JP3272181B2 - Center type butterfly valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer type (thin type) flangeless center type butterfly valve, and more particularly, to a center type valve adapted to correspond to each bolt having a diameter of a bolt hole center circle of various flange standards. Related to butterfly valves.

[0002]

2. Description of the Related Art The main body materials conventionally used in this type of butterfly valve include cast iron, ductile cast iron, cast steel, stainless steel, and aluminum die cast. In particular, due to pressure, temperature, fluid, etc., it was liquid at low pressure and medium temperature, and as a specific example, water and the like were mainly used at less than 10 kg / cm ^{2 and} less than 100 ° C. Therefore, the material of the main body, which is the pressure-resistant part, is exceptionally specified from the regulation, but there is no need for a material having a very high strength.
This is mainly a cast or die-cast product.

[0003] However, the main parts of these cast products and die-cast products must be machined without fail, resulting in an increase in cost due to the processing time and labor costs involved. Although the product was improved, the working environment was never favorable. Furthermore,
In these castings, the dimensional accuracy of the unprocessed portion such as the outer shape was not uniform among the respective raw materials due to the production method, so that troubles often occurred.

On the other hand, in order to use a plurality of bolt holes having the diameter of the center circle of the bolt hole of the flange standard in the main body made of one casting, a centering guide hole is provided at the time of piping. Since the guide holes are not cast with high precision, the guide hole dimensions are large and the backlash is large, and various proposals have been made to improve these.

FIG. 11 shows an example of the above proposal.
(A) is a front view of a main part of the butterfly valve, and (b) is a diagram (a).
FIG. 3 is a sectional view taken along line XX of FIG. When a bolt is inserted into an intermediate hole of a long hole-shaped insertion hole formed in a bolt arrangement portion 1a of a valve body, which has been conventionally used, the valve body may fall down or be slanted. In order to eliminate the drawback that a reliable positioning connection cannot be made due to tilting, a long bolt-shaped insertion hole 2 that allows insertion of bolts at three or more types of positions is formed in the bolt installation portion 1a of the valve body 1, A thin insulator 3 that can be cut inward from the outermost peripheral edge of the bolt insertion hole 2 is integrally extended, and an insertion hole is formed at the cutting position.

According to this structure, by properly selecting the lower hole portion 2a and the intermediate hole portion 2b formed in the opening portion and having different diameters, the positioning connection of the valve body 1 with respect to different types of flanges can be performed. Further, by cutting the blocking portion 3 using a tool or the like, the bolt is positioned by the upper edge of the upper insertion hole 2c opening at the cut portion, so that it is possible to comply with further different flange standards. It has become. (See Japanese Utility Model Publication No. 3-39651)

[0007]

The above-mentioned proposal has a wafer-like, flangeless shape, and the bolt insertion hole (guide hole) 2 is also provided with a bolt mounting portion 1a corresponding to an upper shaft support portion. Therefore, there is a problem that centering is difficult depending on the posture (inverted or horizontal) of the piping.

The main components of the conventional butterfly valve are:
As shown in FIG. 9, both side edges of the elastic seat ring 4 are bent at right angles on the inner peripheral surface of the main body 1, and the ends 4 a are fitted into annular grooves 1 b formed on the side surfaces of the main body 1 to be integrated. In many cases, the operating conditions, that is, the differential pressure,
As shown in FIGS. 10A to 10C, the seat ring 4 fitted therein bulges in the inner diameter direction due to the flow rate, valve opening degree, vacuum, and the like, and the seat ring 4 However, there is a problem in that the contacts A and B at both ends of the flange are pulled, which causes cracks and breaks.

Further, as shown in FIG. 9, the end of the seat ring 4 of the conventional valve is sandwiched between the pipe flanges 6, so that depending on the shape of the end of the seat ring, as shown in FIG. This causes a problem that the rotational torque of the valve body becomes excessive, which makes it difficult to open and close the valve body.

