Patent Publication Number: US-2017350421-A1

Title: Manifold for a directional control valve for a valve actuator

Description:
FIELD 
     The present subject-matter relates to pneumatic and hydraulic control systems for valve actuators of the type used in many industrial processes. 
     INTRODUCTION 
     The flow of fluids and other substances carried in process transport pipes is typically controlled using a process valve. It may be necessary in an industrial process to close, to open, to lock, or to keep open the process valve, in response to specific conditions of the flow and the environment, such as a detected change in the flow rate inside the pipe, temperature inside and/or outside of the pipe, flow pressure, outside environment pressure, etc. 
     Conventional control systems for valve actuators are generally designed to respond to changes in the process flow in one of four modes: fail open, fail close, fail last, and fail last locked. The process valve is typically configured in one of the four modes with tubes leading to the actuator, forming a tube network. Such tube networks of the control systems have to be quite circuitous with multiple fittings and bends to include components such as filter regulators, speed controllers, and so forth. The tube networks also need to be customized for each of the four configurations and therefore demand qualified labor during the installation and maintenance. 
     SUMMARY 
     The following summary is intended to introduce the reader to the more detailed description that follows, and not to define or limit the claimed subject matter, 
     According to a first aspect, the present subject matter provides a valve actuator control system. The control system includes a pneumatic directional valve operable to move the actuator, and also a manifold having multiple internal channels, each channel having a manifold inlet port and a manifold outlet port. 
     The pneumatic directional valve has a valve inlet port and a valve outlet port The manifold is mountable directly to the pneumatic directional valve and is fluidly connectible to it in alternative connections such that the manifold outlet port and manifold inlet port of one active internal channel communicate with the valve inlet port and valve outlet port, respectively, of the pneumatic directional valve, while the other, non-active internal channels are isolated from the pneumatic directional valve. 
     The control system also includes closures that block the manifold outlet port and manifold inlet port of the non-active internal channels. 
     The multiple internal channels of the manifold are configured to provide operability of the actuator control system in at least a plurality of fail modes. 
     In some examples, the multiple internal channels of the manifold are configured to provide operability of the actuator control system in any one of fail-open, fail-close, or fail-last modes. 
     In some examples, the multiple internal channels of the manifold are configured to provide operability of the actuator control system in any one of fail-open, fail-close, fail-last, or fail-last-locked modes. 
     According to another aspect, the present subject matter provides a pneumatic manifold for a directional valve that operates to move the actuator of a valve actuator control system. The manifold is connectable to the directional valve and comprises a unitary body having multiple internal channels, each with a manifold inlet port and a manifold outlet port. The manifold is connectable to the directional valve in alternative connections such that the manifold outlet port and manifold inlet port of one active internal channel communicate with the valve inlet port and valve outlet port, respectively, of the pneumatic directional valve. The multiple internal channels of the manifold are configured to provide operability of the actuator control system in at least a plurality of fail modes. 
     In some examples, the multiple internal channels of the manifold are configured to provide operability of the actuator control system in any of fail-open, fail-close, or fail-last modes. 
     In some examples, the multiple internal channels of the manifold are configured to provide operability of the actuator control system in any of fail-open, fail-close, fail-last or fail-last-locked modes. 
     According to another aspect, the present subject matter provides a manifold block for a directional valve that controls the actuator of a process valve. The manifold block is connectable to the directional valve and comprises a plurality of manifold valve ports that are adapted to receive a plurality of complementary ports of the directional valve. A plurality of manifold channels is located inside the manifold block, each of the manifold channels extending between at least two manifold ports being adapted to conduct pressurized air between them. The manifold block is configured to operatively connect the directional valve to a pressurized air supply in at least one of fail-open, fail-close, fail-last and fail-last-locked operating modes. 
     In some examples, the manifold block is configured so that the directional valve is adapted to control the actuator in at least one operating mode chosen from fail-open, fail-close, fail-last, and fail-last-locked. 
     In some examples, the directional valve is controlled by at least one pilot solenoid valve which is connected to at least two of the input and output manifold ports. 
     In some examples, the manifold block is a unitary body. 
