Abstract:
The current invention relates generally to valves and actuators. This invention further relates to valves where the phenomenon known as “slamming” is completely mitigated and/or eliminated through self-damped valve assemblies. Additionally, this invention relates to valves having an actuator assembly capable of self-damping. Further, this invention also relates to valves that are capable of being externally adjusted without disassembling or removing any of the valve structure.

Description:
FIELD 
       [0001]    The disclosure relates to valves and actuators. More specifically, the disclosure relates to valves having an actuator assembly capable of self-damping. The disclosure further relates to actuators which are capable of being adjusted without removal of the valve structure. 
       BACKGROUND 
       [0002]    A valve is a device that regulates the flow of a substance. Valves are produced in a variety of different styles, shapes and sizes. Typically, valves are used for gases and liquids. However, valves are also used on solids capable of flow, slurries or any other substance capable of flow. Valves are used in almost every industry having a substance that flows. 
         [0003]    One type of valve is a gate valve, also referred to as a sluice valve. A gate valve opens by moving a blocking element from the path of flow. The blocking element may be a round disk, a rectangular element, or a wedge. Gate valves have a blocking element and a seat forming a substantially leak proof seal. In a gate valve, the blocking element can be referred to as a gate valve block, a gate block or a block. In the open position, a gate valve has a bore where the substance is allowed to partially or completely flow through the valve. In a gate valve, the bore may be referred to a gate valve bore. When the gate valve bore is across the valve bore the gate valve is in an open position. When the gate valve block is across the valve bore, the gate valve is in a closed position. 
         [0004]    Gate valves may be operated manually or automatically. One method to automatically operate a gate valve is to use an actuator. An actuator is a mechanical device for moving or controlling a mechanism or system. When an actuator is used in a gate valve, the actuator is typically linked to a stem to repeatedly move the valve gate between open and closed positions. 
         [0005]    Actuators to open and close the gate valves may include manual operators, diaphragm-type operators, pneumatic operators and hydraulic operators. Often, a manual operator is combined with a manual operator with a diaphragm-type, pneumatic or hydraulic operator for back-up and test purposes. Additionally, the actuator may include a bonnet assembly, which interconnects the valve body and the valve gate, and a bonnet stem which is movable with the gate via an operator. 
         [0006]    Pneumatic actuators are often used to move a gate valve which in under pressure such as is often the case with a pneumatic gate valve used on a compressed gas line. However, when the pneumatic gate valve is under pressure, any sudden decrease in pressure across the gate may result in the system seeking rapid pressure equalization such as in the case when the gate valve moves from a closed position to an open position. This rapid pressure equalization can result in the gate valve quickly moving to the open position thus causing the stored control pressure energy of the pneumatic actuator to be rapidly released. The rapid opening of the gate valve and the release of pressure energy from the pneumatic actuator can cause the gate valve to slam open causing damage to the valve components and physically impacting both the actuator and bonnet. Rapid opening of the gate valve can be mitigated somewhat by the use of hydraulic dampeners to limit the speed with which the stem and gate can move from the closed position to the open position. 
         [0007]    Additional issues with gate valves exist. One issue is the requirement that the valve housing be pressurized. In such designs, the internal pressure may be significantly greater than atmospheric pressure. Accordingly, any damage to the housing may compromise the structural integrity of the housing. This may cause a rupture, thus injuring equipment and personnel. 
         [0008]    Another issue with gate valves is the alignment of the gate valve bore with the bore of the valve body, as the valve moves out of alignment with the bore of the valve body over time. This misalignment will require personnel to disassemble parts of the actuator or bonnet assembly and either insert or remove drift spacers or shims until the proper alignment is achieved. Proper alignment is necessary as the American Petroleum Institute specifies that all wellhead gate valves must be of a “through conduit” design, and must be capable of passing a dimensionally specified drift mandrel through the gate valve bore when the valve is in operable condition. 
         [0009]    Because of these issues, maintenance and repair of gate valves can cost both money and time. In typical systems, a large portion of the valve assembly must be disassembled in order to make repairs. Additionally, the cyclical movement of actuators can cause wear on certain parts. 
