Title of Invention

"A VALVE"

Abstract A valve (10) comprising a valve body (11), a bonnet (15) secured to the valve body (11), and a plug (21), characterized by: the plug(21) comprising a spacer tube(22) comprising a proximal end (19), a distal end(24) and an outer surface, the proximal end (19) of the spacer tube (22) being connected to a proximal guide ring (28) and the distal end (24) of the spacer tube (22) being connected to a distal guide ring (31), the spacer tube(22) being fabricated from a first material having a first CTE, the proximal guide ring (28) being fabricated from a second material having a second CTE, and the distal guide ring (31) being fabricated from a third material having a third CTE that is greater than both the first and third CTEs.
Full Text The present invention relates to a valve
Technical Field
A new high temperature valve assembly is disclosed and, more specifically, a valve assembly with a multiple-component valve plug is disclosed which, due to the use of multiple materials in the construction thereof, provides different rates of thermal expansion in the axial and radial direction. In an embodiment, the rates of axial thermal expansion for the valve plug may also differ at the proximal and distal ends of the valve plug in addition to differences in rates of thermal expansion in the axial and radial directions. Background of the Related Art
Valves are commonly used to control the flow characteristics of a fluid. A conventional valve includes a valve body defining an inlet, an outlet, and a fluid flow path extending between the inlet and the outlet. A throttling element, such as a plug, is disposed in the path to control fluid flow. A stem connects the valve plug to an actuator, which moves the valve plug into and out of the flow path. A conventional valve may include a cage extending across the fluid flow path and having orifices or apertures formed therein. The plug has an outer surface sized to closely fit inside an inner cylindrical wall of the, cage. As a result, the plug is slidable inside the cage between a closed position, in which the plug obstructs the orifices, and an open position, in which the plug is clear of at least a portion of the orifices. The plug-can also be positioned between fully open and closed positions to control the flow rate of fluid through the cage. In a fully open position, the downstream or proximal end of the valve plug may be received in a retainer, which may be part of the cage assembly, the bonnet or the valve body.
To effect a seal between the plug and the cage, a seat ring can be disposed at the upstream or inlet end of the cage. The seat ring provides a seating surface for a seat disposed at a distal or upstream end of the valve plug. The combination of the seat on the valve plug and the seating surface on the seat ring define what is known as the trim set for the valve.
Similarly, to effect a seal between the proximal or upstream end of the valve plug and the cage retainer, the proximal end of the valve plug also typically includes some sort of seat or surface for engaging the cage retainer.