[0010] In addition to the above-mentioned problems, as described above, the conventional one is mainly made of a cast product, so that the weight is heavy, the outer shape is not uniform, and machining is required. There was a problem that becomes.

The present invention solves the above-mentioned problems of the prior art, in which the body of the main body, which has conventionally been mainly made of a cast product, is made of a nylon-based resin material, and a plurality of bolt hole centers of a plurality of flange standards are provided. It can also serve as each bolt hole of the circle diameter, and has a reinforced body, ethylene
・ Sheet ring made of propylene rubber is integrated with the body
It is intended to provide a vulcanized butterfly valve.

[0012]

In order to achieve the above-mentioned object, the present invention is directed to a hollow cylindrical main body made of a resin material, and a rotatably supported pivot inside the main body. In a center type butterfly valve having an annular seat ring made of an elastic material mounted between the disc-shaped valve body made of a resin material and a peripheral portion thereof, the annular seat ring is made of ethylene propylene.
The main body is made of nylon resin.
The main body is integrally vulcanized, and an outer peripheral rib portion is integrally provided on the outer peripheral surface of the main body in the vicinity of the surface including the valve shaft axis, concentrically with the main body over the entire circumference excluding the main body shaft supporting portion. In the outer peripheral rib portion, a deformation hole is formed by combining each bolt hole for centering corresponding to each bolt having a diameter of a plurality of flange standard bolt hole center circles , and the main body and the annular seat ring are formed, Chemical joints formed integrally by vulcanization or concave and convex surfaces that fit together with the chemical joints and the joint surface parallel to the fluid passage are removed from the valve stem insertion portion.
The combination of physical bonding to form double-threaded removed, integrally vulcanization, improve the bonding strength, also the inner diameter of both end portions of the seat ring, and equal to the outer diameter of the pipe when the pipe, the shaft An inner diameter portion substantially equal to the inner diameter of the pipe and a flat diameter portion near the valve rod through-hole that is always in sliding contact with the valve body are sequentially formed inward in the direction through an inclined connection portion.

[0013]

The present invention is configured as described above.
According to the first aspect of the invention, the following operation is provided. That is, nylon (P) forming a wafer-type flangeless body is used.
A) A hollow cylindrical main body made of a resin material is sandwiched between pipe flanges provided on both sides, and is concentric with the main body in the vicinity of a surface including the center of the valve shaft on the outer peripheral surface of the main body, that is, in the center in the pipe axis direction. A plurality of flange holes for centering of an outer peripheral rib portion provided integrally over the entire circumference excluding the main body shaft support portion are integrally clamped by piping bolts through deformation holes obtained by combining bolt holes of a plurality of flange standards. At this time, the butterfly valve is JIS5K, 10K in the case of the domestic standard of the pipe flange, or DIN10K, BSNP10, ANSI125Lb in the overseas standard.
However, the bolt holes corresponding to the bolts of the diameter of the bolt hole center circle of these flange standards are not the same, and a deformed hole (multi-type bolt hole) that can correspond to the above-mentioned various flanges with one main body is used. ).

Further, the resin-made main body is reinforced by the outer peripheral rib portion provided integrally on the outer peripheral surface of the main body over the entire periphery except for the main-body supporting portion in a concentric manner with the main body, thereby improving the pressure resistance. In addition, from ethylene-propylene rubber-based elastic materials
The annular seat ring is vulcanized integrally with the body made of a nylon-based resin material, so that the seat ring is irrespective of fluid conditions such as pressure, temperature, valve opening, flow rate, and vacuum. The bulging in the inner diameter direction is prevented, the rotation of the valve body is performed smoothly, and the swing and breakage of the seat ring due to the rotation of the valve body are prevented.

The deformed hole formed in the outer peripheral rib portion integrally provided on the outer peripheral surface of the nylon-based resin body over the entire circumference is accurately formed by a molding die without complicated processing. Sulfur molding can be performed.