         [0010]    Accordingly, what is needed is an actuator and gate valve capable of overcoming these obstacles. 
       SUMMARY 
       [0011]    In general, the various embodiments of the present invention pertain to a fluid control apparatus comprising for opening and closing gate valves. Various embodiments of the present invention generally relate to a fluid control apparatus comprising a valve and an actuator, with the actuator positioned to exert a force to move the valve between a closed position and an open position, wherein a fluid is able to flow when the valve is in the open position, the actuator having a distal end oriented away from the valve and a proximal end oriented towards the valve. The fluid control apparatus additionally comprises a pneumatic assembly nested between the distal end of the actuator and a pneumatic lower plate; a spring assembly nested between the pneumatic lower plate and the proximal end of the actuator; and a lower spring plate abutting the proximal end of the pneumatic lower plate. In such embodiments, the pneumatic lower plate and the lower spring plate each possess a bore, each bore aligned to receive a shaft in a longitudinal direction; and the pneumatic assembly comprises a variable piston area. 
         [0012]    Still further in the aforementioned embodiments, the pneumatic assembly, the lower spring and the top spring plate are contained in an unpressurized housing. 
         [0013]    Additionally, in certain embodiments the fluid control apparatus possesses at least two dampener rods, each of the dampener rods nested between the lower spring plate and the proximal end of the actuator, and wherein the rods are oriented in a longitudinal direction. 
         [0014]    In specific embodiments of the fluid control apparatus concerning the pneumatic assembly, the pneumatic assembly comprises: a diaphragm; a pneumatic conduit in fluid connection with the diaphragm; a pressure relief valve in fluid connection with the diaphragm; and wherein an external source provides pneumatic pressure to pressurize or depressurize the diaphragm through a pneumatic feed line. 
         [0015]    Still further, in certain embodiments, the fluid control apparatus comprises an adjustable downstop, wherein the lower spring plate and the adjustable downstop are separated by a distance when the diaphragm is depressurized; and wherein the adjustable downstop is connected to an actuator lower plate. In such embodiments, rotating the actuator lower plate in relation to the adjustable downstop in one direction increases the distance between the adjustable downstop and the lower spring plate and rotating the downstop in another direction decreases the distance between the adjustable downstop and the lower spring plate. Still further, in such embodiments, the adjustable downstop has at least one adjusting port which is externally accessible. 
         [0016]    In further embodiments of the fluid control apparatus, the apparatus additionally comprises a shaft defining a longitudinal axis and extending from a top plug at the distal end of the actuator and extending through the downstop, the shaft having a flange proximal to the pneumatic lower plate and having a flange below the downstop. In such embodiments, the shaft moves in a proximal direction when the pneumatic assembly is pressurized and moves in a distal direction when the pneumatic assembly is depressurized. Still further, the shaft may comprise a top stem and an operator stem. In such embodiments, the proximal end of the shaft may be connected to valve disposed in a fluid conduit with a defined diameter, the valve having a substantially similar fluid conduit with a substantially similar defined character. 
         [0017]    In embodiments of the fluid control apparatus concerning the valve, the valve may be a gate valve having a gate and a block. 
         [0018]    Other embodiments of the invention pertain to a method of opening or closing a gate valve of the fluid control apparatus of claim of one of the aforementioned embodiments, the method comprising: supplying an external pneumatic source to the pneumatic conduit; wherein the pneumatic assembly becomes pressurized and pushes the shaft in a proximal direction toward the valve; or removing an external pneumatic source to the pneumatic conduit, wherein the pneumatic assembly becomes depressurized and the spring pushes pulls the shaft in a distal direction away from the valve. 
