CN209587161U - Butterfly valve - Google Patents

Abstract

This application discloses a kind of butterfly valves.Butterfly valve includes: valve body, inner seat, spool, valve rod and at least one locating ring.Valve body has arrival end with outlet end and is connected to the axial passage of arrival end and outlet end.Valve rod mounting hole radially is equipped between arrival end and outlet end on valve body.Valve inner is equipped with valve seat mounting portion at position corresponding with valve rod mounting hole.Inner seat is fixedly installed in valve seat mounting portion, and inner seat is tubular element and is equipped with radial through-hole corresponding with valve rod mounting hole on its side wall.Spool is plate-like piece and is installed in inner seat, wherein being equipped with through-hole radially inside plate-like piece.Valve rod sequentially passes through the through-hole of valve rod mounting hole, the through-hole of inner seat and spool；Locating ring is mounted on valve inner and forms sealed connection in the axial sides of inner seat and with inner seat.The butterfly valve seal performance of the application is good.

Description

Butterfly valve

Technical field

The utility model relates to a kind of valves, and in particular to a kind of butterfly valve.

Background technique

The opening ways of existing butterfly valve are the rotation of spool intermediate rotary shaft, and band movable valve plug both sides rotate and open, leakproofness It is usually poor.Especially when butterfly valve is mainly made of plastics, after high-temperature sterilization, leakproofness is worse.

Utility model content

The purpose of the utility model is to provide a kind of butterfly valves of favorable sealing property.

To achieve the above object, the utility model provides a kind of butterfly valve, and the butterfly valve includes:

Valve body, the valve body have arrival end and outlet end and be connected tos the arrival end and the axial direction of the outlet end is led to Road, is equipped with valve rod mounting hole radially on the valve body between the arrival end and the outlet end, in the valve body Portion is equipped with valve seat mounting portion at position corresponding with the valve rod mounting hole；

Inner seat, the inner seat are fixedly installed in the valve seat mounting portion, and the inner seat is for tubular element and in its side Wall is equipped with radial through-hole corresponding with the valve rod mounting hole；

Spool, the spool is plate-like piece and is installed in the inner seat, wherein being equipped with edge inside the plate-like piece Radial through-hole；

Valve rod, the valve rod sequentially pass through the logical of the valve rod mounting hole, the through-hole of the inner seat and the spool Hole；And

At least one locating ring, the locating ring be mounted on the valve inner the axial sides of the inner seat and with The inner seat, which is formed, to be tightly connected.

In one embodiment, the locating ring is arranged such that the valve body and the inner seat in the effect of the locating ring Under, it is formed and is tightly connected.

In one embodiment, the locating ring is arranged so that it generates squeezing action to the inner seat.

In one embodiment, is formed and be tightly connected between the inner seat and the valve body.

In one embodiment, it is provided with sealing surface in the valve body, the sealing with the valve body is provided on the inner seat The sealing bar of face cooperation and the inner seat are additionally provided with sealing surface, and the locating ring is equipped with the sealing surface with the inner seat The sealing bar of cooperation.

In one embodiment, the peripheral surface of the locating ring is equipped with hanging platform, and the valve inner is equipped with and the hanging platform The back-off of cooperation.

In one embodiment, the valve is set there are two locating ring, and described two locating rings are respectively and before the inner seat Side and rear side are tightly connected.

In one embodiment, the valve body is cylindrical and has front waist section, middle part and rear section, wherein the middle part Inner passage internal diameter be less than the front waist section and the rear section inner passage internal diameter, the inside of the middle part is logical The sealing surface for thering is shoulder to be formed between the inner passage of the inner passage and the rear section of road and the front waist section respectively.

In one embodiment, sealing surface is provided in the valve body, the axial sides of the inner seat are equipped with the positioning Circle, the inner seat is cylindrical and has rear side end and front side end, the rear side end and the front side end be equipped with it is radial to The flange of outer protrusion, wherein the side annular surface of each flange and the sealing surface of the valve body form in sealing contact, and institute The sealing surface of the other side and the locating ring of stating flange forms in sealing contact.

In one embodiment, the flange forms side annular surface in sealing contact equipped with sealing bar with the valve body, And the sealing surface towards the flange of the locating ring is equipped with sealing bar.

In one embodiment, the inside of the valve rod is inserted with the metallic pin axially extending along valve rod.

In one embodiment, the valve is additionally provided with outer seat, and the outer seat is installed against the locating ring.

