Note: Descriptions are shown in the official language in which they were submitted.
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BUTTERFLY VALVE
This invention relates in general to butterfly valves.
More particularly, it relates to improvements in a butterfly
valve of the type which includes a seat of rubber or o-ther
resilient material which lines an annular hub in order to
sealably engage with the periphery of a disc rotatable in
the hub to open and close the valve, and a stem for so
rotating the disc which is removable from the hub and seat
to permit assembly and disassembly of the valve when, for
example, the seat and/or disc need repair or replacement.
In butterfly valves of this type, one end of the stem is
journaled within a hole in the hub and the other end thereof
extends through and is journaled in a bore through a neck
extending from the hub so as to provide a part to which an
actuator may be attached for ro-tating the stem. In some
such valves, the stem extends from one end to the other
through a hole in the stem, while in other valves of this
type, the ends of the stem are separate from one another and
extend into opposi-tely disposed holes in the periphery of
the disc. In this latter case, the end opposite that
journaled in the neck extends through a hole in the hub so
that both ends may be removed from the disc during assembly
and disassembly. In either case, the periphery of the disc
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includes annular portions surrounding the ends o -the stem
and adapted to sealably engage annular portions o~ -the seat
through which the ends of the stem extend so as to isolate
the holes in the hub ~rom the interior of the valve.
In those valves in which the stem extends through the
disc, the disc is connected to the stem for rotation there-
with by means of screws or pins which extend through the
sides of the disc and into the stem. These as-teners
provide leak paths past the disc and into the holes in which
the ends of the stem are journaled, and may cause corrosion
between the stem ends and holes in the hub. Also, these
fasteners may cause structural failures as well as undesir-
able flow characteristics due to interrupted flow paths past
the fasteners in the open position of the disc. Addition-
ally, since the fasteners are exposed to fluid in -the valve,
they also are susceptible -to corrosion, thereby making it
difficult to remove the stem in order to disassemble the
parts of the valve. Still further, the weight of the stem
is transmitted to the disc -through the fasteners, and thus
may cause uneven compression on the seat about -the periphery
of -the disc when -the valve is uprlght.
On the other hand, valves in which the stem is made of
separate parts require complicated assembly and repair of
the valve as compared with a valve having a single stem.
Because of the possible leakage of line fluid past the
primary seal between the disc and seat about each of -the
stem portions, and thus the risk of the stem portions being
blown out, one or preferably both of them is held in its
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hole on bore by means of a roll pin. As will be appreci
ated, the roll pins constitute parts which may corrode and
interfere with disassembly of the valve for purposes of
repair and Leplacement.
An object of this invention is -to provide a butterfly
valve of the type described which obviates these and other
problems with prior valves of this type.
A more particular object is to provide a valve of this
type wherein the disc is releasably held in a position
rotatably connected to a one piece stem without the need of
fasteners or other parts exposed to line fluid, and wherein
the stem is retained in such position by means which is
easily and quickly releasable to permit repair or
replacement of parts of the valve with a minimum of time and
effort.
These and other objects are accomplished, in accordance
with the illustrated embodiments of the invention, by a
valve of the type described wherein the stem includes a
portion intermediate its ends which extends through the disc
and includes a non-circular part fitting closely within a
non-circular part on -the disc, whereby the disc may be
rotated by the stem between opened and closed positions by
means of an actuator connected to the end of the stem which
extends through the housing bore. More particularly, the
: stem is movable axially into and out of close-fitting
position within the seat and disc, and the outer end of the
stem is engaged by means on the neck which re-tains it in i-ts
operating position, but which is easily and quickly
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releasable to permit removal of the stem during replacernen-t
and repair of the disc and/or sea-t.
In the illustrated and preferred embodiment of the
invention, the non-circular parts of the stem and hole in
the disc are flat, generally parallel surfaces adjacent the
inner end of the stem so as to minimize reduction in the
strength o~ the stem. Also, the outer end of the bore of
the neck is diametrically enlarged and the stem retaining
means includes a groove about the stem opposite the outer
end of the bore, circumferentially split rings having their
inner edges within the groove and their outer edges fitting
closely within the enlarged outer end of the bore, and means
releasable attachable to the neck and engageable with the
outer edges of the split rings for releasably retaining them
in the outer end of the bore. Preferably, the enlarged
outer end of the bore has a groove thereabout, and a split
ring is adapted to be moved to and out of a position in -the
groove in which it engages the outer edges of the split
rings.
