parts can be suppressed.

The sealing surface 31 of the seat liner 20, the cylindrical liner 34, the boss 37 of the liner 32, and the shaft liner 33 are integrally formed of resin, so that they maintain good corrosion resistance against corrosive fluids such as chlorine.

To describe the sealing performance of each sealing part more specifically, in the air-to-earth sealing part 19, the ring body 22 concentrically arranged on the outer circumference of the upper valve stem 13a and the lower valve stem 13b pushes the valve by the rebound force of the spring 44. The seat liner 20 maintains airtightness. At this time, the air-to-earth seal portion 19 is strongly pressed near the outer periphery of the air-to-earth boss surface 37 of the valve disc 12, thereby reducing the size of the valve disc 12 and the valve body compared with the case of pushing the entire boss surface 37. The sliding resistance of the seat liner 20 is maintained, and the primary sealing performance is maintained to prevent the increase of the opening and closing operation torque of the valve.

In addition, a sealing bush 23 is provided at the shaft sealing portion 18, and the valve seat lining 20 is pushed through the flange portion 23b of the sealing bush 23, so that the end surface 22a of the ring body 22 does not directly push the valve seat lining 20, but The sealing bush 23 made of resin presses the seat liner 20 and transmits the pressing force from the ring body 22 to the seat liner 20 side via the flange portion 23b so as to prevent stress concentration. Therefore, local deformation of the seat liner 20 can be prevented compared with the case where the metal ring body 22 is directly pressed.

Furthermore, the flange portion 23b and the valve seat lining are strongly pressed by the ring body 22, whereby these abutting portions also function as sealing portions, and this pressing portion serves as a function of preventing the above-mentioned leakage called backside leakage. parts function.

Here, as shown in FIG. 5 , on the bottom surface of the flange portion 23b, a tapered surface 26 with an angle θ is provided in a downwardly inclined manner, and on the outer diameter side of the tapered surface 26, the vicinity of the outer periphery of the valve disc 12 is more concentrated in a ring. The air-tightness can be further improved by pushing the air-tightness strongly.

On the other hand, in the shaft seal portion 18, the cylindrical lining portion 34 is in sliding contact with the shaft cylinder lining portion 33, and at this time, the thick-walled seal portion 42 on the inner periphery of the cylindrical lining portion 34 is pushed against the shaft cylinder lining portion. 33 on the periphery and function. Accordingly, high sealing performance can be obtained locally, and leakage between the cylindrical lining portion 34 and the shaft cylinder lining portion 33 can be prevented. The thick seal portion 42 is a resin integrally formed on the cylindrical liner portion 34 , so these secondary seals are in sliding contact with each other. Therefore, if a resin material with a small friction coefficient such as fluororesin is used as these materials, the friction can be greatly reduced compared with the case where the resin cylindrical liner 34 is directly pressed against the metal valve stem 13. The resistance prevents the rise of the opening and closing operation torque of the valve.

A tapered portion 43 with a mountain-shaped cross-section is formed on the thick-walled sealing portion 42, whereby the boundary portion between the tapered portion 43 and the cylindrical lining portion 34 expands in the shape of a mountain foot, and it is easy to press against the cylindrical lining portion 33. stress distribution. This suppresses local deformation of the thick seal portion 42 and also reduces the creep phenomenon to prevent a decrease in sealing performance. When the valve stem 13 is attached to the valve disc 12 , the valve stem 13 can smoothly pass over the thick seal portion 42 and be inserted into the valve disc 12 . When the valve seat liner 20 is manufactured, the thick seal portion 42 protrudes inwardly of the cylindrical liner portion 34 , but the mountain-shaped cross-section of the tapered portion 43 does not hinder removal of the molding die.

In order to sandwich the shaft seal portion 18 as described above, prevent the diameter expansion of the thick-walled seal portion 42 with the ring body 22, and maintain the sealing performance of the secondary seal, the ring body 22 is arranged between the thick-walled seal portion and the thick-walled seal portion as in this embodiment. The opposite position of 42 gets final product. In the present embodiment, in FIG. 4 , the height of the disc-side end portion 42 a of the thick seal portion 42 is set to substantially coincide with the height of the end surface 22 a of the ring body 22 .

The cylindrical portion 23a is sandwiched between the cylindrical liner portion 34 and the ring body 22, and the diameter expansion of the cylindrical liner portion 34 is prevented by the ring body 22 through the cylindrical portion 23a, so that the thick-walled sealing portion 42 is reliably moved toward the shaft. The cylinder liner part 33 is pressed, and the elastic force of the resin-made cylindrical part 23a is further utilized, thereby further improving the shaft sealing performance.

