Abstract:
A fluid system component is provided that includes first and second elements configured to be removably engaged with each other to define a fluid passageway. The first element defines at least one groove. Correspondingly, the second element includes at least one engagement member configured to be received in a corresponding groove. The presence of a line pressure in the passageway substantially forecloses disengagement of the first and second elements until the fluid pressure in the fluid passageway has decreased to a predetermined magnitude. A handling and locking mechanism for selectively securing the second element relative to the first element is included. The locking mechanism includes a pin controlled by a crank arm assembly adjacent a collar handle. The crank arm assembly includes a crank arm handle that rotates to withdrawn the pin from the second element and which facilitates rotation of the first element relative to the second element.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates generally to fluid system components. More particularly, embodiments of the present invention relate to coupling elements for fluid system components, in which the coupling elements facilitate quick and efficient coupling/decoupling of the fluid system components. Further, embodiments of the present invention relate to fluid system components which substantially prevent unintentional removal of a coupling element until the fluid system line pressure, or relative pressure differential, is reduced to a safe level. 
         [0003]    2. Related Technology 
         [0004]    In recent years, environmental concerns have been receiving significantly more attention, and various governmental agencies have responded by implementing stringent regulations to reduce or prevent pollution. Many of these regulations and concerns are directed towards those industries that transport fluids. For example, it is very difficult to transport a fluid without spilling or leaking some of the fluid into the environment. Thus, some environmental regulations require that only minimal leakage occur during handling, processing, or transportation of the fluid. 
         [0005]    These environmental concerns become especially clear when considering the magnitude of the industries that handle hazardous fluids that, if allowed to escape even in relatively small quantities, can cause significant damage. There is a concern, therefore, to protect both the public and the environment from these types of fluids. While some fluids that are transported, such as water and milk, may not significantly pollute the environment when they are leaked or spilled, the loss of fluid into the environment is nevertheless viewed as a general waste of resources. More generally, the loss of fluid into the environment is not desirable even if the fluid does not contribute to pollution. 
         [0006]    Within the transportation industry, a variety of different devices are used to transport a fluid from a source to a destination. These devices often use valve assemblies and conduits of various types to both connect the source to the destination as well as to manage fluid flow through the conduit. Typically, the conduit is pressurized to direct fluid toward the desired destination. With each transfer of fluid, there is a risk that leakage will occur due to human error, equipment malfunctions, or the like. 
         [0007]    A common source of fluid leaks and fluid spills are the valves and other components and devices employed in fluid systems. By way of example, some valves may have leaks that permit flow through the valve even when the valve is secured in the closed position. In other instances, one or more joints defined by constituent elements of the valve, such as in the case of valves designed to be taken down in two or more pieces, and/or one or more joints at least partially defined by the valve, such as a valve-to-flange connection, may be defective, resulting in leakage of some or all of the system fluid. Unfortunately, problems such as these often do not manifest themselves until after flow has been established through the valve, component, or device. 
         [0008]    Thus, in many instances, the system operator is limited in terms of the affirmative steps that can be taken to prevent a spill that may result from one or more defective joints, and oftentimes can only correct the spill when it occurs. This is true in the case of joints that are defectively assembled, or are otherwise defective upon assembly, as well as in the case of joints that become defective over a period of time due to operating, or other, conditions. 
         [0009]    Another concern relates to the coupling and uncoupling of caps, valves, and other fluid system components that are employed, for example, in fuel, chemical, sewage, or other fluid transfer or processing systems. In particular, typical quick coupling devices are configured so that an operator can uncouple the mating halves of the quick coupling device, even in the presence of line pressure. Such an arrangement is problematic for a variety of reasons. 
         [0010]    By way of example, in the event the line wherein the quick coupling device is located is charged with hazardous materials such as chemicals, sewage, fuels, or gases such as chlorine and methane, the operator performing the uncoupling operation could be seriously injured or killed when such materials escape from the line. Moreover, such hazardous materials are pollutants and significant time and cost is often involved in the cleanup of such materials. 
         [0011]    A related problem with typical quick coupling devices concerns the pressure exerted by the material in the line wherein the quick coupling device is located. In particular, such pressure may cause the halves of the quick coupling device to rapidly come apart in an uncontrolled and dangerous manner, thereby injuring the operator and/or damaging nearby equipment. The forces resulting from such pressure can often be significant, even where the line pressure is relatively low. Thus, in a six inch diameter (nominal) pipe for example, even a relatively low pressure of ten (10) lbs./in. 2  (“psi”) would exert a force of about one thousand (1000) pounds on a pipe cap attached to the end of the pipe. 
         [0012]    Not only are such pressures dangerous, but operators may not have any way to verify, in advance of performing the uncoupling operation, whether or not the line is pressurized. Further, even if an operator is aware that pressure is present, the operator may, through inattentiveness, negligence, or for other reasons, nevertheless attempt to uncouple the quick coupling device. 
         [0013]    Additionally, fluid system components are often exposed to extreme temperatures, either from the environment or the fluid flowing through the fluid system. The extreme temperatures can cause the various fluid system components to expand or contract. Further, the various fluid system components may be formed of disparate materials, each having a different thermal expansion rate. Thus as a first component expands or contracts at one rate, and a second component expands or contracts at a another rate, the two components may become frictionally locked together, thereby making it difficult to disengage one component from another. 
         [0014]    In view of the foregoing, what is needed is a fluid system component having features directed to addressing the foregoing exemplary considerations, as well as other considerations not disclosed herein. More particularly, an exemplary fluid system component includes features directed to facilitating the secure engagement, and ready disengagement, of the mating halves of the fluid system component, while at the same time preventing intentional or accidental disengagement of the mating halves when a predetermined pressure is present in the line. 
       BRIEF SUMMARY 
       [0015]    In general, embodiments of the invention are concerned with a fluid system component that, among other things, facilitates the secure engagement, and ready disengagement, of mating halves of the fluid system component, while at the same time preventing intentional or accidental disengagement of the mating halves when a predetermined pressure is present in the line. 
         [0016]    In one exemplary embodiment of the invention, a fluid system component includes a coupling. The coupling itself can include a sleeve coupled to a pipe and a collar. The collar can include a collar handle and at least one engagement member that facilitate selective engagement of the collar with the sleeve. The collar can be rotated relative to the sleeve, in a first direction, thereby disengaging the engagement member from the groove. Disengagement of the engagement member from the groove can also disengage the collar from the sleeve and/or open the pipe. The sleeve and collar can be configured such that the engagement member fully disengages from the groove only when the pipe has a pressure below a certain level, and such that at or above that level, the engagement member is substantially prevented from fully disengaging from the groove. The collar can be coupled to the sleeve by positioning the engagement member within the groove and rotating the collar relative to the sleeve in a second direction that is opposite the first direction. 
         [0017]    Optionally, the coupling includes a locking mechanism that prevents axial rotation of the collar relative to the sleeve. Such a locking mechanism can include a pin that extends through an aperture in the collar and/or is received within a recess in the sleeve. The pin and/or locking mechanism may also include a crank arm handle that facilitates retraction of the pin from the recess in the sleeve. The groove in the sleeve can be formed in an outer surface thereof, and can include an entry segment, a circumferential segment, and/or a terminal segment. In one example, the terminal segment is connected to the intermediate segment and is offset therefrom at an acute angle. The terminal segment may thus be adapted to receive an engagement member and prevent axial rotation of the collar relative to the sleeve. 
         [0018]    The pin can include a head, or other protruding structure, which can be engaged by a cam surface on the crank arm handle. As the crank arm handle is pivoted in a first direction, the cam surface can engage the head of the pin, thereby causing the distal end of the pin to be withdrawn from the recess in the sleeve. The collar can then be rotated relative to the sleeve to disengage the collar from the sleeve. The crank arm handle can be rotated in a plurality of directions to facilitate movement and manipulation of the collar. 
         [0019]    According to another embodiment, a fluid system component includes a coupling having a coupling member, a fluid conduit, and a locking member. The coupling member includes an engagement member and the fluid conduit has a sleeve defining a groove. The sleeve is configured to be received at least partially by the coupling member. Additionally, the groove extends at least partially around the circumference of the sleeve and has a terminal portion notched in the side of the groove. The groove itself is adapted to receive the engagement member and facilitate engagement of the coupling member with the sleeve, and such that the terminal portion, when it receives the engagement member under line pressure, substantially prevents the coupling member from rotating relative to the fluid conduit. The locking member is movably connected to the coupling member and is adapted to engage the sleeve and prevent axial rotation of the coupling member relative to the sleeve. 
         [0020]    The locking member can be disengaged from the sleeve and the coupling member can be rotated axially relative to the sleeve to fully disengage the engagement member from the sleeve, although when line pressure is above a predetermined amount, it substantially locks the engagement member in the terminal segment to prevent full disengagement. After disengagement, the coupling member can be re-engaged with the sleeve by positioning the engagement member in the groove and rotating the coupling member until the engagement member is positioned within, adjacent, or beyond the terminal segment. The locking member can then be engaged with the sleeve to selectively secure the coupling member to the sleeve. 
         [0021]    Any suitable coupling member may be used. For instance, the coupling member may be a collar, an end cap, a portion of a valve, or another coupling member. In another case, the coupling member includes a second fluid conduit for introducing a pressurized fluid into the first fluid conduit. For instance, the second fluid conduit can be a hose that allows air or another fluid to flow into the first fluid conduit in a direction that is opposite the line pressure. Such fluid may, for example, force a cleaning device, known as a pig, in a direction opposite the line pressure to, for example, clean, dewater, dry, or inspect the pipe. 
         [0022]    In another embodiment, a fluid system is described and includes a coupling adapted for mounting to a fluid conduit. The coupling can include an engagement member and a locking member, and can have multiple positions relative to the fluid conduit. For instance, in a first locked position, the engagement member can be received within a circumferential segment of a groove in the fluid conduit while the locking mechanism is received within the terminal segment of the groove. In this manner, the locking mechanism can substantially prevent rotation of the coupling relative to the fluid conduit. In a second locked position, the engagement member can be received within the terminal segment while the locking member is retracted from the groove, such that the engagement member substantially prevents rotation of the coupling relative to the fluid conduit. Additionally, the coupling may be adapted to rotate from the first locked position to the second locked position when the locking member is retracted from the groove and when line pressure exists in the fluid conduit. 
         [0023]    An exemplary embodiment of the present invention further provides a locking mechanism on the fluid system component that substantially prevents takedown of the fluid system component as a result of unintentional or accidental rotation of the fluid system components. The locking mechanism includes a locking pin that extends through the wall of a first portion of the fluid system component and into a recess defined in the outer wall of a second portion of the fluid system component. The locking pin is movably connected to the first of the fluid system components and may be biased so that a distal end of the locking pin protrudes from the inner wall of the first portion of the fluid system component to engage the recess in the second portion of the fluid system component. The engagement between the locking pin and the recess in the second portion of the fluid system component prevents relative rotation of the first and second portions of the fluid system component, and thus takedown of the fluid system component. 
         [0024]    An exemplary locking mechanism of the fluid system component further includes a crank arm handle at or near the proximate end of the locking pin. The crank arm handle allows a user to withdraw the distal end of the locking pin from a recess in the second portion of the fluid system component. The locking pin can include a head, or other protruding structure, which can be engaged by a cam surface on the crank arm handle. As the crank arm handle is rotated in a first direction, the cam surface engages the head of the locking pin, thereby causing the distal end of the locking pin to be withdrawn from the recess in the second portion of the fluid system component. Once the locking pin is disengaged from the recess in the second portion of the fluid system component, the portions of the fluid system component can be rotated relative to each other so that they can be disengaged from each other. The crank arm handle can facilitate movement and manipulation of the fluid system component, such as rotation of the first portion relative to the second portion of the fluid system component. For example, when rotated in the first direction, the crank arm handle can be used to increase the torque applied to the fluid system component to facilitate movement of the fluid system component. The crank arm handle can also be rotated in a second direction to facilitate movement of the fluid system component in multiple directions. The crank arm handle can be biased to a closed or locked position to reduce to profile of the assembly. 
         [0025]    A collar handle can also be formed on the outer wall of the first portion of the fluid system component. The collar handle can facilitate movement and manipulation of the fluid system component, such as rotation of the first portion relative to the second portion of the fluid system component. The collar handle is, in one example, adjacent to the crank arm handle, which is on or near the proximate end of the locking pin. 
         [0026]    These and other aspects of embodiments of the present invention will become more fully apparent from the following description and appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
           [0028]      FIG. 1  depicts an exemplary operating environment for at least some embodiments of the present invention; 
           [0029]      FIG. 2  is a perspective view of an embodiment of a coupling which includes a collar and a sleeve that can be releasably connected to each other and which can be incorporated into a fluid system such as that of  FIG. 1 ; 
           [0030]      FIG. 3A  is a side view illustrating aspects of an exemplary groove arrangement for a coupling such as that of  FIG. 2 ; 
           [0031]      FIG. 3B  is a side view illustrating aspects of another exemplary groove arrangement for a coupling such as that of  FIG. 2 ; 
           [0032]      FIG. 3C  side view illustrating aspects of yet another exemplary groove arrangement for a coupling such as that of  FIG. 2 ; 
           [0033]      FIG. 4A  is an end view of the collar of  FIG. 2 ; 
           [0034]      FIG. 4B  is a cross-sectional side view of the coupling of  FIG. 2  with the collar fully engaged with the sleeve; 
           [0035]      FIG. 5A  is a perspective view of the collar of  FIG. 2 , illustrating a crank arm handle in an extended position to withdraw a locking pin from within the collar and to facilitate axial rotation of the collar for quick and easy coupling/decoupling of the collar and the sleeve; 
           [0036]      FIG. 5B  is a partial end view of the collar of  FIG. 2 , illustrating the various details of the engagement of the locking pin of the collar with the sleeve when the crank arm handle is in a lowered position; 
           [0037]      FIG. 5C  is another partial end view of the collar of  FIG. 2 , illustrating the various details regarding the disengagement of the locking pin of the collar from the sleeve when the crank arm handle is in an extended position; 
           [0038]      FIG. 5D  is another perspective view of the collar of  FIG. 2 , illustrating the crank arm assembly, including the crank arm handle, rotating about the locking pin of the collar to facilitate quick and easy coupling/decoupling of the collar and the sleeve; 
           [0039]      FIG. 5E  is another perspective view of the collar of  FIG. 2 , illustrating the crank arm assembly, including the crank arm handle, fully rotated about the locking pin of the collar to facilitate quick and easy coupling/decoupling of the collar and the sleeve. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    Reference will now be made to figures wherein like structures will be provided with like reference designations. It is to be understood that the drawings are diagrammatic and schematic representations of various embodiments of the invention, and are not to be construed as limiting the present invention, nor are the drawings necessarily drawn to scale. 
         [0041]    With reference first to  FIG. 1 , a portion of one embodiment of a fluid system is indicated generally at  100 . Note that, as contemplated herein, “fluid” is not limited to liquids, but can include a variety of other compositions. For example, the term “fluid,” as used herein, expressly includes liquids, gases, liquid-gas combinations, slurries, liquid-solid combinations, gas-solid combinations, and liquid-solid-gas combinations. In the exemplary embodiment depicted in  FIG. 1 , fluid system  100  includes a fluid source  102  in fluid communication with one or more fluid conduits  104 . According to some example embodiments at least one of fluid conduits  104  may comprise a coupling  200 . Fluid conduits  104  are, in the illustrated embodiment, configured for selective fluid communication between fluid source  102  and fluid destination  106 . 
         [0042]    As discussed elsewhere herein, it will be appreciated that coupling  200  may be located, either in part or in its entirety, at fluid source  102 , at fluid destination  106 , or at an intermediate position between fluid source  102  and fluid destination  106 . It will also be appreciated that the term “conduit” can include any structure or device adapted to facilitate transportation of a fluid, wherein such structures and devices include, but are not limited to, pipes, hoses, tubes, channels, ducts, or the like. Furthermore, fluid conduits  104 , fluid source  102 , and fluid destination  106  may be constructed of one or a combination of any of a variety of materials, including, but not limited to, metals, plastics, rubbers, composites, organic materials, and the like. 
         [0043]    With continuing reference to  FIG. 1 , fluid source  102  and fluid destination  106  are illustrated as aboveground tanks. However it will be appreciated that fluid source  102  and/or fluid destination  106 , may comprise any of a variety of different static or mobile structures and/or vehicles. Such structures and vehicles include, but are not limited to, air, water, or land vehicles, such as, but not limited to, trucks, boats, automobiles, motorcycles, ships, railcars, aircraft, and the like, as well as structures such as tanks, reservoirs, and the like. 
         [0044]    In operation of fluid system  100 , a pressure differential can be established between fluid source  102  and fluid destination  106  so as to cause flow of the fluid through fluid conduits  104  in a desired direction. It will be appreciated that the pressure differential may be established in such a way as to cause flow to proceed in one or more directions, such that fluid may flow from fluid source  102  towards fluid destination  106  and/or from fluid destination  106  towards fluid source  102 . The pressure differential may result from the force of gravity, or may alternatively be established by various types of equipment and devices including, but not limited to, pumps and the like. 
         [0045]    Directing attention now to  FIGS. 2-5E , details are provided concerning exemplary embodiments of a coupling, generally denoted at  200 , which facilitates ready and convenient engagement and disengagement of fluid system components. As illustrated in  FIG. 2 , for example, coupling  200  includes a sleeve  204  that is configured to receive one end of fluid conduit  104  and at least partially define a fluid passageway. In this example, coupling  200  also includes a collar  202  configured to be positioned on sleeve  204 , and which at least partially defines the fluid passageway in connection with fluid conduit  104 . Collar  202  and sleeve  204  can collectively allow for quick and convenient engagement and disengagement of fluid system components. Additionally, collar  202  and sleeve  204  can include various features which substantially prevent fluid leakage and/or undesirable take down of fluid system  100 . 
         [0046]    More particularly, as illustrated in  FIGS. 2 , sleeve  204  can be connected to one end of fluid conduit  104 . In one embodiment, for example, sleeve  204  is adapted to receive the end of fluid conduit  104  therein, and to be coupled thereto. It will be appreciated, however, that sleeve  204  may have other configurations. For example, sleeve  204  may be adapted to be received within fluid conduit  104  and/or may be formed directly on fluid conduit  104 . In this manner, sleeve  204  may be integrally formed with fluid conduit  104  or may be a separate, and optionally removable, attachment thereto. In an example in which sleeve  204  receives fluid conduit  104 , sleeve  204  and fluid conduit  104  can be configured such that the interior surface of sleeve  204  is compatible with the exterior surface of fluid conduit  104 . However, it is desirable in some cases to construct sleeve  204  in such a way that a gap is introduced between the interior surface of sleeve  204  and the exterior surface of fluid conduit  104  so as to accommodate, for example, any differences in the thermal expansion rates of sleeve  204  and fluid conduit  104 . Furthermore, where sleeve  204  and fluid conduit  104  are separately formed, sleeve  204  may be attached to fluid conduit  104  in any suitable manner, such as by methods including, but not limited to, welding, brazing, and soldering. In at least one embodiment, sleeve  204  and fluid conduit  104  each include mating threads so that sleeve  204  can be removably attached to fluid conduit  104 . As noted above, it will be appreciated that fluid conduit  104  and sleeve  204  can also be formed as a single integral piece. 
         [0047]    Generally, sleeve  204  comprises a metallic material that, in at least some instances, is chemically and thermally compatible with fluid conduit  104 . Exemplary materials for sleeve  204  include, but are not limited to, copper and its alloys, steels, iron, aluminum and its alloys, and titanium and its alloys. Moreover, sleeve  204  may be machined, extruded, or cast. Other suitable materials and/or construction methods may additionally, or alternatively, be employed. 
         [0048]    As indicated in  FIGS. 2 and 3A , sleeve  204  defines at least one groove  208 . In some embodiments, a plurality of grooves are formed and are configured and arranged to engage corresponding structure of collar  202 , as discussed in further detail herein. In one example embodiment, each of the one or more grooves  208  can include an entry segment  210  that substantially begins at and opens to the front edge of sleeve  204 , and which is connected to a circumferential segment  212 , and/or a terminal segment  214 . In the illustrated embodiment, for example, entry segment  210  cooperates to create an acute entry angle θ with respect to the front edge of sleeve  204 , although in other embodiments entry segment  210  and the front edge of sleeve  204  can create an entry angle θ that is an obtuse or right angle. Where the entry angle θ is acute, such as is illustrated in  FIG. 3A , any suitable angle may be used. For example, according to one embodiment, the entry angle θ is between about thirty and about sixty degrees, although it will be appreciated that entry angle θ may also be less than thirty degrees or greater than sixty degrees. 
         [0049]    As further seen in  FIGS. 2 and 3A , circumferential segment  212  can be connected to an internal end of entry segment  210  and can extend therefrom circumferentially at least partly around sleeve  204 . In the illustrated embodiment, circumferential segment  212  extends substantially parallel to the front edge and circumference of sleeve  204 , and thus at an obtuse angle relative to entry segment  210 . It will be appreciated that the illustrated embodiment is exemplary only, however, and in other embodiments circumferential segment  212  can extend at an angle relative to the front edge and/or circumference of sleeve  204 . 
         [0050]    Circumferential segment  212  and/or entry segment  210  may further be connected to terminal segment  214 . In the illustrated embodiment, terminal segment  214  extends from circumferential segment  212 , although in other embodiments terminal segment  214  may instead extend from entry segment  210  or may extend from the junction between entry segment  210  and circumferential segment  212 . As shown in  FIG. 3A , in one example embodiment, terminal segment  214  may cooperate with circumferential segment  212  to define an offset angle δ that aids in the engagement of collar  202  with sleeve  204  generally in the manner described herein. For instance, offset angle δ may be between about twenty and about seventy degrees, in one embodiment, although offset angle δ may, in other embodiments, be less than twenty degrees or more than seventy degrees. In the embodiment illustrated in  FIG. 3A , terminal segment  214  is disposed in the side of circumferential segment  212  adjacent the front edge of sleeve  204 . Thus, according to one embodiment, circumferential segment  212  and terminal segment  214  cooperate to create offset angle δ such that terminal segment  214  extends toward the front edge of sleeve  204 . 
         [0051]    As noted herein, one or more grooves  208  can be formed in sleeve  204  or fluid conduit  104 . Accordingly, any of a variety of different numbers of grooves  208  may be used. In one embodiment, for instance, three grooves  208  are machined, cast, or otherwise formed, in the outer surface of sleeve  204 . In such an example, each groove  208  can extend at least partially around sleeve  204 . For instance, each of three grooves may describe an arc β of about one-hundred twenty (120) degrees around the circumference of sleeve  204 . In this manner, each circumferential segment  212  may end at a point that is about aligned with the start of another entry segment  210 . In other embodiments, however, the groove  208  may have different lengths. For instance, each or any of three grooves  208  may extend an arc β less than about one-hundred twenty (120) degrees. In the case of other exemplary embodiments, such as that illustrated in  FIG. 3C  for example, arc β described by each groove may be such that the grooves substantially overlap each other. 
         [0052]    It should be noted that the embodiment of grooves  208  illustrated in  FIGS. 2 and 3A  is exemplary only and aspects of grooves  208  such as, but not limited to, the size, number, geometry, arrangement, arc length β, entry angle θ, offset angle δ, and disposition of one or more of grooves  208  may be varied in accordance with the requirements of a particular application. Accordingly, such exemplary embodiment should not be construed to limit the scope of the invention in any way. For example,  FIGS. 3B and 3C  illustrate alternative embodiments of grooves, generally demoted at  218  and  228 , respectively. 
         [0053]    In particular,  FIG. 3B  illustrates an example embodiment of groove  218 , which includes three segments, namely, an entry segment  220  that opens at the front edge of sleeve  204 , a circumferential segment  222 , and a terminal segment  224 . In the embodiment illustrated in  FIG. 3B , terminal segment  224  is located at, and extends a from, the end of circumferential segment  222  opposite an end of circumferential segment  222  that extends from entry segment  210 . In the illustrated embodiment, terminal segment  224  extends from the end of circumferential segment  222  and toward the front edge of sleeve  204 . Terminal segment  224  and circumferential segment  222  cooperate to create offset angle δ. In light of the disclosure herein, it will be appreciated that the fluid pressure within the fluid passageway cooperates with terminal segment  224  to couple collar  202  and sleeve  204  together until the fluid pressure within the fluid passageway is reduced below a predetermined level. 
         [0054]    In yet other embodiments of the grooves of sleeve  204 , a terminal segment may be generally perpendicular or parallel to a longitudinal axis of sleeve  204 . Moreover, the number and arrangement of intermediate segments in a groove, or grooves, may be varied as desired. In some alternative embodiments, grooves are defined by a structure that is discrete from, but attached or attachable to sleeve  204 . 
         [0055]      FIG. 3C  illustrates yet another exemplary embodiment of grooves  228  defined by, or included in or on, sleeve  204 , and which include a plurality of segments, including an entry segment  230 . Notably, in contrast with other embodiments such as those illustrated in  FIGS. 3A and 3B , grooves  228  further include five intermediate segments denoted, respectively,  232 ,  234 ,  236 ,  238  and  240  as well as a terminal segment  242 . 
         [0056]    Although in the exemplary embodiment illustrated in  FIG. 3C , grooves  228  are illustrated with five intermediate segments, one or more aspects of grooves  228  may be varied as necessary to suit a particular application. For example, intermediate segments  232 ,  236  and  240  are, in some embodiments, generally parallel to each other, while intermediate segments  234  and  238  are generally parallel to each other and to entry segment  230 . In yet other embodiments, such intermediate segments are disposed in a non-parallel arrangement. Moreover, other features such as, but not limited to, the length, width and depth of one or more grooves  228  may be modified as required or desired. Additionally, while intermediate segments  232 ,  234 ,  236 ,  238  and  240  are described as intermediate segments, they can also be effectively considered a single circumferential segment which extends from entry segment  230  to terminal segment  242 . 
         [0057]    As illustrated in  FIGS. 3A-4B , sleeve  204  also, in some embodiments, defines a pin recess  250  formed in the wall of sleeve  204  and is configured to receive an end of a pin  252  therein, as described more fully hereinafter. In the illustrated embodiment, for example, pin recess  250  extends partially through a wall of sleeve  204 . However, it will be appreciated that pin recess  250  may, in other embodiments, extend completely through a wall of sleeve  204  so as to form a hole therein. Pin recess  250  is optionally sized and configured to receive a portion of pin  252  therein, and can be positioned in sleeve  204  so as to align with a pin aperture  254  in collar  202  when collar  202  has fully engaged sleeve  204 , as best illustrated in  FIG. 4B . Additionally, pin recess  250  can comprise the terminal segment within the groove of the sleeve (e.g., terminal segment  214  of groove  208 , as seen in  FIG. 3A ). 
         [0058]    In correspondence with the grooves  208  (or grooves  218  or  228  from  FIGS. 3B and 3C ) defined by sleeve  204 , collar  202  can include a plurality of engagement members  258 , each of which is configured and arranged to be received within a corresponding groove  208  and travel therealong, as suggested by the exemplary travel path illustrated in  FIG. 3A . To that end, each engagement member  258 , may be a bolt, roller or other suitable member, and can have a diameter and/or thickness that generally corresponds with the width and/or depth, respectively, of a corresponding groove  208 . Engagement members  258  are illustrated as disposed within the interior of collar  202 , although other configurations are contemplated. It will also be appreciated that engagement members  258  can be attached to collar  202  in a variety of ways including, but not limited to, welding, brazing, soldering, and the like. Alternatively, collar  202  and engagement members  258  can be formed as an integral piece, or attached or formed in any other suitable manner. In some embodiments of the invention, bearings or similar structures or devices are provided to facilitate ready and reliable rotation of the engagement members  258 . 
         [0059]    With continuing attention to  FIG. 2 , and with additional attention to  FIGS. 4A-4B , further details are provided concerning certain aspects of the illustrated embodiment of collar  202 . In particular, collar  202  includes a collar handle  260  that extends, in this embodiment, around the entire circumference of collar  202 . However, it will be appreciated that a collar handle can comprise one or more collar handles which are not required to extend fully around collar  202 . In the embodiment illustrated in  FIGS. 4A-4B , collar handle  260  is coupled to collar  202  by support members  262 . It will be appreciated that the number, shape, and/or size of support members  262  employed to couple collar handle  260  to collar  202  can be varied while remaining within the spirit and scope of the invention. Support members  262  can also be attached to collar handle  260  and/or collar  202  in a variety of ways including, but not limited to, welding, brazing, soldering, and the like. Alternatively, collar handle  260 , support members  262 , and/or collar  202  can be formed as an integral piece, or attached or formed in any other suitable manner. 
         [0060]    As illustrated in  FIGS. 4A and 4B , collar  202  can define a pin aperture  254 . In one embodiment, pin aperture  254  is formed through a wall of collar  202 , while in other embodiments the pin aperture may extend through a guide that is not fully within a wall of collar  202 , but is nevertheless considered a pin aperture. Pin aperture  254  can be sized and configured to receive a portion of pin  252  therethrough, and can be further sized and configured so as to allow the pin shaft  266  to rotate and/or translate within pin aperture  254 . Pin aperture  254  in this embodiment is positioned in collar  202  so as to be substantially aligned with pin recess  250  of sleeve  204  when collar  202  has fully engaged sleeve  204 . For example, pin aperture  254  is substantially aligned with pin recess  250  when pin  252  can be received in pin recess  250  of sleeve  204  and through pin aperture  254  of collar  202 , as illustrated in  FIGS. 4A and 4B . 
         [0061]      FIGS. 4A-5E  also illustrate various aspects of collar  202 , which may be configured to substantially prevent axial rotation of collar  202  with respect to sleeve  204  when a line pressure above a predetermined level is present in the fluid passageway, and which may be configured to facilitate axial rotation of collar  202  when the line pressure within the fluid passageway is below the predetermined level. 
         [0062]    In the illustrated embodiment, for instance, collar  202  includes a pin  252  having a pin shaft  266  and a pin head  268 . Furthermore, collar  202  also includes a crank arm assembly  270  operatively associated with pin  252 . As described herein, pin  252  is configured to be received within pin aperture  254  and pin recess  250  to prevent axial rotation of collar  202  relative to sleeve  204 . Crank arm assembly  270  may be configured to enable a user to selectively move pin  252 , such as to selectively remove pin  252  from pin recess  250  and/or pin aperture  254 , or to insert pin  252  into pin aperture  254  and/or pin recess  250 . For example, crank arm assembly  270  may be sized and/or shaped to accommodate a particular user, or to accommodate a particular size of fluid conduit  104 . It may be desirable, for instance, for crank arm assembly  270  to be larger if the fluid conduit  104  is larger or smaller if the fluid conduit  104  is smaller. 
         [0063]    As illustrated in  FIGS. 4A and 4B , pin shaft  266  can be coupled to pin head  268 , which, in turn, can be engaged by crank arm assembly  270  so as to cause pin shaft  266  to move as crank arm assembly  270  moves. For example, as a user exerts a force on a distal end of crank arm handle  272  of crank arm assembly  270  so as to extend it in a radial direction away from sleeve  204 , pin  252  can also be caused to correspondingly move in a radial direction and away from sleeve  204 . In particular, crank arm handle  272  is pivotally coupled to collar  202  by way of pivot  274 . Pivot  274  enables crank arm handle  272  to rotate thereabout, thereby allowing the distal end of crank arm handle  272  to move from the position illustrated in  FIGS. 4A and 5B  to the position illustrated in  FIGS. 5A and 5C , for example. 
         [0064]    As crank arm handle  272  rotates about pivot  274 , cam surface  276  of crank arm handle  272  engages pin head  268  and causes pin  252  to be withdrawn from pin recess  250 , as seen in  FIG. 5C . Likewise, as the distal end of crank arm handle  272  is moved toward collar  202 , cam surface  276  disengages from pin head  268 , thereby allowing pin  252  to be received within pin aperture  254  and/or pin recess  250 . Crank arm assembly  270  can thus be configured to enable a user to grip crank arm handle  272  and thereby selectively move pin  252 . Movement of pin  252  in this manner may, for example, partially or fully remove pin  252  from pin recess  250  of collar  202  and/or pin aperture  254  of sleeve  204 . Similarly, movement of pin  252  in an opposite direction may insert pin  252  into pin aperture  254  and/or pin recess  250 . 
         [0065]    In some embodiments, crank arm assembly  270  is coupled to the proximate end of pin  252 , thus eliminating the need for pin head  268  and cam surface  276 . Alternatively, crank arm assembly  270  can be coupled to pin head  268 , while pin head  268  is in turn is coupled to the proximate end of pin  252 . As a result, crank arm assembly  270  can be directly or indirectly coupled to pin  252 . In any configuration, crank arm assembly  270  can be either directly or indirectly coupled to or associated with pin  252  such that inward or outward movement of crank arm handle  272  correspondingly moves pin  252  inward or outward relative to collar  202 . 
         [0066]    Crank arm handle  272  can be biased such that the distal end of crank arm handle  272  tends toward a position adjacent to collar  202 . In particular, crank arm handle  272  can be biased to the position illustrated in  FIGS. 4A and 5B  where both the proximal and distal ends of crank arm handle  272  are adjacent collar  202 . Biasing crank arm handle  272  toward collar  202  provides various benefits. For example, once a user releases the distal end of crank arm handle  272 , the distal end of crank arm handle  272  returns to the position adjacent collar  202 , thereby reducing the overall profile of the coupling assembly. Additionally, when the distal end of crank arm handle  272  biases toward collar  202 , pin  252  is allowed to move into pin aperture  254  and/or pin recess  250  if collar  202  is coupled to sleeve  204 . Thus, when coupling collar  202  to sleeve  204 , a user can rotate the distal end of crank arm handle  272  away from collar  202  and position collar  202  on sleeve  204  as described herein. With crank arm handle  272  being able to bias toward collar  202 , however, a user does not have to manually insert pin  252  into pin recess  250 . In particular, once collar  202  is positioned on sleeve  204  so that pin  252  is properly aligned with pin recess  250 , a user can simply release crank arm handle  272  and allow the biasing mechanism of crank arm assembly  270  to insert pin  252  into pin recess  250 . It will be appreciated that crank arm handle  272  can be biased by any suitable means. For example, crank arm handle can be bias with a 
         [0067]    resilient member, such as a spring. Also, crank arm handle  272  may be positioned on collar  202  such that gravity influences the positioning of crank arm handle  272  when the collar  202  is positioned on sleeve  204 . 
         [0068]    As noted herein, movement of the distal end of crank arm handle  272  away from collar  202  can withdraw pin  252  from pin recess  250 , thereby enabling axial rotation of collar  202  relative to sleeve  204 . In some circumstances, however, axial rotation of collar  202  relative to sleeve  204  may be hindered. For example, extreme temperatures and different thermal expansion rates for collar  202  and sleeve  204  may cause collar  202  and sleeve  204  to become frictionally locked together. Crank arm handle  272  can be employed to overcome the friction created by the extreme temperatures or different thermal expansion rates, or any other hinderment to the axial rotation of collar  202  relative to sleeve  204 . More specifically, once pin  252  is withdrawn from pin recess  250  and crank arm handle  272  is in the position illustrated in  FIGS. 5A and 5C , crank arm handle  272  can be used to increase the torque applied to collar  202  to cause axial rotation of collar  202  relative to sleeve  204 . Thus, crank arm handle  272 , as illustrated in  FIGS. 5A and 5C , can be employed to rotate collar  202  in a counterclockwise direction with greater torque and/or less force than would be required in using only collar handle  260 . 
         [0069]    Furthermore, crank arm assembly  270  can be rotatably mounted on collar  202  so that crank arm handle  272  can be rotated about an axis that is perpendicular to the central axis of collar  202 . For example, in the illustrated embodiment, crank arm assembly  270  is rotatably mounted on collar  202  so that is rotates about the longitudinal axis of pin  252 . Thus, crank arm handle  272  can be rotated from the position illustrated in  FIG. 5A  to the position illustrated in  FIG. 5D , and further rotated to the position illustrated in  FIG. 5E . Rotation of crank arm assembly  270  is this manner allows crank arm handle  272  to be employed to both couple collar  202  to sleeve  204  and decouple collar  202  from sleeve  204 . In particular, as described above, when crank arm handle is in the position illustrated in  FIG. 5A , crank arm handle  272  can be used to rotate collar  202  is a counterclockwise direction to disengage collar  202  from sleeve  204 . Alternatively, crank arm handle  272  can be rotated to the positioned illustrated in  FIG. 5E  and used to rotated collar  202  in a clockwise direction to couple collar  202  to sleeve  204 . While the present embodiment has been described with clockwise rotation of collar  202  to couple collar  202  to sleeve  204  and counterclockwise rotation of collar  202  to decoupled collar  202  from sleeve  204 , it will be appreciated that in some embodiments collar  202  can be rotated clockwise to decouple collar  202  from sleeve  204  and rotated counterclockwise to couple collar  202  to sleeve  204 . 
         [0070]    As illustrated in  FIGS. 2 and 4A , crank arm handle  272  may extend around a portion of the circumference of collar  202 . In the illustrated embodiment, for example, crank arm handle  272  defines an arc of about ninety (90) degrees about the circumference of collar  202 . However, the arc defined by crank arm handle  272  can be larger or smaller than ninety (90) degrees. For example, in other embodiments, crank arm handle  272  defines an arc of about forty-five (45) degrees, about sixty (60) degrees, or about one hundred twenty (120) degrees. 
         [0071]    In the example embodiment of  FIGS. 4A-5E , collar handle  260  and crank arm handle  272  are positioned adjacent to each other. Thus, collar handle  260  and crank arm handle  272  my be positioned such that a user can simultaneously grip both collar handle  260  and crank arm handle  272  with either one or two hands. In other embodiments, however, a recess of about the shape of crank arm handle  272  is formed in collar handle  260 , and crank arm handle  272  is positioned such that it generally corresponds with the recess in collar handle  260 . Accordingly, collar handle  260  and crank arm handle  272  can have a stacked or nested arrangement. 
         [0072]    In the illustrated embodiment, a radius from a central, longitudinal axis of collar  202  to collar handle  260  can be definite and unchanging. The distance from the longitudinal axis of collar  202  to the distal end of crank arm handle  272  may, however, vary. For example, as the distal end of crank arm handle  272  is moved away from collar  202 , the distance between the longitudinal axis of collar  202  and the distal end of crank arm handle  272  increases. In some embodiments, crank arm handle  272 , in an innermost position, has a radius slightly smaller than the fixed radius of collar handle  260 , although in other embodiments crank arm handle  272  has a radius about equal to, or larger, than collar handle  260 . As described herein, the innermost position of crank arm handle  272  can correspond to a biased position of pin  252 . 
         [0073]    As discussed above, pin  252  can move with respect to pin aperture  254  and/or pin recess  250  and may be withdrawn at least partially therefrom. When pin  252  is connected to crank arm handle  272 , this may occur by, for example, exerting a force which pulls the distal end of crank arm handle  272  away from collar  202 . Because pin  252  can be withdrawn from pin aperture  254  and/or pin recess  250  by pulling the distal end of crank arm handle  272  away from collar  202 , the distance between the distal end of crank arm handle  272  and the central axis of collar  202  and/or sleeve  204  can increase. Accordingly, in one embodiment, the distance between the central, longitudinal axis of collar  202  and distal end of crank arm handle  272  can increase to a distance about equal to, or greater than, the radius of collar handle  260 . In one embodiment, when the distal end of crank arm handle  272  is about diametrically aligned with collar handle  260 , pin  252  is withdrawn from pin recess  250 . In some embodiments, crank arm handle  272  can be used to entirely withdraw pin  252  from both pin aperture  254  and pin recess  250 . 
         [0074]    Various configurations of a pin recess  250  are envisioned within the scope of the present invention. One such configuration is illustrated in  FIG. 3A , in which pin recess  250  comprises terminal segment  214  of groove  208 . In other words, pin recess  250  and terminal segment  214  can constitute the same recess within sleeve  204 . Thus, when pin  252  is positioned in pin recess  250  and/or terminal segment  214 , engagement members  258  may be aligned with, and optionally positioned in, circumferential segment  212 . Of course, in other embodiments, pin recess  250  may be aligned with, and potentially include, entry segment  210  or circumferential segment  212 . In still other embodiments, pin recess  250  is not aligned with any portion of groove  208 . 
         [0075]    Pin  252  can be held in position within pin aperture  254  and/or pin recess  250  by any of a number of different mechanisms. For example, pin  252  may be biased into the position illustrated in  FIGS. 4A and 4B  by use of a spring or resilient member (not shown). Alternatively, pin  252  may be biased through an interference fit between pin shaft  266  of pin  252  and one or both of pin aperture  254  and pin recess  250 . Also, pin aperture  254  and pin recess  250  may be positioned in collar  202  and sleeve  204 , respectively, such that when the fluid conduit  104  ( FIG. 1 ) is stationary, pin aperture  254  and pin recess  250  face generally upward or in another alignment that allows gravity to influence the positioning of pin  252 . 
         [0076]    Pin  252  is optionally selectively removable from pin recess  250  and/or pin aperture  254  so as to enable axial rotation of collar  202  with respect to sleeve  204 . For example, the ability of pin  252  to move with respect to pin aperture  254  and/or pin recess  250  enables pin  252  to be selectively removable. In at least one embodiment, pin  252  can be completely removed from both pin aperture  254  and pin recess  250  by a user to enable axial rotation of collar  202  with respect to sleeve  204 . Alternatively, pin  252  can be removed, selectively by a user, by moving pin  252  such that the distal end of pin shaft  266  is no longer received in pin recess  250  of sleeve  204 , thus enabling axial rotation of collar  202  with respect to sleeve  204 . Collar  202  can thus be selectively secured to sleeve  204  by a user positioning pin  252  in pin recess  250  as is sufficient to substantially prevent axial rotation of collar  202  with respect to sleeve  204 . 
         [0077]    While the present invention has been described herein as comprising a collar  202  that allows fluid to flow therethrough, it will be appreciated that collar  202  can comprise other types of fluid coupling components without departing from the scope of the present invention. For example, collar  202  can include an end plate (not shown) that extends across one end of collar  202  in such a way as to assist in defining an end of a fluid passageway from fluid conduit  104  when collar  202  and sleeve  204  are fully engaged. In one embodiment, the end plate and collar  202  comprise a single integral piece. However, in other embodiments, the end plate and collar  202  can comprise discrete structures that are or can be joined together. Thus, collar  202  can comprise an end cap to limits the flow of fluid through the fluid system. 
         [0078]    The operational features relating to the coupling and decoupling of collar  202  and sleeve  204  of the example embodiment of  FIGS. 2-5E  will now be discussed in greater detail. Prior to collar  202  receiving a portion of sleeve  204  therein, the distal end of pin shaft  266  should not extend beyond the inner surface of collar  202 . Otherwise, as sleeve  204  is inserted into collar  202 , pin  252  may inadvertently engage sleeve  204  and make it difficult to couple collar  202  to sleeve  204 . The distal end of pin shaft  266  can be withdrawn from the inner surface of collar  202 , as described above, by simply exerting a force on the distal end of crank arm handle  272  so as to extend the distal end of crank arm handle  272  in a radial direction away from the center of collar  202 , as seen in  FIGS. 5A and 5C . Radial movement of crank arm handle  272  can cause corresponding movement of at least the distal end of pin shaft  266 , thereby withdrawing pin shaft  266  from within the inner surface of collar  202 , as seen in  FIG. 5C . 
         [0079]    With pin  252  withdrawn from the inner surface of collar  202 , engagement of collar  202  and sleeve  204  can be effected by positioning each engagement member  258  in a corresponding groove  208  and causing engagement members  258  to travel along grooves  208  according to the path denoted in  FIG. 3A , for example. More particularly, collar  202  and sleeve  204  may be brought together until each engagement member  258  of collar  256  is positioned at the beginning of an entry segment  210  (see  FIG. 3A ) of a corresponding groove  208  of sleeve  204 . Rotation of collar  202  is then initiated by way of collar handle  260  and/or crank arm handle  272 . As a result of the angular orientation of entry segments  210  with respect to the front edge of sleeve  204 , the initial rotation of collar  202  causes collar  202  to be drawn toward sleeve  204 . In other words, as engagement members  258  are advanced in entry segment  210  of groove  208 , collar  202  rotates relative to sleeve  204 . 
         [0080]    Continued rotation of collar  202  can cause engagement members  258  to complete their traverse of corresponding entry segments  210 , and move into their respective circumferential segments  212 . Engagement members  258  can remain in circumferential segments  212  until such time as a predetermined pressure level is attained in the fluid passageway conduit  104  collectively defined by collar  202 , sleeve  204 , and fluid conduit  104 , or when rotated into that position by a user. 
         [0081]    In the illustrated embodiment, collar  202  and sleeve  204  comprise guide pins  280  and  282 , respectively. Guide pins  280 ,  282  provide a visual confirmation to a user that collar  202  has been fully rotated onto sleeve  204 . Specifically, once collar  202  has been rotated onto sleeve  204  so that engagement members  258  are properly securely positioned within grooves  208 , guide pin  280  will align with guide pin  282 , thereby providing a visual confirmation to the user that collar  202  is securely coupled to sleeve  204 . Guide pins  280 ,  282  can comprise any suitable structure or indicator that is capable of providing a visual indication to a user that collar  202  and sleeve  204  are aligned and securely coupled together. By way of example and not limitation, guide pins  280 ,  282  can be bolts, notches, cutouts, or markings on/in the sides of collar  202  and sleeve  204  that are positioned to align with one another when collar is properly positioned on sleeve  204 . 
         [0082]    In one embodiment, the collar  202  is rotated and positioned such that engagement members  258  are in respective circumferential segments  212 . Once collar  202  is in such a position, fluid can be introduced into fluid conduit  104 , and the distal end of pin shaft  266  can be positioned in pin recess  250  of sleeve  204  so as to substantially prevent axial rotation of collar  202  with respect to sleeve  204 . It will be appreciated in view of the disclosure herein that pin recess  250  of sleeve  204  may extend at least partially along the length of the sleeve such that as pressure is introduced in the fluid conduit  104 , engagement members  258 , attached to collar  202 , may be able to move and lock up into corresponding terminal segments  214  of grooves  208  and remain therein, as indicated in  FIG. 3A . In other embodiments, as fluid is introduced into fluid conduit  104 , pin shaft  266  may be positioned in terminal segment  214  so as to prevent movement of engagement members  258  along circumferential segments  212 . 
         [0083]    In still other embodiments, after the introduction of fluid, and while the line is pressurized, pin shaft  266  may be removed from terminal segment  214  or another recess, thereby allowing engagement members  258  to again move in circumferential segment  212 . Alternatively, pin  252  may be excluded. In either case, the pressure thus exerted by the fluid in fluid conduit  104 , denoted at P in  FIG. 3A , may allow collar  202  to at least partially rotate relative to sleeve  204 . The pressure can, however, transmit a force to collar  202 . Consequently, as engagement members  258  approach terminal segments  214 , the exertion of pressure P in this way forces engagement members  258 , optionally attached to collar  202 , to move into and lock up into corresponding terminal segments  214  of grooves  208  and remain therein, as indicated in  FIG. 3A . 
         [0084]    In the illustrated embodiment, the forward motion of collar  202  may, depending on the position of engagement members  258  at the time of pressurization of fluid conduit  104 , be accompanied by a rotary motion of collar  202  as well. The rotary motion of collar  202  can cause engagement members  258  to travel along circumferential segments  212  and come to rest in terminal segments  214  of grooves  208 . 
         [0085]    Once engagement members  228  are seated in their corresponding terminal segments  214  of grooves  208 , the continuing presence of pressure P exerts a force on collar  202  that resists motion of engagement members  258  in the opposite direction, i.e., out of their corresponding terminal segments  214 , and thereby aids in the retention of engagement members  258  in terminal segments  214 . As a result, collar  202  and sleeve  204  cannot be disengaged from each other by the user until the fluid pressure in fluid conduit  104  has been reduced to a predetermined level. 
         [0086]    Thus, engagement members  258  and grooves  208  cooperate with each other, one feature of which is the employment of the line pressure to ensure a secure connection between collar  202  and sleeve  204  subsequent to pressurization of fluid conduit  104 , and even in the event pin  252  is removed from pin recess  250  during pressurization. Thus, the likelihood of inadvertent, or intentional, removal of collar  202  while a potentially dangerous level of pressure exists in fluid conduit  104  is materially reduced. 
         [0087]    As will thus be appreciated by one of ordinary skill in the art in view of the disclosure herein, if pin  252  is withdrawn from pin recess  250  before the pressure within fluid conduit  104  is released, the pressure in fluid conduit  104  will press against collar  202 . Such pressure can cause engagement members  258  to move along grooves  208  toward entry segments  210 . Without terminal segments  214 , engagement members  258  could exit groove  208 , thereby resulting in disengagement of collar  202  and sleeve  204 . Disengagement of collar  202  and sleeve  204  while fluid conduit  104  is still under pressure can result in numerous dangers. For instance, fluid can leak into the environment and/or the fluid pressure may forcibly cause collar  202  to become dislodged from fluid conduit  104 . Collar  202  may then uncontrollably fly off fluid conduit  104  and hit an operator, user, or equipment, or the fluid itself my forcibly exit and contact a user or equipment, thereby causing serious bodily injury or property damage. 
         [0088]    Notably, when terminal segment  214  is employed, such problems can be entirely or largely prevented. Specifically, if pin  252  is withdrawn from pin recess  250  while the fluid passageway is under pressure, engagement members  258  will begin to move along grooves  208  towards entry segments  210 ; however, before reaching entry segments  210 , engagement members  258  will encounter and engage terminal segments  214  as described above. The groove geometry of terminal segments  214  is configured to use the line pressure in such a way to prevent further movement of engagement members  258  toward entry segments  210 , and thus also prevent disengagement of collar  202  and sleeve  204 . Once the pressure in fluid conduit  104  is released, or reduced beyond a determined level, the line pressure can be overcome and a user will be able to disengage engagement members  258  from terminal segments  214 . Once engagement members  258  are disengaged from terminal segments  214 , collar  202  and sleeve  204  can be safely disengaged. 
         [0089]    While the foregoing are example embodiments in which the line pressure is released before engagement members  258  can be removed from terminal segments  214 , it will be appreciated in view of the disclosure herein that such are exemplary only. For example, in other embodiments, the line pressure need not be entirely reduced. Instead, in one example, engagement members  258  may become fixed within terminal segments  214 , as described above, when the line pressure is above a predetermined level. Once the line pressure is reduced below that predetermined level, which can be zero or greater than zero pressure, the user may be able to overcome the line pressure and disengage engagement members  258  from terminal segments  214 . The predetermined level may be a pressure that does not cause significant leakage of the fluid from conduit  104  and/or a level that is determined to pose minimal or no risk of significant bodily injury. 
         [0090]    The present invention may be embodied in other specific forms without a departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.