    
    
     
       DRAWINGS 
       For a better understanding of the subject matter herein and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings which show at least one exemplary embodiment, and in which: 
         FIG. 1  illustrates a schematic side view of a conventional control system for a process valve. 
         FIG. 2  illustrates a schematic side view of a conventional control system for a process valve. 
         FIG. 3A  shows a schematic representation of an example of a conventional two-position solenoid directional valve for a fail-open configuration. 
         FIG. 36  shows a schematic representation of an example of a conventional two-position solenoid-operated directional valve for a fail-closed configuration. 
         FIG. 3C  shows a schematic representation of an example of a conventional two-position solenoid directional valve for a fail-last configuration. 
         FIG. 3D  shows a schematic representation of an example of a conventional three-position solenoid directional valve for a fail-last-locked configuration. 
         FIG. 4A  shows a schematic representation of a conventional piloted two-position directional valve for a fail-open configuration. 
         FIG. 46  shows a schematic representation of a conventional piloted two-position directional valve for a fail-closed configuration. 
         FIG. 4C  shows a schematic representation of a conventional piloted two-position directional valve for a fail-last configuration. 
       FIG,  4 D shows a schematic representation of a conventional piloted three-position directional valve for a fail-last-locked configuration. 
         FIG. 5  shows a schematic representation of a manifold block for control of an actuator, in accordance with at least one embodiment. 
         FIG. 6  shows a schematic representation of a manifold block adapted for the piloted directional valve, in accordance with at least one embodiment. 
         FIG. 7  shows a schematic perspective view of the manifold block, in accordance with at least one embodiment. 
         FIG. 8  shows a top view, a bottom view, and side views of an example embodiment of the manifold. 
         FIG. 9A  shows a schematic representation of the manifold with the fail-open solenoid directional valve, in accordance with at least one embodiment. 
         FIG. 9B  shows a schematic representation of the manifold with the fail-closed solenoid directional valve, in accordance with at least one embodiment. 
         FIG. 9C  shows a schematic representation of the manifold with the fail-last solenoid directional valve, in accordance with at least one embodiment. 
         FIG. 9D  shows a schematic representation of the manifold with the fail-last-locked solenoid directional valve, in accordance with at least one embodiment. 
         FIG. 10A  shows a schematic representation of the manifold with the fail-open piloted directional valve, in accordance with at least one embodiment. 
         FIG. 10B  shows a schematic representation of the manifold with the fail-closed piloted directional valve, in accordance with at least one embodiment. 
         FIG. 10C  shows a schematic representation of the manifold with the fail-last piloted directional valve, in accordance with at least, one embodiment. 
         FIG. 10D  shows a schematic representation of the manifold with the fail-last-locked piloted directional valve, in accordance with at least one embodiment. 
         FIG. 11  shows a perspective view of an actuator with a pneumatic manifold control system for the actuator. 
     
    
    
     DESCRIPTION OF VARIOUS EMBODIMENTS 
     In the following description, specific details are set out to provide examples of the claimed subject matter. However, the embodiments described below are not intended to define or limit the claimed subject matter. 
     It will be appreciated that, for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements or steps. Numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments of the subject matter described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the present subject matter. Furthermore, this description is not to be considered as limiting the scope of the subject matter in any way but rather as illustrating the various embodiments. 
     In addition, as used herein, the wording “and/or” is intended to represent an inclusive-or. That is, “X and/or Y” is intended to mean X or Y or both, for example. As a further example, “X, Y, and/or Z” is intended to mean X or Y or Z or any combination thereof. 
     Examples of conventional control systems  30  and  60  for a process valve  32  actuated by actuator  34  are shown schematically at  FIG. 1  and  FIG. 2 . A conventional control system  30  (or  60 ) comprises a directional valve  36  (or  62 ), a filter (filter-regulator)  38 , and a plurality of tubes leading to ports of the directional valve  36  (or  62 ). Shown at  FIG. 1  and  FIG. 2  are five-port directional valves  36  and  62  with ports  40 ,  42 ,  44 ,  46 , and  48 . 
     It should be noted that the control system  30  may be pneumatic or hydraulic. Although pneumatic operation using air is described herein, the same operation and schematics can be used in a hydraulic control system  30 , by replacing air with oil. 
