Transmitter mounting bracket with process flange studs

Abstract

The process fluid sensing assembly (50) includes a process fluid conduit (56) having a pair of flange couplings (60), and a mounting bracket (120) attached to at least two process flange studs (104) of at least one flange coupling (60). A field device (124) is attached to the mounting bracket (120). A method (1000) for coupling the field device (124) to the at least one process flange (60) as well as the wedge-type flow meter (50) is also provided.

Description

[Technical Field]

[0001] background A field device is a device that can be coupled to a process, such as a manufacturing or refining process, and supports the process by providing one or more functions of measuring and controlling parameters related to the process. Field devices are so named because they can be installed in the field. The "field" is typically an external area of ​​a process facility that may be exposed to extreme weather, vibrations, humidity changes, electromagnetic or radio frequency interference, or other environmental challenges. Thus, the rugged physical packaging of such field devices provides the ability to operate in the "field" for extended periods of time (such as years) at a time.

[0002] Field devices, such as process variable transmitters, are used in the process control industry to remotely sense process variables. Field devices, such as actuators, are used in the process control industry to remotely control physical parameters of a process, such as flow rate and temperature. Process variables can be transmitted from field devices, such as process variable transmitters, to a control room to provide information about the process to a controller. The controller can then transmit control information to field devices, such as actuators, to modify the parameters of the process. For example, information related to the pressure of a process fluid can be transmitted to a control room and used to control a process, such as an oil refinery.

[0003] Process variable transmitters are used to monitor process variables associated with fluids such as slurries, liquids, steam, and gases in chemical, pulp, oil, gas, pharmaceutical, food, and other fluid processing plants. Process variables include pressure, temperature, flow, level, pH, conductivity, turbidity, density, concentration, chemical composition, and other fluid properties. Process actuators include control valves, pumps, heaters, agitators, coolers, solenoids, vents, and other fluid control devices. Wedge-type differential pressure flow meters can measure flow in applications that are problematic for traditional flow meters, such as orifice plates with impulse lines and other competing technologies. These devices introduce a partial fluid obstruction in the shape of a wedge into a process fluid conduit and measure process fluid pressure both upstream and downstream of the wedge. The difference in process fluid pressure between the upstream and downstream measurements provides an indication of the process fluid flow rate. Some particularly advantageous applications for wedge-type process fluid flow devices include applications where impulse lines may be blocked or clogged. Therefore, wedge-type flow meters are often combined with a remote seal to transmit a differential pressure signal to a differential pressure transmitter. A complete wedge flow meter solution generally consists of a primary wedge spool-style meter, a set of balanced remote seals, and a differential pressure transmitter. Minimizing the capillary length of the remote seal has many benefits, such as better system response time and reduced temperature-related inaccuracies. Summary of the Invention

[0004] The process fluid sensing assembly includes a process fluid conduit having a pair of flanged connections and a mounting bracket attached to at least two process flange studs of at least one of the flanged connections. A field device is attached to the mounting bracket. Methods for coupling the field device to at least one process flange as well as a wedge-type flow meter are also provided. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a schematic diagram of a known wedge-type flow meter with which embodiments described herein are particularly useful. [Figure 2] 1 is a schematic diagram of preferred wedge main element mounting orientations for liquids, gases, and vapors. [Figure 3] 1 is a perspective view of a known "L-shaped" bracket used to mount field devices with pipe clamps. [Figure 4] 1 is a schematic diagram of a typical flange connection for use in conjunction with an embodiment of the present invention; [Fig. 5A-B6A7A-B] 5A, 5B, 6A, 7A, and 7B show various mounting brackets that can be attached to a pair of process flange connection studs on a single flange connection, or to a single stud on each of two parallel flange connections, in accordance with embodiments of the present invention. [Figure 6A-B] 6A and 6B show a bracket for mounting a differential pressure transmitter to a pair of parallel process flanges in accordance with another embodiment of the present invention. [Figure 7A-B] 7A and 7B show a bracket having a pair of spaced apart holes for attachment to the studs of a WSP remote seal flange, according to one embodiment of the present invention. [Figure 8] 1 is a schematic diagram illustrating how a mounting bracket for a field device is attached to a flange stud in accordance with one embodiment of the present invention. [Figure 9A-B] 9A and 9B illustrate the use of a differential pressure mounting bracket in accordance with another embodiment of the present invention. [Figure 10] 1 illustrates a field device mounted to a pair of parallel flanges, according to one embodiment of the present invention. [Figure 11] 1 illustrates a field device mounted to a single flange, according to one embodiment of the present invention. [Figure 12]1 is a schematic exploded view of a process for attaching a field device to a process flange in accordance with an embodiment of the present invention. [Figure 13] 1 is a schematic exploded view of a process for attaching a field device to a process flange in accordance with an embodiment of the present invention. [Figure 14A-B] 14B is a schematic diagram of a mounting bracket (FIG. 14B) coupled to a standard L-bracket for mounting a field device according to one embodiment of the present invention. [Figure 15] 1 is a flowchart of a method for coupling a field device, such as a differential pressure transmitter, to one or more flanges in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0006] One of the challenges in developing a fully integrated wedge flow meter is to mount the differential pressure transmitter and remote seal to the main element in a manner that is recognized as a "direct mount" or "close coupled" while achieving all of the following design goals: locating the differential pressure transmitter in a location that is convenient for accessing the electronics (e.g., commissioning, zeroing, maintenance, etc.); ensuring that the differential pressure transmitter does not overheat when the process fluid pipe contains hot fluid and radiates heat; shortening or minimizing the remote seal capillary length as much as possible; ensuring that the differential pressure transmitter does not experience zero drift (rotation about an axis that offsets the zero point) even under long-term field vibration; providing a cost-effective mounting option compared to alternative solutions; and providing a mounting for the differential pressure transmitter that is consistent with the preferred mounting orientation of the main element.

