IMPROVED FLUID PRESSURE MEASURING SYSTEM FOR CONTROL VALVES

Abstract: A system for improving fluid pressure measurement in a control valve includes placing a flow conditioner adajcent to and upstream from averaging channels located at the inlet and outlet of the control valve, from which averaging channels the fluid is conducted to fluid pressure measuring devices.

Description: IMPROVED FLUID PRESSURE MEASURING SYSTEM FOR CONTROL VALVES FIELD OF THE INVENTION The present invention pertains to control valves; more particularly, the present invention pertains to control valves which include a fluid pressure monitoring system. BACKGROUND 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 minimizing those components of fluid flow which detract from the accuracy of fluid pressure 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. SUMMARY The improved fluid pressure measuring system for control valves ofthe 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 ofthe flow path into the averaging channel on both the inlet and outlet sides of the control valve. DESCRIPTION OF DRAWINGS A better understanding ofthe 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 incoφorating the improved fluid pressure measuring system ofthe present invention; FIGURE 2 is an enlarged cross-sectional view ofthe valve inlet; FIGURE 3 is an enlarged cross-sectional view of the valve outlet; FIGURE 4 is an end view ofthe valve inlet; FIGURE 5 is a perspective view of a control valve, including an external manifold block; and FIGURE 6 is an exploded view ofthe control valve shown in Figure 5 showing the attachment ofthe external manifold block to a flange ofthe control valve. DESCRIPTION OF EMBODIMENTS By refeπing 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 ofthe control valve assembly 100. On the opposite end ofthe body 110 ofthe control valve assembly 100 from the inlet flange 102 is an outlet flange 1 12. Similar to the inlet flange 102, the outlet flange 112 includes a plurality of bolt holes 114 which surround a central opening 116. Note that an inlet fluid flow conditioner 12 and an outlet fluid flow conditioner 52 are placed within the openings 106 and 116 in the flanges 102 and 112, respectively. In Figure 2 it may be seen how the improved pressure measuring system 10 is positioned on the inlet side ofthe 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 conditioner 12 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 1 10. In Figure 3 it may be seen that on the outlet side ofthe 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 provides a radial flow path 38 and a distal end 60 with an external rim 62 to engage the opening 1 16 in the flange 1 12 on the outlet side ofthe control valve assembly 100. The thirty-five openings aπanged in a predetermined pattern in each ofthe inlet fluid flow conditioner 12 and the outlet fluid flow conditioner 52 minimize those fluid flow components which detract from accurate pressure measurement. As previously indicated, both the short cylindrical section 18 on the inlet side of the valve 100 and the short cylindrical section 58 on the outlet side of the valve 60 include a plurality of radial fluid flow paths 38. 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 ofthe valve 100 is substantially perpendicular to the fluid flow through the flow conditioner on either side ofthe 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 refeπing 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 ofthe 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 ofthe radial passage 44. Such configuration may be used on either the inlet or the outlet side ofthe control valve assembly 100. By referring to Figures 1 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 1 12, 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 ofthe control valve assembly 100. In Figures 5 and 6 is shown yet another configuration of a control valve assembly 100 incorporating the improved fluid pressure measuring system ofthe present invention. Specifically, a manifold block 60 is bolted to both the inlet flange 102 and the outlet flange 1 12. 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 ofthe flanges on either end ofthe 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 ofthe 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 ofthe appended claims.