For valves used in high temperature operations, e.g., the transfer of super
heated steam, the seat of the valve plug and the seat ring disposed at the upstream end
of the cage may be fabricated from metal because of the inability of polymeric seals
to withstand such high temperatures. Further, the valve body, the cage and the plug
body or spacer tube of the plug are also typically fabricated from metal, such as alloy
steels and stainless steels.
One problem associated with such high temperature valves is related to the
thermal expansion of the various parts when the valves are used at high operational
temperatures. Typically, the material used to construct the valve body, such as an
alloy steel, will not have the same rate of thermal expansion as that of the trim parts,
i.e., the plug body, seat rings, cage and seat ring, which may be fabricated from
different alloy steels or stainless steels. Thus, as a metallic valve assembly operates at
high temperatures, the critical dimensions of the various components will change and
the valve may not open and seal properly or throttle properly. As a result, the valve
does not function well and the valve stem may be prone to premature breakage and/or
other failures.
One solution to this thermal expansion problem would be to fabricate all of the
components from the same material. However, for larger valves operating at over
1000° F, such a strategy is not practical. For corrosion inhibition, reduced
maintenance and for fabrication issues, the cage is preferably fabricated from a
stainless steel. For cost considerations, the large valve body is preferably fabricated
from a cheaper, alloy steel.
Depending upon the particular design, at high temperatures, the axial
•expansion of a valve assembly is dominated by the valve body and the radial
expansion of the valve assembly is dominated by the cage, the plug body and the cage
retainer, if a retainer structure is employed. Therefore, there is a need for an
improved valve assembly whereby the valve plug expands axially in the same manner
as the valve body and radially in the same manner as the cage and the retainer.
SUMMARY OF THE DISCLOSURE
In satisfaction of the aforenoted needs, an improved valve plug for high
temperature operation is disclosed. The valve plug is fabricated from multiple
materials which enable the valve plug to have an axial thermal expansion rate that is
different than the radial thermal expansion rate of the plug. Further, in a refinement,
the distal or upstream end of the valve plug can expand radially at a different rate than
the radial expansion of the downstream or proximal end of the valve plug.
In a further refinement, various improved high temperature valve assemblies
are also disclosed. In an embodiment, a two-piece cage assembly is provided that is
connected to the valve body. The downstream or proximal cage component, or cage
retainer, is connected to an upstream component, referred to as the cage. The cage
retainer can be fabricated from an alloy steel while the cage is preferably fabricated
from a stainless steel such as an austenitic stainless steel. The valve plug comprises a
spacer tube having a proximal or downstream end connected to a proximal guide ring
and a distal or upstream end connected to a distal guide ring. The proximal guide ring
is fabricated from material having a coefficient of thermal expansion (CTE) that
approximates that of the material used to fabricate the cage retainer. Further, the
distal guide ring is fabricated from a material having a CTE that approximates that of
the material used to fabricate the cage. Finally, the spacer tube is fabricated from a
material having a CTE that approximates that of the material used to fabricate the
valve body.
In an embodiment, a one-piece page cage construction is provided without a
separate retainer component and therefore the proximal guide ring and distal guide
ring are fabricated from a material have a CTE that approximates that of the material
used to fabricate the one-piece cage component and the spacer tube is fabricated from
a material with a CTE that approximates that of the valve body.
In another refinement, the bonnet of the valve assembly forms a cage retainer
to which a cage structure is connected. The proximal or downstream guide ring and
the spacer tube are fabricated from materials having a CTE that approximates that of
the material used to fabricate the bonnet while the distal or upstream guide ring is
fabricated from a material having a CTE that approximates that of the material used to
fabricate the cage.
Similarly, in another embodiment, if the cage retainer is an integral part of the
valve body, the spacer tube and proximal guide are fabricated from materials having a
CTE that approximates that of the material used to fabricate the valve body while the
distal or upstream guide ring is fabricated from the material a CTE similar to that of
the material used to fabricate the cage.
Thus, a number of improved valve assemblies and valve plug designs are
provided whereby the radial expansion of the proximal or downstream end of the
valve plug, the axial expansion of the valve plug and the radial expansion of the distal
or upstream end of the valve plug are all matched to simulate that of the cage, cage
retainer, bonnet or valve body components with which they interact during operation.
Other features and advantages of the disclosed valves and valve plugs will be
apparent to those skilled in the art from the following detailed description and
accompanied drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosed embodiments are described more or less diagrammatically in the
following drawings wherein:
Fig. l i s a sectional view of a valve assembly made in accordance with this
disclosure, illustrating a 2-piece cage and a multi-component valve plug;
Fig. 2 is an enlarged sectional view of the valve plug shown in Fig. 1;
Fig. 2 A is an enlarged partial sectional view of the downstream or proximal
guide ring of the valve plug shown in Fig. 2;
Fig. 3 is an enlarged partial sectional view of the valve assembly shown in Fig.
i;
Fig. 4 is an alternative valve plug made in accordance with this disclosure;
Fig. 5 is yet another alternative valve plug made in accordance with this
disclosure;
Fig. 6 is a sectional view of the 2-piece cage assembly of the valve assembly
shown in Fig. 1; and
Fig. 7 is a sectional view of the valve body of valve assembly shown in Fig. 1.
It should be understood that the drawings are not necessarily the scale and that
the embodiments are illustrated by graphic symbols, phantom lines, diagrammatic
representations and fragmentary views. In certain instances, details which are not
necessary for an understanding of the disclosed valves or which render other details
difficult to perceive may have been omitted. It should be understood, of course, that
this disclosure is not limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION OF THE
PRESENTLY PREFERRED EMBODIMENTS
Fig. 1 illustrates a valve 10 that includes a valve body 11 designed for high
temperature operation. The valve body 11 defines an inlet 12, an outlet 13 and a third
opening 14 that is covered by a bonnet 15 that is connected to the valve body 11 by a
plurality of fasteners shown at 16. The bonnet 15 includes an axial passageway 17
that slideably accommodates a stem 18 which, in turn, is connected to a downstream
or proximal end 19 of a valve plug assembly 21. The stem 18 is connected to an
actuator (not shown) for opening and closing the valve 10.
Referring to Figs. 1-3 together, the valve plug assembly 21 comprises a spacer
tube 22 that includes the proximal or downstream end 19 and a generally cylindrical
body portion 23 that terminates at an open distal or upstream end 24. The proximal
end 19 includes an opening 25 for connection to the stem 18 (see Fig. 1) and a
plurality of through openings shown at 26 which permit the pressure on either side of
the proximal end 19 of the spacer tube 22 to be equalized. The proximal end 19 of the
spacer tube 22 includes a recess 27 that accommodates a proximal guide ring 28.
Further, the distal or upstream end 24 of the spacer tube 22 also includes a recess 29
that similarly accommodates a distal or upstream guide ring 31. As seen in Fig. 2 A,
the recess 27 includes one or more thread channels shown at 32 for accommodating a
complimentary thread 33 of the proximal guide ring 28 to connect the guide ring 28 to
the proximal end 19 of the spacer tube 22. The guide ring 28 may also be welded or
connected to the spacer tube with suitable fasteners. Further, the proximal guide-ring
28 also includes a plurality of recesses 34 for accommodating rings shown in phantom
at 39 that frictionally engage the interior surface 35 of the cage retainer 36 (see Figs. 1
and 3). The rings 31,28 are preferably carbon rings which are known in the art. As
known to those skilled in the art, other materials, such as N07718 Nickel Alloy,
stainless steel can be used. The recess 40 (not in Figures) defined by the guide ring
28 and body 23 of the spacer tube 22 accommodates a "C" seal 50 as shown in Fig.
2A.
Returning to Fig. 2, the distal or upstream guide ring 31 can be connected to
the distal end 24 of the spacer tube 22 by any conventional means, such as welding, as
indicated by the welds shown at 37. A peripheral slot 38 in the distal guide ring 31 is
provided to define a lower annular flange 39 for frictionally engaging the seat ring 41
(see Figs. 1 and 3) which provides a seat for the distal end 24 of the valve plug 21.
Referring to Figs. 1, 3 and 6, as noted above, the valve body 11 defines an
inlet 12 and an outlet 13. Fluid is communicated through the inlet 12, through the seat
ring 41 to an interior of the cage assembly 42 which, as noted above, includes the
cage retainer 36 which is connected to a lower cage or simply "cage" 43. In the 2-
piece cage assembly 42 shown in Figs. 1, 3 and 6, the lower cage structure 43
comprises a permeable cylinder having a proximal end 44 connected to a distal end 45
of the cage retainer 36. The cage 43 also includes a distal end 46 that is connected to
the seat ring 41 as shown in Figs. 1 and 3.
Further, in Figs. 1 and 3, the valve 10 is in a closed position, with the valve
plug 21 blocking flow from the inlet 12 through the cage 43 to the outlet 13. In
operation, to open the valve 10, the actuator (not shown) moves the stem 18 upward
thereby lifting the proximal end 24 of the spacer tube 22 off of the seat ring 41 and
exposing some or all of the inner surface 46 of the cage 43 to flow between the inlet
12 and outlet 13 of the valve body 10.
In contrast to the permeable cage structure 43, the cage retainer 36 is a solid,
non-permeable structure. The cage retainer 36 shown in Figs. 1 and 3 can be a
separate component that is connected to the valve assembly 10 by way of the annular