In one embodiment, the valve body, the inner seat, the spool and the locating ring are made of plastics.

The utility model has the beneficial effects that the components of transmission are few, manufacturing process is good, and structure is simple, space utilization rate Height, the minimum that valve is done.Unlatching torque is small, and sealing performance is good.

Detailed description of the invention

Fig. 1 is the decomposition diagram of butterfly valve according to the present utility model.

Fig. 2 is the axial sectional view of butterfly valve according to the present utility model.

Fig. 3 (a) and 3 (b) is the prelocalization circle of butterfly valve according to the present utility model and the perspective view of rear locating ring respectively.

Fig. 4 (a) and 4 (b) is the valve body of butterfly valve according to the present utility model respectively from the perspective view in terms of front side and rear side.

Fig. 5 (a) is the locating rod of butterfly valve according to the present utility model and the perspective view of handle.

Fig. 5 (b) and Fig. 5 (c) is the longitudinal section view of the perspective view of metallic pin and locating rod in locating rod respectively.

Fig. 6 (a) and 6 (b) is the perspective view and axial sectional view of the spool of butterfly valve according to the present utility model respectively.

Fig. 7 (a) is the valve seat of butterfly valve according to the present utility model from the perspective view in terms of rear side.

Fig. 7 (b) is the axial sectional view of the valve seat of butterfly valve according to the present utility model.

Fig. 8 (a) is the decomposition of the valve body of butterfly valve according to the present utility model, prelocalization circle, rear locating ring and inner seat Perspective view.

Fig. 8 (b) is the axial direction of the valve body of butterfly valve according to the present utility model, prelocalization circle, rear locating ring and inner seat Cross-sectional view.

Fig. 9 (a) is the assembling of the valve body of butterfly valve according to the present utility model, prelocalization circle, rear locating ring and outer seat Perspective view.

Fig. 9 (b) is the assembling of the valve body of butterfly valve according to the present utility model, prelocalization circle, rear locating ring and outer seat Axial sectional view.

Figure 10 be butterfly valve according to the present utility model under valve opening state from the perspective view in terms of front side.

Specific embodiment

The preferred embodiment of the utility model is described in detail below with reference to attached drawing, to be clearer to understand this reality With novel objects, features and advantages.It should be understood that embodiment shown in the drawings is not the limit to the scope of the utility model System, and simply to illustrate that the connotation of technical solutions of the utility model.

In the following description, elaborate certain details to provide for the purpose for illustrating various disclosed embodiments To the thorough understanding of various open embodiments.But it one skilled in the relevant art will recognize that can be in without these details One or more details the case where practice embodiment.Under other circumstances, well known device associated with this application, knot Structure and technology may not be illustrated in detail or describe to avoid unnecessarily obscuring the description of embodiment.

Unless context has other needs, and in the whole instruction and claim, word " comprising " and its modification, such as "comprising" and " having " should be understood meaning that is open, including, that is, should be interpreted that " including, but are not limited to ".

Expression is in conjunction with the embodiments described to be referred to " one embodiment " or " embodiment " throughout the specification Certain features, structure or feature are included at least one embodiment.Therefore, in each position of the whole instruction " at one In embodiment " or " in an embodiment " in appearance without all referring to identical embodiment.In addition, certain features, structure or feature It can combine in any way in one or more embodiments.

The singular as used in the specification and appended " one " and " described " include plural object, are removed It is clearly dictated otherwise in non-text.It should be noted that term "or" is usually used with the meaning that it includes "and/or", unless literary In clearly dictate otherwise.

In the following description, the structure and working method of the utility model in order to clearly demonstrate, will be by all multidirectionals Word is described, and wherein "front", "rear" refers respectively to the left and right direction of Fig. 1 and Fig. 2, "outside", "inner", " outside ", " to It is interior ", "upper", the Word Understandings such as "lower" for convenience of term be not construed as word of limitation.

Butterfly valve 100 according to the present utility model is specifically described with initial reference to attached drawing.The butterfly valve 100 goes out commonly used in container Mouthful, and be generally made of plastic material.Hereinafter, shown in Fig. 1 and 2, as shown in Figure 1, butterfly valve 100 includes: valve body 101, valve rod 102, spool 103, inner seat 104, outer seat 105, prelocalization circle 106, rear locating ring 107 and handle 108.Reference Fig. 2, inner seat 104 are mounted in valve body 101, and spool 103 is mounted in inner seat 104, prelocalization circle 106 and rear locating ring 107 are located at the front side of inner seat 104 and rear side.It should be understood that locating ring after prelocalization circle 106 can also only be arranged or be only arranged 107 without departing from the scope of the utility model.Here, locating ring 106 and 107 is independently of the part of valve body 101.Due to can be just In replacement or convenient for being made of more suitable material.The setting of outer seat 105 101 inside fic circle 106 of valve body (if there is If) front side.The front side of valve body 101 is arranged in valve deck 111.Flange 110 is also equipped in the rear side of valve body 101.Flange is close Seal 109 is arranged between valve body 101 and flange 110.111 front side of valve deck is mountable anti-theft fastener 112.

Specifically, there is outlet end in substantially cylindric integral structure with further reference to Fig. 8 (a) and 8 (b) valve bodies 101 113 with arrival end 114 and are connected to the axial passage of outlet end 113 and arrival end 114.Valve body 101 includes the connection that follows one another Front waist section 1011, middle part 1012 and rear section 1013.Front waist section 1011, middle part 1012 and rear section 1013 are in substantially Cylindrical shape simultaneously has corresponding inner passage, the inner passage of valve body 101 is collectively formed.Wherein middle part 1012 forms valve seat Mounting portion, for accommodating inner seat 104.

In the illustrated embodiment, the internal diameter of the inner passage of middle part 1012 is less than the interior of the inner passage of front waist section 1011 Diameter, and the internal diameter of the inner passage of also less than rear section 1013.In the inner passage of middle part 1012 and front waist section 1011 The sealing surface 1014a and 1014b for thering is shoulder to be formed between portion channel and the inner passage of rear section 1013 respectively.Sealing surface 1014a and 1014b is the anchor ring respectively for front side and rear side.

Back-off 1015 is additionally provided on the inner surface of the inner passage of front waist section 1011 and rear section 1013, thus preceding fixed Position circle 106 is from front side out of rear side is installed to front waist section 1011 inner passage and/or after rear locating ring 107 is installed to from rear side Prevent prelocalization circle 106 and/or rear locating ring 107 from deviating from when in the inner passage of section 1013 from inner passage.Back-off 1015 In the form of the circumferential ridge before direction in the circumferential ridge and rear section 1013 of direction in such as front waist section 1011 backward is detailed.In In illustrated embodiment, circumferentially spaced four back-offs 1015 are respectively provided in front waist section 1011 and posterior end 1013.Certainly, Other quantity, form and arrangement can be used, as long as applying resistance when prelocalization circle 106 and rear locating ring 107 are exited from valve body 101 Power.

It is respectively provided in the peripheral surface of front waist section 1011 and rear section 1013 and is matched with valve deck 111 and flange 110 Connection structure.In the illustrated embodiment, the connection structure is external screw thread, it should be appreciated that the connection structure is also possible to example Connection structure as known to other of engaging protrusion or engaging slot etc.

Referring to Fig. 1, Fig. 4 (a) -4 (b) and Fig. 8 (a) -8 (b), it is equipped on the circumferential wall of middle part 1012 radial logical Hole 1016, for being inserted into for valve rod 102.Correspondingly, it is equipped in the position opposite with 1016 diameter of radial through-hole and is located at radial wall Interior counterbore 1017, when valve rod 102 is inserted, which is used to accommodate the end of valve rod 1017.

Referring to Fig. 7 (a) -7 (b), there are two axial ends, i.e. rear side end and front side in substantially cylindric and tool for inner seat 104 End.The circumferential wall of inner seat 104 is equipped with two opposite through-holes 1043 and 1044 of diameter, for wearing for the insertion of valve rod 102 It crosses.The flange 1041 and 1042 projected radially outward is respectively equipped in the rear side end and front side end of inner seat 104.Its flange The annular surface 1041a of 1041 (in figure downwards) forward be used to be formed with the sealing surface 1014b of valve body 101 it is in sealing contact, and Annular surface 1041b towards rear (in figure upwards) is used to form sealing with the sealing surface 1071 (seeing below) of rear locating ring 107 and connect Touching.The annular surface 1042a towards rear (in figure upwards) of flange 1042, which is used to be formed with the sealing surface 1014a of valve body 101, to be sealed Contact, and annular surface 1042b (in figure downwards) is used to connect with the formation sealing of the sealing surface 1061 of prelocalization circle 106 forward Touching.Each pairs of surface in sealing contact: annular surface 1041a and sealing surface 1014b is being formed each other；Annular surface 1041b and sealing Face 1071；Annular surface 1042a and sealing surface 1014a；It, can on wherein at least one face in annular surface 1042b and sealing surface 1061 It is provided with sealing bar 115.In the illustrated embodiment, annular surface 1041a and annular surface 1042a and sealing surface 1061 and 1071 It is equipped with sealing bar 115.Pressing contact between sealing bar 115 and corresponding annular surface or sealing surface is capable of forming good Sealing.

Circumferential seal muscle 1046 is additionally provided in the inner peripheral surface 1045 of inner seat 104.The wherein circle of through-hole 1042 and 1043 The heart is located on the circle at 1046 place of circumferential seal muscle.The circumferential seal muscle 1046 encloses in the inner peripheral surface 1045 of inner seat 104 Extend around the entire periphery of two through-holes 1042 and 1043, as shown in Fig. 7 (a).The spool of circumferential seal muscle 1046 and spool 103 Compression abutting between sealing surface 1031a (as described below) is capable of forming good sealing effect.

Preferably, be mounted in valve body 101 for the ease of inner seat 104, it can be by the flange 1041 and 1042 of inner seat 104 The outer diameter for being arranged to one (being illustrated as flange 1042) is smaller, so that the flange of smaller outer diameter is first passed through valve body 101 Valve seat mounting portion, so that inner seat 104 be installed in place.

Preferably, inner seat 104 is located at 1046 front side of circumferential seal muscle and rear side for the ease of the installation of spool 103 Inner peripheral surface can be in internal diameter towards the slightly widened taper in both ends.

Referring to Fig. 6 (a) and 6 (b), spool 103 is equipped with the valve of substantially tubular around the periphery of plectane in substantially circular plate shape The outer peripheral surface of edge 1031, the valve edge 1031 is used as valve core sealed cover 1031a.In addition, being equipped in spool 103 straight radially across it The through hole of diameter is used as valve rod mounting hole 1032.In order to make 103 lighting of spool, the plectane part of spool 103 can be arranged to It is relatively thin, and the part for being equipped with valve rod mounting hole 1032 is relatively thick, to form the valve rod mounting hole of relatively large inside dimension 1032.Preferably, being equipped with spool salient point 1034 in the inner peripheral surface of the valve rod mounting hole 1032.In the illustrated embodiment, if There is a pair of spool salient point 1034 relative to each other, it should be appreciated that other suitable suitable numbers of position setting can be set as needed The spool salient point 1034 of amount.

In the embodiment of diagram, due to the sealing bar 1046 in inner peripheral surface 1045, valve core sealed cover 1031a energy Enough inner peripheral surfaces 1045 with inner seat 104 form in sealing contact.It should be understood that sealing bar can also be arranged in valve core sealed cover 1031a it is upper and around valve rod mounting hole 1032 periphery rather than in inner peripheral surface 1045.

Valve rod mounting hole 1032 is for accommodating valve rod 102.The perspective view of valve rod 102 is shown in Fig. 5 (a).Valve rod 102 wraps Include stem body 1021.The cross-sectional shape of the stem body 1021 and the cross sectional shape complementary of valve rod mounting hole 1032.But It should be understood that the cross-sectional shape should be non-circular shape, prevent valve rod 102 is in valve rod mounting hole 1032 from rotating, from And the rotation of valve rod 102 is able to drive the rotation of spool 103.In the shown embodiment, the cross section of stem body 1021 is in big Cause rectangle.And valve stem spacing concave point 1022 is equipped in the peripheral surface of stem body 1021.Wherein limit concave point 1022 and valve The shape of die bumps 1034 is substantially complementary, and limits the position of concave point 1022 and the position and quantity of quantity and spool salient point 1034 It is corresponding.Cooperation assembling is carried out by valve stem spacing concave point 1022 and spool salient point 1034 between valve rod 102 and spool 103, is assembled It is not easily to fall off afterwards.Stem body 1021 is additionally provided with axially hollow channel, is equipped with metallic pin 1023 in the axially hollow channel, As shown in Fig. 5 (b) and Fig. 5 (c).It can in the case where high-temperature steam sterilization due to assembling metallic pin 1023 in valve rod 102 Resist the deformation of spool 103 caused by high temperature.So that the sealing performance resistant against high temperatures high pressure of butterfly valve 100, meets requirement.

It is equipped with handle receiving structure 1023 on the head of valve rod 102, which is two equipped with pin hole A protrusion.Handle 108 has cam part 1081, and cam part 1081 is mountable between two protrusions.The cam part 1081 Two sides be equipped with pin, which can be inserted into the pin hole of handle receiving structure 1023, and handle 108 can be rotated around the pin.And hand Handle 108 is able to drive valve rod 102 around the rotation of longitudinal contour of valve rod 102, to rotate with movable valve plug 103 to open or close Butterfly valve 100.

Referring to Fig. 3 (a) and 3 (b), the perspective view of prelocalization circle 106 and rear locating ring 107 is respectively illustrated.It is fixed before wherein The back end surface of position circle 106 is sealing surface 1061, and the front end face of prelocalization circle 1071 is sealing surface 1071.Sealing surface 1061 and 1071 be equipped with ring packing muscle 115, and for respectively with the annular surface 1042b of inner seat 104 and annular surface 1041b It is formed in sealing contact.It should be understood that ring packing muscle 115 can also be formed again on annular surface 1042b and annular surface 1041b rather than On sealing surface 1061 and 1071.Sealing bar 115 abutted with the compression of opposite sealing surface or annular surface be capable of forming it is good close Seal effect.

Preferably, being also each equipped with 1062 He of hanging platform in the peripheral surface of prelocalization circle 106 and rear locating ring 107 1072, as shown in Fig. 3 (a) and 3 (b).Fig. 8 (b) is seen also, valve body 101, prelocalization circle 106, rear locating ring is shown 107 and inner seat 104 axial sectional view.Hanging platform 1062 and 1072 is shown.Wherein hanging platform 1062 and 1072 is in side To the form respectively forwardly with rearwardly projecting circumferential ring, thus with 1015 collective effects of back-off prevent prelocalization circle 106 and after Locating ring 107 is exited from valve body 101.

In addition, being additionally provided with valve deck 111 in the front side of valve body 101, the valve deck 111 is as shown in Figure 1.Valve deck 111 has circle Cover board 1111 and the circumferential lid edge 1112 extended from 1111 periphery of cover board to rear side.Example is equipped in the inside of the circumferential direction lid edge 1112 Such as the connection structure of screw thread, for the cooperation of the matching connection structure of such as screw thread in 101 front side peripheral surface of valve body, thus Valve deck 111 can be fastened to valve body 101.

More preferably, in the also settable anti-theft fastener 112 in the front side of valve deck 111.It in this case, can be in the front side of valve deck 111 Recessed portion for accommodating anti-theft fastener 112 is set.Anti-theft fastener 112 has main part 1121 and the diameter from main part 1121 The buckle arm 1122 that opposite place extends to rear side, the end of the buckle arm 1122 are equipped with the hook portion 1123 extended radially inwardly.Phase Ying Di is set there are two recess 1113 in the diameter of the circumferential lid edge 1112 of valve deck 111 with respect to place, for accommodating two buckle arms 1122.Settable two cavitys in corresponding position on the front side periphery of valve body 101 are respectively used to accommodate two buckle arms 1122 Hook portion 1123.It, can not be by valve deck 111 from valve in the case where not removing anti-theft fastener 112 due to the presence of anti-theft fastener 112 Body 101 removes.

It is also preferable that being additionally provided with outer seat 105 between prelocalization circle 106 and valve deck 111.Before the outer seat 105 is located at Between the front end face and valve deck 111 of locating ring 106, and form sealing therebetween.In the shown embodiment, referring specifically to Fig. 2 and Fig. 8 (b), outer seat 105 is in generally annular, and inner circumferential surface is equipped with stage portion, so as to abut the front side of prelocalization circle 106 End face is simultaneously positioned around periphery leading edge.The outer seat 105 is preferably made of elastic material, when valve deck 111 is in valve body 101 It is upper fastening it is in place when, which is in pressured state.

Flange 110 is additionally provided in the rear side of valve body 101.Flange 110 has in substantially cylindrical shape from flange 110 The flange 1101 that outer peripheral surface extends radially outwardly.It is equipped with the connection structure of such as screw thread in the inner peripheral surface of flange 110, is used for Match with the connection structure in 101 rear side peripheral surface of valve body, is fastenedly connected to be formed.In flange 110 and valve body 101 Flange seal ring 109 is additionally provided between rear end face.As shown in Fig. 2, the inner peripheral surface in flange 110 is equipped with annular groove 1102, For accommodating the flange seal ring 109.When in use, which is fixedly attached to appearance in bulk often through modes such as welding Device.The flange seal ring 109 is made of elastic material, when flange 110 fastens in place relative to each other with valve body 101, the method Blue sealing ring 109 is in pressured state.