[0016] Also, the embodiments of the integrated vulcanization of the main body and the annular seat ring in action noted above, chemically bonding to vulcanize integrally molded with the body and an annular seat ring, said chemical bonding and fluid There is a mode of integrally vulcanizing by using together the physical joining of forming two- steps , excluding the valve rod insertion part, on the uneven surface that fits mutually on the joining surface parallel to the passage. The most secure and strong joint. In the above-mentioned chemical bonding, it is needless to say that a material having compatibility (affinity) between the resin material of the main body and the elastic material of the seat ring needs to be selected, and in the present invention, a nylon (PA) resin An ethylene-propylene rubber (EPDM) -based elastic material is used for the main body .

[0017] Also, the inner diameter of both end portions of the seat ring, and equal to the outer diameter of the pipe when the pipe, in its axially inward, and approximately equal to the inner diameter portion and the inner diameter of the pipe, is always sliding a valve element Since the flat diameter portion near the valve stem through hole is sequentially formed through the inclined connection portion, the seat ring is prevented from bulging in the inner diameter direction at the flange connection portion after piping, and the flat diameter portion is also formed. As a result, the bearing acts as a bearing for supporting the thrust in the valve stem direction acting on the valve element.

[0018]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention. The right half of the line YY is a longitudinal sectional view, and the left half is an external side view.

In [0019] FIG, 10, the body der of the butterfly valve is, a resin material of nylon (PA) system, a hollow substantially cylindrical shape forming a cylindrical fluid passage 11 therein, on both sides It has a wafer shape (thin shape) without a flange. Inside the main body 10, a disc-shaped valve body 12 for opening and closing a fluid passage 11 is rotatably supported by upper and lower valve rods 15, 16 guided and supported by upper and lower valve rod guides 13, 14. The valve body 12 is made of a resin material or a corrosion-resistant material.

[0020] Na by the inner to the peripheral surface, an annular seat ring 17 consisting et styrene <br/> · propylene rubber (EPDM) based elastic material is integrally (baking) vulcanization of the fluid passage 11
It is integrally joined to a main body 10 made of an iron-based resin material , and the outer peripheral edge of the valve body 12 comes into contact with and separates from the inner peripheral surface of the seat ring 17 to open and close the flow path.

At the position in the diameter direction of the valve body 12, the valve stem 1
The main body shaft supporting portions 10-1 and 10-2 are projected from diametrically opposed positions on the outer peripheral surface of the main body 10 through valve stem guides 13 and 14 that support the valve bodies 5 and 16. Joint 14
The upper valve stem 15 communicated by an appropriate method such as -1 extends outward from the main body shaft support 10-1 and is connected to a desired actuator (not shown). Valve stem 1
The gland packing 18 and the O-ring 19 are inserted into the valve stem guides 13 and 14 that support the shafts 5 and 16 to prevent external leakage, and the valve stem guides 13 and 14 are ejected by the holding plate 20 and the bottom cover 21. Has been prevented.

As means for integrally joining the main body 10 and the seat ring 17 to each other, in addition to the above-mentioned chemical means by calcination addition forming, the joint strength is obtained by using both the chemical means and the physical means. As the above-mentioned physical joining means, there are two inverted trapezoidal shapes 17E on the main body side except for the valve stem insertion portion on the outer peripheral portion of the seat ring 17 corresponding to the joining surface parallel to the flow path 11. It is formed so as to fit with the same-shaped recess. In addition to the inverted trapezoidal shape, as shown at 17F in FIG. 4, irregularities may be provided on the joint surface such as a mountain shape to fit each other.

The above-mentioned gland packing 18 is an O-ring case 18-1 as another embodiment as shown in FIG.
The O-ring 18-2 may be inserted into the inside to prevent external leakage from the valve stems 15, 16. In the same figure, a seat ring 17 protrudes by α from the main body shaft support 10-1 to serve as a gasket. Note that the protruding portion for this α is compressed and fixed in the main body 10 after the pipe connection as shown in FIG. 2, and this α portion serves as a compression allowance for the gasket, thereby preventing external leakage from the flange connection portion. .