flange 47 that is sandwiched between the bonnet 15 and the flange 48 of the valve
body 11. In contrast, the cage retainer 36 may be integrally connected or form a part
of the bonnet 15 or, the cage retainer 36 may be integrally connected to or form a part
of the valve body 11. As another alternative, a one-piece cage structure can be
provided and therefore the permeable cage structure 43 can be connected to the valve
body 11 or bonnet 15 directly without a retainer structure such as the one shown at 36
in Figs. 1 and 3.
As shown in Fig. 6 the cage 43 may be connected to the cage retainer 36 by
way of a threaded connection between the proximal end 44 of the cage 43 and the
distal end 45 of the cage retainer 36. Other suitable attachment mechanisms, such as
welding or frictional fit may be employed. The distal end 48 of the cage 43 mateably
receives flange 49 of the seat ring 41. The connection between the distal end 46 of
the cage 43 to the flange 49 of the seat ring 41 is preferably a slip fit to compensate
for the effects of thermal expansion.
As shown in Figs. 3 and 7, the seat ring 41 is connected to the inlet 12 of the
valve body 11 by way of the flange 51 being mateably received in the inlet opening
52. Again, the connection between the flange 51 of the seat ring 41 and the opening
52 of the valve body 11 can be a threaded connection or a welded connection, as
exemplified by the weld bead shown at 53 or other suitable connection method. In
addition, an opening 54 (Figs. 1 and 3) may be provided in the valve body 11 for
purposes of receiving a pressure release valve 55 as shown in Fig. 7.
Turning to Figs. 4 and 5, variations of the valve plug 21 are shown at 21a and
21b, respectively. In the embodiment shown at 21 a in Fig. 4, the spacer tube 22a is a
generally cylindrical structure consisting essentially of the cylindrical body portion
23a that is sandwiched between the proximal guide ring 28a and distal guide ring 31a.
The guide ring 28a may be welded to the proximal end 19a of the spacer tube 22a and
the guide ring 3 la may be welded to the distal end 24a of the spacer tube 22a as
shown.
In contrast, the valve plug 21b shown in Fig. 5 includes a spacer tube structure
22b with a proximal end 19b having a recess 27b formed therein for accommodating
the proximal guide ring 28b, which may be connected to the spacer tube 22b by
welding as shown. Similarly, the distal end 24b of the spacer tube 22b includes a
recess 29b that accommodates the distal end guide ring 31b that also may be
connected to the spacer tube 22b by welding as shown.
Returning to Fig. 1, as the valve 10 is exposed to high temperatures, such as,
1000° F, various components of the valve 10 will expand both radially and axially.
Specifically, the spacer tube 22 of the valve plug 21 will expand both axially, that is
along the axis shown at 60 as well as radially. The cage 43 is also prone to both axial
and radial expansion.
In order for the valve 10 to achieve a proper closed and sealed position and
proper throttling performance as shown in Fig. 1, the radial expansion of the plug 21
must generally match the radial expansion of the cage 43. To meet this end, the plug
21 is equipped with the distal guide ring 31 which is fabricated from a material having
a coefficient of thermal expansion (CTE) that closely approximates the CTE of the
material used to fabricate the cage 43. In an embodiment, the cage 43 is fabricated
from an austenitic stainless steel for corrosion resistance at high temperatures and for
other manufacturing purposes. Thus, the distal guide ring 31 should be fabricated
from a material having a CTE similar to that of the austenitic stainless steel used to
fabricate the cage 43. In a preferred embodiment, both the cage 43 and the distal
guide ring 31 are both fabricated from austenitic stainless steels and, most preferably,
are fabricated from the same austenitic stainless steel. One suitable example of an
austenitic stainless steel for the cage 43 and distal guide ring 31 for high temperature
applications (i.e., 1000°F) is S30409 SST. Another suitable example for high
temperatures is S31609 SST. S31603 SST and S30403 SST austenitic stainless steels
can be used for lower temperature applications.
Due to economies of scale, the larger valve body 11 is preferably fabricated
from an alloy steel such as a C12A or equivalent alloy steel. Other suitable alloy
steels for high temperature (i.e., > 1000°F) include WC9 and WC6 alloy steels while
WCC alloy steel can be used for lower temperature applications. Additional suitable
alloy steels will be apparent to those skilled in the art. These alloy steels can also be
used to fabricate the spacer tube 23 and proximal guide 28 for certain designs as
discussed below.
In contrast, to effect a seal between proximal end 19 of the valve plug 21 and
the cage retainer 36, the proximal end 19 of the valve plug 21 must have a radial
expansion that closely matches that of the cage retainer 36 as shown in Fig. 1. If the
proximal end 19 of the valve plug 21 has a significantly higher CTE than the cage
retainer 36, the valve 10 may not be able to open properly. If the proximal end 19 of
the valve plug 21 has a significantly lower CTE than the cage retainer 36, excessive
rattling, vibrating or breakage of the valve stem 18 may occur. Thus, in the
embodiment illustrated, the proximal guide ring 28 should be fabricated from a
material with a CTE that closely matches that of the cage retainer 36 or other valve
body structure in which it is accommodated.
In the event a single cage structure is utilized (not shown), the cage 43 would
be directly connected to either the valve body 11 or the bonnet 15. The valve body 11
and bonnet 15 would preferably form some sort of retainer component for mateably
receiving the proximal end 19 at the spacer tube so as to permit a majority of the
spacer tube 22 to be drawn through the cage 43 to permit communication between the
inlet 12 and outlet 13 of the valve body 11. Thus, in such a situation, the materials
selected for the guide ring 31 and cage 43 would be closely matched so that the radial
expansion of the guide ring 31 closely matches the radial expansion of the cage 43.
However, the proximal guide ring 28 could be fabricated from the less expensive
alloy material used to fabricate the valve body 11, bonnet 15 or other retainer
structure connected to either the valve body 11 or bonnet 15. Similarly, because the
axial expansion of the valve 10 is dominated by the valve body 11 or retainer
structure that is formed as part of the bonnet 15 or valve body 11, the spacer tube 22
can be fabricated from a less expensive alloy material so that the axial expansion of
the spacer tube 22 closely matches that of the valve body 11 or retainer structure that
forms a part of the valve body 11 or bonnet 15.
However, if a one-piece cage structure is provided whereby a lower section
such as a perforated cage section 43 is integrally connected to an upper section such
as an impermeable retainer section similar to that shown at 36 in Fig. 1, the radial
expansion of both guide rings 28, 31 would then preferably match the radial
expansion of the one-piece cage structure (36,43). hi such a situation, if the cage
structure (36,43) is fabricated from an austenitic stainless steel, the guide rings 28, 31
would also need to be fabricated from an austenitic stainless steel with a similar CTE.
In contrast, if the proximal end 19 of the spacer tube 22 is received in a retainer
structure that is integrally connected to the bonnet 15 or valve body 11, then the
proximal guide ring 28 should be fabricated from a material similar to that used the
valve body 11 or bonnet 15. If however, the proximal guide ring 28 is received in a
section of a stainless steel cage structure, the guide ring 28 would need to be
fabricated from a stainless steel having a similar CTE.
Thus, one skilled in the art will appreciate that numerous combinations and
possibilities exist but it is important to know that the structures of the valve plug 21
should be fabricated with material similar to those of the components in which they
interact during operation. Specifically, the distal guide ring 31 should be fabricated
from a material having a CTE similar to that of the cage 43. The spacer tube 22
should be fabricated from a material with a CTE similar to that of the valve body 11.
Similarly, the proximal guide ring 28 should be fabricated from a material similar to
that used to fabricate the structure in which it is received, such as that of the cage
retainer 36 or similar retainer structure formed by the bonnet 15 or valve body 11.
Further, more than two materials can be used to fabricate the valve plug 21.
Specifically, if a two-piece cage assembly 42 is provided with a cage retainer 36 and a
cage 43, then the proximal guide ring 28 would need to be fabricated from a material
similar to that of the cage retainer structure 36 the spacer tube would be fabricated
from a material that closely matches that of the valve body 11 and the distal guide
ring 31 would be fabricated from the material that closely matches that of the cage 43.
Thus, the valve plug 21 could be fabricated from two or three different materials.
Generally, the coefficient of thermal expansion of the components that need to
be matched, e.g., the distal guide ring 31 and the cage 43, should be within about 10%
of each other, more preferably within about 7% of each other and, most preferably
within about 1% or be fabricated from the same material, thereby providing a similar
CTE and therefore a similar radial or axial expansion. The differences between the
coefficient of thermal expansion of alloy steels and stainless steels are substantial,
generally about 35 percent. Thus, if the cage 43 is fabricated from an austenitic
stainless steel the distal guide ring 31 is preferably fabricated from a stainless steel,
and more preferably from an austenitic stainless steel as well. If the valve body 11 is
fabricated from an alloy steel, the spacer tube 22 should be fabricated from an alloy
steel as well. If a retainer structure is provided that is fabricated from an austenitic
stainless steel, the proximal guide ring 28 should be fabricated from an austenitic
stainless steel or a suitable stainless steel. Finally, if the retainer structure is
fabricated from an alloy steel, the proximal guide ring 28 should be fabricated from
an alloy steel as well. In certain designs, however, the proximal guide ring may be
retained in a stainless steel structure and therefore should be fabricated from a
stainless steel as well.
The foregoing detailed description has been given for clearness of
understanding only, and no unnecessary limitation should be understood therefrom as
modifications would be obvious to those skilled in the art.