Claims: I claim: 1. A system for improving fluid pressure measurement at both the inlet and the outlet of a control valve, said control valve constructed and arranged to utilize said fluid pressure measurement to control flow, said system for improving fluid pressure measurement comprising: a fluid flow conditioner; a substantially circular averaging channel located substantially outboard from and downstream from said fluid flow conditioner; and a conduit for conducting flowing fluid from said substantially circular averaging channel to a fluid pressure measurement device. 2. The system as defined in Claim 1 wherein said fluid flow conditioner is a plurality of openings formed in a plate mounted axially within the control valve. 3. The system as defined in Claim 1 wherein fluid flow to said substantially circular averaging channel is through a plurality of fluid flow paths positioned substantially radially to the flow of fluid through the control valve. 4. A system for measuring fluid pressure in a control valve with a pressure measuring device, said control valve having an inlet mounting flange, an outlet mounting flange, and a valve body there-between, said system comprising: an inlet fluid flow conditioner positioned within the inlet mounting flange; a substantially circular inlet averaging channel located substantially outboard from and downstream from said fluid flow conditioner; 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; 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. 5. The system as defined in Claim 4 wherein said passage for conducting fluid from said substantially circular inlet averaging channel to the pressure measuring device passes through the valve body. 6. The system as defined in Claim 4 wherein said passage for conducting fluid from said substantially circular outlet averaging channel to the pressure measuring device passes through the valve body. 7. The system as defined in Claim 4 wherein said substantially circular inlet averaging channel is fed by a plurality of substantially radial flow paths. 8. The system as defined in Claim 4 wherein said substantially circular outlet averaging channel is fed by a plurality of substantially radial flow paths. 9. 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 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 substantially outboard from and downstream from said inlet fluid flow conditioner; an outlet fluid flow conditioner positioned within the outlet mounting; a substantially circular outlet averaging channel located substantially outboard from and downstream from said outlet fluid flow conditioner; 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. 10. The control valve as defined in Claim 9 wherein said passage for conducting fluid from said substantially circular inlet averaging channel passes through the valve body. 11. The control valve as defined in Claim 9 wherein said passage for conducting fluid from said substantially circular outlet averaging channel passes through the valve body. 12. The control valve as defined in Claim 9 wherein said substantially circular inlet averaging channel is fed by a plurality of substantially radial flow paths. 13. The control valve as defined in Claim 9 wherein said substantially circular outlet averaging channel is fed by a plurality of substantially radial flow paths. 14. The control valve as defined in Claim 9 further including a manifold block in fluid communication with said passage for conducting fluid from said substantially circular inlet averaging channel and said passage for conducting fluid from said substantially circular outlet averaging channel. 16. A method for measuring fluid flow pressure with a fluid pressure measuring device at the inlet or the outlet of a control valve, said method comprising the steps of: conditioning the flow of fluid; conducting said conditioned fluid flow to a substantially circular averaging channel located adjacent to and downstream from said fluid flow conditioner; and conducting fluid from said substantially circular averaging channel to the fluid flow pressure measuring device. 17. The method as defined in Claim 16 wherein fluid flow to said substantially circular averaging channel is through a plurality of flow paths positioned substantially radially to the flow of fluid. 18. A method for improving the fluid pressure measurement in a control valve, said fluid pressure measurement being sensed by a fluid pressure measuring device, said method comprising the steps of: conditioning the fluid flow substantially at the inlet to the control valve; conducting said conditioned flowing fluid to a substantially circular inlet averaging channel located outboard from and downstream from said inlet fluid flow conditioner; conducting said conditioned flowing fluid from said substantially circular inlet averaging channel to the fluid pressure measuring device; conditioning the fluid flow substantially at the outlet to the control valve; conducting said conditioned flowing fluid to a substantially circular outlet averaging channel located outboard from and downstream from said outlet fluid flow conditioner; conducting said conditioned flowing fluid from said substantially circular outlet averaging channel to the fluid pressure measuring device. 19. The method as defined in Claim 18 wherein the fluid flow to said substantially circular inlet averaging channel is through a plurality of flow paths positioned substantially radially to the flow of fluid through the control valve. 20. The method as defined in Claim 18 wherein the fluid flow to said substantially circular outlet averaging channel is through a plurality of flow paths positioned substantially radially to the flow of fluid through the control valve.

Inventors: BOGER HENRY W, BOGER, HENRY, W.
Applicants: DRESSER IND, DRESSER INDUSTRIES, INC.
Application year: 1996
Main classification: G01F
IPC codes: F16K37, F16K47, G01F1, G01L7, G01L13, G05D7, G05D16