     Depending on the type of the actuator  34  to be controlled and other requirements for the control system for the actuator  34 , either a solenoid-operated directional valve  36  or a piloted directional valve  62  can be used in the control system for the actuator  34 . 
       FIG. 1  illustrates a schematic side view of a conventional pneumatic control system  30  for the process valve  32  using a five-port solenoid-operated directional valve  36 . The solenoid-operated directional valve  36  may be operated using at least one solenoid  37 . As shown at  FIG. 1 , a plurality of tubes  50 ,  52 ,  54 ,  56 , and  58  form a network of tubes which connects the directional valve  36  to the actuator  34 , an input air filter  38 , and exhaust controls (not shown). The solenoid  37  of the solenoid-operated directional valve  36  is electrically connected to the installation site&#39;s control system. Failure of this source (power failure, initiated emergency-stop of process shutdown) deactivates solenoid valve  37  which reverts to a known (‘fail’) position. A five-port directional valve  36  typically has a pressure port (P-port)  40 , a first exhaust valve port  42 , a second exhaust valve port  44 , as well as two output ports: A-port  48  and B-port  46 . The P-port  40  is an input port and is operatively connected to an input tube  50  which brings air from the filter  38 . The output ports A-port  48  and t 3 -port  46 , are connected to the actuator  34  through the A-tube  54  and B-tube  52 . The first and the second exhaust valve ports  42 ,  44  are connected to exhaust tubes  56 ,  58 , respectively, which may be connected, for example, to an exhaust flow control device (not shown at  FIG. 1 ). 
       FIG. 2  illustrates a schematic side view of a conventional pneumatic control system  60  for the process valve  32  using, a five-port piloted directional valve  62 . In addition to previously discussed P-port  40 , A-port  46 , B-port  48 , and the first and the second exhaust valve ports  42 ,  44 , the piloted directional valve  62  has at least one pilot port. At least one pilot solenoid valve can operate the piloted directional valve  62  through at least one pilot port. 
     Shown at  FIG. 2  is the piloted directional valve  62  with a first pilot port  64  and a second pilot port  66 . The first pilot port  64  may be operatively connected through a first pilot tube  68  to a first pilot solenoid valve  70 . The second pilot port  66  may be operatively connected through a second pilot tube  72  to a second pilot solenoid valve  74 . The first or the second solenoid pilot valves  70 ,  74  can operate the five-port piloted directional valve  62  using air pushed through the first or the second pilot tubes  68  and  72  to the first or the second pilot ports  64 ,  66 . When the signal to the pilot solenoid valve fails, the corresponding pilot valve,  70  or  74  stops pushing air to the corresponding pilot port  64 ,  66  of the piloted directional valve  62 . 
     Typically, a control system  30  for the actuator  34  of process valve  32  can operate in one of four configurations: fail-open, fail-close, fail-last, and fail-last-locked. 
     Each of the four configurations demands a specifically configured directional valve  36  or  62 .  FIGS. 3A, 3B, 3C, and 3D  show conventional five-port solenoid directional valves  36   a ,  36   b ,  36   c , and  36   d , each operating in one of the four configurations. 
       FIGS. 3A, 3B, 3C, and 3D  also schematically show an actuator  34  having a moving piston &amp; piston rod  130  which separates the actuator&#39;s cylinder in two portions: a rod portion  132  and a cap portion  134 . The A-port of any one of the solenoid directional valves  36   a ,  36   b ,  36   c , and  36   d  may be connected via the tube  54  to the cap portion  134  of the actuator  34 , while the B-port of any one of the solenoid directional valves  36   a ,  36   b ,  36   c , and  36   d  may be connected via the tube  52  to the rod portion  132  of the actuator  34 . 
     The five-port directional valve  36  (or  62 ) may be a five-port three-position directional valve or a five-port two-position directional valve, depending on the configuration it is used for. 
     Fail-open 
     In a fail-open configuration, the process valve  32  needs to open when there is a failure of the solenoid valve&#39;s electrical signal 
       FIG. 3A  shows a schematic representation of an example of a conventional two-position solenoid directional valve  36   a  for fail-open configuration (”FO solenoid directional valve“) connected to the actuator  34  through the tubes  52  and  54 . Such a FO solenoid directional valve  36   a  can be operated by a solenoid  100   a  and a spring  102   a.    