[0007] FIG. 1 is a schematic diagram of a known wedge-type flow meter for which the embodiments described herein are particularly useful. The most common transmitter mounting solution for a wedge-type flow meter 50 with a remote seal 52 is to mount the transmitter 54 remotely from a main element 56 using a relatively long capillary tube 58 and a conventional transmitter mounting bracket or equivalent. The main element 56 typically includes a pair of process fluid pipe flanges 60 and a pair of pressure branches 62, each with a process flange 64 that also couples to the remote seal 52. The pressure branches 62 are located on either side of a partial fluid obstruction (i.e., wedge) 66, shown cut away for illustrative purposes. This technique requires a relatively long capillary tube 58, which can result in longer system response times and greater temperature effects. It also results in higher costs for users, as they must pay for the longer capillary tubes and transmitter installation.

[0008] Some commercially available wedge-type flow meters offer relatively close-coupled differential pressure transmitter mounts, but such close-coupled wedge-type flow meter transmitter mounts require welding a metal pipe or bar piece to the meter body and attaching the transmitter to the protruding pipe via a mounting bracket.

[0009] Known approaches have several limitations. One such limitation is cost. While relatively simple, the direct material costs of 2-inch NPS pipe, rectangular bar, or C-channel, in addition to the mounting brackets, machining, and welding labor, add $15 to $40, leaving room for improvement. Another limitation is the need for welding. Welding the pipe section or metal bar to the meter requires welding and preparation work, and the pipe or bar may need to be contoured to match the outer diameter of the meter spool. Generally, a design goal is to minimize welding on the meter spool to prevent unnecessary deformation of the spool due to welding heat and internal stresses. Furthermore, reducing welding minimizes meter-to-meter variation and results in a more predictable spool.

[0010] Yet another limitation relates to the orientation and location of the transmitter. In some known transmitter installations, the transmitter orientation does not match the recommended orientation of the installed wedge flow meter. For all fluid types (liquid, gas, and steam), the ideal installation orientation for a wedge meter is "sideways," or exiting horizontally with the differential pressure branch rather than up or down (see Figure 2). This preferred orientation prevents gas pockets, droplets, and / or debris from building up on the remote seal and allows particulate matter to flow past the wedge element. Some commercially available differential pressure transmitter installation methods include placing the transmitter directly above the process fluid pipe, which is undesirable in high-temperature processes because the transmitter can overheat, or placing the transmitter directly below the pipe, which is undesirable because the floor or ground can become an obstacle, making access to the transmitter electronics more difficult. Finally, mounting brackets welded to the meter offer less adaptability to unexpected space issues than those bolted to any number of available locations. Yet another limitation is aesthetics, as protruding cantilevered supports can appear like an afterthought in an integrated meter design.

[0011] According to various embodiments described below, systems and methods are provided for mounting a field device, such as a differential pressure transmitter, to a process pipe flange or spool-style flow meter using a stud that seals the flange connection. When mated with the stud of the flange connection, the mounting bracket positions the field device to be vibration resistant while reducing or minimizing the possibility of zero drift, reducing or minimizing the remote seal capillary length, and a safe distance from overheating between the high-side and low-side remote seal flange pressure taps.