On the tertiary sealing side, the O-ring 24 inserted in the cylindrical portion 23a of the sealing bush 23 is brought into sliding contact with the cylindrical lining portion 34 of the valve seat lining 20, whereby the O-ring 24 can be made The pressing force makes sliding contact with the respective outer peripheries of the upper stem 13a and the lower stem 13b to ensure sealing performance and prevent three leaks from the periphery of the stem 13 . Furthermore, by incorporating the holding portion 23c in the ring body 22, the ring body 22 is also used to prevent the diameter of the holding portion 23c from expanding, so that parts can be shared and the shaft sealing performance can be further improved.

Furthermore, by virtue of the tertiary sealing function of the O-ring 24 around the valve stem 13, even when the valve disc 12 moves to the secondary side due to fluid pressure, tertiary leakage around the valve stem can be prevented. 23 Common use of parts, while preventing stress concentration and exerting the triple sealing function.

In FIG. 3 , when a fluid pressure of 1.0 MPa is applied from the primary side (right side in the figure) to the fully closed valve body (nominal diameter 100A) 10, the valve disc 12 and the valve stem 13 move toward the two sides. The secondary side (left side in the picture) has shifted slightly by about 0.2mm.

Here, the sealing surface 31 of the valve seat lining 20 is sealed with the boss surface 37 covering the boss portion 36 of the valve disc 12 to form a world seal, and the cylindrical lining portion 34 of the valve seat lining 20 and the outer periphery of the valve stem 13 are covered. The shaft cylinder lining part 33 of the valve seat lining 20 is sealed to form a shaft seal, so on the flow path part 30 of the valve seat lining 20, as the valve disc 12 and the valve stem 13 move to the secondary side, the sealing surface 31 and the cylindrical lining part are applied. 34 forces moving together to the secondary side.

At this time, a movement space 40 having a width of 0.2 mm is provided in advance on the valve body 11 at the edge position of the flange portion 16 on the flow path portion 30 side, so that the flow path portion 30 of the seat liner 20 is shown in FIG. 6 . As shown, it can be deformed within the range of the movement space 40 (maximum width 0.2 mm), and can move 0.2 mm to the secondary side following the movement of the valve disc 12 and the valve rod 13 to the secondary side.

Therefore, it is possible to maintain the respective airtightness of the sky-earth seal brought about by the boss surface 37 and the sealing surface 31 and the shaft seal brought about in the direction orthogonal to the flow path portion 30 of the valve seat liner 20 . The formed cylindrical liner portion 34 and the barrel liner portion 33 are brought together. Thereby, primary leakage on the side of the sky-earth seal and secondary leakage on the side of the shaft seal can be prevented.

In addition, by providing a movement space through the tapered surface 40 formed by notching the edge portion of the flow path port 15 of the valve body 11 on the end surface side of the valve body 11, the flow path portion of the seat liner 20 can be made to flow while preventing stress concentration. 30 moves, so consumption of the seat liner 20 can be suppressed.

Furthermore, by fitting the O-ring 24 to the inner periphery of the cylindrical portion 23 a of the seal bush 23 , tertiary leakage between the seal bush 23 and the barrel lining portion 33 can be prevented.

Next, a second embodiment of the liner type butterfly valve of the present invention is shown in FIG. 7 . In addition, after this embodiment, the same part as the said embodiment is denoted by the same code|symbol, and the description is abbreviate|omitted.

In the valve main body 50 of this embodiment, the edge portion of the flow path port 15 of the valve body 11 is notched in a step shape to form a circumferential step surface 51 , and the seat liner 20 is provided on the step surface 51 so that the valve seat liner 20 can follow and move. mobile space.

In this case, the flange portion 16 on the side of the valve body 11 can be notched at a predetermined depth to form the stepped portion surface 51, so the stepped portion surface 51 can be easily processed without requiring high precision. form. At this time, by forming the step surface 51 as shallow as possible, it is also possible to avoid stress concentration in the valve seat liner 20 in the vicinity of the boundary of the step surface 51 .

A third embodiment of the liner type butterfly valve of the present invention is shown in FIG. 8 . In the valve main body 60 of this embodiment, a tapered taper space 61 is formed as a notch at the connection portion between the flow path portion 30 of the valve seat liner 20 and the flange end, and the taper space 61 serves as a movement space.

