Note: Descriptions are shown in the official language in which they were submitted.
BUTTERFLY VALVE 2 ~ 7 8 2 8 1
The present Invention refers to a connection between the parts of a butterfly
valve~ It is particularly applicable, but not e~clusively so, to the connection between
the valve element and the a~le of a butterfly valve~
Furthermore, the invention refers to the valve seating and a stop mechanism in
the butterfly valve~
Many of the s~ud butterfly valves are designed with a connection from the a~cle
to the valve element using bolts placed in holes that pass through the item and the
axle. The problem related to this design is in the initial working of the disc when
adapting to the seating or rising from it, causing high tensions on the bolts which wear
and finally may break.
According to the present invention, a connection is offered between the
elements, one of which passes through the other, and with this layout each element is
formed with a spline that can be aligned to allow a cotter pin to be introduced and
then disaligned to leave the pin held by the internal element within the other element,
to thus fL~ the pin in the element and thus join the two elements together.
In the best e~ample of the invention, the two elements are the axle and the discshaped valve element in a butterfly valve. The a~le spline is shorter than that of ~e
valve part and the same length as the pin. The pin has a part with a small height and
the height of this part is equal to the depth of the spline in the a~le. The spline in the
valve element is longer than in the a~cle and the sum of the depths of both splines is
equal to the height of the pin. The pin has a groove that allows it to be lifted to
remove it from the splines when the splines are in line, for e~ample with the aid of a
screwdriver. The a~le is stepped at one end to limit the disalignment of the splines
due to the movement of the a~le in the valve element and forms an end plate to hold
the a~le in this position iD relation to the valve part and avoid access to the end of the
a%le.
The invention also refers to a seating for a butterfly valve.
Such seatings are placed between the disc shaped valve part and the body of
the valve, and many well known e~arnples already exist.
According to the present invention, a valve seating is supplied for a butterfly
valve that may include any novel combination of the follo ving characteristics:
(a) the seating is metal.
(b) It projects either from the valve body or from the disc on the valve
closure element.
(c) It has an external part that pr~jects radially from the disc.
(d) It has a convolution joined to the radially projecting portion.
(e) It has a seating tip joined to the convolution.
(f) ` It has a support tip connected to the sea~ing tip.
(g) The metal is Inconel 718 ~Kegistered Trademark).
(h) The seating is made of a polymer, for e~ample a fluoroplastic such as
P.T.F.~..
(i) The seating includes an anchoring portion, a neck portion and
projection from the seating.
G) The seating has metal and polymeric sections ne~ct to each other along
the whole face.
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2 8 1
According to the present invention~ a seating is offered for a butterfly valve
that includes a metal element and an element of synthetic plastic materiaL shaped to
be in contact along the length of a portion of their e~temal surface, with the metal
element having a flange with which it can be joined to the body of the valve or the
valve disc; a convolution for ~reater fle~cibilit~: a seating ~p intended to make
contact for an hermetical closure with the disc or valve bodv and a support tip
intended to serve as a stop for the seating in the valve body or valve disc under
specific conditions pressure from the valve disc.
The present invention refers also to a stop mechanism for a butterfly valve.
In the said type of valve it is necessary to ensure as far as possible that the
valve element is co~rectly orientated in the valve body when the latter is in the closed
position~ that is, with its face at a right angle to the flow a~cis of the valve. Valves are
known in which the stops are formed on the outside of the valve on the a~cle on which
the valve element is mounted, but this system can give rise to a lack of precision
bcause the a~le rnay be twisted between the stops and the valve element. Valves are
also known in which stops are formed inside the body of the valve, corning into
contact with the perimeter of the valve element when the element is in the closed
position, but this system can also give rise to a lack of precision because the a~cle
bends under the pressure and the element may have a tendency to pivot round the stop
rather than round the a~cle~ giving rise to unequal wear in the valve seating. One
aspect of the invention is intended to mitigate these problems.
According to the present invention, a butterfly valve is offered that has a valve
body~ a valve element placed so as to turn within the body of the valve, to movebetween a first position in which the element stops the flow of fluid through the valve,
to a second position in which the fluid is allowed to flow through the valve, and
means to avoid the movement of the valve element beyond the fully open position~formed by a stop in the body of the valve and a stop on the valve element, with each
stop having two stop faces that work to make contact with the other two sides of the
stop respectively.
