Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to an eccentrically rotatable
valve for controlling fluid flow, and particularly relates
to improvements in a no-flange-type eccentrically rotatable
valve.
Many valves of this kind have been developed
heretofore. For example, there is shown a horizontal
cross section of a conventional eccentric rotary valve
in Fig. 1, in which a valve disk 11 is eccentrically
pivoted within a valve body 14 by means of a valve
stem 12 in a valve chamber 10 of the valve body 14 so
that the center line of the disk 11 coincides with that
of the flow path through the valve body 14 when the disk
11 is brought into the fully closed contact position,
while the pivot axis of the valve stem 12 is offset from
the center line.
However, the valve discribed above is not without
defects. For instance, such a construction involves
the provision of a bearing hole 16 of a bonnet 15 for
pivotally supporting the stem 12 eccentrically disposed
to correspond with the eccentrically rotatable disk 11,
and accordingly the manufacture of the valve body 14 is
complicated.
Further, when the valve is mounted between pipes
for actual operation, it is inserted between the flanges
attached to the ends of the pipes and is fixed by bolts
17 passed through the two flanges of the pipes. In this
case, however, since the bonnet 15 is arranged in an
offset position in the valve body 14, as described above,
one of the bolts 17 will be obstructed by the bonnet 15.
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In order to overcome this prob:Lem, the valve body 14 has
to be provided with a pair of lug members 18 in its end portions,
through which short bolts are passed for mounting the valve to
the pipes avoiding the bonnet 15. Consequently, the construc-
tion of the valve is made even more complicated and its mounting
operation is also rather troublesome.
The present invention seeks to provide an improved
eccentrically rotatable valve free from the abovementioned
defects.
The present invention further seeks to provide an improved
no-flange-type eccentrically rotatable valve which has a simple
construction and is readily mounted for operation between pipes.
According to the present invention there is provided an
eccentrically rotatable valve having: a valve body having a
valve chamber and flow path openings which lead to the valve
chamber; a valve seat member having an internal seating surface
arranged in one of the flow path openings; an annular retainer
removably mounted in the valve body and clampingly engaging an
outer portion of the valve seat member to retain said valve seat
member in said valve body; a valve stem pivotally mounted on
the valve body and having the pivot axis thereof passing through
the center of the valve chamber; and a valve disc secured to the
valve stem for rotation therewith and having an external seating
which in one position forms a proper seating contact with the
internal seating surface of the valve seat member; wherein said
valve disc has a central axis perpendicular to the plane of the
external seating surface of the valve disc which does not inter-
sect the axis of rotation of the valve stem, said valve seat mem-
ber has an inner portion spaced from said retainer permitting
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limited bending of said valve seat me~ber during closing of the
valve; and wherein said valve seating surface is in a plane angul-
arly disposed wlth respect to a fluid path therethrough; said
valve body further comprises face portions around each of the
flow openings adapted to mate with corresponding surfaces of
pipes to which the valve is to be connected; and said retainer
is provided with a circular groove around an inner end portion
thereof providing said spacing permitting limited bending of
said valve seat member.
The present invention will now be described in detail in
terms of several embodiments thereof illustrated in the accom-
panying drawings, which are given by way of illustration only
and thus are not limitative of the present invention, in which:
Fig. 1 is a horizontal central section of a conventional
eccentric rotary valve;
Fig. 2 is a vertical central section of an embodiment of
an eccentrically rotatable valve according to the present
invention;
Fig. 3 is a horizontal central section of the eccentrically
rotatable valve of Fig. 2;
Figs. 4 and 5 are horizontal central sections of other
embodiments of a seat ring used in an eccentrically rotatable
valve according to the present invention; and
Fig. 6 is a horizontal central section of another embodi-
ment of the eccentrically rotatable valve according to the
present invention.
In Figs. 2 and 3 is shown an embodiment of an
eccentrically rotatable valve of the present invention.
A valve body 21 having a substantially spherical valve
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chamber 22 provides a pair of circular flow path
openings 23 and 24 in its opposite ends, which lead to
the chamber 22.
A seat ring 25 which forms a part of the wall
of the chamber 22 and includes a flow path hole which
leads to the chamber 22, is coaxially disposed in the
opening 23, held by an annular retainer 26 by engaging
the threaded outer surface of the retainer 26 with
the threaded inner surface of the opening 23 in the
valve body. The flange portion 25a of the seat ring
25 is interposed between the annular ratainer 26 and
the shoulder portion 27 of the valve body 21. The
seat ring 25 may be made of any suitable metallic
material or plastic material such as tetrafluoroethylene.
The retainer 26 is provided with a circular
groove 28 around its inner end so as to allow for the
bending tolerance of the seat ring 25.
The inner end portion 25b of the seat ring 25
projects into chamber 22 from the opening 23. A
spherical seating surface 25c is formed in the inner
end portion 25b of the seat ring 25.
The plane of the inner end portion 25b of the
seat ring 25 is inclined at an angle ~ to the mounting
plane of the flange 25a of the seat ring 25; that is,
at an angle ~ to the planes of the mating surfaces of
the valve and the pipes. Accordingly the central
axis X - X of the seating surface 25c, that is, the
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line perpendicular to the plane of the inner end
portion 25b passing through the center of the inner
end portion 25b, is inclined at an angle ~ to the
central axis Y - Y of the valve, which contains a
central point O of the axis of rotation of a valve
stem 31.
Other embodiments of the seat ring are shown
in Figs. 4 and 5. The seat ring 25 shown in Fig. 4
has a flexible coupling portion 25d between the flange
portion 25a and the seat portion, so that the seat
ring 25 may move flexibly via the flexible coupling
portion 25d.