We claim:
1. A valve (10) comprising a valve body (11), a bonnet (15) secured to the
valve body (11), a plug (21) and jbptionally comprising a case (43) and a
seal ring (41)^ and
characterized by:
the plug(21) comprising a spacer tube(22) comprising a proximal end (19), a distal end(24) and an outer surface, the proximal end (19) of the spacer tube (22) being connected to a proximal guide ring (28) and the distal end (24) of the spacer tube (22) being connected to a distal guide ring (31), the spacer tube(22) being fabricated from a first material having a first CTE, the proximal guide ring (28) being fabricated from a second material having a second CTE, and the distal guide ring (31) being fabricated from a third material having a third CTE that is greater than both the first and third CTEs.
2. The valve (10) as claimed in claim 1, wherein the second CTE is within 10% of the first CTE.
3. The valve (10) as claimed in claim 1 or 2, wherein the first and second materials are alloy steels and the third material is an austenitic stainless steel.
4. The valve (10) as claimed in any one of claims 1 to 3, wherein the first and second materials are the same and are an alloy steel and the third material is an austenitic stainless steel.
5. The valve (10) as claimed in claim 1, wherein the cage (43) comprises a cage assembly (42) defining a bore extending along an axis, the cage assembly (42) comprising a cage retainer (36) having a proximal end connected to the valve body (11) and a distal end coaxially connected