     The FO solenoid directional valve  36   a  may be in a rest position  110   a  (or home position, or default position), or in an activated position  120   a . The A-port (represented schematically at  FIG. 3A  as port  116   a  in the rest position  110   a  and as port  126   a  in the activated position  120   a ) of the FO solenoid directional valve  36   a  is connected to the cap portion  134  of the actuator  34 , while the B-port (represented schematically as  114   a  and  124   a  at  FIG. 3A ) of the FO solenoid directional valve  36   a  is connected to the rod portion  132  of the actuator  34 . 
     When the FO solenoid valve  36   a  is in its rest position  110   a , the air, received from the filter  38  to the P-port  112   a , passes from the P-port  112   a  to the B-port  114   a . From the B-port  114   a , the air passes via the tube  52  to the rod portion  132  of the actuator  34 , pushing, the piston &amp; piston rod  130  and expanding the rod portion  132 . The air from the cap portion  134  of the actuator  34  returns through the tube  54  to the A-port  116   a  and passes through the directional valve  36   a  to the exhaust port  119   a.    
     When the solenoid  100   a  is activated, the FO solenoid valve  36   a  is in the activated position  120   a . In this activated position  120   a , the air passes from the P-port  122   a  to the A-port  126   a , the cap portion  134  of the actuator  34  is therefore filled with air, and the process valve  32  is closed. 
     When the solenoid  100   a  is deactivated the FO solenoid valve  36   a  is returned to the rest position  110   a  by means of the spring  102   a . In the rest position  110   a , the air is brought from P-port  112   a  to B-port  114   a  and returns from the A-port  116   a  to the exhaust valve port  119   a . In this rest position  110   a , the air pushed from the B-port  114   a  via the tube  52  fills the rod portion  132  of the actuator  34  and the piston &amp; piston rod  130  retracts in the−z direction and opens the process valve  32 . The air from the cap portion  134  exhausts through the tube  54  via the port  116   a  and then through the port  119   a.    
     Fail-Closed 
     In a fail-closed configuration, the process valve  32  needs to close if there is a failure of the solenoid valve&#39;s electrical signal 
     Shown at  FIG. 3B  is a schematic representation of a two-position solenoid-operated directional valve  36   b  for fail-closed (”FC”) configuration (“FC solenoid directional valve”), connected to the actuator  34  through the tubes  52  and  54 . The B-port (represented schematically as  114   b  and  124   b  at  FIG. 3B ) of the directional valve  36   b  is connected to the rod portion  132  of the actuator  34 , while the A-port (represented schematically as  116   b  and  126   b  at  FIG. 3B ) is connected to the cap portion  134  of the actuator  34 . Such a directional valve  36   b  can be in a rest position  110   b  or in an activated position  120   b.    
     The FC solenoid directional valve  36   b  has a solenoid  100   b  for activation and a spring  102   b . The FC solenoid directional valve  36   b  is in the activated position  120   b  when it is activated by the solenoid  100   b  and the air passes from the P-port  122   b  to the B-port  124   b . The B-port  124   b  is connected to the rod portion  132  of the actuator  34 , the rod portion  132  is filled with air, the rod is retracted in the−z direction and the process valve  32  is opened. 
     When there is no signal coming from the solenoid  100   b , for example, when the industrial process has failed, the spring  102   b  moves the directional valve  36   b  to the rest position  110   b . In the rest position  110   b , the air passes from the P-port  112   b  to the A-port  116   b  and fills the cap portion  134  of the actuator  34  with air, thereby closing the process valve  32 . The air from the rod portion  132  of the actuator then returns via the tube  52  to the port  114   b  and then exhausts through the port  118   b.    
     Fail-Last 
     Shown at  FIG. 3C  is an example of a two-position solenoid directional valve for the fail-last configuration (“FL solenoid directional valve”)  36   c . The. FL solenoid directional valve  36   c  is activated by a first solenoid  104  or the second solenoid  105 , and does not have springs, The FL solenoid directional valve  36   c  can be in a first position  140  or in a second position  150 . 
     The B-port (represented schematically as  144  and  154  at  FIG. 3C ) of the directional valve  36   c  is connected to the rod portion  132  of the actuator  34 , while the A-port (represented schematically as  146  and  156  at  FIG. 3C ) is connected to the cap portion  134  of the actuator  34 . 