In a best example of the invention~ the means to avoid movement are formed
by a stop in the body of the valve and a stop on the valve element. Each stop has two
stop faces that work to make contact respectively with the two stop faces on the other
stop. A pair of stop faces make contact with the valve element in the fully closed
position and the other p3ir make contact with the valve element in the fully open
position. The first pair of stop faces make contact at a right angle to the plane of the
front face of the valve element. The other pair make contact on a 45 plane to the
plane of the front face.
So that the present invention may be more clearly understood, described below
is a practical version of the same as an example~ taking as a reference the a~ched
drawings, in which:
Figure 1 s~.ows a side, sectional view of a partially assembled butterfly valve,according to the invention; and
Figure 2 shows the valve of Figure 1 completely assembled.
Figure 3 shows a sectional view of part of a butterfly valve.
Figure 4 is a sectional view, par~ally schematic, of a butterfly valve in the
closed position.
Figure S is a sectional view, partially schematic, of the butterfly valve in
Figure 4, in the open position.
2~2~1
Figure 6 is a partial view in perspective of a detail of the valve in Figures 4
and 5; and
Figure 7 is also a partial view in perspective of a detail of the valve.
Referring to the drawings~ the butterfly valve has a valve body 1 in which a
disc shaped valve element 2 is mounted on an axle 3 in order to turn. The a~le 3passes through holes in the body 1 and element 2. The axle has a stepped portion 4 at
its upper end which is placed in an additional part S of the internal diameter of the
valve body. The valve element 2 and the a~le 3 in which it is introduced, are
specially formed to allow mutual connection between element 2 and the a~le 3. The
groove on the a~le is indicated by reference 7 and that on element 2 by reference 8.
The pin 6, oblong and of a constant thickness. has a hei~ht correspondin~ to
the depth of the open groove 8 in element 2, plus the depth of groove 7 in the axle 3.
A third of the length of the pin has a lesser height at 10, corresponding to the hei8ht
of the axle groove. A groove 9 for a screwdriver is forrned in the end of the pin 6,
covering its whole width. The groove on pin 7 is formed to the e~cact length of the
pin 6 at the exact depth of the height reduced by one third. The groove of the spline
8, forrned on the dorsal part of element 2, runs through the corresponding hole to the
a~le 3. The length of the groove 8 is appro~imately a third grea~er than the length of
the pin.
The valve is assembled as follows. The disc shaped part 2 is placed in the
body of the valve 1. The a~le 3 is passed through the lower hole in the body 1,
introducing it into the pass hole element until the spline groove of the axle 7 is visible
through the groove of the spline in element 8. The pin 6 is introduced into the
element 2, in the grooves in the disc and the a~le, with the ponion of the pin with
reduced height 10 looking in the direction of the final mountin~ position of the a~cle.
After the pin 6 is introduced. the a~cle 3 is pushed up to its final position, drawing the
pin upwards in the internal diameter of the element until the stepped portion 10 of the
pin 6 makes contact with the end of the groove 8 in the disc element 2. The lower
end of the axle 3 is held by a retainer on the axle 11 to avoid axial displacement of the
axle 3~ and which hold the pin 6 in place. To dismount the axle 3 and element 2. the
a~le retainer 11 is first removed. The a~le 3 is then pushed down until the pin 6 can
no longer be seen in the spline groove 8. Ieaving the groove for the screwdriver in the
lower end of the pin 6. uncovered. By placing an instrument in the groove 9, the pin
can be raised and removed from the grooves in the a%le and disc element 7 and 8.The axle 3 can now b,e removed through the lower hole in the valve body.
The valve is formed by a valve body I that forms the main element of the
valve 12 in which is situated a closing element in the valve, formed by the disc 2,
which can rotate. A valve seating is placed in the body of the valve 1 between the
body and the closing part 2, and held in place by means of a retainer on the seating 13
joined to the valve body 1 by screws 14. Between the retainer 13 and the body of the
valve 1 sealing washers are placed 14a. The valve seating is of comple~c design and
construction. The design is mainly a combination of a seating with a metal element
15 and a second element 16 of polymeric material. The polymeric material causes the
primary hermetic sealing and the metal the secondary hermetic seal in case the
primary seal fails due to e~cessive temperature, abrasion, etc.. Each element can be
used independently with small modifications to the tooling of the retainer andlor the
body.
