MXPA98008337A - Valve actuator with multiple for the assembly of an instrume - Google Patents

Abstract

The present invention relates to a valve actuator with a mounting cushion of the instrument and a manifold in a combination of power module and cylinder head for mounting a valve control instrument without pipe or mounting brackets. A cover encloses the feedback joint between the actuator and the instrument. The actuator includes a second mounting cushion for the instrument and the manifold, so that the power module is reversible to accommodate fail-safe or safe closed valve conditions. A combination of valve actuator and instrument is not higher than the actuator only

Description

VALVE ACTUATOR WITH MULTIPLE FOR THE ASSEMBLY OF AN INSTRUMENT This invention relates, in general, to devices for controlling the flow of fluids and, in particular to actuators for valves for fluid flows.

BACKGROUND OF THE INVENTION Various valves for fluid flow control and corresponding valve actuators are used to activate / deactivate the control or throttling of fluid flow, such as a gas or oil pipeline system, or in other oil systems. process fluids. The valves for the control of the flow of fluids are usually control valves with sliding rod or rotary action control valves and are operated by a valve actuator such as a pneumatic piston or diaphragm actuator that responds to the output of a valve positioner or valve control instrument to control the precise throttling of the valve. For example, the valve for fluid control is usually mounted in a piping system with a pneumatic actuator fitted on top of a valve for fluid control and coupled with the valve fluid control element , such as a sliding rod or rotating shaft. If used, a valve positioner or valve control instrument is mounted on the top side of the actuator using suitable mounting brackets and pneumatic tubes are provided between the pneumatic output of the positioner and the pneumatic inlet of the valve actuator . In this way, the complete valve, actuator and positioner unit can be a very large and heavy combination of elements extending from some distance over the valve and projecting to this envelope and to the side of the pipe and possibly beyond the own valve. In addition, an articulated mechanism is provided between the actuator and the positioner to provide feedback information to the positioner relative to the open / closed position of the valve. Usually, this feedback joint includes a console for mounting the joint with the actuator and a pivoting arm on the outside of the positioner, thereby exposing the feedback joint with the means that, in the case of pipeline means Normal or other fluid systems of processes media can be extremely oily and dirty and in some cases corrosive. Also, the requirement of the discharge piping and mounting brackets for the actuator and positioner devices in combination results in long installation times, higher installation costs, higher total life cycle costs, high maintenance costs and the requirement to manufacture and / or inventory a substantial amount of new gear and spare parts for these devices. In addition, it is desirable to have a valve actuator that can accommodate a valve in an open or closed valve state in the event of failure in the event of an operating pressure loss of the actuator. In various actuators currently available, this necessary investment of the actuator can not be achieved or can be achieved only with a substantial disassembly of the actuator and with the replacement of some actuator gaps, that is, it effectively requires a reconstruction of the actuator. In all currently known valve actuators available, there is an inability to solve all the problems described above. That is, in some cases, in current devices, a positioner can be directly mounted to an actuator without a mounting bracket and with a contained articulated feedback mechanism. However, in these currently available devices, the pneumatic piping is exposed or the integrated positioner and actuator are added significantly to the overall height of the combined positioner, actuator and control valve. In other cases, the insertion of the actuator to interrupt from an open valve state with the fault to closed with the fault can not be achieved without disassembly and assembly that consumes time with additional parts, even where the available units have eliminated the pneumatic piping and have isolated the articulated retroaction mechanism of the atmosphere. It is therefore desired to provide an actuator for fluid control valves, and in particular a combination of actuator and valve controller instrument that can fulfill all the aforementioned problems and desirable characteristics.

