Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02228575 2006-O1-11
PATENT
Docket No. DRE340/4-8
IMPROVED FLUID PRESSURE MEASURING SYSTEM
FOR CONTROL VALVES
The present invention pertains to control valves; more particularly, the
present
invention pertains to control valves which include a fluid pressure monitoring
system.
HyOUND
In recent years it has become extremely important for control valve
manufacturers
to develop valve positioning mechanisms that can accurately sense fluid
pressures at both
the valve inlet and the valve outlet. The sensed pressures may then be used
for various
purposes to include adjusting fluid flow through the control valve. Thus,
accurate fluid
pressure measurement is critical.
Detracting from the accuracy of fluid pressure measurements through control
valves are complex fluid flow components such as swirl, secondary or counter-
rotational
vortex flow, boundary layer flow and/or high-core velocity flow. Accordingly,
an
accurate measurement of fluid pressure at both the inlet and the outlet of a
control valve
can only be obtained by aninimizing those components of fluid flow which
detract from
the accuracy of fluid presstue measurement.
Therefore, a need exists in the art to provide a system by which those
components
of fluid flow which detract from the accuracy of fluid pressure measurement in
a control
valve are minimized to increase the accuracy of fluid pressure measurement.
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CA 02228575 2006-O1-11
PATENT
Docket No. DRE340/4-8
SUMMARY
The improved fluid pressure measuring system for control valves of the present
invention minimizes those aspects of fluid flow which detract from the
accuracy of fluid
pressure measurement in control valves.
Specifically, a fluid flow conditioner is placed upstream and inboard of a
substantially
circular averaging channel. Once having passed through the fluid flow
conditioner and into
the averaging channel, fluid is conducted from the averaging channel to a
fluid pressure
measuring device. Thus, those components of fluid flow which detract from an
accurate
pressure measurement are removed by the fluid flow conditioner before the
fluid ever enters
the averaging channel on its way to the pressure measuring device. In the
preferred
embodiment, a fluid flow conditioner is located upstream of the flow path in
the averaging
1 S channel on both the inlet and outlet sides of the control valve.
In one particular embodiment there is provided a system for improving the
fluid
pressure measurement at both the inlet and the outlet of a control valve, said
control valve
being constructed and arranged to utilize said fluid pressure measurement to
control flow
through said control valve, said system for improving fluid pressure
measurement at both the
inlet and the outlet of a control valve comprising: fluid flow conditioners
constructed and
arranged to fit within the inlet and the outlet of the control valve; a
substantially circular
averaging channel located outboard from and downstream from said fluid flow
conditioners;
said substantially circular averaging channels constructed and arranged to
surround the inlet
and the outlet of the control valve; and conduits for conducting flowing fluid
from said
substantially circular averaging channels to a fluid pressure measurement
device.
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In another embodiment there is provided a system for measuring fluid pressure
at both
the inlet and the outlet of a control valve with a pressure measuring device,
said control valve
having an inlet mounting flange, an outlet mounting flange, and a valve body
therebetween,
said system comprising: an inlet fluid flow conditioner positioned within the
inlet mounting
flange; a substantially circular inlet averaging channel located outboard from
and
downstream from said fluid flow conditioner, said substantially circular inlet
averaging
channel having a diameter greater than the inlet of the control valve, but
less than the outer
diameter of the inlet mounting flange; an outlet fluid flow conditioner
positioned within the
outlet mounting flange; a substantially circular outlet averaging channel
located substantially
outboard from and downstream from said outlet fluid flow conditioner, said
substantially
circular outlet averaging channel having a diameter greater than the outlet of
the control
valve, but less than the outer diameter of the outlet mounting flange; a
passage for conducting
fluid from said substantially circular inlet averaging channel to the pressure
measuring
device; and a passage for conducting fluid from said substantially circular
outlet averaging
channel to the pressure measuring device.
In a further embodiment there is provided an adjustable flow control valve,
said
adjustable flow control valve being responsive to inlet and outlet pressures,
said adjustable
flow control valve comprising: an inlet mounting; an outlet mounting; a valve
body located
between said inlet mounting and said outlet mounting; an inlet fluid flow
conditioner
positioned within the inlet mounting; a substantially circular inlet averaging
channel located
outboard from and downstream from said inlet fluid flow conditioner, said
substantially
circular inlet averaging channel surrounding the inlet mounting of the control
valve; an outlet
fluid flow conditioner positioned within the inlet mounting; a substantially
circular outlet
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CA 02228575 2006-O1-11
averaging channel located outboard from and downstream from said outlet fluid
flow
conditioner, said substantially circular outlet averaging channel surrounding
the outlet
mounting of the control valve; a passage for conducting fluid from said
substantially circular
inlet averaging channel; and a passage for conducting fluid from said
substantially circular
outlet averaging channel.
DESCRIPTION OF DRAWINGS
A better understanding of the improved fluid flow pressure measuring system
for
control valves of the present invention may be had by reference to the figures
wherein:
FIGURE 1 is a cross-sectional view of a control valve incorporating the
improved
fluid pressure measuring system of the present invention;
FIGURE 2 is an enlarged cross-sectional view of the valve inlet;
FIGURE 3 is an enlarged cross-sectional view of the valve outlet;
FIGURE 4 is an end view of the valve inlet;
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FIGURE 5 is a perspective view of a control valve, including an external
manifold block; and
FIGURE 6 is an exploded view of the control valve shown in Figure 5 showing
the attachment of the external manifold block to a flange of the control
valve.