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The pro~le of the metal seating can be broken down into t^our different
geometric sections~ each one of which has identifiable functions: e.g. a radial flange
17, a radial arm with convolution 18~ a seating tip 19 and a support tip 20.
The functions of these parts are as follows:
Radial Flange
This section is radial to the centre of the valve 12 and projects from the
e~ternal diameter of the seating to the beginning of the radial convolution. It has a
flat surt^ace fitting between the retainer of the seating 13 and the body l, through
which pass an appropriate number of retaining screws 14, to anchor the seating 15 to
the body l. The joints 14, that sit in hollows in the retainer 13 of the seating and the
body l, can be attached to either side of the seating IS to avoid le~aks to the
atmosphere. When installed on the valve, this radial flange also helps to hold the
polymeric seating 16 and thus completes the anchoring chamber for this seating.
Radial Arm with Convolution
This section begins at the beginning of the curvature immediately inside the
radial flange 17 and is generally radial with a single convolution projecting in the
opposite direction to the retainer for the seating 13. This simple convolution 18
carries out various critical functions:
a) It gives support and flexible energization to the polymer seating 16
whose profile coincides exactly with this surface. (The polymer will normally befluoroplastic, for e~ample P.T.F.F., that has a limited memory and resistence topermanent deformation. The metal seating, with the described profile, when made of
material such as Inconei 718 can serve to support and erergize the polyment under all
service conditions of nominal pressure/temperature in the valvel.
b) It mechanically holds the polymer seabng 16 in place.
c) It creates a flexing displacement point for the radial arm 17, thus
increasing the reaction capacity of the seating.
Seatin~ Tip
The seating tip 19 is formed on the end of a generally conve~ surface started atthe centre of the perpendicular curvature of the spherical surface of the seating on the
perimeter of the closing element of the disc 2. This conve~c surface begins at the
enternal end of the radial arm.
When the disc element 2 moves to the closed position~ itS seating edge wi)l
thus make contact tangentally with the seating tip and the obstacle formed between the
two seating surfaces will have optimum characteristics for hennetical sealing and the
turn force of the valve.
Support Tip
The support tip 20 is formed in the vortex of a generally convex surface,
starting from a curved centre generally perpendicular to the ramp angle of the seating
retainer (indicated by reference number 21) and therefore with a curvature that is the
opposite of the seating tip described above. This ramp 21 on the seating retainer 13
forms an angle of approxima~elylS with a tangent drawn to the spherical surface of
the disc seating 2 at its point of contact with the metal seating lS when the disc 2 is in
the closed position.
It its free state, the support tip 20 is not in contact with the rasnp angle 210f
the seating re~ainer, but as a growing seating load is generated by the closing of the
disc 2, the support tip 20 is obliged to make contact with the ramp angle 21, thus
increasing the rigidity of the seating lS and thus the closure force. The increase in
~782~1
the closure load makes the support tip rise up the ramp 21 of the seatin~ retainer~ thus
maintaining the closure force.
Description of the SoR Seating
The soft seating 16 is made of polymetic material and is a round ring held in a
hollow 22 generally with a square section~ formed in the bod~ and held in the said
hollow by the metal seating 15.
A radial surface on the polymeric seating 16 corresponds e~actly to the surface
coinciding with the metal seating 15, while the other radial surface is flat
corresponding on its external half with a reduced section to fonn an internal seating
projection 23 achieved thanl~s to a bevelled surface.
This bevelled surface is opposite the hollow formed by the convolution on the
other surface, thus forming a neck 24 that effectively divides the seating into an
external anchoring part 14 and an interior closure part 23. The neck 24, with its
lesser section, allows fle~ing by the seating projection under tbe influence of closure
forces and/or pipeline pressure. The internal stem of the seating is conve~ withdimensions to form a blockage on the spherical perimeter of the seating of the disc 2
seating when it is in the closed position.
