Title of Invention

"A VALVE FOR CONTROLLING THE RATE OF FLOW OF FLUID"

Abstract A valve for controlling the rate of flow of fluid comprising: (a) a body having a fluid inlet, an inlet passageway in communication with the fluid inlet, an outlet passageway, a fluid outlet in communication with the outlet passageway, a conduit coupling the inlet passageway and the outlet passageway; (b) a seat ring disposed about the conduit; (c) a valve trim having a valve plug and plug tip, the valve trim having a plurality of anti-cavitation notches therein, Characterized in that at least two of the plurality of anti-cavitation notches are arranged at an acute angle to one another, wherein the valve trim has two or more levels of notches in the valve trim, and wherein at least one of said levels of the valve trim has a pair of the notches, said notches of the pair forming a wedge shape, and being separated from one another at a narrowest part of the wedge-shape. Fig. 2
Full Text The present invention relates to a valve for controlling the rate of flow of fluid.
Field of the Disclosure
(0001) This disclosure relates generally to fluid control valves and, more particularly,
to improvements in the trim and seat design of fluid control valve plugs.
Background
(0002) There have been efforts made to design a valve trim or profile having
symmetrically placed notches therein to define a preferred flow path for fluid within the
valve. Typical of such efforts are the anti-cavitation trims of the LINCOLNLOG™ valves of
Masoneilan/Dresser Industries, Inc. Anti-cavitation trims stage pressure drops through a
control valve. These valves have suffered from a number of shortcomings. For example, the
notch locations are, at least in some cases, too close to one another to provide proper staging.
As a result, fluid within the valve is able to flow from one restriction to the next without
utilizing the interstage plenum, as intended, which is necessary to achieve desired staging so
as to avoid cavitation. This problem is referred to herein as "short-circuiting."
(3) Another shortcoming is that these valves, when used with conventional plug tips, do not direct fluid away from the seating surfaces of the plug so as to minimize unbalance forces in the region of the seating surfaces. It would be desirable if the unbalance forces, produced by the fluid pressure drop in the valve, could be reduced, and one manner of reducing the unbalance forces is to minimize the unbalance area in the vicinity of the searing surfaces of the plug.
(4) The manner in which these and other shortcomings are overcome are explained in the following Summary and Detailed Description of the Preferred Embodiments.
Summary
(0005) In order to provide an anti-cavitation trim that avoids short-circuiting of fluid
to subsequent stages within a valve, it is effective to provide pairs of notches at rotated
to subsequent stages within a valve, it is effective to provide pairs of notches at rotated

locations along the valve plug. In particular, instead of positioning notches of a given pair (i.e. the two notches at a given height along the valve plug) directly parallel with one another, the notches are positioned such that they are at an acute angle to one another. Each pair of notches thus forms a wedge-shape, with a distance 5 separating the two notches at the narrowest part of the wedge. The distance 5, while preferably small, is also preferably an easily machinable dimension for facilitating manufacture. This arrangement of notches advantageously forces fluid within the valve to travel through more of the plenum space, and thus spend more time in the plenum, thereby allowing the fluid to recover pressure prior to entering the next stage.
(6) Another improvement is to employ a plug tip having a radius of about 0.03
inch, and preferably 0.031 inch, which forms a seat ring angle in the range of about 70-75°,
and most preferably, 75°, from a plane normal to a longitudinal axis of the valve plug. It is
also desirable for the valve plug to have a trim that directs flow away from the seating
surfaces of the plug and seat ring. It is found that this plug tip radius and seat ring angle
result in a very small unbalance area, on the order of an approximately 90% reduction in
unbalance area as opposed to anti-cavitation trim plugs without such plug tip dimensions,
which minimizes unbalance forces produced by the fluid pressure drop within the valve.
Advantageously, this feature minimizes actuator thrust requirements at elevated pressure
drops.
(7) In addition, the plug tip radius and seat ring angle produce relatively high
seating stress levels, which advantageously achieve extremely tight shutoff leakage
performance, thereby minimizing leakage. The plug seating surface is also favorably
protected against impinging fluid and entrained paniculate and other debris, thereby
increasing the service life of the trim and ensuring that even after long use, the valve plug and