to the cage (43), the cage retainer (36) and valve body (11) being fabricated from a fourth material having a fourth coefficient of thermal expansion CTE, the cage (43) being fabricated from fifth material having a fifth CTE, the proximal end (19) of the spacer tube (22) is received in the cage retainer (36) the distal end (24) of the spacer tube (22) is received in the cage (43), the outer surface of the plug (21) and the proximal and distal guide rings (28,31) being sited to fit inside the bore defined by the cage assembly (42) and for slidable movement along the axis of the bore, the first CTE being within 10% of said fourth CTE, the second CTE being within 10% of said fourth CTE, and the third CTE being within 10% of said fifth CTE.
6. The valve (10) as claimed in claim 5, wherein the fourth, first and second materials are alloy steels and the fifth and third materials are austenitic stainless steels.
7. The valve (10) as claimed in claim 5 or 6, wherein the fourth, first and second materials are the same and are an alloy steel and the fifth and third materials are the same and are an austenitic stainless steels.
8. The valve (10) as claimed in any one of claims 5 to 7, wherein the valve body (11) is fabricated from an alloy steel.
9. The valve (10) as claimed in claim 1, wherein the valve body (11) is fabricated from a fourth material having a fourth coefficient of thermal expansion CTE, the cage (43) defines a bore extending along an axis, the cage (43) comprising a proximal end connected to the valve body (11) and a distal end mateably received in the seat ring (41), the cage (43) being fabricated from a fifth material having a fifth coefficient of thermal expansion CTE; the outer surface of the plug (21) and the proximal and distal guide rings (28,31) being sized to fit inside the bore defined by the