         [0019]    Additional embodiments of the invention pertain to a method of adjusting valve bore drift comprising: adjusting a valve assembly, the valve assembly having at least one external accessible adjusting port; an adjustable downstop connected to an actuator lower plate, the downstop having an external accessible adjusting port and a position securing device; a gate valve having a gate valve bore; and, a valve body having a valve bore. The method further comprises inserting a mechanical device in the adjusting port; and applying force with the mechanical device to move the adjustable downstop relative to the actuator lower plate, between a first position that moves the gate valve bore in an upward direction and a second position that moves the gate valve bore in a downward direction, wherein the movement of the adjustable downstop relative to the actuator lower plate causes the gate valve bore to adjust relative to a valve bore. 
         [0020]    Still further, in certain embodiments, the method further comprises securing the adjustable downstop using a position locking device. 
         [0021]    In additional embodiments, the method further comprises measuring a position of the gate valve bore relative to the valve bore. 
         [0022]    In embodiments involving the method of adjusting valve bore drift, the method may involve the use of an actuator comprising: a valve; an actuator positioned to exert a force to move the valve between a closed position and an open position, wherein a fluid is able to flow when the valve is in the open position, the actuator having a distal end oriented away from the valve and a proximal end oriented towards the valve; a pneumatic assembly nested between the distal end of the actuator and a pneumatic lower plate; a spring assembly nested between the pneumatic lower plate and the proximal end of the actuator; a lower spring plate abutting the proximal end of the pneumatic lower plate, wherein the pneumatic lower plate and the lower spring plate each possess a bore, each bore aligned to receive a shaft in a longitudinal direction; and wherein the pneumatic assembly comprises a variable piston area. 
         [0023]    In such embodiments, the method may further comprise securing the adjustable downstop using the position securing device. 
         [0024]    Additionally, when the method pertains to applying force with the mechanical device to move the adjustable downstop relative to the actuator lower plate, such movement may comprise rotating the adjustable downstop relative to the actuator lower plate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a cross-section of one embodiment of the device with actuator and external adjustment of the present invention shown in an open position. 
           [0026]      FIG. 2  is a cross-section of one embodiment of the device shown in a closed position. 
           [0027]      FIG. 3  is an external view of one embodiment of the device. 
       
    
    
     LIST OF REFERENCE NUMERALS 
       [0000]    
       
         
           
             valve assembly  10   
             protective housing  12   
             actuator lower plate  16   
             operator stem  20   
             pneumatic assembly  30   
             lower spring assembly  50   
             adjustable downstop  70   
             valve bonnet  90   
             valve gate assembly  100   
             valve body  110   
             top plug shelf  13   
             top plug assembly  14   
             top stem  22   
             mounting point  15   
             connective devices  18   
             operator stem  20   
             threaded joint  23   
             upper flange  25   
             lower flange  27   
             lower stem threaded connector  28   
             pneumatic upper plate  34   
             pneumatic lower plate  36   
             spring bolts  40   
             lower spring plate  52   
             threaded central bore  53   
             outer diameter threads  21   
             lower spring retainer plate  64   
             dampener rods  58   
             lower portion of the dampener rods  60   
             upper portion of the dampener rods  56   
             pneumatic conduit  38   
             pneumatic feed line  41   
             pressure relief valve  44   
             through bolts  60   
             downstop threaded joint  72   
             threaded opening  78   
             external adjustment ports  74   
             positional securing device  76   
             bonnet ledge  92   
             packing retainer  93   
             bonnet well  97   
             valve bore  114   
             valve body lower well  116   
             gate bore  104   
           
         
       
     
       DETAILED DESCRIPTION 
       [0072]    Introduction 
         [0073]    The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. 
         [0074]    The following definitions and explanations are meant and intended to be controlling in any future construction unless clearly and unambiguously modified in the following examples or when application of the meaning renders any construction meaningless or essentially meaningless. In cases where the construction of the term would render it meaningless or essentially meaningless, the definition should be taken from Webster&#39;s Dictionary 3 rd  Edition. 
         [0075]    The following definitions and explanations are meant and intended to be controlling in any future construction unless clearly and unambiguously modified in the following examples or when application of the meaning renders any construction meaningless or essentially meaningless. In cases where the construction of the term would render it meaningless or essentially meaningless, the definition should be taken from Webster&#39;s Dictionary 3rd Edition. 