seat ring will continue to exhibit tight shutoff performance. The increased contact stress efficiency achieved also desirably minimizes actuator thrust requirements. Brief Description of the Several Views of the Drawing
(8) FIG. 1 is a fragmented sectional view of a conventional fluid control valve
with an anti-cavitation trim;
(9) FIG. 2 is a fragmented sectional view of a fluid control valve with an anti-
cavitation trim having a plug tip and seat ring angle in accordance with an embodiment of
this disclosure;
(10) FIG. 2A is an enlarged sectional view taken along line 2A of FIG. 2;
(11) FIG. 3 is an elevated perspective view of a valve trim having a rotated notch
arrangement in accordance with another embodiment of this disclosure;
(12) FIG. 4 is a perspective view of the valve trim shown in FIG. 3, taken from a
lower elevation than that of FIG. 3;
(13) FIG. 5 is a front plan view of the valve trim shown in FIG. 3;
(14) FIG. 6 is a cross-sectional view taken along lines 6-6 of FIG. 5;
(15) FIG. 7 is a cross-sectional view taken along lines 7-7 of FIG. 5;
(16) FIG. 8 is a cross-sectional view taken along lines 8-8 of FIG. 5; and
(17) FIG. 9 is an enlarged perspective view, broken away, of the valve trim shown
in FIGS. 3-5, taken from a lower elevation than that of FIG. 4.
Detailed Description of the Preferred Embodiments
(0018) FIG. 1 shows a conventional valve 10 with an anti-cavitation trim. The valve
10 includes a fluid inlet 12, a fluid outlet 14, and a fluid inlet passageway 16 which couples
the fluid inlet 12 through an orifice 15 to a fluid outlet passageway 18. The valve 10 is of the
flow-up variety, in which the fluid inlet 12 and fluid inlet passageway 16 are disposed at a
lower level than the fluid outlet 14 and fluid outlet passageway 18. A valve plug 20 is

connected via a valve stem 22A to an actuator, which is not shown, but which would be positioned above the valve stem 22A. One or more apertures 22B are provided near the top of the valve plug 20 to receive, for example, a groove pin (not shown) to secure the valve plug 20 to the valve stem 22A. A cage 23 is positioned in the fluid flow path to influence desired characteristics of the fluid flow. An outer surface 24 of the valve plug 20 contacts a surface 26 of a seat ring 28, with the surface 26 of the seat ring 28 forming a valve seat for the valve plug 20.
(19) In an effort to prevent cavitation within the valve 10, it is desirable to provide
an anti-cavitation trim. An anti-cavitation trim may utilize a plurality of symmetrically
placed notches 29 to define a staged flow path. The notches 29 are provided to facilitate
keeping fluid flowing past the seat ring 28 at a relatively high pressure, and gradually
allowing the pressure to decrease as the fluid reaches higher stages.
(20) In operation, the actuator selectively moves the valve stem 22A, and thus
moves the valve plug 20, downwardly towards, and upwardly away from, the seat ring 28 in
order to respectively close and open the valve 10. Because the position of the valve plug
surface 24 with respect to the surface 26 of the seat ring 28 determines the rate at which fluid
flows between the valve plug 20 and the seat ring 26, controlling the relative position of the
valve plug surface 24 and surface 26 of the seat ring 28 can, to an extent, control the rate at
which fluid flows through the valve 10.
(21) However, due to the geometrical shape of the valve plug surface 24 along its
area of contact with the surface 26 of the seat ring 28, fluid passing through the orifice 15
from the inlet passageway 16 toward the outlet passageway 18 is not directed away from the
seating surfaces 24, 26 of the valve plug 20 and seat ring 28 to a satisfactory extent in order
to optimally minimize unbalance forces in the region of the seating surfaces 24,26.

(22) Also, due to the proximity of the notches 29 to one another, there is a problem
of the fluid short-circuiting, i.e. passing from one restriction to the next without making use
of the interstage plenum, resulting in the pressure dropping too quickly and thus not
sufficiently avoiding cavitation.
(23) In the remaining drawing figures, like reference numbers are utilized to refer
to those features shared among the conventional valve 10 described above and the preferred
embodiments of the present disclosure.
(24) In FIG. 2, a valve 30 is shown in which a valve trim 31 includes a valve plug
32 having a valve plug surface 34 with a particularly advantageous geometric shape,
implemented in order to reduce the unbalance forces in the region of seating surfaces
associated with the valve plug 32. The valve plug 32 has a plug tip 34 having a radius of
preferably about 0.03 inch, and more preferably, 0.031 inch. The surface 26 of the seat ring
28 is preferably angled about 75° from a plane normal to a longitudinal axis of the valve plug
32. This angle, referred to generally herein as a seat ring angle "a" of about 75°, in
combination with the plug tip 34 having a radius of about 0.03 inch, and more preferably,
0.031 inch, advantageously directs fluid flow away from the seating surfaces of the valve
plug 32 and seat ring 28, which results in a significantly reduced unbalance area, thereby
minimizing unbalance forces produced by the fluid pressure drop. FIG. 2A is an enlargement
of the region of the radius R of the plug tip 34 of the valve plug 32.
(25) This combination of the 75° seat ring angle a and the radius R of the plug tip
of about 0.03 inch, and more preferably, 0.031 inch, is also found to result in an extremely
tight shutoff when the valve plug 32 is closed, thereby improving resistance to leakage
resulting from high seating stress levels, when compared to conventional valve plug and seat
ring arrangements such as that shown in FIG. 1. The unbalance area is also reduced by
approximately 90% as compared to such conventional valve plug and seat arrangements by