SUMMARY OF THE INVENTION In accordance with the principles of the present invention, there is provided an actuator for operating a control element used to regulate fluid flow by a fluid control valve in response to a control valve positioning instrument, where the actuator includes a pair of coaxially aligned members, one fixed with respect to the other. A chamber is defined between adjacent ends of the members so that, when the chamber is subjected to fluid under pressure, the actuator operates to move the moving member between the positions of the valve actuator. A mounting cushion extends transversely outward from the fixed member and includes a surface mounting portion of the instrument beyond the movable member for mounting a control valve positioning instrument. A fluid pressure inlet port in the mounting surface portion of the mounting pad instrument is provided for fluid or hydraulic communication with the control valve setting instrument, and fluid conduits are provided in the mounting pad and the fixed member for hydraulic communication between the inlet port and the chamber for connecting the fluid under pressure of the instrument for placing the control valve with the chamber during valve actuation. The movable member and the fixed member define a power module that is selectively reversible between a first and a second position. The first position can, for example, correspond to a safe open valve state in case of failure wherein the expansion of the camera moves the movable member generally towards the control element. In the same way, the second position can conform the state of the closed valve in case of failure in which the expansion of the camera moves the mobile member generally away from the control element !. Thus, when it is desired to exchange from a fail-safe open valve position to a fail-safe closed valve state, this can easily be achieved by removing the module from the power of the actuator and reversing the power module to, for example, the second position. In a preferred embodiment of the invention, a second mounting pad is provided which extends transversely outwardly from the fixed actuator member and which includes a second surface mounting portion of the instrument beyond the movable member for mounting a positioning instrument. of the control valve. A second fluid pressure inlet port is provided in the second surface mounting portion of the instrument, and a second fluid conduit in the second mounting pad, and in the fixed actuator member provides hydraulic communication between the second inlet port of the instrument. hydraulic pressure and the chamber, to couple the fluid under pressure from an instrument for placing the control valve to the chamber. This allows the first mounting cushion to be used with an instrument for placing the control valve in, for example, a state of the open valve safe against failure. When the actuator must operate in a closed, fault-tolerant valve state, the instrument is removed from the mounting pad, the power module is removed from the actuator and inverted in position so that the valve placement instrument of control is mounted to the second surface mounting portion of the instrument with the fluid pressure output of the instrument in communication with the second fluid pressure inlet port. The preferred embodiment further includes a bladder mounted in the chamber with the entrance of the bladder fluidly coupled with the fluid conduits in the mounting cushion and the fixed member. The preferred embodiment further includes a fixed internal member and an external mobile member axially movable with respect to the fixed internal member. By subjecting the bladder to a fluid inlet pressure from the control valve positioning instrument, the actuator is operated and the moving external member moves away from the fixed internal member from a first position of the valve actuator to a second position of the valve. actuator of the valve and against the opposing forces of a return spring. When operating fluid pressure is removed from the bladder, the return spring can move the axially mobile member remote from the second position of the valve actuator to the first position of the valve actuator. A combined valve actuator and valve actuator instrument is provided with a valve controller instrument mounted to the mounting portion of the instrument and having a fluid pressure outlet coupled with the fluid pressure inlet port on the valve cushion. mounting. An articulated feedback mechanism is mounted intermediate the actuator and instrument, and a cover is removably mounted on the actuator to cover the feedback joint to protect the articulation from the environment. The mounting cushion is substantially provided halfway between opposite ends of the reversible power module so that at any position of the selectively reversible power module the instrument for positioning the control valve mounted on the mounting cushion does not project the instrument beyond the height of the actuator with the lid. The improved actuator of the present invention includes a power module unit with an internally branched or distributed instrument mounting cushion, a cylinder head, and a cover for accommodating a valve position controller mounted on the mounting pad of the power module. power. This eliminates the discharge pipe and mounting brackets, and without exposed joints. In addition, the sealed reversible power module offers opening or closing action against failures, by means of a spring, to control the valve simply by reorienting the power module in the cylinder head of the actuator. The unique significant advantages for the present actuator and actuator and actuator instrument of the control valve in combination are as follows: (A) the action of the actuator (ascending against failure, or spring or downward against failure, spring loaded) can be reversed with minimum disassembly and no additional parts. The insertion of the actuator includes removing the mounting screws of the positioner, the connection screws of the rod and the feedback joint, inverting the actuator power module and reassembling the positioner. Separation / repositioning of the positioner includes welding and reinstalling the threaded screws without laborious disconnection and reinstallation of pneumatic tubing between the positioner and the actuator, without routing and routing the pneumatic supply line or the signal or conduit pipe to a location other than the positioner, or the reorientation of the mounting brackets; (B) The integration of the positioner is not added to the total height of the actuator. The height is not added to the actuator to accommodate the mounting of the positioner or to allow space for the position of the articulated feedback mechanism; (C) the positioner / instrument can be removed and replaced with an identical unit with minimum disassembly that does not include the pneumatic piping between the positioner and the actuator; (D) the positioner / instrument can be upgraded to a higher capacity device by simply unscrewing the initial instrument and replacing it with another instrument that has some multiple mounting configuration; and (E) access to the components of the articulated feedback system is much simpler because there is less disassembly and greater accessibility than with the integrated actuator / instrument units currently available. Therefore, the significant benefits derived from these characteristics are significant savings without cost and assembly time and the reduction in the susceptibility of damage to the actuator and / or the instrument. In addition, providing a ramped mounting cushion on the actuator power module offers the opportunity to add auxiliary elements, such as, for example, a fail-safe solenoid system that does not require discharge pipes from a solenoid to the actuator, a pressure booster or a relay or servomotor.