[0012] While the embodiments described herein offer significant advantages over wedge-type flow meters, those skilled in the art will appreciate that embodiments can be implemented in any application where a field device must be mounted relatively close to a process fluid conduit and where threaded fasteners, such as studs, bolts, and nuts, are used to connect process fluid conduit flange connections. Furthermore, embodiments can be implemented in combination with commercially available mounting brackets, such as the standard L-shaped mounting bracket available from the Rosemount business unit of Emerson Automation Solutions. This bracket, shown in FIG. 3, is highly versatile and widely adopted in the industry. However, it requires the installation of a pipe clamp on the 2-inch pipe, which also means the user is responsible for properly positioning the 2-inch pipe. Any field device, including but not limited to differential pressure transmitters, can achieve cost savings by mounting the device directly to process flange studs, where possible, according to the embodiments described herein.

[0013] The embodiments described herein generally utilize the presence of flange connections for mounting and coupling field devices. Figure 4 shows a typical flange connection 100 in which flanges 108, 110 are brought together around a gasket or O-ring 112 and sealed or sealed by tightening a nut 102 onto a stud 104 that passes through an opening 106. This standard process remains unchanged when utilizing the embodiments described herein. The disclosed field device mounting system and method allows field devices to be installed or removed without damaging the flange seal or loosening the pressure-retaining nut.

[0014] 5-7 show various mounting brackets according to embodiments of the present invention that can be attached to a pair of process flange connection studs on a single flange connection or to a single stud on each of two parallel flange connections.

[0015] FIG. 5A illustrates a bracket 120 having a pair of holes or slots 122 for mounting to the studs 104 of a single process fluid flange, according to one embodiment of the present invention. The illustrated bracket is suitable for a 2-inch NPS 150# to 600# flange and mounts a differential pressure transmitter 124 (shown in FIG. 5B) in an upright position. Additionally, the bracket 120 may include a rib 126 bent approximately 90 degrees from the plane of the bracket 120 to provide additional strength. While the rib 126 is shown at the end of the bracket 120, it is expressly contemplated that the rib 126 may be positioned in a different location. Additionally, additional ribs 126 or other suitable structures may be used to strengthen the bracket 120.

[0016] As shown, the mounting bracket 120 includes a major surface 126 with through holes 122, 128 for attaching a transmitter 124 (and coplanar adapter) or device to the bracket and for attaching the mounting bracket 120 to the flange studs 104 and nuts. In the example shown, the bracket 120 positions the transmitter 124 outside the flange area, ideally flush with the horizontal, and sufficiently spaced from the process to prevent exposure to unacceptably high temperatures due to heat radiation and convection under high-temperature process conditions. The through holes 122 for the flange studs can be slots (as shown) so that one design can be applied to multiple flange pressure classes or line sizes.

[0017] 6A and 6B show a bracket 140 for mounting a differential pressure transmitter 124 to a pair of parallel process flanges 142, 144, according to another embodiment of the present invention. In the illustrated embodiment, the bracket 140 includes two elongated slots 146, 148 configured to mount to the studs 104 on each of the process flanges. The bracket 140 also includes a pair of mounting holes 150 configured to mount the differential pressure transmitter 124. The bracket 140 may also include structural ribs (not shown).

[0018] 7A and 7B show a bracket 160 having a pair of spaced apart holes 162, 164 for mounting to studs 104 of a WSP remote seal flange 166, according to one embodiment of the present invention. Bracket 160 also includes a pair of mounting holes 168 positioned for mounting to differential pressure transmitter 124. Bracket 160 is also shown to have a rib 170 similar to rib 126 of bracket 120 (shown in FIG. 5).

[0019] FIG. 8 is a schematic diagram illustrating a method for attaching a field device mounting bracket, such as brackets 120, 140, or 160, to a flange stud, according to an embodiment of the present invention. The process flange connection is sealed or sealed using conventional installation methods and conventional components / hardware, except for two of the flange studs 178, which have extended lengths that extend beyond pressure-retaining flange nuts 180. The mounting bracket is then positioned adjacent to the back of the pressure-retaining flange nuts 180 on the extended-length studs 178, with an additional set of nuts 182 threaded onto the extended lengths of the studs 178. An optional set of washers 184 is sandwiched between the bracket and nuts 180, 184. FIG. 8 also shows the transmitter 124 with a coplanar adapter 186 attached to the transmitter mounting bracket using transmitter bracket bolts 188 and transmitter bracket washers 190.

