Patent Publication Number: US-2017370482-A1

Title: Sub-plate mounted valve

Description:
TECHNICAL FIELD 
     The present disclosure relates to sub-plate mounted valves and manifolds and sub-plate containing sub-plate mounted valves. Sub-plate mounted valves are generally used to control flow of pressurized fluids in hydraulic systems, including subsea blow out prevention systems. 
     BACKGROUND 
     Subsea hydrocarbon recovery systems can include a blowout preventer for sealing, controlling, and monitoring well operations. Control and operation of the blowout preventer and related equipment is typically achieved through a system of hydraulic actuators controlled by a manifold or sub-plate having multiple control valves. Among the control valves commonly used in such systems are sub-plate mounted valves. 
     One or more sub-plate mounted valves may be installed directly into the manifold or sub-plate. The manifold or sub-plate defines at least three ports: a function port, a supply port, and a return port. Generally, the supply port provides high pressure fluid to control or actuate hydraulic equipment connected to the function port while the return port provides a means for venting or otherwise relieving pressure within the hydraulic system. Each valve is operable between at least two positions. In the first position, the valve permits fluid flow from the supply port to the function port. In the second position, the valve relieves pressure in the hydraulic circuit by permitting flow through a return loop or venting the fluid. 
     Subsea operations continue to progress into deeper and harsher oceanic environments and there is a growing need for equipment capable of operating effectively and efficiently under such conditions. The efficiency of a valve is highly dependent on the flow path through the valve because restrictions and tortuous redirections within the valve cause pressure losses. As operating pressure increases, the losses associated with an inefficient valve can be amplified. As a result, systems including inefficient valves may require pumps and other equipment to be oversized to account for any losses and to ensure that adequate fluid pressure is maintained. Due to the demands of the subsea environment such oversizing may require stronger materials, improved seals, and other significant and costly equipment upgrades. 
     In addition to issues regarding flow efficiency, the overall costs of designing, constructing, and installing a piece of subsea equipment can be significantly impacted by the size of components included in the equipment. For example, if a footprint of a given piece of equipment is limited, significant design efforts may be required to ensure that all components of the equipment fit within the footprint. Even absent stringent footprint requirements, larger equipment can significantly increase manufacturing, shipping, handling, and installation costs of the equipment. 
     In light of the above, there is demand for a compact and efficient sub-plate mounted valve. 
     SUMMARY 
     Embodiments of the present disclosure are directed to a sub-plate mounted valve having improved flow characteristics and a compact design, and a manifold including such a sub-plate mounted valve. 
     In accordance with the present disclosure, the sub-plate mounted valve includes a valve body containing a pilot-driven spool. By selectively supplying pressure to a piston disposed on the spool, the spool is movable within the body between an open and closed position. In the open position, fluid flow is permitted between a supply port and a function port of a manifold or sub-plate in which the valve is installed. In the closed position, flow is permitted between a return port and the function port. In addition to the piston, the valve may include one or more springs for biasing the spool in one of the open and closed positions. 
     Sub-plate mounted valves according to this disclosure may also include features to permit proper alignment of the sub-plate mounted valve when installed in a manifold or sub-plate. Specifically, the sub-plate mounted valve may be rotated in place after insertion into a valve pocket of a manifold or sub-plate to properly align holes of the valve with corresponding ports of the manifold or sub-plate. The alignment process may be facilitated by indicators located on the manifold and valve corresponding to the ports and holes, respectively. Once aligned, a locking plate may be installed to prevent any rotational movement of the valve that would otherwise lead to misalignment. 
     These and various other features and advantages will be apparent from a reading of the following detailed description and drawings along with the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments and advantages of the present disclosure may be best understood by one of ordinary skill in the art by referring to the following description and accompanying drawings. In the drawings: 
         FIGS. 1A and 1B  are cross-sections of an embodiment of a sub-plate mounted valve according to this disclosure in the closed and the open positions, respectively. 
         FIG. 2  is an isometric view of an embodiment of a sub-plate mounted. 
         FIG. 3  is a cutaway view of an embodiment of a sub-plate mounted valve installed within a manifold. 
         FIG. 4  is a detailed view of the locking plate and valve cap of a sub-plate mounted valve according to one embodiment. 
         FIGS. 5A and 5B  are cross-sections of another embodiment of a sub-plate mounted valve according to this disclosure in the closed and the open positions, respectively. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A  is a cross-sectional view of a sub-plate mounted valve  100  according to one embodiment of the present disclosure. The valve  100  is depicted as being installed in a manifold  102 . Alternatively, the valve  100  may be installed into a sub-plate. 