BRIEF DESCRIPTION OF THE DRAWINGS The features of this invention that are considered novel are set forth with particularity in the appended claims. The invention should be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which the like reference numbers identify identical elements in the various figures, and in which: Figure 1 is a perspective view that illustrates a combination of valve actuator and position instrument of the control valve, in accordance with the principles of the present invention; Figure 2 is an exploded view illustrating a valve actuator, a valve positioning instrument, an articulated feedback mechanism, and a cover with respect to the combined unit of Figure 1; Figure 3 is a perspective view illustrating the actuator of Figure 1 with mounting cushions for mounting a control valve positioning instrument; Figure 4 is an exploded view illustrating the actuator of the present invention with a reversible power module and cylinder head components; The. figure 5 is an elevation view partly in section illustrating the actuator of figure 5 with the power module in a first installed position; and the. Figure 6 is an elevation view partly in section illustrating the actuator of Figure 1 with the power module inverted to a second position.

DETAILED DESCRIPTION Initially, with reference to FIGS. 1-3, there is illustrated a valve actuator 10 according to the principles of the present invention including a mounting cushion 12 in the form of a ring for mounting a positioning instrument of the valve 14. An articulated retraction mechanism 16 interconnects the actuator 10 and the valve positioning instrument 14. A cover 18 is provided for removably mounting on the actuator 10 so that, as shown in Figure 1, the cover 18 completely covers the feedback joint 16. Also, it can be seen in figure 1, that the mounting of the valve positioning instrument 14 on the mounting cushion 12 does not extend the height of the actuator 10 beyond the cover 18. The actuator 10 includes a power module unit 20 which is mounted by screws with a thread to a cylinder head 22. The mounting cushion 12 projects outwards from the p-module. oder 20 as shown in figures 2 and 3 and includes instrument mounting positions, respectively, 24, 26 for mounting a valve control instrument such as the valve positioning instrument 14 using screws with threads. Two mounting positions of the instrument are provided so that the actuator can accommodate a state of the fault-open valve closed against faults as will be described more particularly hereinafter with respect to the reversal of the position of the power module 20, as shown in Figures 5 and 6. If desired, a third mounting position 28 on the mounting pad 24 is provided (and a fourth mounting position opposite to the position 28 is also provided) for adding auxiliary elements as set forth above. In Figure 1, the actuator of the valve 10 is shown coupled to a mechanical control element 30 for controlling, for example, a fluid control valve 32, such as a slide rod valve mounted on a pipe 34. The rod connector 36 (see Figure 4) is used to interconnect the valve stem or control element 30 with the moving element within the power module of the actuator 20. The combined actuator and instrument are mounted to a valve cap 33 of the control valve 32, with the cylinder head of the actuator 22 held in place by a suitable safety nut threadably connected in the cap 33 and threaded until the detent against a lower flange of the cylinder head 35. The valve 14 can be a digital valve controller, as it can be a current-to-tire communicating instrument based on a microprocessor. In addition to the normal function of converting an input current signal into a pneumatic output pressure, the digital valve controller using a communications protocol can provide easy access to information crucial to the operation of the process. In this way, it is possible to obtain information from the main component of the process, that is, the control valve 32, using a compatible communication device in the control valve or in an inductor field connection box, or using a computer personnel or operator console within a 'room of controls. Otherwise, the instrument can be an analog device or a pneumatic positioner. As can be seen from the overview of Figures 1-3, the actuator as illustrated in greater detail in Figures 4-6 provides various desired characteristics not available in the units currently commercially available, ie: ( 1) a reversible, sealed power module that provides safe opening action against failures or safe closing against control valve failures; (2) the elimination of assembly consoles; (3) the elimination of external pipe; (4) the removal of any accessories usually necessary between the instrument and the actuator; and (5) protection of the environment feedback link. Likewise, a purge ventilation of the positioner is provided under the cover 18 which allows the air that exists in the chamber, surrounded by the cover, to be purged from the chamber with clean air from the purge ventilation. In particular, a pneumatic outlet port 37 in the valve positioner 14 is mounted in line with an inlet port 38 in the mounting cushion 12 in the mounting position of the instrument 24 with a ring -0 between them. The positioner 14 is then securely mounted on the mounting cushion 12 in the mounting position 24 by suitable screw means as a pair of cap screws. Another inlet port 39 is provided in the mounting cushion 12 in the mounting position of the instrument 26. Additional mounting flanges 42 are provided as auxiliary mounts for a filter regulator or other instruments or auxiliary elements. The feedback link 16 includes an end 46 that connects to a pivoting console 48 in the positioner 14, while another end of the feedback link 50 is securely mounted to a moving member of the actuator 52. Because the mobile member of the actuator 52 is interconnected with the rod of the valve or control element 30, the position of the valve stem is detected by the positioner 14 by the articulated feedback mechanism 16. Referring now to FIGS. 4-6, others are illustrated details of the valve actuator having a mounting pad to provide a mounting