On the other hand, the outer peripheral surface of the main body 10
In the vicinity of a plane including -Y, that is, in the central portion of the main body in the tube axis direction, an outer peripheral rib having a reinforcing function of the main body portion over the entire circumference excluding the main body support portion 10-1 concentrically with the main body 10. 10
As shown in FIGS. 5, 6, and 7, the outer peripheral rib 10-3 is provided with a centering hole corresponding to each bolt having a diameter of a bolt hole center circle of various flange standards. Deformed holes (multi-type bolt holes) obtained by combining the bolt holes are formed, and correspond to the various flanges.

As an example of this, FIG. 5 shows that the upper right quadrant is JIS 5K and the lower right quadrant is JIS 10 for the aperture of 80A.
K, the lower left quadrant represents DIN10K, and the upper left quadrant represents a deformed hole formed by combining bolt holes having the diameter of the bolt hole center circle of the three types of flange standards. Therefore, by forming the combined deformed hole on the entire surface, the above three types of flange standards can be met, and the same product can be produced in large quantities at low cost by the manufacturer. Regardless of the standard, it can be used for all applicable flange standards, which is convenient for procurement convenience and stock amount, and both can improve efficiency.

FIG. 6 shows a specific example for a diameter of 150A, and FIG. 7 shows a specific example for a diameter of 300A.
Depending on the diameter, for example, the deformation hole is relatively simplified at 150A (FIG. 6), but is more complicated at 300A (FIG. 7). However, these deformed holes are all opened by a molding die because the material of the main body 10 is made of resin, and there is no necessity for machining at all unlike a conventional casting.

The diameter of the bolt hole center circle and the size of the bolt hole in the above flange standard are roughly classified into JIS for Asian series, DIN and BS for European series, and ANSI standard for American series. Few of the dimensions match, and as an example, 80A, 150A and 300A are shown in Tables A, B and C below.

[0028]

In Tables A, B and C, the following 4
The point is important and I will add an explanation. PCD: diameter of bolt hole center circle (commonly referred to as pitch circle diameter) n: number of bolts h: bolt hole Bolt diameter: size of bolt diameter That is, the above numerical values are as shown in Tables A to C, but the left end Japan, the United States, and Europe represent the three major areas, and each has various flange standards.

FIGS. 5 to 7 show that three types of flanges having the greatest possibility of use among these various flange standards are selected and synthesized to produce three poles (worldwide). It can be commonly used.

FIG. 2 shows a state in which the pipes are connected.
The right side of the line is a sectional view, and the left side is a side view. In the figure, the same reference numerals as those shown in FIG. 1 indicate the same or similar parts. In the figure, when the valve body 10 is sandwiched between the pipe flanges 6 and the bolts 7 arranged on both sides, the amount of α at the end of the seat ring 17 (FIG. 3)
At the same time as it is compressed into zero.
2 have the same dimensions so that both outer surfaces abut the pipe flange 6 surface. That is, when the valve body is opened or closed, the rotating torque is applied to the main body shaft supporting portions 10-1 and 10-2 to be reinforced.

The both ends of the seat ring 17 are
By creating the large-diameter portion 17A and the small-diameter portion 17B, external leakage from the flange surface after piping is prevented, and the large-diameter portion 17A is made as large as possible within a range that does not interfere with various flange standards. As shown in FIG. 2, the outer diameter (SGP, OD) of the pipe 8 at the time of piping is equal to the outer diameter of the gas pipe as shown in FIG. Is prevented. Note that the outer diameter of all the steel pipes is the same, and they are used for high temperature and high pressure depending on the thickness.