[0020] Figures 9A and 9B illustrate the use of a differential pressure mounting bracket according to another embodiment of the present invention. The transmitter mounting bracket shown in Figures 9A and 9B is similar to that shown in Figures 7A and 7B. The embodiment shown in Figures 9A and 9B is designed so that the transmitter and bracket can be conveniently positioned without interference (Figure 9B) when the differential pressure branches are as close as possible to each other on a wedge flow meter conforming to ISO 5167-6 [Measurement of fluid flow rate by differential pressure devices inserted into a water-filled circular cross-section conduit—Part 6: Wedge meters]. Otherwise, material is minimized, and the plate thickness and ribs are designed to provide stiffness equivalent to that of a standard transmitter L-bracket to reduce vibrations perceived by the transmitter. When the transmitter is flange-mounted as shown in Figure 9A, the length of the capillary coupling is significantly reduced compared to conventional designs such as that shown in Figure 1.

[0021] When a wedge-type flow meter has 2-inch NPS flanged branches, two different mounting bracket designs are used depending on whether the flanged branches are close together (Figure 10) or far apart (Figure 11). Both bracket designs work with flanges from 150# to 600#, and combining the two brackets allows use within the limits of ISO 5167-6 without interference. The reason for two designs is that as the differential pressure branch flanges get closer together, a single flange bracket (Figure 11) would prevent access to the studs and nuts on the parallel branch flanges unless a spanning bracket (Figure 10) is used.

[0022] 12-14 are schematic exploded views of a field device mounted on a process flange according to an embodiment of the present invention.

[0023] 12 shows the transmitter mounting bracket 160 using process flange studs 178 to mount the differential pressure transmitter 124 near the WSP differential pressure branch 200. Transmitter bracket bolts 188 are positioned through the transmitter mounting holes 168 and threaded into the coplanar adapter 186. The bracket 160 is then slid onto the process flange studs 178 and a nut 182 is tightened onto each process flange stud 178. The process fluid coupling from each pressure branch 200 to the differential pressure transmitter can be implemented in any suitable manner.

[0024] 13 shows a transmitter mounting bracket 140 using a process flange stud 178 that straddles two parallel flanges 204, 206 for a 2-inch NPS flanged branch 200. The transmitter bracket bolts 188 pass through the transmitter mounting holes 150 and enter the coplanar adapter 186 of the transmitter 124. A nut 182 is threaded onto the process flange studs 178 to mount the transmitter 124 to the parallel flanges 204, 206. As shown, the transmitter 124 is mounted in an upright position, neither directly above nor directly below the process fluid conduit 208.

[0025] 14A and 14B are schematic diagrams of a mounting bracket 250 (FIG. 14B) coupled to a standard L-bracket 252 for mounting a field device 124, according to one embodiment of the present invention. As shown, the mounting bracket 250 includes a pair of holes 254 for attachment to process flange studs. Additionally, the bracket 250 also includes a plurality of holes 256 for coupling to the L-bracket 252. As with other embodiments, the bracket 250 can include one or more ribs 258 for added strength.

[0026] FIG. 15 is a flowchart of a method for coupling a field device, such as a differential pressure transmitter, to one or more flanges, according to one embodiment of the present invention. Method 1000 begins at block 1020, where at least one process flange is coupled together. As discussed above, this typically involves multiple threaded studs extending through mounting holes in both portions of the process flange coupling and a mating nut for drawing the two portions together. An O-ring or other suitable sealing element (as shown in FIG. 4) is typically disposed between the two portions. Note that while the embodiment is described with respect to coupling a mounting bracket to the studs after the flange coupling is created, it is expressly contemplated that such coupling can occur during the creation of the flange coupling. In such an example, blocks 1020 and 1040 are combined. However, there are advantages to coupling a bracket to two or more process studs after the flange coupling is created. In particular, if the bracket is coupled later, it can be subsequently removed without affecting the process flange coupling. As shown in block 1040, coupling the bracket to at least two flange studs can be performed on two studs of a single flange, as shown in reference numeral 1060, or on studs of two different parallel flanges, as shown in reference numeral 1080.

[0027] Method 1000 continues at optional block 1100, where washers can be attached to the process flange studs, if desired. Next, at block 1120, additional nuts are attached to the process flange studs to tighten the bracket to the process flange studs. In embodiments where the bracket is attached during creation of the process flange joint, such additional nuts are not required. Next, at block 1140, a field device is attached to the bracket. However, it is also contemplated that the field device may be attached to the bracket before the bracket is coupled to the process flange stud.