         [0076]    Various embodiments of the disclosure pertain to apparatuses for fluid control. A fluid control apparatus may comprise an actuator assembly, having a valve and an actuator. 
         [0077]    In one embodiment of the invention, an actuator assembly may comprise a valve, a pneumatic assembly, a lower spring assembly, an actuator lower plate and an adjustable downstop. In such an embodiment, the pneumatic assembly may rest on a pneumatic lower plate, and the lower spring assembly may be positioned between the lower spring plate and the actuator lower plate. Still further, the adjustable downstop may be positionally connected to the actuator lower plate. 
         [0078]    In another embodiment of the invention, the actuator pneumatic upper plate may be connected to the actuator lower plate with the adjustable downstop positionally connected to the actuator lower plate. 
         [0079]    Referring to the drawings, and more particularly,  FIG. 1 , a valve assembly  10  is represented in an open position, wherein the valve assembly  10  comprises a protective housing  12 , actuator lower plate  16 , operator stem  20 , pneumatic assembly  30 , lower spring assembly  50 , adjustable downstop  70 , valve bonnet  90 , valve gate assembly  100  and valve body  110 . 
         [0080]      FIG. 1  shows protective housing  12  positioned on top plug shelf  13  which is located on top plug assembly  14 . Top stem  22  is slidably disposed through the center of top plug assembly  14 .  FIG. 3  shows protective housing  12  as part of valve assembly  10  and affixed at mounting point  15  located on actuator lower plate  16  using connective devices  18 . Protective housing  12  may be affixed at any mounting point on valve assembly  10  that does not interfere with valve assembly operations. Protective housing  12  may be affixed by any means known to those skilled in the art such as bolts, screws, pegs and the like. Protective housing  12  is removable without affecting the function or performance of valve assembly  10 . Protective housing  12  is preferably made out of high-strength polyethylene, but any high density thermoplastic material, metal or metal compound will provide the same protective function and prevent ultraviolet ray damage to the underlying components. An advantage of using high-strength polyethylene is that is recyclable. 
         [0081]    One advantageous characteristic of protective housing  12  is the ability for it to function as a protective shield, preventing damage to pneumatic assembly  30  and lower spring assembly  50 . If structural damage does occur to protective housing  12 , the protected inner components are not affected and will continue to function. Non-limiting examples of potential damage to protective housing  12  may be from weather, animals or during wellhead assembly. Personnel safety is enhanced because protective housing  12  is not pressurized, and thus poses no danger of rupture or risk of injury to nearby personnel. 
         [0082]      FIG. 1  illustrates the interaction between top stem  22  and operator stem  20 . Top stem  22  is preferably rigidly affixed to operator stem  20  at threaded joint  23 . However, it is anticipated that any connector capable of rigidly affixing top stem  22  and operator stem  20  will perform satisfactorily in this invention so long as the connector does not prohibit fully opening or closing the valve. Even though the invention is described as comprising a top stem  22  and an operator stem  20 , it is anticipated that the top stem  22  and the operator stem  20  will function in an equivalent manner when formed out of a single element. 
         [0083]    Top stem  22  is slidably disposed through top plug assembly  14  and pneumatic lower plate  36 . Top stem  22  has upper flange  25  positioned above threaded joint  23 . 
         [0084]    Operator stem  20  is slidably disposed through adjustable downstop  70 , and valve bonnet  90 . Operator stem  20  has lower flange  27  positioned above lower stem threaded connector  28 . Lower stem threaded connector  28  is rigidly affixed to gate valve assembly  100 . 
         [0085]    Referencing  FIG. 1 , distal to the pneumatic assembly  30  is preferably a pneumatic upper plate  34 . Proximal to the pneumatic assembly  30  is a pneumatic lower plate  36 . The pneumatic assembly is preferably affixed to the pneumatic upper plate  34  and the pneumatic lower plate  36  via spring bolts  40 . Pneumatic assembly  30  will operate without being affixed to either pneumatic upper plate  34  or pneumatic lower plate  36 . Also, pneumatic assembly  30  will operate with only the pneumatic upper plate  34  affixed or pneumatic lower plate  36  affixed. 
