RELATED APPLICATIONS

This application claims priority to United States Provisional Patent Application No.

61 /935,473, entitled "EZ Stack Individual Fluid Connectors," filed February 4, 2014, which fully incorporated herein by reference for all purposes.

TECHNICAL FIELD

This disclosure relates to connection systems for fluid connections. More particularly, some embodiments of this disclosure relate to fluid connectors for use in high purity environments such as semiconductor manufacturing. Even more particularly, some embodiments relate to easily engaged fluid connectors and connection systems that are configured to prevent, or inhibit, disengagement.

BACKGROUND

[0003] Semiconductor manufacturing processes are highly sensitive to contamination. Therefore, materials that contact the process fluids are often formed from polymers that are non- reactive with process fluid. In many cases, however, these materials are relatively deformable and may exhibit significant creep at higher temperatures or pressures.

Consequently, it is difficult to provide fluid connections that do not leak.

[0004] Some filtration systems rely on threaded connections. In these systems, the other fitting includes external fitting threads, while the other fitting includes a screw cap with inner threads. The screw cap is screwed onto the filter so that the fittings seal together. However, the loosening of fittings following temperature excursions caused by processes such as autoclaving or pressure excursions such as encountered in performance testing is a common problem in the semiconductor industry. More specifically, the application of an axial load may result in the disengagement of the fittings after such processes or for other reasons.

[0005] This problem may be even more of an issue when the fittings are made of a material that is deformable, such as perfluoroalkoxy polymer (PFA). Existing PFA fittings typically use relatively fine v-shaped threads (such as Unified or metric screw threads). Such materials may have a low coefficient of friction, resulting in a leak, or otherwise having a seal between the fittings broken. The problem is further exacerbated in cases where the pitch of the threads of the fitting is steep (for example, when multi-start threads or the like are used in such fittings).

[0006] These types of threaded fittings may have several other shortcomings. As one example, traditional threaded fittings do not provide a quick connect mechanism by which fittings may easily be aligned and sealed together. What is desired then, are connectors and connection systems which allow fittings to be more easily sealed together and which may provide a mechanism to prevent or inhibit the disengagement of such fittings.

SUMMARY

[0007] Embodiments of just such connectors and connection systems that can be used in a variety of applications, including in semiconductor manufacturing applications, are described. One embodiment provides a connection system that may use a locking nut that includes internal multi-start threads that can seal fluid fittings with less than 360 degrees of rotation of the locking nut. A locking sleeve may receive the locking nut and be mated to the locking nut such that the locking sleeve and locking nut are rotatable about a first fitting as an assembly. The first fitting may be sealed to a second fitting by engaging the internal threads with external threads on the second fitting. The locking sleeve is additionally configured to translate along a center axis of the first fitting to a locked position where first locking features of the locking sleeve are aligned with one or more corresponding second locking features on the second fitting to inhibit rotation of the locking sleeve. The second locking features may, for example disposed on a rib of the second fitting. In certain embodiments, a recessed ledge configured to accommodate this rib when the locking sleeve is in the locked position may be formed in the locking sleeve.

[0008] According to various embodiments the locking sleeve may translate in different directions in order to align the locking features. For example, in one embodiment, the locking sleeve is configured to translate toward the second fitting to align the first locking features with the corresponding second locking features on the second fitting while in another embodiment the locking sleeve is configured to translate away from the second fitting to align the first locking features with the corresponding second locking features on the second fitting. In embodiments such as these, the locking sleeve may also be configured to translate toward the second fitting so the first locking features pass through second locking features on the second fitting, for example, before the locking sleeve is rotated to engage the threads of the fittings. These locking features may also serve to align a first thread start on the set of internal threads with a second thread start of the set of second fitting external threads when the first locking features pass through the second locking features on the second fitting.

[0009] Embodiments as disclosed herein may also include circumferential channels formed in the inner surface of the locking sleeve. The circumferential channel may serve to retain shoulder formed on fingers of the locking nut. For example, one circumferential channel may retain the shoulders when the locking sleeve is in a locked position while another circumferential channel may be configured to retain the shoulders when the locking sleeve is in an unlocked position (e.g., a position other than the locked position). In certain embodiments, a radiused transition structure is disposed between the circumferential channels and the fingers may be configured to deflect radially inward (e.g., as pressure is applied radially inward to the shoulders of the fingers as they translate over the transition structure).