     The first solenoid  104  can move the FL solenoid directional valve  36   c  into a first position  140 , where the air passes from the P-port  142  to the A-port  146 , filling the cap portion  134  with air. As the cap portion  134  is filled with air, the process valve  32  is closed. When the solenoid  104  is deactivated, the directional valve  36   c  remains in the first position  140 . 
     When the second solenoid  105  is activated, it can move the FL solenoid directional valve  36   c  into a second position  150 , where the air passes from the P-port  152  to the B-port  154 , filling the rod portion  132  of the actuator  34  with air. As the rod portion  132  is filled with air, the process valve  32  is opened. When the solenoid  105  is deactivated, the directional valve  36   c  remains in the second position  150 . 
     Fail-Last-Locked 
       FIG. 3D  shows an example of a three-position solenoid directional valve for the fail-last-locked configuration (“FLL solenoid directional valve”)  36   d . The FLL solenoid directional valve  36   d  has a first solenoid  106 , a second solenoid  107 , and a first spring  108  and a second spring  109 . The FLL solenoid directional valve can be in a first position  160 , a second position  170 , or a third (middle) position  180 . 
     When the first solenoid  106  is activated, the directional valve  36   d  is in the first position  160  and the air passes from the P-port  162  to the A-port  166 . The cap portion  134  of the actuator  34  is filled with air and the process valve  32  is closed. The air from the rod portion  132  returns (exhausts) through the B-port  164  to the exhaust valve port  168 . 
     When the first solenoid  106  is deactivated, the first and the second springs  108  and  109  move the FLL solenoid directional valve  36   d  into the third (middle) position  180 . In the third position  180 , the FLL solenoid directional valve  36   d  is closed and no air passes from the P-port  182  to either the A-port  186  or the B-port  184 . 
     When the second solenoid  107  is activated, the directional valve  36   d  is in the second position  170  and the air passes from the P-port  172  to the B,-port  174 . In this case, the rod portion  132  of the actuator  34  is filled with air and the process valve  32  is opened. The air from the cap portion  134  exhausts through the A-port  176  to the exhaust valve port  179 . 
     When the second solenoid  107  is deactivated, the first and the second springs  108  and  109  move the FLL solenoid directional valve  36   d  into the third (middle) position  180 , closing the FLL solenoid directional valve  36   d  such that no air passes from the P-port to either the A-port or the B-port. 
     Referring back to  FIG. 2 , the directional valve can be piloted by one or two pilot valves. The pilot valve or valves ( 70  and/or  74 ) can control the piloted directional valve  62  by means of the airflow. When the system fails, the pilot valve or valves stop sending air to the piloted directional valve  62 , sending therefore a “failure” signal to the piloted directional valve  62 , It should be noted that, typically, the solenoid directional valves  36  and the piloted directional valves  62  have different physical dimensions. 
       FIGS. 4A, 4B, 4C and 4D  show piloted directional valves  62   a ,  62   b ,  62   c , and  62   d , each adapted to operate in one of four configurations: fail-open, fail-closed, fail-last or fail-last-locked. 
       FIG. 4A  shows a piloted directional valve for a fail-open configuration (“FO piloted directional valve”)  62   a . The FO piloted directional valve  62   a  operates in a similar manner to the FO solenoid directional valve  36   a  discussed above, except that the piloted valve  62   a  is activated by a pilot valve  70   a . The pilot valve  70   a  controls the FO piloted directional valve  62   a  by the flow of the air. 
     When the pilot valve  70   a  pushes the air to the FO piloted directional valve  62   a , the FO piloted directional valve  62   a  is in the activated position  120   a . In the activated position  120   a , the air received by the P-port  122   a  is transmitted to the A-port  126   a , and then through the pipe  54  to the cap-portion  134  of the actuator  34 , thereby closing the process valve  32 . 
     On failure of pilot valve  70   a , it stops sending/transmitting air to the piloted directional valve  62   a . With the absence of air from the pilot valve  70   a , the spring  102   a  moves the directional valve  62   a  into its rest position  110   a . In this rest position  110   a , the input air from the P-port  112   a  is transmitted to the B-port  114   a , and then, via tube  52 , to the rod portion  132  of the actuator  34 , thereby forcing the piston &amp; piston rod  130  to move in the−z direction, opening the process valve  32 . 