The inner diameter 17C of the seat ring 17 is
The inner diameter of the pipe 8 is almost equal, and the flat diameter 17D is
The valve is formed to be slightly smaller than the size of 2, and the valve is opened and closed by the contact and separation of the valve body 12. The flat diameter 17D is a portion that causes external leakage via the valve stem 15, has a flat surface, and has a so-called thrust bearing effect.

FIG. 8 is a sectional view of a main part of a manufacturing apparatus for vulcanizing and molding an elastic seat ring to be integrally joined to the inner peripheral surface of a resin body of the butterfly valve according to the present invention.
The right side of the Z line represents the valve shaft hole, and the left side represents the outer diameter direction of the main body which is turned by 90 ° therefrom.

In the figure, the manufacturing apparatus is formed by integrally joining an upper mold 26 serving also as an elastic material injection container pushed out by a plunger 25 of an elastic injector, and a valve body 10 and an annular seat ring 17 therein. The molding middle mold 27 and the lower mold 28 having a molding space formed by molding are joined so as to overlap each other. The procedure of the manufacturing method is as follows.

(I) First, the outer diameter portion of the main body 10, that is, the main body outer diameter portion 10-4 is attached to the inner diameter portions 28 a and 28 b of the lower mold 28.
And the main body outer peripheral rib 10-3 part is fitted. in this way,
The outer diameter of the main body outer diameter portion 10-4 and the outer diameter portion of the main body outer peripheral rib 10-3 are closely fitted to the lower die 28 and the inner diameter portions 28a and 28b of the middle die described below, so that the main body can be accurately positioned in the mold. Will be set to Accordingly, it is possible to prevent the seat ring from being eccentric and becoming uneven in thickness, so that accurate fitting of the outer diameter portion of the main body outer diameter portion 10-4 and the outer diameter portion of the main body outer peripheral rib 10-3 into the lower mold is not required. This is the first necessary standard for the molding die during sulfurization.

(Ii) Next, the middle mold 27 is fitted into the outer diameter portion 10-4 of the main body 10 from above, and at the same time, is fitted into the central projection 29 of the lower mold 28 so that the lower mold 28 and the middle mold 27 are mutually connected. set. The joint surface 30 of the two molds 27 and 28 is formed at a position shifted to the side (downward in the figure) without coincident with the contact surface between the seat ring 17 and the valve body 12 when the valve is closed. The smaller and more precise the gap at the joining surface 30, the less burrs after vulcanization. Also, a valve rod hole forming die 31 is inserted from the outside of the valve shaft hole on the valve body shaft support 10-1 side,
Connected to the screw hole 32 of FIG.

(Iii) Next, the upper mold 26 of the elastic material injection container
Is inserted into the center of the middle mold 27, and the plunger 25 of the elastic injector is set. With this set, the injection holes 34 of the upper die 26 and the middle die 27 are configured to coincide with each other, so that the injection holes 34 formed from the injection holes 34 on the flange contact surface of the main body 10 form the seat ring forming space. A path is formed to be injected into location 36.

(Iv) After setting as described above, a predetermined amount of the elastic material 35 is put into the upper mold 26, and the plunger 25 is pushed down so that the elastic material 35 passes through the injection hole 34 and the middle mold 27.
And into the molding space 36 defined in the lower mold 28.
Thereafter, these middle and lower dies 27 and 28 are for example 150
C. for 30 minutes to perform vulcanization molding of the elastic material 35,
The seat ring 17 is integrally vulcanized on the inner peripheral surface of the main body 10. After vulcanization molding, each mold is released and the seat ring 17 integrally joined to the main body 10 is taken out.

When the main body 10 is set in the molding die, the main body 1 for integrally vulcanizing the seat ring 17 is used.
Needless to say, processing of the inner peripheral surface of No. 0 and release processing of the mold and the seat ring are performed.

In the above-described embodiment, the outer die 10-4 and the outer rib 10-3 of the main body 10 are connected to the lower mold 28.
And fitted into the middle mold 27, but either one may be used. Further, as in the present invention, since the material of the main body 10 is a resin and has no rigidity, it is preferable that the fitting portion set in the mold is large, so that the expansion deformation due to the pressure during vulcanization is small, and as a result, the stable Quality can be obtained.