utilizing the combination of the 75° seat ring angle a and the radius R of the plug tip of about 0.03 inch. Such a substantial reduction in the unbalance area greatly reduces the actuator thrust requirements for elevated pressure drops. By reducing the area of contact between the plug tip 34 and seat ring 28, there is increased contact stress efficiency, which further minimizes actuator thrust requirements.
(26) The further employment of an anti-cavitation trim on the valve 30, such as the
utilization of notches 29 spaced along the valve plug 32 enhances the tight shutoff, and also
advantageously provides the combined benefits of a reduced unbalance area in a valve with a
staged flow path. The enhanced shutoff tightness is particularly advantageous because it
serves not only to prevent leakage, but also to protect the plug seating surfaces from
impinging fluid, as well as from entrained paniculate and other debris, thereby increasing the
installed life of the valve 30. It is recognized that the plug tip 34 may be used with a
conventional valve plug 20 such as that shown in FIG 1, which shares the same arrangement
of notches 29 as the valve shown in FIG. 2.
(27) FIGS. 3-9 show an alternate embodiment for a valve trim 40. The details of
the plug tip 34 of a radius R of about 0.03 inch, and more preferably, 0.031 inch, and the
relationship to a valve seat (not shown in FIGS. 3-9) having a ring angle a of about 75°, are
the same for this embodiment as in the embodiment shown in FIG. 2, as best shown in FIG.
9. Another feature in the detail of the plug tip 34 best shown in FIG. 9 is the stepped-slope
geometry of the plug tip 34 in a region beyond the plug tip radius R that selectively engages
the seat ring (below the plug tip radius R shown in FIG. 9).
(28) A first portion of this region of the plug tip 34 beyond the plug tip radius R
forms a first angle of preferably about 30° from a longitudinal axis of the valve plug 32. A
more distal second portion of this region of the plug tip 34 beyond the plug tip radius R has a
more gradual slope than the first portion, and forms a second angle of preferably about 60°

from the longitudinal axis of the valve plug 32. This stepped-slope region of the plug tip 34 advantageously enhances the direction of flow away from the seating surfaces of the valve plug 32 and seat ring 28. By directing the flow away from the seating surfaces, a significantly reduced unbalanced area is achieved and unbalanced forces produced by the pressure drop are minimized.
(29) To overcome the problem of short-circuiting experienced with anti-cavitation
valve trims, the embodiment of FIGS. 3-9 advantageously provides a plurality of notches 42,
44,46, 48, 50, 52 disposed at locations rotated relative to the notches 29 of conventional anti-
cavitation trims shown in FIG. 1. Each pair of notches of a given elevation, for example
notches 42, 52, are disposed at an acute angle to one another, forming a wedge-shape, rather
than parallel to one another as are notches of conventional anti-cavitation trims. A distance 8
separates the two notches 42, 52 of each pair at the narrowest part of the wedge-shape, as best
shown in the cross-sectional view of FIG. 6. Preferably, the distance 5 is a small but
reasonably machinable dimension.
(30) Each pair of notches along the valve trim 40 is preferably rotated relative to
the adjacent pair or pairs of notches, as best shown in FIGS. 3-8, such that the distance 8
separating the narrowest part of the wedge-shape formed by notches 42, 52 is offset 180°
from the narrowest part of the wedge-shape formed by the adjacent, next-higher pair of
notches 44, 50. Furthermore, the narrowest part of the wedge-shape formed by the pair of
notches 46,48 is offset 180° from the narrowest part of the wedge-shape formed by the pair
of notches 44,50. Thus, the notches 46,48 are arranged in the same orientation as the
notches 42, 52. Fewer or additional pairs of notches, as well as other relative orientations,
such as offsets other than 180°, may be provided instead.
(31) This rotated, wedge-shaped arrangement of notches 42,44,46,48, 50, 52
results in fluid passing from the inlet passageway 16 to the outlet passageway 18 to spend