cage (43) and adapted for slidable movement along the axis of the bore, the first CTE being within 10% of said fourth CTE, the second CTE being within 10% of said fifth CTE.
10. The valve (10) as claimed in claim 9, wherein the fifth and second materials are austenitic stainless steels.
11. The valve (10) as claimed in claim 9 or 10, wherein the fourth and first materials are the same and are an alloy steel.
12. The valve (10) as claimed in claim 1, wherein the valve body (11) comprising an inlet (12), an outlet (13) and a third opening (14) covered by bonnet (15), the bonnet (15) being secured to the valve body (11) at the third opening (14) and comprising a cylindrical retainer (36) having an open distal end connected to a proximal end of the cage (43), the bonnet (15) and valve body (11) being fabricated from a fourth material having a fourth coefficient of thermal expansion CTE, the cage (43) and cylindrical retainer (36) of the bonnet (15) defining a bore extending along an axis, the cage (43) comprising a distal end coaxially connected to the seat ring (41), the seat ring (41) connected to the inlet (12) of valve body (11), the cage (43) being fabricated from a fifth material having a fifth coefficient of thermal expansion CTE, the outer surface of the plug (21) and the proximal and distal guide rings (28, 31) being sized to fit inside the bore defined by the cage (43) and cylindrical retainer (36) of the bonnet (15) and adapted for slidable movement along the axis of the bore, the first CTE being within 10% of said fourth CTE, the second CTE being within 10% of said fourth CTE, the second CTE being within 10% of said fourth CTE and the third CTE being within 10% of said fifth CTE.