[0042]

As described above, according to the present invention ,
And full inner peripheral surface of the hollow cylindrical body made of wood fat material, between the peripheral edge of the disk-shaped valve body consisting rotatably supported by the resin material within the body, an annular made of an elastic material In the center type butterfly valve equipped with a seat ring, the annular seat ring is made of ethylene / propylene rubber,
The body is made of a nylon-based resin and integrally vulcanized. The outer periphery of the body is formed on the outer peripheral surface of the body in the vicinity of the plane including the valve stem axis, concentrically with the body over the entire circumference excluding the body support. a rib portion integrally, the outer peripheral rib, forms a deformed hole combines the bolt holes for centering for each bolt diameter of the bolt hole center circle of the plurality of flange rating, also, the body Physical bonding in which an annular seat ring is integrally vulcanized and formed by chemical bonding, or two-dimensionally forming an uneven surface that fits into the bonding surface parallel to the chemical bonding and the fluid passage except for the valve rod insertion portion. the combination of the joining, integrally vulcanization, improve the bonding strength, also the inner diameter of both end portions of the seat ring, and equal to the outer diameter of the pipe when the pipe, in its axially inward, the pipe The inner diameter part which is almost equal to the inner diameter of the valve, and the flat diameter part near the valve rod through hole which always slides on the valve body By sequentially formed via an inclined connecting portion, the following advantages.

(I) The main body is clamped by the bolt of the pipe flange through the centering deformation hole of the outer peripheral rib portion provided integrally on the outer peripheral surface of the main body concentrically over the entire circumference. It is possible to cope with each bolt having a diameter of a bolt hole center circle of various flange standards, and moreover, it is possible to easily and reliably perform centering of the valve main body during piping.

(Ii) Moreover, the resin main body is reinforced with pressure resistance by the outer peripheral rib portion, and the resin body is made of nylon resin.
From the body and an ethylene-propylene rubber elastic material comprising
Since the seat ring is integrally vulcanized, the bonding strength of the seat ring is improved, the swing and breakage of the seat ring due to opening and closing of the valve are prevented, and the pressure, temperature,
It can be widely applied to fluid conditions such as valve opening, flow rate, and vacuum.

(Iii) Since the main body including the outer peripheral rib portion is made of resin, the joint surface between the main body and the seat ring and the formation of the deformation hole for centering the outer peripheral rib portion are also precisely formed by no processing. Significant cost reduction can be achieved, including amount and weight.

(Iv) This kind of resin butterfly valve is suitable mainly for medium and small diameter ones due to its moldability, mass production, strength and economy, etc. It is possible to easily cope with environmental conditions at the time of use, for example, by using a resin containing a black pigment having higher weather resistance than a place where the valve is mounted.

[0047] (v) In addition, chemical bonding, or said chemical valve stem through an irregular surface to which are fitted to each other in parallel bonding surface to the bonding fluid passage for vulcanization molded integrally with the body and the seat ring Department
By jointly using the physical joining that forms two strips excluding the above, the two can be more securely and firmly joined together.

[0048] (vi) or, the inner diameter of both end portions of the seat ring, and equal to the outer diameter of the pipe when the pipe, in its axially inward, and approximately equal to the inner diameter portion and the inner diameter of the pipe, a valve element By forming the flat-diameter portion in the vicinity of the valve stem through-hole that is always in sliding contact through the inclined connection portion, it is possible to prevent the seat ring from bulging in the inner diameter direction at the flange connection portion after the piping. The radial portion also serves as a bearing for supporting the thrust in the valve stem direction acting on the valve element.

[0049]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view on the right side of a YY line showing an embodiment of the present invention, and an outer side view on the left side.

FIG. 2 shows a state in which pipes are connected; the right side of the line YY is a longitudinal sectional view, and the left side is an external view.