A seal ring is disposed about the stem within the outer
enlarged end of the bore for sealably engaging -therebetween,
and a bushing surrounds the stem within the ou-ter end of -the
bore intermediate the seal ring and split ring to absorb
lateral thrust on the stem due to the actuator. The seal
ring is preferably of such construction as to seal in both
directions and thus protect the interior of the valve
against foreign matter outside of it as well as to protect
-the retaining means agains-t the corrosive effects of line
fluid.
In the drawings, wherein like reference characters are
used throughout to indicate like parts:
Fig. 1 is a vertical sectional view of a valve con-
structed in accordance with the present invention and
installed between the ends of a conduit shown in broken
lines and showing the disc thereof in closed position;
Fig. 2 is an end view of the valve, as seen along broken
lines 2-2 of Fig. l;
Fig. 3 is a horizontal cross-sectional view of the
valve, on an enlarged scale, and as seen along broken lines
3-3 of Fig. 2;
Fig. 4 is an enlarged sectional view of the upper end of
the stem, showing the seal ring, bushing and stem retain-
ing means installed within the enlarged ou-ter end of the
bore through the neck;
Fig. 5 is a view from the top of -the valve, as seen
along broken lines 5-5 of F'ig. ~; and
Fig. 6 is a perspective view of the upper end of the
s-tem and housing, as shown in Fig. 4, and showing -the outer
end of the stem raised and the parts for retaining the stem
in exploded positions.
With reference now to the details of the abovedescribed
drawings, the overall valve, which is indicated in its
entirety by reference character 10, includes a valve body 11
having an annular hub 12 and a neck 12 extending outwardly
from the side of the hub and having a bore 13 therethrough
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which extends radially of the hub. As shown in Fig. 1, the
ends of the hub are adapted to be disposed between flanges
14 on the ends of conduits 15 and a flange 17 on the hub has
holes therethrough which are adapted to receive bolts 19
extending through holes in the flanges to support the hub in
axial alignment with the conduits. Thus, nuts 20 may be
made up with the bol-ts to draw the flanges of the conduits
toward one another and thus hold the ends ~f the hub tightly
therebetween, or backed off to permit the hub to be removed
from between the flanges upon removal of the bolts from
within the holes ln the flange 17.
The valve also includes an annular seat 21 of rubber or
other suitable material having an inner wall 22 over the
inner diameter of the hub and flanges 23 extending outwardly
from each end of the inner wall and disposed over the ends
of the hub in position to be sealably engaged by the flanges
14 on the conduits when the flanges are drawn toward one
another with the hub disposed between them. The seat is
releasably retained on the hub by means of a tongue and
groove connection between them comprising a "T" shaped
member 24 on the hub, and a correspondingly shaped groove 25
formed about the seat for fitting over the member 24 whereby
-the flanges of the seat may be spread to permit the seat to
be installed and removed from the "T'l shaped member. The
outer wall of each flange has an annular bead 26 formed
thereon which is adapted to be engaged by the flanges of the
conduits and deformed into tight sealing engagement there-
with.
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The valve also includes a disc 27 having an outer
periphery adapted to fit tightly within the inner wall of
the seat and mounted on a stem 28 for ro-tation therewith
between a position iII which it extends across the seat to
close the valve, as shown in Fig. 1, 2 and 3, and another
position, not shown, in which the disc is disposed trans-
verse to the seat so as to open the valve. The stem 28
includes an outer end 28A which is closely received in the
bore 13 of the neck 12 for rotation therein, an inner end
28B which is closely received in a hole 29 in the hub
diametrically opposite the bore 13 for rotation therein, and
an intermediate portion 28C which extends through a hole 31
diametrically through the disc 27. The inner and ou-ter ends
of the stem also extend closely through diametrically
opposed holes 30 in the inner wall of the seat so as to form
a sliding seat therewith upon rotation of the stem.
The end of the intermediate portion 28C of the stem
adjacent inner end 28B thereof has flat surfaces 32 formed
thereon which are parallel to one another and close:ly
engageable with flat surfaces 33 formed in the end of ho:le
31 through which the central portion of the stem extencls so
as to provide a driving or rotatable connection between
them. More particularly, the surfaces lie within planes
which are parallel to the axis of rotation of the stem so
that the stem may be moved axially into and out of the
operating position of Figs. 1 and 2. The inner end 28B of
the stem is of a diameter approximately as large as the
distance beween the flat sides 32 of the stem.