         [0086]    Pneumatic lower plate  36  is affixed to top shaft  22  distal to the upper flange  25 . At least some portion of upper flange  25  fits within the pneumatic lower plate  36  without any impingement. 
         [0087]    Lower spring plate  52  of the lower spring  50  preferably has a threaded central bore  53 . The top stem  22 , distal to the upper flange  25  may have outer diameter threads  21 . Although the threaded central bore  53  and the outer diameter threads  21  are shown as a threaded engagement, any connective means providing similar rigidity will work as an acceptable substitute. 
         [0088]    Distal to, and in fluid connection with the lower spring  50  is a lower spring plate  52 . Proximal to, and in fluid connection with the lower spring  50  is a lower spring retainer plate  64 , which rests within the proximal portion of the threaded downstop  70 . 
         [0089]    As illustrated in  FIG. 2 , dampener rods  58  fit within the inner circumference of the lower spring and connect the lower spring plate  52  with the lower spring retainer plate  64 . Dampener rods  58  can be collapsible such that when the lower spring is in a compressed position, the rods themselves collapse with the lower portion of the dampener rods  60  entering the upper portion of the dampener rods  56 . The dampener rods can be bolted, welded or otherwise affixed to the lower spring plate and the lower spring retainer plate as needed. In alternative models, the dampener rods can be reversed in position such that the lower portion of the dampener rods is distal to the upper portion of the dampener rods  56 . Although  FIG. 2  is a cross sectional illustration, more than two dampener rods may be used in the actuator. For example, 3, 4, 5, 6, 7, 8, 9, 10 or more dampener rods may be positioned within the spring and between the lower spring plate and the lower spring retainer plate. The dampener rods serve to prevent slamming upwards or distal from the gate valve when pressure is removed from the pneumatic assembly  30 . Alternatively, the dampener rods can prevent slamming downwards or towards the gate valve when pressure is supplied to the pneumatic assembly. 
         [0090]    In practical application, the dampener rods act as a shock absorption system. Upon pressurization of the pneumatic assembly  30 , the dampener rods contract and provide some resistance against the downward or proximal force of the now pressurized assembly. Likewise, upon depressurization of the pneumatic assembly  30  the dampener rods provide resistance to keep the lower spring  50  from causing the top stem  22  from slamming upwards with great force. 
         [0091]      FIG. 2  more particularly illustrates the pneumatic action of the actuator. In this embodiment, pneumatic upper plate  34  has a pneumatic conduit  38  connected to pneumatic feed line  41 . Pneumatic conduit  38  connects with a pneumatic post which would penetrate the pneumatic upper plate  34 . The combined linkage of pneumatic feed line  41 , pneumatic conduit  38  and a pneumatic post provides pneumatic pressure to the pneumatic assembly  30  from an external source. Pressure relief valve  44  is shown affixed to and penetrating pneumatic upper plate  34 . Through bolts  60  connect the pneumatic upper plate  34  to the lower actuator plate  16 . This may result in increased stability of the actuator. 
         [0092]    Preferably as in  FIG. 1 , adjustable downstop  70  is adjustably connected to actuator lower plate  16  at downstop threaded joint  72 . Preferably, actuator lower plate  16  has a threaded opening  78 . Downstop threaded joint  72  may be referred to as a second receiver positioned on adjustable downstop  70 . In the preferred embodiment, adjustable downstop  70  is movable by rotating upward or downward within the threads of downstop threaded joint  72 . Movement of adjustable downstop  70  in a first direction pulls actuator lower plate  16  in an upward direction. Movement of adjustable downstop  70  in a second direction pushes actuator lower plate  16  in a downward direction. The upward or downward movement of actuator lower plate  16  causes lower spring assembly  50  to compress or decompress. 