     As shown in  FIG. 1A , the manifold  102  is machined to have a valve pocket  104  to receive the valve  100  and a series of ports for directing fluid through the valve  100 . The ports include a function port  106 , a supply port  108  through which a fluid is provided, a return port  110 , and a pair of pilot ports  112 A,  112 B. The function port  106  is connected to a pneumatic or hydraulic circuit for performing a particular function when pressurized fluids are supplied to the circuit. As depicted in  FIG. 1 , the supply port  108  and the return port  110  can be located on the same side of the valve pocket  104 . In other embodiments, the supply port  108  and the return port  110  may be located on different sides of the valve pocket  104 . Similarly, the supply port  108  is depicted in  FIG. 1A  as being above the return port  110 , however in other embodiments, the position of the supply port  108  and the return port  110  may be switched such that the return port  110  is located above the supply port  108 . 
     According to one embodiment, the valve  100  includes a valve body  114  comprising a cage  116  and a valve cap  122 . 
     In the embodiment of  FIG. 1A , the cage  116  is generally cylindrical and defines various holes. The holes include supply hole  118  and return hole  120  that correspond to the supply port  108  and the return port  110 , respectively. Although  FIG. 1A  depicts only one supply hole  118  and one return hole  120 , the valve cage  116  may include multiple supply holes and return holes arranged around the cage. For example,  FIG. 2  is an isometric view of a sub-plate mounted valve  200  including a cage  216  that defines multiple return holes, including return holes  220 A,  220 B. Accordingly, the specific number and location of the supply holes and the return holes may vary across different embodiments. 
     Returning to  FIG. 1A , the valve body  114  may also include a valve cap  122 . Generally, the valve cap  122  is coupled to the cage  116  and retains the internal components of the valve  100 . Although the valve cap  122  and cage  116  are depicted in  FIG. 1A  as being two separate components, in other embodiments, the valve cap  122  may be integrally formed with the cage  116 . 
     In reference to  FIG. 1A , the valve  100  may be retained within the valve pocket  104  by a locking plate  134 . The locking plate  134  may be coupled to the manifold  102  by a series of bolts  136 A,  136 B, or any other suitable fastener. A locking nut  138  and a slip ring  140  may also be used to install the valve  100  within the valve pocket  104 . As will be discussed in more detail later in this disclosure, the locking nut  138  and slip ring  140  permit rotational movement of the valve  100  within the valve pocket  104  before installation of the locking plate  134  such that the valve  100  can be properly aligned with the various ports of the manifold  102 . 
     A spool  123  is disposed within the valve body  114 . Generally, the spool  123  is a hollow elongate body movable along a linear axis of the valve body  114  between a closed and an open position. The closed and open position are depicted in  FIGS. 1A and 1B , respectively. The spool  123  is movable between the open and closed positions by applying pressure to a piston  126 . The piston  126  is disposed on an outside surface of the spool  123  and seals against an inside surface of the cage  116 . Although the piston  126  and the spool  123  are depicted as two separate components of valve  100  in the embodiment depicted in  FIGS. 1A and 1B , in other embodiments, the piston  126  and the spool  123  may be integrally formed. 
     Sub-plate mounted valves in accordance with this disclosure may also include a spring for biasing the spool in one of the open and closed positions. For example, in the embodiment depicted in  FIGS. 1A and 1B , a spring  130  for biasing the spool  123  is disposed within chamber  124 A. The spring  130  exerts a force on the piston  126  such that the piston  126  and the spool  123  are biased into the open position, shown in  FIG. 1B . In other embodiments, a spring may instead be inserted into chamber  124 B such that the spring biases the piston  126  and spool  123  into the closed position. Although the spring  130  of  FIGS. 1A and 1B  is depicted as a single helical coil spring, other embodiments in accordance with this disclosure may include any suitable number of springs of any suitable spring type. The valve body  114  also includes seals  132 A and  132 B that seal against the outside surface of the spool  123  at opposite ends of the valve body  114 . The piston  126  and seals  132 A and  132 B define two chambers  124 A and  124 B. Supplying pressurized fluid through pilot port  112 A into chamber  124 A causes the piston  126  and spool  123  to move into the closed position, shown in  FIG. 1A . Conversely, applying pressurized fluid through pilot port  112 B into chamber  124 B causes the piston  126  and spool  123  to move into the open position, shown in  FIG. 1B . 