13. The valve (10) as claimed in claim 12 , wherein the fourth,' first and second materials are alloy steels and the fifth and third materials are austenitic stainless steels.
14. The valve (10) as claimed in claim 12 or 13, wherein the fourth, first and second materials are the same and are an alloy steel and the fifth and third materials are the same and are an austenitic stainless steel.
15. The valve (10) as claimed in claim 1, wherein the valve body (11) comprises an inlet (12), an outlet (13) and a cylindrical cage retainer (36) disposed therebetween, the cylindrical cage retainer (36) having an open distal end axially connected to a proximal end of the cage (43), the valve body (11) being fabricated from a fourth material having a fourth coefficient of thermal expansion CTE, the cage (43) and cylindrical retainer (36) of the valve body (11) defining a bore extending along an axis, the cage (43) further comprising a distal end coaxially connected to the seat ring (41),the seat ring (41) connected to the inlet (12) of valve body (11), the cage (43) being fabricated from a fifth material having a fifth coefficient of thermal expansion CTE, the outer surface of the plug (21) and the proximal and distal guiderings (28, 31) being sized to fit inside the bore defined by the cage(43) and cylindrical retainer (36) of the valve body (11) and adapted for slidable movement along the axis of the bore, the first CTE being within 10% of said fourth CTE, the second CTE being within 10% of said fourth CTE and the third CTE being within 10% of said fifth CTE.
16. The valve (10) as claimed in claim 15, wherein the fourth, first and second materials are alloy steels and the fifth and third materials are austenitic stainless steels.