position for forming a valve actuator and integrated valve controller instrument, combined. The power module 20 includes a stationary internal member 56 with lateral extensions 58, 59 formed integrally with the ring-shaped mounting cushion 12, which mounting pad includes the respective instrument mounting positions 24, 26 previously described as well as the auxiliary mounting position 28 (and the opposite mounting position not shown). The mounting cushion 12 is assembled in a mounting flange 60 of the cylinder head 22 and mounted to the flange of the cylinder head by means of a series of suitable head screws. The stationary internal member 56 of the power module 20 is in the form of a stationary piston with an open lower end 62 as shown in Figure 5, and an opposite closed end provided by an end wall 64. The power module 20 also includes the movable external member 52 in the form of a cylindrical can or receptacle aligned on the axis with and surrounding the stationary internal member 56. A cavity / dome shaped cap 66 forms an end of the movable external member 52, and an end wall with dome shape, identical 68 in the lower part of the movable member 52 forms the opposite end wall of the movable external member. A connector plate of the respective rod 36 is welded to the cover 66 and the cover 68, with each of the connecting plates of the rod 36 including a central opening for receiving the valve stem 30. It can be observed, therefore, that the power module 20 has a symmetrical shape and is reversible simply by removing the cap screws that attach the mounting pad 12 to the mounting flange of the cylinder head 60 and then reversing the power module so that, as shown in the figure 6, the cover 66 is in the lower part and the cover 68 is in the upper part in reverse of the position of the power module, as seen in figure 5. A guide ring 70 is mounted in a suitable manner the lower part of the stationary internal member 56 (see Figure 5) and in sliding engagement against the inner surface of the movable external member 52 to help guide the sliding movement of the movable external member 52 in the direction of the axis in the stationary internal member 56. The stationary internal member 56 includes an internal member wall 72 that includes a conduit 74 communicating with the inlet port 38, in the mounting cushion 12 by a connecting duct 76 in the lateral extension 58 extending from the end wall 72. Similar multiple ducts through the actuator are provided on opposite sides of the power module 20 and through respective opposite lateral extensions. 58, 59 as shown in Figure 5, giving rise to the respective input ports 38, 39. In Figure 5, a small plug 77 is threadedly inserted into the conduit 79 when the instrument 14 is mounted in the mounting position 24, and a larger plug 81 is threadedly inserted into the conduit 76. Within a chamber 78 defined between the end wall of the stationary internal member 64 and the end wall of the movable external member 66, there is provided a formed, sealed bladder 80 having respective inlet orifices 82 coupled to the respective ends of the conduits 74. This allows communication fluid between the pneumatic outlet port 37 of the valve controller instrument 14 coupled to the inlet port 38 and through the conduits 76, 74 to enter the chamber 78 defined within the bladder 80. The upper part of the bladder 80 in Figure 5 is formed to form the end wall 66 of the movable member 52 and the lower part of the bladder is formed to form the end wall 64 of the stationary member 56. One part Peripheral bladder ion 83 provides a rolling action of the diaphragm to move the movable member 52 in response to the pressurizing fluid through the admission opening of the bladder 82. A spring 84 is mounted within the stationary internal member and between the respective end walls of the bladder. the actuator members, i.e., between the end wall 64 of the stationary internal member and the cover 68 of the movable external member. A pair of opposed adjustable seals are provided by respective threaded screws 86 each threadably connected to a respective side extension 58, 59 with suitable locknuts to help maintain the position of the adjustable seals. In this way, the movable external member 56 can move downward in FIG. 5 until the edge 88 abuts against the threaded bolt 86, and the movable external member 52 can move upwardly until an edge 90 contacts the stop against the threaded bolt 86. During the operation of the actuator 10, the fluid under pressure, such as pneumatic pressure provided by the valve control instrument 14 towards the inlet port 38 is coupled via the conduits 76, 74 in the chamber 78 inside the bladder 80 which extends the bladder and in a winding action of the diaphragm causes the movable external member 52 to move up in Figure 5 to carry with it the attached mechanical control element 30 which would be a shank of valve or motion conversion joint if used with a rotary shaft valve. In any case, the driven motion of the mobile outer member 52 compresses the spring 84 so that the mobile outer member has been moved in an upward direction, with respect to the stationary internal member 56. In a single actuating configuration, the input port in the mounting position of the instrument 26 would be closed with the plug 77. The release of the pressure within the bladder 80 by the action of the valve control instrument 14 allows the compressed spring 84 to push the movable external member 52 downwards in the configuration shown in figure 5. Initially, in the assembly of the actuator of the valve 10 with the fluid control valve, it must be decided whether a state of closure against failure or opening against valve failures is desired in the case in which there is a loss of operating pressure of the actuator. In the illustration of Figure 5, the actuator is configured to operate with a valve in a fail-safe closing position since it can be seen that if there is no operating pressure supplied to the inlet port 38 from the valve controller instrument 14, the spring 84 holds the movable external member 52 in a fully indicated low position that will normally close the associated fluid control valve.