       FIG. 4B  shows a piloted directional valve for a fail-closed configuration (“FC piloted directional valve”)  62   b , which operates in a similar manner as the FC solenoid directional valve  36   b , with the exception that the piloted valve  62   b  is activated by a pilot valve  70   b  (instead of the solenoid  100   b ). 
       FIG. 4C  shows a piloted directional valve for a fail-last configuration (“FL piloted directional valve”)  62   c , which operates in a similar manner as the FL solenoid directional valve  36   c , with the exception that the FL piloted directional valve  62   c  is activated by a first pilot valve  70   c  and a second pilot valve  74   c  (instead of the first and the second solenoids  104  and  105 ). 
       FIG. 4D  shows a piloted directional valve for a fail-last-locked configuration (“FLL piloted directional valve”)  62   d , which operates in a similar manner as the solenoid directional valve  36   d , with the exception that the FLL piloted valve  62   d  is activated by the first pilot valve  70   d  or the second pilot valve  74   d  (instead of the first and the second solenoids  106  and  107 ). 
     Referring back to the conventional control systems  30  and  60  at  FIGS. 1-2 , the network of tubes  50 ,  52 ,  54 ,  56 , and  58 , leading from the directional valves  36  or  62  to the actuator  34  and to supporting components, should be designed, adapted and installed specifically for each control system. Interconnecting tubing is prone to leakage because of the numerous connection points, is subject to failure due to mechanical damage and/or vibrations, and is not well suited for compact assemblies. 
     Manifold 
     Referring now to  FIG. 5 , shown therein is a schematic representation of an example embodiment of a manifold block  200  for control of an actuator  34 . For example, the manifold  200  may be a parallelepiped. For example, the manifold may be a rectangular parallelepiped. Different materials can be used to build the manifold; steel, ductile iron, aluminum or stainless-steel. 
     The manifold  200  comprises a plurality of manifold ports and a plurality of manifold channels. Each manifold channel may have two or more ports and may permit the air to pass in the manifold channel from at least one port to at least another port of the same manifold channel. Each manifold port may permit the air to enter and exit one of the manifold channels at an external surface  201  of the manifold  200 . The manifold ports may be located at different sides (facets) of the manifold  200 . 
     In at least one embodiment, the manifold channels of the manifold  200  may shorten or even replace the conventional tube network of the control system  30  (or  60 ). In at least one embodiment, the filter  38 , a pressure relief valve, as well as exhaust flow control devices (valve/muffler), and/or other devices, may be operatively connected directly to the manifold  200 . 
     In at least one embodiment, the manifold  200  may be operatively coupled to the directional valves  36  or  62 . In at least one embodiment, five ports of the manifold  200  (ports  240 ,  242 ,  244 ,  246 , and  248 ) may be adapted to receive the ports of the solenoid directional valve  36 . The ports of the manifold  200  may be complementary to the ports of the directional valves  36  or  62 . 
     The solenoid directional valve  36  for any one of the four configurations fail-open ( 36   a ), fail-closed ( 36   b ), fail-last ( 36   c ) or fail-last-locked ( 36   d ) as discussed herein may be operatively connected (coupled) to the manifold  200 . The filter  38 , at least one exhaust flow control device, as well as a pressure relief valve may also be operatively coupled to the ports of the manifold  200 . 
     Referring to  FIG. 5 , the manifold  200  comprises at least one air input channel  212 , which may have at least one input port  202  and an output port  240 . The output port  240  of the air input channel  212  may be operatively connected to the P-port  40  of the directional valve  36 . The input port  202  may be operatively connected to the filter  38 . 
     Shown at  FIG. 5  is an example embodiment with the air input manifold channel  212  having three input manifold ports (a first input manifold port  202 , a second input manifold port  204 , and a third input manifold port  206 ) and three channel portions  207 ,  208 , and  203 , merged at a node  210  into the air input manifold channel  212 . The air input manifold channel  212  then leads to the output port  240  of the air input manifold channel  212 . For example, the air input manifold channel  212  may have further channel portions, each merged into the air input manifold channel  212  or into at least one of its portions. 