Alternatively, the seat ring 25 shown in Fig. 5,
made of a matallic material is provided with a groove
25e in its inner end portion 25h, which is adapted to
receive a seat 25f of a soft material such as tetra-
fluoroethylene.
Referring again to Figs. 2 and 3, the valve disk
29 is mounted to the valve stem 31 in its eccentric
position in the valve chamber 22, via a disk arm 30
which is integrally coupled to the valve disk 29.
When the disk 29 is pivoted to the fully closed
contact position, and an outer spherical seating
surface 29a of the disk 29 is contacted with the inner
spherical seating surface 25c of the seat ring 25,
the central axis of the disk 29 is inclined at an
angle ~ to the central axis Y - Y of the valve.
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The valve stem 31, as shown in Fig. 2, is pivotally
arranged in the valve chamber 22 of the valve body 21.
The upper portion of the stem 31 is rotatably received
into a bearing 34 mounted in a cylindrical bonnet 32 and
the lower end portion of the stem 31 is rotatably received
into a lower bearing 35 mounted in a bearing recess 33.
The central axis of the bonnet 32 is perpendicular
to the central axis Y - Y of the valve and passes through
the center O of the valve chamber 22. Hence, the central
axis of the stem 31 coaxially fitted into the bonnet 32
is also perpendicular to the central axis of the circular
openigs 23 and 24 and passes through the center O of the
valve chamber 22. Thus, the disk 29 mounted on the
stem 31 pivots about a central axis of the valve body 21.
Between the stem 31 and the bonnet 32, above the
bearing 34 are inserted a tubular spacer 36, a packing
means 37 above the spacer 36, and a packing stop member
20 38 above the packing means 37. A stop plate 39 is
fixed to a flange 40 of the bonnet 32 above and outside
of the packing stop member 38 by screw means 41 such
as bolts and nuts.
The top end of the stem 31 projects above the
bonnet 32 and a handle (not shown) may be mounted to it.
A stop pin 43 prevents the stem 31 from coming out
upwards from the valve body 21.
When the valve is to be mounted for operation
between two popes, a plurality of fixing bolts 42 are
threaded through holes in the flanges of the two pipes
and around the outside of the valve body 21 to hold
the two pipes to the valve.
The fully open position of the disk 29 is shown
in Fig. 3 by the two-dotted lines. From this position,
the disk 29 is pivoted to the seat ring 25 by rotating
the stem 31, as shown by an arrow. While the disk 29
is truning, the seating surface 29a of the disk 29
does not contact the seating surface 25c of the seat
ring 25. Then the seating surface 29a of the disk 29
is brou~ht into contact with the seating surface 25c,
and as the disk is further pivoted, both the surfaces
25c and 29a are brought into full contact with each
other due to the eccentric pivot center of the arm 30
of the disk 29, as shown in Fig. 3 by the solid lines.
The seat ring 25 is permitted to bend by the
circular groove 28 of the retainer 26, as described
above, and the surfaces 25c and 29a are flexibly contacted
with each other,thereby obtaining a reliable contact
pressure therebetween.
In the embodiment shown in Fig. 4, when the disk
29 is brought into contact with the seat ring 25, the
surfaces 25c and 29a are held in proper contact with
each other by the pivoting force through the flexible
coupling portion 25d.
In the embodiment shown in Fig. 5, when the disk
29 is brought into contact with the soft seat material
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25f of the seat ring 25, the seat material 25f is
deformed according to the pivoting force, thereby
obtaining the proper contact therebetween.
On the other hand, if the stem 31 is rotated
in the reverse direction from the closed position,
the contact pressure between the surfaces 25c and 29a
is gradually decreased and the surfaces 25c and 29a
are separated each other to the open position in the
reverse manner of that described above.
In a valve according to the present invention,
since the stem 31, the bonnet 32 and the bearing hole 33
; are positioned on the center line of the chamber 22,
no eccentric processing is necessary in the construction
of the body 21, which thus may be manufactured very much
easier than a conventional one. Further, when this valve
is to be mounted between the flanges of the flow pipes,
since the stem 31 and the bonnet 32 are arranged radially
with respect to the valve body 21, the fixing bolts may
be properly arranged in the flanges so that no fixing
bolt is obstructed by the bonnet 32. Consequently, no
lug member is necessary on the valve body for avoiding
the obstruction of a bolt by the bonnet.
The seat ring 25 provided with an inclined
spherical internal seating surface 25c is easily
mounted, the valve construction is very simple, and
accordingly the manufacturing process is very straight-
forward. Furthermore, the fixing operation of thevalve between the flanges is easily performed.
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In Fig. 6, there is shown anoiher embodiment of
the eccentrically rotatable valve of the present
invention. This embodiment has the same construction
as that described above except that the seating surface
25c of the seat ring 25 is not inclined but parallel
to the plane perpendicular to the central axis of the
chamber 22 or of the seat ring 29 and that the central
line X - X of the seating surface 25c is parallel to
- the axis Y - Y of the chamber 22 and is displaced a
certain distance from the axis Y - Y when the seating
surface 29a of the valve disk 29 is brought into fully
closed contact with the seating surface 25c of the seat
ring 25.
In this embodiment, it is apparent that the same
results as described above can be obtained.
Although the invention has been described in terms
of several preferred embodiments, it will be understood
by those skilled in the art that various changes and
omissions in the form and detail thereof can be made
therein without departing from the scope of the invention.
For example, the seat ring may be connected integrally
to the valve body, or may be a part of the valve body.
Further, the shapes of the valve chamber, the valve seat
and so forth may vary, as long as the axis of rotation
of the valve stem is central and yet does not intersect
the central axis of the valve disk member.
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