If it was requested that the valve be placed in an open situation against faults, then the power module 20 simply needs to be inverted in the position. If the instrument 14 is in the mounting position 24, it must first be removed. The reversal of the power module can be easily accomplished by removing the cap screws mounted between the mounting pad 12 and the flange of the cylinder head 60, and inverting and positioning the power module 20 in the position as shown in FIG. Figure 6. Accordingly, as shown in Figure 5, the bladder 80 is in the upper part of Figure 5, and when the power module 20 is separated from the stock 22 (see Figure 4) and reversed and reinserted and reassembled in its position in the cylinder head 22, the bladder 80 is at the bottom, as shown in figure 6. Note that the actuator 20 has been positioned so that the inlet port 39 is now in communication with the output port of the instrument 37. A small plug 77 is inserted into the conduit 76 and the large plug 81 is inserted into the conduit 79. With the power module 20 thus inverted, the mobile external member 52 will initially be in the ascending position (v Figure 6) under the action of the spring 84 so that the valve will be open, and applying inlet pressure to the inlet port will move the mobile external member 52 in the downward direction tending to close the valve, the position of the actuator of the valve of figure 6 provides an opening situation against failures because if there is a loss of operating pressure of the actuator, the spring 84 will return the mobile external member 52 to the upward position of figure 6 which will normally open the valve control of the associated fluid. Accordingly, the present invention not only accommodates a combined valve actuator and valve controller instrument but also provides a reversible power module in such a combination that it can provide safe opening action against failures or safe closing against failures by means of a spring for the control valve without replacing components or rebuilding the actuator as in the currently available units. The detailed description mentioned above has been provided for clarity and understanding only, and no unnecessary limitation should be understood from it, as the modifications will be apparent to those skilled in the art.

Claims (10)

1. In an actuator for operating a control element used to regulate fluid flow by a fluid control valve in response to a positioner instrument of the control valve, the actuator includes a pair of coaxially aligned members, a mounted external mobile member in an external position with respect to the other internal member fixed and movable in the direction of the axis with respect to the fixed internal member, having the adjacent end members, wherein a chamber is defined between the adjacent ends to move the mobile external member away from the member fixed internal during operation of the actuator, the means for coupling the control element with the mobile external member and wherein the chamber when subjected to fluid under pressure operates the actuator and moves the mobile external member away from the fixed internal member from a first position of the valve actuator to a second position of the valve actuator, the improvement with system: a mounting cushion extending transversely outward from the fixed member and including a surface mounting portion of the instrument beyond the movable external member for mounting a control valve positioning instrument; an inlet port of the fluid pressure in the surface mounting portion of the instrument for fluid communication with the control valve positioning instrument; and fluid conduits in the mounting pad and the fixed internal member for fluid communication of the fluid pressure inlet port and the chamber for coupling the fluid under pressure from the control valve positioning instrument to the chamber.