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As shown in Figs . 1 and 2, -the lower end o~ the stem 28B
is seated within the hole 29 -to hold a shoulder 34 at the
intersection of the upper part of the stem above surfaces 32
above a shoulder 35 formed at the upper ends of the hole 31
abo~e the flat sides 33. Thus, th.e weight of -the stem is
supported from the hub, rather than from the seat, to reduce
the likelihood of uneven compression of -the seat when the
valve is mounted in an upright position, as shown in Figs. 1
and 2.
As previously described, the periphery of the disc is
adapted to tightly engage the inner wall of the seat, and
thus to sealably engage therewith. Preferably, the periph-
ery is spherically shaped about a center along the axis of
rotation of the stem midway the opposite ends of the hole 31
to facilitate movement of the annular portions of the
periphery at each end of the hole through the disc into
tight sealing engagement with the flat i.nner side of the
inner wall of the seat. As shown, the opposite ends o~ the
inner wall 22 of the seat are shaped conically to further
acilitate movement o: the disc periphery into sealing
enyagement with the seat.
The ou-ter end 13A of the bore 13 through the neck is
diametrically enlarged, and the stem is adaped to be
retained in its operating position mounting the disc for
rotation between opened and closed position by means which
includes a pair of C-rings 40 having inner edges adpated to
: fit within a groove 41 abou-t the outer end 28A of the stem
~ and outer edges which fit closely within the outer end of
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the bore so as to ho:ld them in -the groove. ~ore
particularly, a spring type, split re-tainer ring 42 is
ad~pted to snap into a groove 43 ~ormed about the bore in
position to yieldably engage the outer edges of C-rings and
thus hold them and the stem within the bore.
The ends of the retaining ring 42 may be engaged by a
suitable tool to distort it into a position in which it may
be removed from within the groove and thus raised from the
outer end 13A of the bore. As shown in Fig. 6, this permits
the stem to be raised upwardly and thus removed from the
disc and seat for repair or replacement. In order to
assemble or reassemble the valve, the stem is held in a
raised position to permit C-rings 40 to be installed in the
groove 41, and then lowered with the C-rings into a position
in which the stem is seated in the hole 29 and the C-rings
are closely received beneath the groove 43 in the bore. The
retainer ring 42 may be compressed by pulling its ~ree ends
toward one other to permit it to slide into the upper end o~
the enlarged portion 13A of the groove and opposite the
groove 43, and -then released to permit it to snap into the
groove.
As shown, the neck 12 is ~ormed as one piece with the
hub, and the flange 17 is formed as one piece with the hub
- and neck. The neck has a flange 50 on its upper end on
which an actuator (not shown) may be mounted for engaging a
non-circular part 52 on the outermost end of end 28 of the
stem in order to impart rotation thereto. The neck is shown
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to be of a leng-th which permits insulation or the like to be
disposed abou-t it intermediate the flange 50 and -the hub.
As best shown in Figs. 4 and 6, a seal ring 53 sur-
rounds the outer end 28A of -the stem within the enlarged
portion 13A of the bore for seating therebe-tween, and a
bushing 54 is closely received between the stem and bore to
absorb side thrust of the actuator. The seal ring is
supported on a seat at the end of the bore 13A, and the
bushing is above the ring below split ring 40 to hold them
in place. The seal ring S3 has lips on its opposite ends
which are tightly engaged between the end of the stem and
the bore so as to seal in both directions -- i.e., against
intrusion of foreign material from outside of the valve as
well as to provide a secondary seal to preven-t line fluid
from moving therepast.
From the foregoing it will be seen that this invention
is one well adapted to attain all of the ends and objec-ts
hereinabove set forth, together with other advantages which
are obvious and which are inherent to the appara-tus.
It will be understood that cer-tain features and subcom-
binations are of utility and may be employed without refer-
ence to other features and subcombinations. This is contem-
plated by and is within the scope of the claims.
As many possible embodiments may be made o the in
vention without departing from the scope thereof, it is to
be understood that all matter herein set orth or shown in
the accompanying drawings is to be interpreted as illustra-
tive and not in a limiting sense.