     In the closed position depicted in  FIG. 1A , fluid flow is permitted between the return port  110  and the function port  106 , but the spool  123  blocks flow between the supply port  108  and the function port  106  by sealing against a first valve seat  138 . In the embodiment of  FIG. 1A , the first valve seat  138  is depicted as a disc-shaped insert in the valve cap  122 . The seal created between the spool  123  and the valve seat  138  in combination with the seal created between seal  132 A and the outer surface of the spool  123 , prevents fluid at the supply port  106  from passing through the valve  100  to the function port  106 . Additionally, the spool  123  is configured such that in the closed position, the spool  123  permits flow between the return port  110  and the function port  106 . 
     In the open position depicted in  FIG. 1B , fluid flow is permitted between the supply port  108  and the function port  106 , but the spool  123  blocks flow between the return port  110  and the function port  106  by sealing against a second valve seat  140 . In the embodiment of  FIG. 1B , the second valve seat  140  is depicted as a washer-like ring disposed opposite the first valve seat  138 . The seal created between the spool  123  and the second valve seat  140  in combination with the seal created between seal  132 B and the outer surface of the spool  123 , prevents fluid from passing between the function port  106  and the return port  110 . However, the open position permits fluid flow between the supply port  108 , through the spool  123 , and to the function port  106  via a hole  142  defined in the second valve seat  140 . 
     Although the first valve seat  138  and the second valve seat  140  are each depicted in  FIGS. 1A and 1B  as sealing against end faces of the spool  123 , other embodiments may include alternative sealing arrangements. For example, in certain embodiments either valve seat may instead be a cylinder-type seal that seals around the outside surface of the spool  123 . 
     One of ordinary skill in the art having the benefit of this disclosure will appreciate that the above description regarding the open and closed position of valve  100  may be modified to accommodate different arrangements of the supply port  108  and the return port  110 . For example, in embodiments in which the locations of the supply port and the return port are reversed, the open position described above more accurately describes a closed position, i.e., a position in which the valve permits flow between the return port and the function port while preventing fluid flow between the supply port and the function port. 
       FIG. 2  depicts an isometric view of a sub-plate mounted valve  200  that is not installed in a valve pocket. The valve  200  includes a valve body including a cage  216 . The cage  216  defines a supply hole  208  and a plurality of return holes  210 A,  210 B To improve efficiency of flow through the valve, the supply hole  208  and return holes  210 A,  210 B are generally aligned with corresponding supply and return ports of the manifold in which the valve  200  is installed. Although misalignment between the holes of the cage and the ports of the manifold can create unnecessary restrictions to flow through the valve, leading to unnecessary pressure losses, proper alignment of sub-plate mounted valves is often complicated by the fact that the manifold ports and holes of the cage are not visible when the sub-plate mounted valve is installed within a valve pocket. Accordingly, certain embodiments may include features for assisting an operator in properly aligning the cage holes and manifold ports during installation. 
       FIG. 3  depicts an isometric cutaway of a sub-plate mounted valve  300  partially installed in a valve pocket  304  of a manifold  302 . Specifically, the sub-plate mounted valve  300  has been inserted into the valve pocket  304 , but a locking plate is yet to be installed. The valve body  314  includes a valve cap  322  that extends partially out of the valve pocket  304 . 
     The valve  300  is retained within the manifold by a lock nut  338 . In the embodiment depicted in  FIG. 3 , the lock nut  338  is threaded into the top of the valve pocket  304 . When the lock nut  338  is threaded in place, the valve body  314  is prevented from moving along the longitudinal axis of the valve pocket  304 . However, because the lock nut  338  does not engage the valve body  314  itself, the valve body  314  may still be rotated within the valve pocket  304  to properly align the valve  300  with ports of the manifold  302 . The valve cap  322  may be shaped to be gripped by hand or a tool in order to facilitate rotation of the valve body within the valve pocket  304 . For example, the valve cap  322  is depicted as having a rectangular protrusion that may be used to grip the valve body  314 . To minimize friction between the lock nut  338  and the valve body  314 , a slip ring  340  composed of a low friction material may also be inserted between the lock nut  338  and the valve body  314 . 
     In certain embodiments, proper alignment of the valve within the valve pocket may be further facilitated by indicators placed on the manifold, the locking plate, and/or the valve cap. For example,  FIG. 4  depicts a sub-plate mounted valve installed in a valve pocket of a manifold  402 . The manifold includes a port indicator  450  for indicating the location of ports within the manifold  402 . 