2. The actuator according to claim 1 includes a bladder mounted in the chamber, the bladder defining an interior space for receiving fluid, and the means for fluidly interconnecting the fluid conduits with the interior space of the bladder.

The actuator according to claim 2, wherein the movable external member and the fixed internal member define a power module; the power module is selectively reversible between a first position and a second position; the first position being a position in which the expansion of the camera moves the mobile external member generally toward the control element; and the second position being a position in which the expansion of the camera moves the mobile external member generally away from the control element.

4. The actuator according to claim 3, including a second mounting pad extending transversely outward from the fixed internal member and including a second surface mounting portion of the instrument beyond the movable outer member for mounting the positioning instrument of the instrument. the control valve, and further includes, a second inlet port of the fluid pressure in the second surface mounting portion of the instrument, and a second fluid conduit in the second mounting pad and the fixed internal member for fluid communication of the second inlet port of the fluid pressure and the chamber for the coupling of the fluid under pressure from the positioning instrument of the control valve to the chamber.

The actuator according to claim 4, wherein the bladder includes the means for fluidly communicating the second fluid conduit with the interior space of the bladder.

6. A fluid valve and combined valve actuator to regulate fluid flow in response to a control valve positioning instrument, valve and valve actuator combined, consist of: a fluid control valve which includes a flow control element for controlling the flow of fluid through a pipeline; a valve actuator that includes, (a) a stationary internal member mounted to the fluid control valve; (b) a movable external member coaxially aligned with and mounted axially so that it can move about the stationary member, the movable outer member and the stationary member having adjacent ends, wherein a chamber is defined between the adjacent ends; (c) the means for coupling the movable member with the flow control element; (d) the means for coupling the chamber with a fluid pressure source of the actuator to move the movable member axially on the stationary member from a first position of the valve actuator to a second position of the valve actuator to control the corresponding fluid flow through the fluid valve; and e) the return means for moving the movable member axially from the second position of the valve actuator to the first position of the valve actuator; a mounting pad extending transversely outward from the stationary internal member and includes a surface mounting portion of the instrument beyond the movable external member for mounting the control valve positioning instrument; a fluid pressure inlet port in the surface mount portion of the instrument for fluid communication with the control valve positioning instrument; and fluid conduits in the mounting pad and the stationary internal member for fluid communication of the fluid pressure inlet port and the chamber for coupling the fluid under pressure from the positioning instrument of the control valve with the chamber.

7. A valve controller instrument and the combined valve actuator apparatus for operating a flow control element used to regulate the flow of fluid through a flow control valve in response to the valve controller instrument, the actuator and the valve actuator. Combined instrument consist of: a valve actuator includes, (a) a stationary internal member mounted to the fluid control valve; (b) a movable external member coaxially aligned with and movably mounted on the stationary member, the movable external member and the stationary member having adjacent ends, wherein a chamber is defined between adjacent ends; (c) the means for coupling the movable member with the flow control element; (d) the means for coupling the chamber with a fluid pressure source of the actuator to move the movable member axially on the stationary member from a first position. from the actuator of the valve to a second position of the valve actuator to correspondingly control the fluid flow through the fluid valve, and e) the return means for moving the axially moving member from the second position of the valve actuator to the first position of the valve actuator; a mounting cushion extending transversely outward from the stationary internal member and including a surface mounting portion of the instrument beyond the movable external member for mounting the control valve control instrument; an inlet port of the fluid pressure in the surface mount portion of the instrument for fluid communication with the control valve control instrument; fluid conduits in the mounting pad and the stationary internal member for fluid communication of the fluid pressure inlet port and the chamber for coupling the fluid under pressure from the control valve controller instrument to the chamber; and a valve controller instrument mounted to the surface mount portion of the instrument and having fluid pressure outlet coupled with the fluid pressure inlet port. The combined actuator and instrument according to claim 7 include an intermediate mounted feedback joint with the actuator and the instrument, and a cover removably mounted on the actuator and covering the retroaction joint to protect the joint of feedback on the environment. The combined actuator and instrument according to claim 7, wherein the movable external member and the stationary internal member define a power module; the power module is selectively reversible between a first position and a second position; the first position being a position in which the expansion of the camera moves the mobile external member generally toward the control element; and the second position being a position in which the expansion of the camera moves the mobile external member generally away from the control element. The actuator and combined instrument according to claim 7 includes a fluid control valve mounted to the stationary internal member and includes a flow control element mounted on the movable external member.