more time in the plenum as compared to conventional anti-cavitation trims. By spending more time in the plenum, the fluid is better able to recover pressure prior to entering the next stage, which reduces cavitation.
(32) Alternatively, the angled notches 42-52 may be positioned independently or in
combination as pairs of notches, or even alternate between independent notches and pairs of
notches, in either a repeating or non-repeating pattern, to provide maximum expansion and
pressure recovery prior to proceeding to the next stage. This advantageously provides an
enhanced ability to achieve desired pressure staging. For example, instead of in all angled
notches 42-52 being arranged in pairs, they could be arranged such that at a first level of the
valve trim (corresponding to a first stage) there is a pair of notches 42, 52, at a second level
of the valve trim (corresponding to a second stage) there is another pair of notches, 44, 50, at
a third level of the valve trim (corresponding to a third stage) there is only a single notch 46,
with no other notch at that third level, and at a fourth level of the valve trim (corresponding to
a fourth stage), there again could be a pair of notches. This might be described as a "2-2-1-2"
arrangement of notches, wherein the numbers indicate the number of notches provided at
each respective level.
(33) Thus, a "2-1-2-1" arrangement would indicate a pair of notches 42, 52, at the
first level, a single notch 44 at the second level, a pair of notches 46,48 at the third level, and
a single notch at the fourth level. Preferably, the notches at the levels including only a single
notch would still be arranged askew, i.e. at an acute angle, with respect to the notches of at
least one of the next-higher and next-lower levels.
(34) While the notches 42-52 are preferably angled and the orientation of adjacent
pairs of notches preferably alternate in the manner described, the valve plug 32 may still have
a random orientation relative to the cage 23 (not shown in FIGS. 3-9). Advantageously, by
achieving more reliable and more gradual pressure staging, certain restrictions typically

utilized in a fluid flow system in which control valves are utilized may be relaxed, or opened up, at least slightly, thereby producing a higher capacity valve without sacrificing pressure drop capabilities.
(0035) Although this disclosure focuses on certain preferred embodiments, it is not intended to be so limiting. Variations may be made to the embodiments described herein without departing from the scope of the present disclosure and that are still within the scope of the appended claims. For example, the valve could be a flow-down valve or other type of valve, rather than the flow-up valve as shown in the drawings.























We Claim:
1. A valve for controlling the rate of flow of fluid comprising:
(a) a body having a fluid inlet, an inlet passageway in communication with the fluid inlet, an outlet passageway, a fluid outlet in communication with the outlet passageway, a conduit coupling the inlet passageway and the outlet passageway;
(b) a seat ring disposed about the conduit;
(c) a valve trim having a valve plug and a plug tip, the valve trim having a plurality of anti-cavitation notches therein,
characterized in that
at least two of the plurality of anti-cavitation notches are arranged at an acute angle to one another, wherein the valve trim has two or more levels of notches in the valve trim, and wherein at least one of said levels of the valve trim has a pair of the notches, said notches of the pair forming a wedge shape, and being separated from one another at a narrowest part of the wedge-shape.
2. The valve as claimed in claim 1, wherein a plurality of the levels of the valve trim
has pairs of the notches and wherein the notches in the pairs of notches at each of said
plurality of levels are disposed at an acute angle to one another, whereby said notches of
each said pair of notches form a wedge-shape.
3. The valve as claimed in claim 2, wherein the notches in said plurality of pairs of notches are separated from one another at a narrowest part of the wedge-shape.
4. The valve as claimed in any of claims 2 to 3, wherein both notches of at least one of said pairs of notches are off-set relative to both notches of an adjacent of said pairs of notches.
5. The valve as claimed in any of claims 2 to 3, wherein a narrowest part of the wedge-shape of said at least one pair of notches is off-set 180° relative to a narrowest part of the wedge-shape of the adjacent of said pairs of notches.
6. The valve as claimed in any of claims 1 to 3, wherein the seat ring is disposed at an angle of 75° from a plane extending through a longitudinal axis of the valve plug.
7. The valve as claimed in any of claims 1 to 3, wherein the plug tip has a radius of 0.03 inch.
8. The valve as claimed in any of claims 1 to 3, wherein the plug tip has a radius of 0.031 inch.
9. A valve trim for a valve as claimed in claim 1 comprising a valve plug and a plug tip, the valve trim having a plurality of anti-cavitation notches therein,
the plurality of anti-cavitation notches are arranged in at least one pair of said notches along a length of the valve trim, and wherein the notches in the at least one pair of notches are disposed at an acute angle to one another, whereby said notches form a wedge-shape.
10. The valve trim as claimed in claim 9, wherein the notches in said at least one pair are separated from one another at a narrowest part of the wedge-shape.
11. The valve trim as claimed in any of claims 9 to 10, including a plurality of pairs of the notches and wherein the notches in the plurality of said pairs of notches are disposed at an acute angle to one another, whereby said notches of each said pair of notches form a wedge-shape.
12. The valve trim as claimed in claim 11, wherein the notches in said plurality of pairs of notches are separated from one another at a narrowest part of the wedge-shape.
13. The valve trim as claimed in claim 11, wherein at least one of said pairs of notches is off-set relative to an adjacent of said pairs of notches.
14. The valve trim as claimed in claim 11 wherein a narrowest part of the wedge-shape of said at least one pair of notches is off-set 180° relative to a narrowest part of the wedge-shape of the adjacent of said pairs of notches.
15. The valve trim as claimed in any of claims 9 to 10, wherein the plug tip has a radius of 0.03 inch.
16. The valve trim as claimed in any of claims 9 to 10, wherein the plug tip radius is 0.031 inch.
17. The valve trim as claimed in any of claims 1 and 9, the plug tip having a plug tip radius that selectively engages the seat ring and a stepped-slope region beyond the plug tip radius, the stepped slope region having a first portion adjacent the plug tip radius, said first portion having a first angle relative to a longitudinal axis of the valve plug, and
a second portion having more gradual slope than the first portion, said second portion located more distal to the plug tip radius than the first portion and having a second angle relative to the longitudinal axis of the valve plug, whereby the stepped-slope region serves to direct flow away from at least two seating surfaces defined by the plug tip radius and the seat ring.