[0028] The embodiments described herein offer many advantages over current designs, including, but not limited to: reduced installation costs compared to cantilevered pipes or bars welded to the meter; locating the transmitter in an accessible location between the high- and low-pressure taps of the wedge flow meter on the same side as the remote seal, allowing for minimal capillary length while remaining outside of radiant heat impact from the hot process pipe; locating the transmitter in a location that supports a preferred orientation of the wedge meter with a horizontally projecting differential pressure branch (as shown in FIGS. 12-13 ); bolting to the flow meter allows for position adjustment (no welding to the meter required); mechanically avoiding zero drift under long-term process pipe vibration; and ensuring that the transmitter does not rotate, as would be the case if a pipe clamp were used.

Claims

1. 1. A process fluid detection assembly comprising: a process fluid conduit having a pair of flange connections; a mounting bracket attached to at least two process flange studs of at least one flange connection; and a field device attached to the mounting bracket; 1. A process fluid detection assembly comprising:

2. 10. The process fluid detection assembly of claim 1, wherein the mounting bracket is configured to be attached to an extended length process flange threaded stud with an additional flange nut.

3. 2. The process fluid detection assembly of claim 1, wherein the bracket has at least one opening in a main bracket face for engaging at least two process flange studs, and engagement with the two flange studs inhibits rotation of the field device due to vibrations in a field pipeline.

4. The process fluid detection assembly of claim 3 , wherein the at least one opening comprises at least one slot.

5. The process fluid detection assembly of claim 1 , wherein the mounting bracket has through holes for bolting to the field device.

6. The process fluid sensing assembly of claim 1 , wherein the mounting bracket is coupled to the first and second flange couplings.

7. 10. The process fluid sensing assembly of claim 1, wherein the process fluid conduit includes first and second horizontally extending pressure branches.

8. The process fluid detection assembly of claim 1 , wherein the field device is mounted vertically.

9. 10. The process fluid sensing assembly of claim 1, wherein the mounting bracket positions the field device between a high side differential pressure branch and a low side differential pressure branch of a wedge flow meter.

10. The process fluid sensing assembly of claim 9 , wherein the field device is a differential pressure transmitter.

11. 10. The process fluid detection assembly of claim 1, wherein the mounting bracket is configured to position the field device at a sufficient distance from a process pipe to protect the field device's electronics from excessive process fluid temperatures.

12. The process fluid detection assembly of claim 1 , wherein the mounting bracket has ribs.

13. 1. A wedge-type flow meter comprising: a spool configured to attach to a process pipe, the spool having a wedge disposed therein to partially block process fluid flowing through the spool, the spool also having a pair of differential pressure branches, each branch having a process flange; a first remote seal coupled to one process flange of the differential pressure branch, the first remote seal having a first capillary tube extending therefrom; a second remote seal coupled to the other process flange of the differential pressure branch, the second remote seal having a second capillary tube extending therefrom; a bracket attached to a pair of threaded fasteners on the at least one process flange; and a differential pressure transmitter fluidly coupled to the first capillary tube and the second capillary tube, the differential pressure transmitter mounted to the bracket; Includes a wedge type flow meter.

14. 14. The wedge-type flow meter of claim 13, wherein the pair of threaded fasteners attaching the bracket to at least one process flange each have a length greater than other threaded fasteners connecting the process flanges.

15. 14. The wedge-type flow meter of claim 13, wherein the pair of differential pressure branches are configured to extend horizontally and the bracket is configured to mount the differential pressure transmitter vertically.

16. 14. The wedge-type flow meter of claim 13, wherein the threaded fastener is a flanged stud.

17. 14. The wedge-type flow meter of claim 13, wherein the bracket is coupled to a threaded fastener on each of the two process flanges.

18. 1. A method for coupling a field device to at least one process flange, comprising: creating at least one process flange connection; coupling a bracket to the at least two flange fasteners of the at least one process flange coupling; and coupling the field device to the bracket; A method comprising:

19. 20. The method of claim 18, wherein coupling the bracket to at least two flange fasteners comprises coupling the bracket to two flange fasteners on a single pressure branch of a spool configured to attach to a process pipe.

20. 20. The method of claim 18, wherein coupling the bracket to at least two flange fasteners comprises coupling the bracket to two pressure branches of a spool configured to attach to a process pipe.

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