         [0093]    Adjustable downstop  70  is externally accessible through external adjustment ports  74  shown in  FIG. 3 . External adjustment ports  74  are accessible without having to remove protective housing  12 . A mechanical device may be used to perform adjustments to adjustable downstop  70  through external adjustment ports  74 . Once adjustable downstop  70  is positioned, it may be locked into position using a positional securing device  76 , such as a set screw. (Illustrated in  FIG. 1 ) However, positional securing device  76  may be any type of device capable of locking adjustable downstop  70  into position and preventing movement of adjustable downstop  70 . The many types of devices capable of locking adjustable downstop  70  into position are known to those skilled in the art. Regardless of the type of positional securing device  76  utilized, it must be capable of being released from the locked position to allow the adjustment of adjustable downstop  70 . Although downstop threaded joint  72  is discussed in terms of being threaded, it is anticipated that any connection allowing adjustable downstop  70  and actuator lower plate  16  to adjust relative to each other will be an acceptable substitute. 
         [0094]    Referencing  FIG. 1 , a bonnet ledge  92  is positioned distal to the valve bonnet  90 . Actuator lower plate  16  is held into position on bonnet ledged  92  by any standard means such a clip a weld forging, casting, or bolting. 
         [0095]    Valve bonnet  90  preferably has packing retainer  93 . Operator stem  20  is shown slidably disposed in packing retainer  93 . Valve bonnet  90  preferably retains lower flange  27  in bonnet well  97 . 
         [0096]    Valve bonnet  90  is affixed to valve body  110 . Operator stem  20  is preferably connected to valve gate assembly  100 . In the preferred embodiment, operator stem  20  is threadably connected to valve gate assembly  100 . However, other connective mechanisms known to those skilled in the art may be used. Valve gate assembly  100  is shown positioned across and blocking valve bore  114 . Valve bore  114  is also referred to as a fluid conduit. When valve gate assembly  100  is in the closed position, all fluid is prohibited from flowing through valve bore  114 . Referencing  FIG. 1 , valve gate assembly  100  is disposed in valve body lower well  116  and gate bore  104  is positioned across valve bore  114 . When gate bore  104  and valve bore  114  are at least partially aligned, fluid is allowed to pass through the valve body  110 . 
       Operation of the Embodiments 
       [0097]    To open or close the valve, a controller sends an input to a pneumatic source. In this instance, upon receiving the signal, pneumatic pressure is sent across the pneumatic line to the valve assembly  10 . The pneumatic pressure causes the pneumatic assembly  30  to inflate or deflate. The expanding or inflating action causes the actuator to put force upon pneumatic lower plate  36 , thus causing the pneumatic lower plate to move in a downwards or proximal direction. This action also causes movement of the top stem  22  and the operator stem  20 . The movement of the operator stem  20  forces the valve gate assembly  100  to move into the valve body well  116 . The gate bore  104  is now positioned across the valve bore  114  and allows flow through valve body  110 . To block flow across valve bore  114 , the operation is reversed. 
         [0098]    The valve  10  is self-damping. The self-damping function is found in the pneumatic assembly  30  itself. As the pneumatic assembly  30  is inflated, the cross-sectional area of the piston is decreased. That is, the cross-sectional area decreases as the thickness, or height, of the pneumatic assembly is increased. Force is decreased as more energy is required to inflate the pneumatic assembly across a longer vertical distance, or height. This height is the piston of the pneumatic assembly. The diaphragm is self-damping as the piston exerts less force. This action continually reduces the force the pneumatic assembly  30  exerts on the plates beneath the pneumatic assembly  30  through the piston stroke. Further, a second self-damping function is from the lower spring assembly  50 . As the bottom plates move, each transmits force to the top stem  22  and/or the operator stem  20  stem and to the pneumatic lower plate  36  and the lower spring plate  52 . The pneumatic assembly  30  resists the force of movement. The resistance of force creates a second self-damping function for valve assembly  10 . The pre-loaded spring effectively eliminates all force that the gate block will see once it impacts valve body lower well  116 . The two aforementioned self-damping functions substantially mitigate the slamming effect of valve gate assembly  100  to a point that slamming is essentially eliminated.