How it Functions
a) The pressure applied to the side of the valve corresponding to the
seating retainer, means that any reflex action of the disc 2 akes place in an axial
direction against the seating retainer, thus tending to reduce the obstruction between
the seating elements 15 and 16 and the perimeter of the seatin~ of the disc 2. Thus
the desing of the seating elements 15 and 16 must be able to ~ke a~ial deflection to
compensate this possible disc movement. The fluid will f~rst be found in metal
seating 15 and will apply a~ial forces to the radial are with convolution 20, which will
increase the closure force between the seating tip l9 and the spherical perimeter of the
disc. The a~ial deflection of tbe radial arm 18 will also cause deflecti of the soft
seating 16, due to the intimate contact between the two seating components. Thisdeflection of the soft seating 16 will also cause the seating projection 23 to pivot
round the section of the neck 24, thus increasing the blochge with the sph~ricalsurface of t'ne disc. Therefore it can be seen that applying pressure in this direction.
both metal and soft seatings work in an energized way under pressure. Therefore an
increase in pressure will cause an increase of the closure pressure in both seatings.
b) The pressure applied from the side of the valve corresponding to the
body (i.e. the side of the a~le of the disc 2) will make any disc deflection take a
generally axial direction, moving towards the seating retainer 13 and thus increasing
the blockage between the spherical perimeter of the disc and t~e two seating elements
15 and 16. lhe pressure will also act on the primary soft seating 16 that, in this case,
is held by means of the metal seating 15 t'nat energiæs it. The metal seating will give
resilence and energization to the soft seating 16, allowing it to effeciently tolerate
transitory temperatures and pressures. In cse of failure or destruction of the soft
seahng 16, the pressure will then act directly on the metal seating 15, moving it in an
direction; i.e. the radial aIm with convolution ~,vill come nearer to the retainer
seating. At the same ~me the suppsrt tip 20 will rise by the rarnp angle of the
retainer ~n the seating and rnaintain the closing force betwee~ the seating tip 19 and
the spherical seating perimeter of the disc 21.
Referring ~o Figures 4 to 7, the butterfly valve is formed by a valve body 1, inwhich the valve element 2 is placed and able to rotate. Tbe valve element 2 is
-- 6 ~ 1~ 7 8 2 3
mounted on an axle 3 which~ in turn, is mounted in the bodv of the valve. Both the
valve element 2 and the valve ~dy 1 have stops 26 and 27. These stops cooperate in
two different valve positions, the fully closed position (shown in Figure 4) and the
fully open position (shown in Figure 5!- As can be seen, both stops have
complementary faces to form contact surfaces in both positions. Thus faces 28 and 29
~oin when the valve is closed and faces 30 and 31 when it is open.
Stop 26 is shown in more detail in Figure 6 and stop 27 is shown in greater
detail in Fi~ure 7. Figure 6 shows the valve element 2 from the rear. It defines a
hole 8a that projects from the upper to the lower part~ in which is lodged the axle 3
(not shown~. At one end of this valve hole. the material surrounding it is made to
form two stop faces 28 and 30. The stop face 28 is at 90 from the plane of the front
face of the valve element 2 and stop face 30 is 45 from the front face of valveelement 2.
Figure 7 shows the formation of the stop faces 29 and 30 in the valve body. It
has a projection 32 tbat surrounds an opening 33 through which the axle 3 runs (not
illustrated). The stop face 29 is pa~llel to the front face of the valve element 2 and
the stop face 31 forms an angle of 45 with this front face when the valve element is
in the fully open position.
With the device described aboYe, when the valve is in the closed position the
valve element 2 is held firmly and its angular deflection reduced. With the valve
closed and applying pressure in eitber direction, the element 2 can move lineally in
relation to the flow and also maintain a uniforrn deflection inwards and outwards in
the valve body 1. In this way, there is a reduction of angular deflection caused bv
element 2 mounted excentrically that has areas of unequal pressure, and unequal wear
on the seating is eliminated. The presence of open stops means that the valve element
will not open further than the fully open position.
It is understood that the practical example above has been described solely as
an example and many variations are possible without deviatin~ from the scope of the
invention.