     In at least one embodiment, the second input port  204  may be operatively connected to the pressure relief valve. In at least one embodiment, one or more of input ports may be plugged. Multiples of the internal channels offers the possibility of interconnecting different peripheral devices (such as a pressure relief valve and/or piloting solenoid valves) and/or simplifying interconnections on different faces of the manifold to optimize compactness of the final assembly. All unused ports, with the exception of the exhaust ports  224  and  226 , must be plugged with appropriate plugs. 
     The manifold  200  may further comprise a first exhaust manifold channel  256  and a second exhaust manifold channel  258 . The first exhaust channel  256  may have two manifold exhaust ports  242  and  224 , and the second exhaust channel  258  may also have two manifold exhaust manifold ports  244  and  226 . In at least one embodiment, the first and the second exhaust manifold ports  258  and  244  may be adapted to receive the first and the second exhaust valve ports  58  and  44  of the directional valve  36 , such that the manifold  200  may be operatively connected to the directional valve  36 . 
     The exhaust manifold ports  224  and  226  may be adapted to receive the exhaust flow control mufflers. If no accessories are required for the exhaust function, these ports are to be left opened. 
     The manifold  200  may further comprise an A-channel  254  and a B-channel  252 , each having at least two ports. A first manifold A-port port  248  of the A-channel  254  may be adapted to connect to the A-port  48  of the directional valve  36 . At least one exit manifold B-port (for example, port  231  or port  233 ) of the B-channel may be operatively connected to the actuator  34 , the unused port is thus appropriately plugged. 
     A first manifold B-port  246  of the B-channel  252  may be operatively connected to the B-port  46  of the directional valve  36 . At least one exit manifold B-port (for example, port  231  or port  233 ) of the B-channel  252  may be operatively connected to the actuator  34 , the unused port is thus appropriately plugged. 
     In at least one embodiment, at least one exit manifold A-port may have one form and/or dimension and/or standard, and the other exit manifold A-port may have another form and/or dimension and/or standard. Similarly, at least one exit manifold B-port may have one form and/or dimension and/or standard, and the other exit manifold B-port may have another form and/or dimension and/or standard. For example, the exit manifold ports  233  (and/or  235 ) may have the NAMUR standard, and exit manifold ports  231  (and/or  237 ) may have the National Pipe Thread (NPT) standard. Having two different ports may allow reducing the number of components, such as adapters, to be used in the control system. ‘NAMUR’ describes a mechanical interface pattern used to mate a directional valve onto a flat surface and is typically used in pneumatic rotary actuators. Other port types can also be integrated such as BSP and SAE. 
     For example, when one manifold A-port  237  is used, the other A-port  235  may be blocked/plugged with an appropriate port plug (plug appropriate for the type of port, NPT, BSP, SAE, NAMUR). 
     Shown at  FIG. 6  is a schematic representation of another example embodiment of a manifold block  260  adapted for the piloted directional valve  62 . In addition to the manifold channels and ports discussed herein in reference to the manifold block  200 , the manifold block  260  may have at least two pilot manifold channels: a first pilot channel  268  and a second pilot channel  272 , each having at least two ports. The first and the second pilot channels  268  and  272  are adapted to be operatively connected to the first and the second pilot valves  70  and  74 , respectively. Channels  214  and  216  forward inlet air to ports  215  and  217  respectively which can be used by the externally connected pilot valves  70  and  74  as the air source to be directed toward pilots  64  and  66 . This feature greatly enhances the compactness and reliability of the assembly by eliminating the requirement of external interconnections. 
     Shown at  FIG. 7  is a schematic perspective view (three-dimensional view) of an example embodiment of the manifold  260 . It should be noted that the manifold channels may be of any form. For example, the manifold channels may have similar or different cross-sections. For example, a cross-section of at least one manifold channel may have round, elliptical or a convex polygon form, The form and at least one dimension of the cross-section of at least one manifold channel may be constant over at least one portion of the at least one manifold channel and/or may vary along the length of the at least one manifold channel. 
       FIG. 8  shows a top view, a bottom view, and side views of an example embodiment of the manifold  260 . 