18. The valve trim as claimed in claim 17, wherein the first angle relative to the longitudinal axis of the valve plug is 60°, and wherein the second angle relative to the longitudinal axis of the valve plug is 30°.

Documents:

5357-DELNP-2005-Abstract-(30-11-2009).pdf

5357-DELNP-2005-Abstract.pdf

5357-DELNP-2005-Assignment.pdf

5357-DELNP-2005-Claims (25-01-2010).pdf

5357-DELNP-2005-Claims-(30-11-2009).pdf

5357-delnp-2005-claims.pdf

5357-DELNP-2005-Correspondence-Others (11-01-2010).pdf

5357-DELNP-2005-Correspondence-Others (25-01-2010).pdf

5357-DELNP-2005-Correspondence-Others-(30-11-2009).pdf

5357-delnp-2005-correspondence-others.pdf

5357-DELNP-2005-Description (Complete)-(30-11-2009).pdf

5357-delnp-2005-description (complete).pdf

5357-DELNP-2005-Drawings-(30-11-2009).pdf

5357-DELNP-2005-Form-1-(30-11-2009).pdf

5357-delnp-2005-form-1.pdf

5357-delnp-2005-form-18.pdf

5357-DELNP-2005-Form-2-(30-11-2009).pdf

5357-delnp-2005-form-2.pdf

5357-DELNP-2005-Form-3-(30-11-2009).pdf

5357-delnp-2005-form-3.pdf

5357-delnp-2005-form-5.pdf

5357-DELNP-2005-GPA-(30-11-2009).pdf

5357-delnp-2005-gpa.pdf

5357-delnp-2005-pct-101.pdf

5357-delnp-2005-pct-210.pdf

5357-delnp-2005-pct-237.pdf

5357-delnp-2005-pct-304.pdf

5357-DELNP-2005-Petition-137-(30-11-2009).pdf

5357-DELNP-2005-Petition-138-(30-11-2009).pdf

abstract.jpg


Patent Number 241862
Indian Patent Application Number 5357/DELNP/2005
PG Journal Number 32/2010
Publication Date 06-Aug-2010
Grant Date 28-Jul-2010
Date of Filing 22-Nov-2005
Name of Patentee FISHER CONTROLS INTERNATIONAL LLC
Applicant Address 8100 WEST FLORISSANT AVENUE, ST. LOUIS, MO 63136,USA
Inventors:
# Inventor's Name Inventor's Address
1 NATHAN J. HAMBLIN 701 ARLINGTON DRIVE, MARSHALLTOWN, IA 50158,USA
2 TED A. LONG 3806 W. WISTERIA CIRCLE, SUGARLAND, TX 77479, USA
PCT International Classification Number F16K 47/04
PCT International Application Number PCT/US2004/006368
PCT International Filing date 2004-03-02
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/449,641 2003-05-30 U.S.A.