[0010] In order to configure the locking sleeve and locking nut to rotate (e.g., about the fitting) as an assembly, the locking nut may have one or more ribs formed on an outer surface while locking sleeve has one or more complementary grooves formed on an inner surface. These ribs and grooves may also cooperate to limit the translation of the locking nut relative to the locking sleeve.

[001 1 ] As noted above, in some embodiments, the internal threads of the locking nut can be multi- start threads that can be configured to create a seal between the first fitting and a second fitting with less than 360 degrees of rotation. In some embodiments, less than 360 degrees of rotation may result in at least 360 degrees or more of thread engagement and in other embodiments may result in less than the 360 degrees of thread engagement. The thread engagement may provide a circumferential axial sealing force (e.g., an axial sealing force of at least 360 degrees or, in some cases, less than 360 degrees). For example, in one embodiment, the multi-start threads can comprise a first thread running 120-180 degrees from a first start, a second thread running 120-180 degrees from a second start and a third thread running 120-180 degrees from a third start. Other embodiments may include other numbers of starts and the threads may run less than 120 degrees and greater than 180 degrees.

[0012] A method for connecting a first fluid fitting and a second fluid fitting, can include aligning multi-start inner connection nut threads of a locking nut with external fitting threads of the second fluid fitting, wherein the locking nut is rotatable about the first fluid fitting in a locking sleeve, where the locking sleeve is mated to the locking nut such that the locking sleeve and locking nut are rotatable about the first fitting as an assembly, rotating the connection nut less than 360 degrees (in some cases less than 180 degrees, including less than 135 degrees) to seal the first fluid fitting to the second fluid fitting, and translating the locking sleeve along a center axis of the first fitting to a locked position where first locking features of the locking sleeve are aligned with one or more corresponding second locking features on the second fitting to inhibit rotation of the locking sleeve.

[0013] Components of the connector can be made from a variety of materials including polymeric materials, such as but not limited to oleophilic resins, perfluorinated resin, (such as, but not limited to, PTFE, FEP), PFA, PVDF, polyimide, polyetherimide, polycarbonate, PP, PE, PEEK, or other materials. [0014] Embodiments can thus provide a quick connector and connection system that may be used to more easily seal fittings and lock to reduce the risk of unintentional separation of the fittings. Embodiments of such connectors and connection systems may be useful applied in a variety of setting, including high purity settings and with processes that require high temperatures such as autoclaving or performance testing. Moreover, embodiments may be incorporated into a variety of other contexts where a reliable fluid tight seal is desired. For example, embodiments of such connectors and connection systems may be usefully applied to a cap for a fluid fitting. These types of caps may be useful when a fluid tight seal is needed on a fitting, including, for example, when performing internal processing of components during manufacture or test, or for shipping certain components that may be wet during shipping including, for example, pre-wet filters or the like.

[0015] These, and other, aspects of the disclosure will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating various embodiments of the disclosure and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions and/or rearrangements may be made within the scope of the disclosure without departing from the spirit thereof, and the disclosure includes all such substitutions, modifications, additions and/or rearrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings accompanying and forming part of this specification are included to depict certain aspects of embodiments of the invention. A clearer impression of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings, wherein identical reference numerals designate the same components. Note that the features illustrated in the drawings are not necessarily drawn to scale.

[0017] FIGURES 1 A and 1 B are diagrammatic representations of one embodiment of a connector for use in a connection system.

[0018] FIGURES 2A-2C are diagrammatic representations of one embodiment of a connection system using an embodiment of a connector.

[0019] FIGURES 3A and 3B are diagrammatic representations of one embodiment of a connector for use in a connection system.

[0020] FIGURES 4A and 4B are diagrammatic representations of another embodiment of a

connector for use in a connection system.

[0021 ] FIGURES 5A-5C are diagrammatic representations of an embodiment of a connection system using an embodiment of a connector.

[0022] FIGURES 6A-6C are diagrammatic representations of one embodiment of a connector for use in a connection system.

[0023] FIGURES 7A-7C are diagrammatic representations of one embodiment of an end cap having fittings.

[0024] FIGURES 8A and 8B are diagrammatic representations of one embodiment of cassette having fittings. DESCRIPTION

[0025] Connection systems and the various features and advantageous details thereof are

explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well- known starting materials, processing techniques, components and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating preferred

embodiments, are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions and/or rearrangements within the spirit and/or scope of the underlying concept will become apparent to those skilled in the art from this disclosure.

[0026] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, article, or apparatus that comprises a list of elements is not necessarily limited only those elements but may include other elements not expressly listed or inherent to such process, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0027] Additionally, any examples or illustrations given herein are not to be regarded in any way as restrictions on, limits to, or express definitions of, any term or terms with which they are utilized. Instead, these examples or illustrations are to be regarded as being described with respect to one particular embodiment and as illustrative only. Those of ordinary skill in the art will appreciate that any term or terms with which these examples or illustrations are utilized will encompass other embodiments which may or may not be given therewith or elsewhere in the specification and all such embodiments are intended to be included within the scope of that term or terms. Language designating such nonlimiting examples and illustrations includes, but is not limited to: "for example," "for instance," "e.g.," "in one embodiment." Furthermore, while certain items may be referred to as "first," "second," "third," "fourth," etc. (e.g., a first sidewall, second sidewall) it would be understood that such terms are used for explanation and any one of multiple such items may be considered the "first," "second," etc.

[0028] Many fittings that can withstand higher pressures must be rotated several times in order to complete a seal. Such connections are difficult to use, especially in cramped spaces, and do not facilitate filter changes by robots. Additionally, such connections may unintentionally become disengaged or unable to withstand certain processes or temperatures. Therefore, a new fluid connection is needed.

[0029] To this end, embodiments described herein provide a quick connect connection that can be utilized in a variety of applications, including in semiconductor manufacturing systems. The quick connection system may lock to prevent or inhibit unintentional disengagement of the connection. Additionally, the quick connect connection can further provide features to prevent insertion errors or incorrect seating. Such a quick connect connection can also provide o-ringless sealing. The quick connection system can thus, among other advantages, both ease engagement of fittings and inhibiting their disengagement. Moreover, the quick connection system may provide more reliable high temperature or high pressure operation and reduce contamination.

[0030] FIGURES 1 A and 1 B are diagrammatic representations of one embodiment of a connector that may be used in a connection system. Specifically, FIGURE 1 A depicts an exploded view of the connector while FIGURE 1 B depicts a view of the assembled connector.

Connector 100 includes a fluid fitting 1 12 (which may be formed at the end of fluid tubing or as part of a cap, etc.), locking sleeve 102 and locking nut 104 formed annularly around central axis 190. It will be understood with reference to the drawings that the terms inner surface when used in conjunction with a feature means the surface of that feature nearest to the center axis 190 and an outer surface is the surface of the feature opposite the inner surface.

[0031 ] Here, fluid fitting 1 12 provides a fluid flow passage open to the end of first fitting 1 12 and configured to mate or abut with a second fitting (not shown) so that the first fitting 1 12 and the second fitting may be connected to form a continuous flow passage. Preferably, the fittings are complementary fittings that are configured to form a seal under axial force, such as a FlareMount™ fitting, a Pillar fitting, a machined or molded fitting, or other fitting known or developed in the art. While fitting 1 12 is illustrated as a female fitting, in other

embodiments, fitting 1 12 can be a male fitting and the second fitting a female fitting. One of the fittings can be part of an end cap of a cassette (e.g., as shown in FIGURE 7A), a fitting on a pressure transducer, a fitting on a liquid flow controller or other device.

[0032] In one embodiment a seal 126 such as an o-ring or other type of gasket may be disposed on annular shoulder 124 formed in fluid fitting 1 12. Seal 126 may serve to avoid wear and tear on certain types of fittings, including for example, fittings that utilize plastic-to-plastic contact such as FlareMount™ style fittings. Other embodiments a connector may be o-ringless, which may serve to improve contamination control and provide more reliable higher temperature operation

[0033] Fluid fitting 1 12 is at least partially received by locking nut 104. Specifically, locking nut 104 encircles the end portion of fitting 1 12 and is rotatable about central axis 190. The opening through the nut 104 can have areas of different diameter including an area of smaller diameter and an area of greater diameter. According to one embodiment, the opening of the locking nut 104 has an area of greater diameter at the first portion of locking nut 104 proximate fitting 1 12 and an area of narrower diameter at a second portion of locking nut 104 proximate the area of greater diameter, forming stepped shoulder 140.

[0034] According to one embodiment, fitting 1 12 can be shaped so that a first portion of the fitting passes through the portion of narrower diameter of the locking nut 104 while a second portion has a larger diameter (or other shaped footprint) than the area of narrower diameter. In this embodiment, the locking nut 104 and fitting 1 12 form complementary radial shoulders that are shaped and positioned to abut one another during use (e.g., a shoulder 140 on the inner surface of locking nut 104 abuts an external shoulder on outer surface of fitting 1 12). A set of locking nut threads 146 are disposed proximate to the end of lock nut 104 nearest fitting 1 12 and can be designed to engage the threads on a second fitting as will be discussed in more detail.

[0035] Locking sleeve 102 includes a nut receiving area for receiving locking nut 104. Specifically, locking sleeve 102 may include one or more circumferential channels 122 formed on the inner surface of locking sleeve 102. A first circumferential channel 122 may be disposed at an end of the locking sleeve 102 distal from the fitting 1 12 and configured to receive one or more keepers 160. Keepers 160 are circular or semi-circular and formed annularly around fitting 1 12 such that they abut outer surface of fitting 1 12 when disposed in the first circumferential channel 122 of the locking sleeve 102. When so disposed keepers 160 limit the translation of locking sleeve 102 relative to locking nut 104 and server to prevent unintentional disassembly of locking sleeve 102 and locking nut 104, or other components of connector 100.

[0036] Additionally, in some embodiments, locking nut 104 has one or more fingers 1 16. Features

1 18 at the ends of fingers 1 16 may include raised shoulders 1 19 that are configured to be engaged with, and retained in, the one or more circumferential channels 122 formed on the inner surface of locking sleeve 102. In one embodiment, when locking sleeve 102 is translated along center axis 190 in the direction of fitting 1 12, keepers 160 may contact fingers 1 16 such that locking nut 104 is also translated along center axis 190. When locking nut 104 is translated into a position where the shoulder 140 on the inner surface of locking nut 104 abuts an external shoulder on outer surface of fitting 1 12, raised shoulders 1 19 at the end of fingers 1 16 may be disposed in first circumferential channel 122 of locking sleeve 102. Similarly, when locking sleeve 102 is translated along center axis 190 in a direction away from fitting 1 12 (in order, for example, to lock the first fitting 1 12 to a second fitting as will be discussed in more detail later herein) raised shoulder 1 19 at the end of fingers 1 16 may be disposed in a second circumferential channel 122 of locking sleeve 102 configured to receive the shoulders 1 19. The engagement of shoulders 1 19 in such a circumferential channel 122 may serve to prevent the translation or other movement of locking nut 104.

[0037] One or more ribs 106 (e.g., three) are formed on the outer surface of locking nut 104 and project radially outward from the center axis 190. One or more complementary grooves 108 (e.g., three) are formed on the inner surface of locking sleeve 102 such that the ribs 106 on the locking nut 104 mate with the grooves 108 on the inner surface of the locking sleeve 102. The ribs 106 and grooves 108 thus cooperate to allow the locking sleeve 102 to translate (e.g., relative to the locking nut 104) along the center axis 190 while simultaneously serving to retain the ribs 106 within the grooves 108 such that locking sleeve 102 and locking nut 104 rotate around the center axis 190 as an assembly. To aid in rotating locking sleeve 102 and locking nut 104, one or more features such as channels or the like may be formed in outer surface of locking sleeve 102 in order to aid a human or machine (e.g., robot) in gripping locking sleeve 102. In some embodiments, grooves 108 or ribs 106 may extend less than the length of the locking sleeve 102 (e.g., in the case of grooves 108) or locking nut 104 (in the case of ribs 106) along the center axis 190 thereby cooperating to limit the distance along the center axis 190 locking sleeve 102 may translate relative to locking nut 104.

[0038] Locking sleeve 102 can also include one or more locking features that may cooperate with complimentary locking features on the second fitting to prevent rotation of the locking sleeve 102 and locking nut 104 around the center axis 190, for example when the locking features are aligned. According to one embodiment, for example, locking sleeve 102 may include a set of inner projections 150 while the second fitting can comprise a rib spaced from the second fittings external threads that includes a set of notches. These inner projections 150 may, for example, be flush with the surface of locking sleeve 102 nearest second fitting, project radially inward from inner surface of locking sleeve 102 and be spaced 120 degrees apart. When the locking sleeve 102 is translated into a position such that the inner projections 150 are aligned (e.g., along an axis substantially perpendicular to center axis 190) with the corresponding notches in the rib of the second fitting further rotation of the locking sleeve 102 around the center axis 190 is prevented, locking the first fitting to the second fitting by inhibiting rotation of locking sleeve 102 and disengagement of the threads 146 with the threads of the second fitting. With brief reference to FIGURE 7B, for example, projections 150 may fit through notches 716 in rib 714. In some cases, the locking features can be configured so that only certain components may be connected, or may be only connected in certain positions (e.g., to ensure proper components are utilized together). For example, the inner projections 150 and corresponding notches can be altered in geometry, spacing, or other aspect for different fittings/connection nuts.

[0039] Projections 150 may also serve as alignment features to ensure proper alignment of threads between locking nut threads 146 and external threads on a second fitting. Specifically, in one embodiment, projections 150 can be spaced such that the set of locking nut threads 146 cannot engage the fitting external threads unless the projections 150 mate, or pass through (so that the locking sleeve 102 may rotate), the corresponding features of the second fitting. Again, with brief reference to FIGURE 7B, projections 150 may be spaced such that locking nut threads 146 cannot engage the fitting external threads (e.g., threads 712 of FIGURE 7B) unless projections 150 pass through the corresponding notches. Projections 150 may be located so that locking nut threads 146 can only engage the external threads on the second fitting when locking nut 104 is in a specific orientation in relation to the threads of the second fitting such that, for example, the thread starts on the threads of locking nut threads 146 is aligned with the thread start of the second fitting (e.g., threads 712).

[0040] Embodiments of a connector as depicted can be adapted to different port sizes. The internal and external threads can change based on the port size, axial travel requirements, load requirements and seal performance requirements. Components of the connector can be made from a variety of materials including polymeric materials, including high purity perfluooropolymers or perfluoroelastomers such as, but not limited to, oleophilic resins, perfluorinated resin, (such as, but not limited to, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP)), perfluoroalkoxy alkanes (PFA), polyvinylidene fluoride (PVDF), polyimide, polyetherimide, polycarbonate, polypropylene (PP), polyethylene (PE), polyether ether ketone (PEEK), or other materials. In some cases, if high temperatures are expected, it may be desirable to use materials that exhibit lower creep. Thus, for example, it may be preferable to use PFA for the locking nut, locking sleeve and fittings when applications exceed 120 degrees Celsius, as PTFE exhibits more creep at these temperatures.

According to one embodiment, the connectors or features thereof can be formed primarily of PFA or other high-temperature polymer that will not deform at temperatures that occur during autoclaving or other high temperature processes which may be around 120 degrees Celsius or higher, including up to or around 200 degrees Celsius. In this manner an ultra- clean PFA, locking, quick connect, temperature resistant seal connection for the

semiconductor industry may be provided.

[0041 ] A connection system employing embodiments of such a connector may be used in a variety of applications, including with stand-alone fittings, straight union fittings, elbow fittings or other fittings and may be integrated into other devices. While the fittings illustrated above feature a FlareMount™ fitting or seal mechanism, other styles of fittings may be used, including, for example, Primelock® fittings, FlareLock® fittings (e.g., FlareLock® II fittings) Flaretek® fittings, PrimeLock® fittings, Quikgrip® fittings, Pillar® fittings (e.g., Super Type Pillar® fittings or Super 300 Type Pillar® fittings), Flowell® fittings (e.g., Flowell® 60 series fittings or Flowell® 1 1 series fittings), Parflare® Fittings, Furon® fittings (e.g.,

Furon®FlareGrip® II fittings or Furon® Grab Seal™ Fittings. The fittings may be Purebond® welded to pipe or tubing or molded with a tubing connection at one or both ends. The fittings may also be inserted into flared ends of tubing. One of the fittings may also be welded onto or molded into a purification device housing (e.g., a Chemline or Chemlock ® filter housing or other filter housing, for example).

[0042] In operation then, the ends of first fitting 1 12 and a second fitting can be brought together and the locking sleeve 102 translated along the center axis 190 toward the second fitting until the projections 150 pass through the corresponding notches of the rib of the second fitting. When the end portion of the second fitting, the locking sleeve 102 and the locking nut 104 are at the appropriate location, locking sleeve 102 can be rotated to fully engage the nut inner threads 146 of locking nut 104 with the outer thread of the second fitting until a hard stop is reached (where the fitting 1 12 meets the second fitting and no further rotation of the threads is possible) to create a seal between the fittings. The locking sleeve 102 can then be translated in the opposite direction (e.g., away from the second fitting along the center axis 190) until projections 150 align with corresponding notched of the rib of the second fitting (the locked position), locking the connector 100 by inhibiting further rotational movement of locking sleeve 102 and locking nut 104. Additionally, shoulders 1 19 of fingers 1 16 of locking nut 104 may be engaged in a circumferential channel 122 on the inner surface of locking nut 102 inhibiting translation of locking nut 104 and locking sleeve 102.

[0043] It may now be helpful to an understanding of certain embodiments to discuss in more detail the use of embodiments of such a connector in a connection system. To that end, attention is now directed to FIGURES 2A, 2B and 2C, where FIGURE 2A depicts one embodiment of a connection system in the unlocked and unengaged position, FIGURE 2B depicts the connection system in a rotated position with the threads engaged at a hard stop but unlocked and FIGURE 2C depicts the connection system in a rotated and locked position. Turning first to FIGURE 2A, connection system 200 comprises locking sleeve 102, a locking nut 104 disposed in the nut receiving area of locking sleeve 102, a first fitting 1 12, and a second fitting 1 14. First fitting 1 12 provides a fluid flow passage open to the end of first fitting 1 12 proximate to locking sleeve 102 and locking nut 104, and second fitting 1 14 provides a fluid flow passage open to an end of second fitting 1 14 proximate to first fitting 1 12. First fitting 1 12 and second fitting 1 14 are configured to mate or abut so that the flow passages may be connected to form a continuous flow passage. As discussed above, the fittings are complementary fittings that are configured to form a seal under axial force, such as a Primelock® fitting, FlareMount™ fitting or other fitting known or developed in the art.

[0044] Second fitting 1 14 may include an end portion 142 that is received through the locking

sleeve 102 and at least a portion of the locking nut 104. The received portion of second fitting 1 14 may include outer threads 144. Rib 168 including notches 166 is disposed on second fitting 1 14 proximate outer threads 144. A set of connection nut inner threads 146 on the inner surface of locking nut 104 are disposed proximate to the end of locking nut 104 and can be designed to engage the external threads 144 of second fitting 1 14.

[0045] In particular, in one embodiment, connection system 200 can be used to help maintain seals, particularly for fittings where seals are formed or promoted by axial force. According to one embodiment, nut inner threads 146 create axial force (force that pushes second fitting 1 14 toward first fitting 1 12) 360 degrees around second fitting 1 14 without requiring that locking nut 104 rotate 360 degrees. That is, nut inner threads 146 can engage fitting outer threads 144 360 degrees around the fitting without requiring locking nut 104 to rotate 360 degrees to create the 360 degree engagement. To this end, nut inner threads 146 and fitting outer threads 144 can be multi-start threads, such as double start threads, triple start threads, etc. A double start, triple start or other multi-start thread can provide 360-degree axial loading around the full seal connection with roughly a half-of-a-rotation or less. Nut inner threads 146 and fitting outer threads 144 can be threads that accept high axial loads. The threads may include various standard thread profiles including, but not limited to 1 -12 UNF threads, buttress threads, acme threads or other threads. Additionally, custom or proprietary threads may be used.

[0046] In one embodiment, nut inner threads 146 and fitting outer threads 144 can be double start threads with each thread start offset by approximately 180 degrees and the threads running at least 180 degrees from each start. In this case, the locking nut 104 can be rotated to engage the double start threads. Rotating locking nut 104 180 degrees will cause the double start threads to engage 360 degrees around fitting 1 14. More particularly, using the start of a first thread as the reference, the first thread of nut inner threads 146 starting from the first start may contact the fitting outer threads 144 from 0-180 degrees and a second thread of nut inner threads 146 starting from a second start may contact the fitting outer threads 144 from 180-360 degrees such that there is an axial force on fitting 1 14 360 degrees around the fitting. While 180 degrees was used as an example, other embodiments may include double start threads that run for other lengths.