In this case, the taper space 61 can be formed at one time on the valve seat liner 20 side during molding without processing the valve body 11, and it is more preferable to form the valve seat liner 20 in close contact with the valve body 11. By forming the tapered space 61, the influence of the permeation resistance with respect to a fluid can also be suppressed.

Claims (14)

1. a kind of lining type butterfly valve, it is to be opened and closed the butterfly valve for being provided with valve disc freely via valve rod in tubular valve body, institute State tubular valve body to be covered by valve seat lining, the valve disc is covered by lining portion, it is characterised in that

The sealing position of aforementioned stem is clamped between circle body and valve rod, the expanding of the sealing position is thus prevented, and And pushed with the bounce for the spring being located in the axle dress portion of foregoing valve body via foregoing circle body positioned at the world of foregoing valve disc Valve seat lining in boss face, thus keeps the sealing of the world sealing position.

2. lining type butterfly valve as claimed in claim 1, it is characterised in that

Foregoing world sealing position pushes the periphery neighbouring position in the seal boss face in the world of foregoing valve disc strongly.

3. lining type butterfly valve as claimed in claim 1 or 2, it is characterised in that

Foregoing circle body pushes foregoing valve seat lining via the ring-type flange department for the seal cartridge for being located at aforementioned axis sealing position.

4. lining type butterfly valve as claimed in claim 3, it is characterised in that

On the bottom surface of aforementioned cyclic flange department, it is provided with external diameter and declines the inclined conical surface.

5. such as lining type butterfly valve according to any one of claims 1 to 4, it is characterised in that

Inner circumferential in tubular lining portion sets heavy wall sealing, and the heavy wall sealing is pressed against on the periphery in beam barrel lining portion, The tubular lining portion is extended on foregoing valve seat lining, and the beam barrel lining portion is extended on the lining portion of valve disc On.

6. lining type butterfly valve as claimed in claim 5, it is characterised in that

The conical surface portion of section chevron shape is formed with foregoing heavy wall sealing.

7. the lining type butterfly valve as described in claim 5 or 6, it is characterised in that

Make to form the cylindrical portion on aforementioned seal bushing and be clipped between foregoing tubular lining portion and foregoing circle body, by foregoing circle body The expanding of foregoing tubular lining portion is prevented via foregoing cylindrical portion.

8. the lining type butterfly valve as any one of claim 3~7, it is characterised in that

The O-ring sliding contact in the cylindrical portion of aforementioned seal bushing is inserted in the tubular lining portion of foregoing valve seat lining in making On.

9. such as lining type butterfly valve according to any one of claims 1 to 8, it is characterised in that

Aforementioned stem and foregoing valve disc split are formed.

10. such as lining type butterfly valve according to any one of claims 1 to 9, it is characterised in that

The stream mouthful and flange part of the foregoing valve body of short tubular are covered with foregoing valve seat lining, the flow path portion in said flange portion At the edge part position of side, moved slightly to secondary side provided with the foregoing valve disc of fluid pressure that ought be when fully closed and aforementioned stem When, foregoing valve seat lining can follow mobile mobile space.

11. lining type butterfly valve as claimed in claim 10, it is characterised in that

Foregoing lining portion possesses the boss face of the boss portion covering above and below foregoing valve disc and is covered in from the boss face foregoing Beam barrel lining portion on the periphery of valve rod, and above and below foregoing valve seat lining be extended have from foregoing flange part in foregoing stream It is extended in portion and the sealing surface that is tightly connected with foregoing boss face and is sealedly attached to foregoing beam barrel lining from the sealing surface The tubular lining portion of the periphery in portion, and brought by foregoing valve disc is followed to the movement of secondary side by foregoing mobile space Valve seat lining flow path portion movement, maintain foregoing boss face and sealing surface world sealing and foregoing beam barrel lining portion with The sealing of the sealing in tubular lining portion.

12. the lining type butterfly valve as described in claim 10 or 11, it is characterised in that

Foregoing mobile space is the conical surface formed by end face lateral incision by the edge part of the stream mouthful of valve body in valve body.

13. the lining type butterfly valve as described in claim 10 or 11, it is characterised in that

Foregoing mobile space is the edge part by the stream mouthful of valve body with stage portion face formed by stage portion shape otch.

14. the lining type butterfly valve as described in claim 10 or 11, it is characterised in that

Foregoing mobile space is that the cone of the taper of the connecting portion office of the flow path portion and flange end that are located at foregoing valve seat lining is empty Between.