     In reference to  FIG. 4 , the sub-plate mounted valve may be retained within the manifold  402  by a locking plate  434 . The locking plate  434  includes a cutout  436  shaped to receive a portion of valve cap  422 , the valve cap  422  being part of a valve body disposed within the valve pocket. Due to the rectangular shape of the cutout and the valve cap  422 , the locking plate  434  prevents the valve body from rotating within the valve pocket when the locking plate  434  is bolted to the manifold  402 . The locking plate also includes a hole indicator  452  for indicating the location of supply and return holes of the valve body. As a result, when the locking plate  434  is installed such that the hole indicator  452  aligns with the port indicator  450 , the ports of the manifold and the holes of the valve will be similarly aligned. 
     Although  FIG. 4  depicts the manifold  402  having a single port indicator  450  and the locking plate  434  having a single hole indicator  452 , embodiments are not limited to this arrangement. Either of the manifold and the locking plate may include multiple indicators for indicating other features of the manifold and valve. For example, in embodiments in which the supply port and the return port are not placed on the same side of the valve pocket, separate indicators may be used to identify the location of the supply port and the return port. Multiple hole indicators may similarly be used to indicate the location of supply and return holes of the valve. As an alternative to including a marker on the top of the locking plate, certain embodiments may instead place the indicator or indicators on the valve cap  422 . Similarly, the shape of the valve cap itself may be used to indicate the location of the valve supply or return holes. 
       FIGS. 5A and 5B  depict an alternate arrangement for a sub-plate mounted valve  500  in accordance with this disclosure. Referring to  FIG. 5A , the valve  500  is installed in a valve pocket  504  of a manifold  502 . The manifold  502  includes a function port  506 , a supply port  508 , and two pilot ports  512 A,  512 B. 
     The valve  500  includes a valve body  514  comprising a cage  516  and a valve cap  522 . The cage  516  defines a supply hole  518  corresponding to the supply port  508 . The valve cap  522  is coupled to the cage  516  and defines a return port  510 . The return port  510  may be connected to a broader hydraulic circuit and the valve cap  522  may include threads, flanges or other suitable means for connecting the return port  510  to the hydraulic circuit. 
     Similar to previously discussed embodiments, the valve  500  may be retained within the valve pocket  504  by a locking plate  534  and bolts  536 A,  536 B. The locking plate  534  may include a cutout for receiving a portion of the valve cap  522 . The valve  500  may also include indicators, a slip ring  540 , and a locking nut  538  to assist in aligning the valve  500  within the valve pocket  504 . 
     Similar to earlier discussed embodiments, a spool  523  is disposed within the valve body  514 . The spool  523  is movable between a first and a second position by supplying pressurized fluid through pilot ports  512 A,  512 B into corresponding chambers  524 A,  524 B. As pressurized fluid enters chambers  524 A,  524 B, it acts on a piston  526  disposed on an outside surface of the spool  523 , causing the spool  523  to move between the first and the second position. 
     In the first position, depicted in  FIG. 5A , fluid flows between the function port  506  and the return port  510  defined by the valve cap  522 . While in the first position, the spool  523  also seals against a valve seat  540  preventing flow between the supply port  508  and the function port  506 . In the second position, depicted in  FIG. 5B , the spool  523  is positioned to permit flow between the supply port  508  and the function port  506 , but to prevent flow between the return port  510  and the function port  506 . To prevent flow between the return port  508  and the function port  506  when the spool  523  is in the second position, a plug  550  seals against a valve seat  552  of the return port  508 . 
     In the embodiments of  FIGS. 5A and 5B , the plug  550  is a tapered plug. However, in other embodiments, the plug  550  may be of any suitable shape for sealing against the valve seat  552 . For example, the plug may be a polished bearing, or disc. 
     Similar to the previously discussed embodiments, a spring may also be inserted between the valve body  514  and the spool  523  such that the spring biases the spool  523  into one of the first and the second position. 
     One of ordinary skill in the art having the benefit of this disclosure would appreciate that the locations of the supply and return port as shown in  FIGS. 5A and 5B  may be reversed. Specifically, the supply port may be defined by the valve cap and the return port may be defined by the manifold. 
     While numerous characteristics and advantages of embodiments of the present disclosure have been set forth in the foregoing description and accompanying figures, this description is illustrative only. Changes to details regarding structure and arrangement that are not specifically included in this description may nevertheless be within the full extent indicated by the claims.