S
~JESCR1_PTION OF EMBODIMENTS
By referring to Figure 1, it will be seen that the improved fluid pressure
measurement system 10 of the present invention is used in conjunction with a
globe type
control valve assembly 100. While illustrated and described for use with a
globe type
control valve assembly 100, those of ordinary skill in the art will understand
that the
present invention may be used with a wide variety of different types of
control valves.
The control valve assembly 100 includes an inlet flange 102 which has a
plurality
of axial bolt holes 104 for connecting the control valve assembly 100 to a
flange on
another valve or to a fluid conduit such as a pipe, elbow or tee (not shown).
A central
opening 106 within the inlet flange 102 allows fluid to pass into the interior
of the control
valve assembly 100.
Located downstream from the inlet flange 102 is the body 110 of the control
valve
assembly 100. On the opposite end of the body 110 of the control valve
assembly 100
from the inlet flange 102 is an outlet flange 112. Similar to the inlet flange
102, the
r
outlet flange i 12 includes a plurality of bolt holes I 14 which surround a
central opening
1 I6. Note that an inlet fluid flow conditioner I2 and an outlet fluid flow
conditioner 52
are placed within the openings 106 and 116 in the flanges i 02 and 112,
respectively.
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In Figure 2 it may be seen how the improved pressure measuring system 10 is
positioned on the inlet side of the control valve assembly 100. A similar
arrangement for
the outlet side of the control valve assembly 100 is shown in Figure 3. A
fluid flow
r
conditioner I2 is fitted to mount within the opening 106. As shown in Figure
4, in the
preferred embodiment, the fluid flow conditioner 12 includes thirty-five
openings 14
within a plate portion 16 sized to fit within the opening 106 in the inlet
flange 102.
Extending downstream from the plate portion 16 on the inlet side is a short
cylindrical
section 18 which both provides a radial fluid flow path 38 and a distal end 20
which
positions the fluid conditioner 12 by abutting a shoulder 39 within the
control valve
housing l I0.
In Figure 3 it may be seen that on the outlet side of the control valve
assembly
100 is a second fluid flow conditioner 52. The thirty-five openings 54 are in
a plate
portion 56 which abuts a shoulder 55 within the control valve housing 110.
Extending
downstream from the plate portion 56 is is a short cylindrical section 58
which both
I S provides a radial flow path 38 and a distal end 60 with an external rim 62
to engage the
opening I 16 in the flange I 12 on the outlet side of the control valve
assembly 100.
The thirty-five openings arranged in a predetermined pattern in each of the
inlet
fluid flow conditioner 12 and the outlet fluid flow conditioner 52 minimize
those fluid
flow components which detract from accurate pressure measurement.
ZO As previously indicated, both the short cylindrical section 18 on the inlet
side of
the valve I00 and the short cylindrical section 58 on the outlet side of the
valve 60
include a plurality of radial fluid flow paths 38.
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Outboard of the fluid flow paths 38 on both the inlet and the outlet sides of
the
control valve 100 is an averaging channel into which the flow conditioned
fluid passes.
Fluid flow to the averaging channel on either the inlet or outlet sides of the
valve 100 is
substantially perpendicular to the fluid flow through the flow conditioner on
either side
of the control valve 100.
Flow conditioned fluid is collected in the inlet averaging channel 42 before
passing on to a fluid pressure measuring device 48. By referring again to
Figures 1 and
2, it may be seen that, on the inlet side, flow conditioned fluid passes
through the fluid
flow paths 38 formed in the short cylindrical section 18 of the flow
conditioner 12, thence
through a radial passage 44 formed in the inlet flange 102 to a set of either
tapered or
straight pipe threads 46 formed in the inlet flange 102 at the end of the
radial passage 44.
Such configuration may be used on either the inlet or the outlet side of the
control valve
assembly 100.
By referring to Figures l and 3, it may be seen that on the outlet side of the
control valve assembly 100 is an alternate configuration for the opening 84
leading away
from the averaging chamber 82 and on to a fluid pressure measuring device 88.
Instead
of passing directly through the outlet flange 112, an axial passage 84 extends
from the
averaging chamber 82. This axial passage 84 then turns a right angle and
terminates at
a set of tapered or straight pipe threads 86 formed in the valve body 110.
Such
configuration may be used on either the inlet or outlet side of the control
valve assembly
100.
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In Figures 5 and 6 is shown yet another configuration of a control valve
assembly
100 incorporating the improved fluid pressure measuring system of the present
invention.
Specifically, a manifold block 60 is bolted to both the inlet flange 102 and
the outlet
flange 112. The fluid flow configuration from the averaging chambers 42 and 82
is like
that shown in Figure 2. To assure a leak-proof connection between one or both
of the
flanges on either end of the control valve assembly 100, a variety of
different arrays of
hardware may be used. Shown in Figure 6 is but one example of a hardware
connection
utilizing a small connecting collar 62 encircled by two O-rings 64. A valve
manifold 68
is sealingly connected to the manifold block 60 which extends between the two
flanges
on either end of the control valve assembly 100.
A differential pressure transmitter 69 may be sealingly connected to the valve
manifold 68.
Inlet and outlet pressures may be blocked by closing valves 66. A third valve
67
may be opened to equalize pressure to the differential pressure transmitter
for calibration.
There is provided by the present invention a system for improving fluid
pressure
measurement at either the inlet side of a control valve, the outlet side of a
control valve,
or both.
While the preferred embodiments of invention have been explained in the
foregoing description, those of ordinary skill in the art will understand that
variations to
the disclosed embodiments are possible. Such variations shall fall within the
scope and
meaning of the appended claims.
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