       FIG. 9A  shows a schematic representation of the manifold  200  with the FO solenoid directional valve  36   a .  FIG. 9B  shows a schematic representation of the manifold  200  with the FC solenoid directional valve  36   b .  FIG. 9C  shows a schematic representation of the manifold  200  with the FL solenoid directional valve  36   c .  FIG. 9D  shows a schematic representation of the manifold  200  with the FLL solenoid directional valve  36   d.    
     The same manifold  200  may be operatively connected to receive any of the directional solenoid valves  36   a ,  36   b ,  36   c , or  36   d , each adapted to a different configuration, such as fail-open, fail-close, fail-last, and fail-last-locked, 
       FIG. 10A  shows a schematic representation of the manifold  260  with the FO solenoid directional valve  62   a .  FIG. 10B  shows a schematic representation of the manifold  260  with the FC solenoid directional valve  62   b .  FIG. 10C  shows a schematic representation of the manifold  260  with the FL solenoid directional valve  62   c .  FIG. 10D  shows a schematic representation of the manifold  260  with the FLL solenoid directional valve  62   d.    
     The solenoid directional valves  36  and the piloted directional valves  62  typically have different dimensions. Nevertheless, the manifold  260  may be adapted to receive a solenoid direction valve  36 , all the unused ports of the manifold  260  are plugged with the exception of the exhaust ports. 
       FIG. 11  shows a perspective view of an actuator  34  with a pneumatic manifold control system for the actuator. Shown at  FIG. 11  is an example embodiment of the manifold  260 , operatively connected to the directional valve  62 . Two pilot valves  70  and  74  are operatively connected to the manifold  260 . 
     The pneumatic manifold control system for an actuator may comprise the directional valve  36  or  62 , the pressure relief valve  199 , the filter  38 , and the manifold block  260 . The manifold block  260  may connect using the manifold channels the filter  38 , the pressure relief valve  199 , and the directional valve  36  or  62 , with each other and with the actuator  34 . 
     As shown at  FIG. 11 , only two tubes  52  and  54  may lead from the manifold block  260  to the actuator  34 . Comparing  FIG. 11  to  FIG. 2 , the conventional control system  60  would need a larger number of tubes in order to connect the directional valve  36  to the control devices (such as the filter  38 , the pressure relief valve  199 , and the exhaust flow control device). The number of tubes in the control system  300  may be considerably reduced due to the manifold  260 . The manifold channels as described herein replace the tubes of the conventional control system  60  (or  30 ). 
     The directional valve may be the solenoid directional valve  36  or the piloted directional valve  62 , piloted by at least one pilot solenoid valve  70  (and/or  74 ). The pilot solenoid valves  70  and/or  74 , as shown at  FIG. 11 , may be connected directly to the manifold  260 , i.e. to the manifold channels  268  and/or  272 . 
     As described herein, the pneumatic manifold control system for a valve actuator may operate in at least one of the control configurations. The control configuration of the pneumatic manifold control system may be one of fail-open, fail-close, fail-last, and fail-last-locked configurations and is dependent of the directional valve used in the system. 
     The manifold  260  may be attached to the plate  303 , while the plate  303  may be attached to the actuator  34 . 
     Different manifold blocks may be provided, each with the functionality indicated herein, to suit different size directional valves: a ¼ size manifold block to suit the ¼ size solenoid operated directional valve  36 ; a ½ size to suit the ½ size piloted directional valve  62 ; and a size 1 to suit a 1 size piloted directional valve also depicted by  62 . The physical sizes of these blocks are: ¼ size−4 in long×4 in wide×1.5 in high; ½ size−8 in long×4 in wide×2.25 in high; and 1 size−10 in long×4.25 in wide×3.5 in high. 
     The manifold based control system offers numerous advantages over the existing methods used in the industry: increased reliability, compactness and cost effectiveness of the final assembly by eliminating the majority of external component interconnections, optimized modularity permits four different control schemes by changing a single component (FO, FC, FL, FLL), and simplifies the addition of numerous accessories, easy physical installation since the block is used as a mounting platform for all accessories, cost effective manufacturing of the block since it can be mass produced, numerous port options, configurations and physical installation possibilities permit its use in a wide scope of applications. 
     While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto.