Butterfly valve is widely used on the pipeline because of it is simple in structure, easy to use, cost is low.Adopt surface of revolution (as the sphere or the conical surface) to cooperate for the valve plate of the working pressure butterfly valve that improves butterfly valve and fit system between the sealing seat have developed into from initial simple extruding, thereby the open and close torque of the two eccentric structures between valve plate and the valve rod is greatly reduced.
Yet the extrusion friction repeatedly that is subjected to valve plate owing to sealing seat in opening and closing operation causes wearing and tearing, and therefore the sealing effect between sealing seat and the valve plate obviously reduces in use for some time, begins to produce and leaks.In a single day this phenomenon appears in the tradition butterfly valve, and whole butterfly valve is promptly accused and scrapped, and brings very big economic loss to the user.For this reason, be to seek the subject matter that solves in the present technique field for many years the working life that how to prolong butterfly valve.
The applicant has proposed a kind of adjustable butterfly valve in Chinese utility model patent numbers 91215020.3.Adopted sphere to cooperate between the valve plate of this butterfly valve and the sealing seat, sealing seat adopts polytetrafluoroethylmaterial material to make.Especially, in this patent, also proposed to solve some controlling mechanisms or the device that the sealing seat wearing and tearing are adopted.Wherein, a kind of controlling device adopts adjustable eccentric shaft to connect between valve plate and valve rod.This structural cost is higher, and need unload lower valve with valve plate when close regulating sealing seat, and it is very inconvenient to operate.Second kind of controlling device is to install pad additional between valve plate and valve rod, so that the distance between valve rod and the valve plate increases, to reach valve plate close to sealing seat.The device of this structure also need be pulled down valve, operation inconvenience when regulating.The third controlling device is taked to be connected with screw thread between valve seat flap and valve body, although easy, has just increased the leakage point between valve body and the flap.Once imagination solved this leakage point problem with O type circle, still, wore out owing to O type circle is subject to dielectric corrosion, can not fundamentally be resolved.
The objective of the invention is to be to provide a kind of improved adjustable butterfly valve, when sealing seat weares and teares can by dwindle distance between flap and the valve body make realize again between sealing seat and the valve plate sealing and simple in structure, adjusting or easy to operate, and can allow tight seal between flap and the valve body.
For achieving the above object, adjustable butterfly valve of the present invention comprises valve body, flap, remains on the nonmetal sealing seat of valve body inboard by flap, and the valve plate and the valve rod that are positioned at valve body.The sealing surface of sealing seat has identical surface of revolution shape (geometrical shape) with the sealing surface of valve plate.In addition, it is the tapered portion of conical surface that sealing seat also has its outer circumferential face, and the radius of this conical surface dwindles gradually from flap one side direction valve body one side.Valve body openings projecting ring section inner peripheral surface has a conical surface that matches with sealing seat tapered portion conical surface.Flap is installed on the valve body by a controlling mechanism, and this controlling mechanism can be along axial (direction) adjusting flap of pipeline and the distance between the valve body.
The sealing seat of this butterfly valve can still be used nonmetallic material, and for example teflon is made.Do not reach being worn under the sealing effect situation, can regulate, force flap close gradually and further dwindle distance between sealing seat and the valve body, reach at last and make sealing seat be adjacent to the sealing state of valve plate again to valve body by controlling mechanism.Adopt the fit system of conical surface in this butterfly valve between sealing seat and the valve body especially, guaranteed the sealing between sealing seat and the valve body.Especially when regulating, make the conical surface between sealing seat and the valve body paste tightlyer on the one hand, sealing effect is better, and valve body forces sealing seat to be out of shape to pipeline center on the other hand, thus more closely obvolvent on the valve plate, make the sealing effect between sealing seat and the valve plate better.So, the present invention when regulating, not only sealing seat along pipeline axial and also radially be adjacent to valve plate, regulating effect is good and easy to adjust easily.
Please referring to Fig. 1, it shows the butterfly valve structure of first preferred embodiment of the present invention earlier.This butterfly valve comprises valve body 1, valve plate 2, valve rod 3 and the valve seat that is made of sealing seat 4 and flap 5.
Sealing seat 4 usefulness nonmetallic material are made, and such as using teflon, tetrafluoro is filled or material such as rubber is made, wherein, select for use usually wear-resisting, corrosion resistant performance is good and teflon that have certain degree of hardness is even more ideal as the sealing seat material.
Sealing seat 4 adopts spherical shape with the sealing surface of valve plate 2, and the fit system of this complementation can improve the working pressure of butterfly valve significantly.Butterfly valve is when closure, and the centre of sphere of valve plate sphere is positioned on the radial plane by the valve rod central axis.Like this, can guarantee in keying the contact of the extruding between the valve plate 2 and sealing seat 4 and make friction reduce to minimum.Certainly, in order to guarantee sealing, the spherical radius of valve plate 2 should be slightly larger than the spherical radius of sealing seat 4, to produce an amount of interference fit.Sealing surface also can adopt the surface of revolution of other shape, such as conical surface.
In addition, in order to reduce open and close torque power, generally connect into the mutual alignment relation with two eccentric (not drawing among the figure) by link (structure) 6 between valve plate 2 and the valve rod 3, this is technology of knowing to those skilled in the art, gives unnecessary details so locate not add.
Valve seat is made up of flap 5 and sealing seat 4, and flap 5 can remain on sealing seat 4 opening of valve body and near between flap 5 inwalls and the relative inner ring surface of valve body 1 opening.Specifically, flap 5 is provided with an annular groove 13 towards valve body 1 one side wall surfaces, and this groove has less inner circle wall 13a of a diameter and the bigger periphery wall 13b of a diameter, and periphery wall 13b is provided with internal thread 8.
Sealing seat is provided with the cylindrical peripheral face in the form of a ring on the outer wall of direction one side (right side) that it is provided with conical outer circumferential face on it on outer wall of sealing surface equidirectional one side (left side), sealing surface is relative on it.
The inwall system of the opening projecting ring section of valve body is made up of a conical inner peripheral surface and a columniform inner peripheral surface.All 1 ecto-entad direction reduces the radius of the conical inner peripheral surface of valve body 1 and the conical outer circumferential face of sealing seat 4 gradually from flap 5 to valve body.Has an outside thread that is meshed with the internal thread 8 of the periphery wall 13b of flap 5 grooves on the outer wall of described valve body openings projecting ring section.
Described sealing seat 4 can be embedded between the inner circle wall 13a and valve body 1 projecting ring section inner peripheral surface of flap groove 13, and, the conical outer circumferential face of sealing seat 4 and the conical inner peripheral surface of valve body 1 fit, thereby sealing seat 4 is remained in the groove 13 of flap 5 reliably.
Flap 5 also has a radial plane respect to one another respectively with valve body 1, is separated by an O type circle 9 therebetween.The O shape circle of being made by rubber 9 can stop foreign material to enter in the valve from the outside, simultaneously on the one hand, also gives between flap 5 and the valve body 1 on the other hand and leaves certain clearance, so that flap and valve body are axially made relative adjustment along it.
Also be distributed with a plurality of wrench holes 10 that are the radial blind holes shape on the outer circumferential face of flap 5 equably.
When sealing seat 4 weares and teares because of long-term work and produce leakage, just can utilize structure of the present invention to regulate.Concrete grammar is: valve plate 2 is maintained in its closed position, then wrench is inserted the just rotatable flap 5 in back in the wrench hole 10, make it axially promote, drive sealing seat 4 simultaneously and move to valve plate 2 to valve body 1, eliminate up to leaking.
Conical surface fit form between sealing seat 4 and the valve body 1 has not only guaranteed the sealing between sealing seat 4 and the valve body 1, and when flap 5 when valve body 1 advances, valve body 1 forces sealing seat 4 radially to internal strain, thereby holds valve plate 2 tightly, has promoted regulating effect.
The butterfly valve that has shown an alternative embodiment of the invention among Fig. 2.In this butterfly valve, taked the controlling mechanism different with last embodiment except between flap 5 and the valve body 1, other structure is basic identical.
See also Fig. 2, the cylindrical portion of sealing seat 4 is embedded between the inside and outside anchor ring or sidewall of flap 5 grooves 13.Relative with flap 5 and valve body 1 near the radial plane between be stacked with the thin annular gasket 12 of multi-disc and adopt flush bolt 11 that flap 5 and annular gasket 12 are fixed on the valve body 1, the sealing that pad 12 has played between flap 5 and the valve body 1 separates effect again.
Like this, when needing to regulate, only need looser a bolt 11 when sealing seat 4 wearing and tearing, take out one or several pad 12, load onto again again flap 5 and 11 fixing by bolt, can reach the adjusting purpose.
This embodiment's butterfly valve structure is comparatively simple, does not also have the difficulty in the processing when the bore of valve is big, but bothers a little a little when regulating.
Butterfly valve of the present invention can make valve plate keep the origin-location when regulating usually, and sealing seat is carried out extrusion moulding.When being sphere, the sealing seat sealing surface still can keep matching, having reduced friction and turn round refuse (power) with the sealing surface (sphere) of valve plate.
In addition, in first and second embodiments of the present invention, still have two eccentric relative position relations between valve plate and the valve rod.