FIG. 3 is a sectional view of a main part of FIG. 1;

FIG. 4 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 5 is an explanatory view showing a bolt hole having a diameter of the center circle of a bolt hole of various flange standards in the case of 80A, and a deformed hole for centering of the present invention obtained by combining the bolt holes.

FIG. 6 is an explanatory view showing a bolt hole having a diameter of the center circle of a bolt hole of various flange standards in the case of 150A, and a deformed hole for centering of the present invention in which these are combined.

FIG. 7 is an explanatory view showing a bolt hole having a diameter of a bolt hole center circle of various flange standards in the case of 300A, and a deformed hole for centering of the present invention in which these are combined.

FIG. 8 is a sectional view in which the valve body of the present invention is set in a vulcanization molding die.

FIG. 9 is an enlarged cross-sectional view of an end portion of a conventional seat ring.

FIGS. 10 (a), (b) and (c) are explanatory views showing a state of a conventional seat ring when a valve element is operated.

11A and 11B show a conventional example, wherein FIG. 11A is a front view of a main part, and FIG.
FIG. 3 is a cross-sectional view of a main part taken along line XX of FIG.

[Explanation of symbols]

 Reference Signs List 6 piping flange 7 bolt 8 pipe 10 main body 10-1, 10-2 main body shaft support 10-3 outer peripheral rib 11 fluid passage 12 valve body 13, 14 valve rod guide 15, 16 valve rod 17 seat ring 17E inverted trapezoidal shape 17F mountain Shape 18 Gland packing 19 O-ring 20 Holding plate 21 Bottom lid 25 Plunger of elastic injector 26 Upper mold for molding 27 Middle mold for molding 28 Lower mold for molding 29 Center projection 30 Joining surface 31 Mold for molding valve stem hole 32 Screw part 33 Central concave part 34 Injection hole 35 Elastic material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-221774 (JP, A) JP-A-61-272262 (JP, U) JP-B 1-59470 (JP, B2) JP-B 5-5- 31033 (JP, B2) Jigyo Hei 3-2062 (JP, Y2) Jigyo Hei 3-39651 (JP, Y2) Jigyo Hei 3-2063 (JP, Y2) Handbook of Plastics Processing Technology, Japan Society of Polymer Science , Japan, Nikkan Kogyo Shimbunsha, June 12, 1995, first edition, 3-25, 143-153 (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 1/16-1/226 F16K 27/00-27/02

Claims (1)

(57) [Claims] An elastic material is provided between the entire inner peripheral surface of a hollow cylindrical main body made of a resin material and a peripheral portion of a disk-shaped valve body made of a resin material rotatably supported in the main body. In a central butterfly valve equipped with an annular seat ring made of material,
The annular seat ring is made of ethylene / propylene rubber.
The main body is made of a nylon-based resin and is integrally vulcanized, and the main body supporting portion is formed concentrically with the main body on the outer peripheral surface of the main body in the vicinity of the plane including the valve shaft axis. An outer peripheral rib portion is provided integrally over the entire circumference except for the above, and a plurality of bolt holes for centering corresponding to each bolt having a diameter of a bolt hole center circle of a plurality of flange standards are synthesized on the outer peripheral rib portion. Form a deformed hole and insert the valve stem through a chemical joint in which the main body and the annular seat ring are integrally vulcanized and formed, or an uneven surface that fits together with the chemical joint and a joint surface parallel to the fluid passage. Excluding part 2
The combination of physical bonding to Article formed integrally vulcanization,
To improve bonding strength, also the inner diameter of both end portions of the seat ring, and equal to the outer diameter of the pipe when the pipe, in its axially inward, and approximately equal to the inner diameter portion and the inner diameter of the pipe, valve body and constantly A center type butterfly valve, wherein a flat portion in the vicinity of a valve rod through-hole which slides is formed sequentially through an inclined connecting portion.