17. The valve (10) as claimed in claim 15 or 16, wherein the fourth, first and second materials are the same and are an alloy steel and the fifth and third materials are the same and are an austenitic stainless steel.
18. The valve (10) as claimed in any one of the preceding claims, wherein the outer surface of the spacer tube(22) comprises a proximal recess (34) that accommodates the proximal guide ring (28) and a distal recess (29) that accommodates the distal guide ring (31).
19. The valve (10) as claimed in any one of the preceding claims wherein the proximal guide ring (28) is welded to the proximal end (19) of the spacer tube (22) and the distal guide ring (31) is welded to the distal end (24) of the spacer tube (22).

Documents:

29-DELNP-2006-Abstract-(10-09-2008).pdf

29-delnp-2006-abstract.pdf

29-DELNP-2006-Claims-(10-09-2008).pdf

29-DELNP-2006-Claims-(16-03-2009).pdf

29-DELNP-2006-Claims-(24-03-2009).pdf

29-delnp-2006-claims.pdf

29-delnp-2006-complete specification (granted).pdf

29-DELNP-2006-Correspondence-Others-(10-09-2008).pdf

29-DELNP-2006-Correspondence-Others-(16-03-2009).pdf

29-DELNP-2006-Correspondence-Others-(23-10-2008).pdf

29-DELNP-2006-Correspondence-Others-(27-01-2009).pdf

29-delnp-2006-correspondence-others-1.pdf

29-delnp-2006-correspondence-others.pdf

29-delnp-2006-description (complete)-10-09-2008.pdf

29-delnp-2006-description (complete).pdf

29-DELNP-2006-Drawings-(10-09-2008).pdf

29-delnp-2006-drawings.pdf

29-DELNP-2006-Form-1-(10-09-2008).pdf

29-delnp-2006-form-1.pdf

29-delnp-2006-form-18.pdf

29-DELNP-2006-Form-2-(10-09-2008).pdf

29-delnp-2006-form-2.pdf

29-DELNP-2006-Form-3-(10-09-2008).pdf

29-delnp-2006-form-3.pdf

29-delnp-2006-form-5.pdf

29-DELNP-2006-GPA-(23-10-2008).pdf

29-delnp-2006-pct-101.pdf

29-delnp-2006-pct-210.pdf

29-delnp-2006-pct-237.pdf

29-delnp-2006-pct-304.pdf

29-DELNP-2006-Petition-137-(10-09-2008).pdf

29-DELNP-2006-Petition-137-(27-01-2009).pdf

29-DELNP-2006-Petition-138-(10-09-2008).pdf


Patent Number 233294
Indian Patent Application Number 29/DELNP/2006
PG Journal Number 13/2009
Publication Date 27-Mar-2009
Grant Date 27-Mar-2009
Date of Filing 02-Jan-2006
Name of Patentee FISHER CONTROLS INTERNATIONAL LLC.
Applicant Address K-ANNEX,8100 WEST FLORISSANT AVENUE, ST. LOUIS, MO 63136, U.S.A.
Inventors:
# Inventor's Name Inventor's Address
1 KIMBALL RALPH BARRON 2627 160TH STREET, MARSHALLTOWN, IA 50158, U.S.A.
2 PAUL T. ALMAN 1906 BAILEY DRIVE,MARSHALLTOWN, IA 50158, U.S.A.
PCT International Classification Number F16K 27/00
PCT International Application Number PCT/US2004/021033
PCT International Filing date 2004-06-25
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/613,300 2003-07-03 U.S.A.