In the above-described embodiments, by the sealing surface 1014a and 1014b of valve body 101 annular surface with inner seat 104 respectively The valve core sealed cover of sealing bar 1046 and spool 103 between 1042a and 1041a, in the inner peripheral surface 1045 of inner seat 104 Between 1031a and the annular surface 1041b and/or 1042b of inner seat 104 respectively at rear locating ring 107 sealing surface 1071 And/or by forming sealing, the sealing effect between sealing bar and respective surfaces between the sealing surface 1061 of prelocalization circle 106 Well, also ensuring that at high temperature under high pressure will not leak.In addition, can also between valve rod 102 and valve rod mounting hole 1032 No longer needing to setting sealing structure can ensure that butterfly valve 100 relative to extraneous sealing.

The preferred embodiment of the utility model has already been described in detail above, it is understood that if desired, embodiment can be modified Aspect provide other embodiment to use the aspect, feature and design of various patents, application and publication.

In view of detailed descriptions above, these and other variation can be made to embodiment.In general, in claim In, term used should not be construed as limited to specific embodiment disclosed in description and claims, but be understood that Being includes whole equivalency ranges that all possible embodiment is enjoyed together with these claims.

Claims (11)

1. a kind of butterfly valve, which is characterized in that the butterfly valve includes:

Valve body, the valve body have arrival end with outlet end and are connected to the axial passage of the arrival end and the outlet end, Valve rod mounting hole radially is equipped between the arrival end and the outlet end on the valve body, the valve inner exists Valve seat mounting portion is equipped at position corresponding with the valve rod mounting hole；

Inner seat, the inner seat are fixedly installed in the valve seat mounting portion, and the inner seat is for tubular element and on its side wall Equipped with radial through-hole corresponding with the valve rod mounting hole；

Spool, the spool is plate-like piece and is installed in the inner seat, wherein being equipped with radially inside the plate-like piece Through-hole；

Valve rod, the valve rod sequentially pass through the through-hole of the valve rod mounting hole, the through-hole of the inner seat and the spool；With And

At least one locating ring, the locating ring be mounted on the valve inner the axial sides of the inner seat and with it is described Inner seat, which is formed, to be tightly connected.

2. butterfly valve according to claim 1, which is characterized in that form sealing between the inner seat and the valve body and connect It connects.

3. butterfly valve according to claim 1, which is characterized in that the locating ring is arranged such that the valve body and the internal valve Seat is formed and is tightly connected under the action of the locating ring.

4. butterfly valve according to claim 1, which is characterized in that the locating ring is arranged so that it produces the inner seat Raw squeezing action.

5. butterfly valve according to claim 1, which is characterized in that sealing surface is provided in the valve body, on the inner seat It is provided with and is additionally provided with sealing surface with the sealing bar of the sealing surface of valve body cooperation and the inner seat, the locating ring is set There is the sealing bar with the cooperation of the sealing surface of the inner seat.

6. butterfly valve according to claim 1, which is characterized in that the peripheral surface of the locating ring is equipped with hanging platform, described Valve inner is equipped with the back-off cooperated with the hanging platform.

7. butterfly valve according to claim 1, which is characterized in that the butterfly valve sets described two positioning there are two locating ring Circle is tightly connected with the front side of the inner seat and rear side respectively.

8. butterfly valve according to claim 1, which is characterized in that the valve body is cylindrical and has front waist section, middle part And rear section, wherein the internal diameter of the inner passage of the middle part is less than the inner passage of the front waist section and the rear section Between the inner passage of internal diameter, the inner passage of the middle part and the front waist section and the inner passage of the rear section respectively The sealing surface for thering is shoulder to be formed.

9. butterfly valve according to claim 1, which is characterized in that sealing surface is provided in the valve body, the inner seat Axial sides are equipped with the locating ring, and the inner seat is cylindrical and has rear side end and front side end, the rear side end and The front side end is equipped with the flange projected radially outward, wherein the side annular surface of each flange and the valve body is close Cover formed it is in sealing contact, and the sealing surface of the other side of the flange and the locating ring formed it is in sealing contact.

10. butterfly valve according to claim 9, which is characterized in that being formed with the valve body for the flange is in sealing contact Side annular surface is equipped with sealing bar and the sealing surface towards the flange of the locating ring is equipped with sealing bar.

11. butterfly valve according to claim 1, which is characterized in that the inside of the valve rod is inserted with axially extending along valve rod Metallic pin.