[0047] Using the example of triple start threads, each start can be offset by approximately 120

degrees and the threads can run approximately 135 degrees from each start. In this case, rotating locking nut 104 about 135 degrees will create 360 degrees of engagement. In this example, a first thread of nut inner threads 146 starting at a first start can contact fitting outer threads 144 from 0-135 degrees, a second thread of nut inner threads 146 starting from a second start may contact the fitting outer threads 144 from 120 degrees to 255 degrees and a third thread starting from a third thread may contact fitting outer threads 144 from 240 degrees to 15 degrees, such that there is an axial force on fitting 1 14 360 degrees around the fitting. While 135 degrees was used as an example, other embodiments may include triple start threads that run for other lengths.

[0048] Thus, multi-start thread configurations can be used to provide 360-degree axial loading

around the full seal connection with less than 360 degrees, and in some cases less than 180 degrees of rotation of locking nut 104. In other embodiments, the axial loading may be applied through less than 360 degrees of threaded engagement, while remaining sufficient to create a seal. For example, small gaps may exist in the loading profile provided the seal can still hold with the gaps (e.g., where there is an angular range where there is no thread engagement). One of ordinary skill in the art would understand that the thread examples provided are provided by way of example and other configurations of multi-start threads may be used.

[0049] Nut inner threads 146 and fitting outer threads 144 can, for example, be modified buttress threads. An American Standard buttress thread has a load flank angle of 7 degrees to the normal axis and a relief flank angle of 45 degrees to the opposite side of the normal axis, resulting in a thread angle (the angle between a load flank and adjacent relief flank) of 52 degrees. Embodiments of nut inner threads 146 and fitting outer threads 144 may have a relief flank angle of less than 45 degrees. According to one embodiment, the relief flank angle is between 15-40 degrees, but may be less. The load flank angle may be between 0- 15 degrees and may be to the same or opposite side of the normal axis as the relief flank angle. In one embodiment, for example, the relief flank angle is approximately 30 degrees and load flank angle is approximately 3 degrees to provide a 33 degree thread angle. In one embodiment, the load flank may be angled so that the thread angle is less than the relief flank angle. In other words, the load flank and relief flank may be angled to the same side of the normal axis as the relief flank.

[0050] Additionally, in some embodiments, the load flank angle of fitting outer threads 144 may be different than the load flank angle of nut inner threads 146 to increase interference. For example, the load flank of the fitting outer threads, as illustrated, may by approximately 0 degrees while the load flank of the connection nut inner threads is angled toward the fitting thread load flank several degrees.

[0051 ] In operation then, the projections 150 on locking sleeve 102 may be aligned with notches

166 on rib 168 of second fitting 1 14 and the locking sleeve 102 translated in the direction of the second fitting 1 14. Thus, projections 150 on locking sleeve 102 may pass through complementary notches 166 on the rib 168. Additionally, when locking sleeve 102 is translated in the direction of the second fitting 1 14, keepers 160 retained in circumferential channel 122a may contact fingers 1 16 of locking nut 104 (where shoulders 1 19 of fingers 1 16 may be captured in circumferential channel 122a), serving to translate locking nut 104 in the same direction as locking sleeve 102 until shoulder 140 of locking nut 104 and complementary shoulder 172 of fitting 1 12 abut one another. In this position the ends of first fitting 1 12 and second fitting are brought together and locking nut threads 146 formed on the inner surface of locking nut 104 contact outer threads 144 on second fitting 1 14. According to one embodiment, the projections 150 and complementary notches 166 are also utilized as aligning features such that the respective thread starts of locking nut threads 146 and outer threads 144 are aligned.

[0052] Moving now to FIGURE 2B, locking sleeve 102 can now be rotated. As discussed above, locking ribs (not shown) formed on outer surface of locking nut 104 are engaged with corresponding grooves (not shown) on inner surface of locking sleeve 102. Thus, the rotation of locking sleeve 102 serves to rotate locking nut 104 engaging the nut inner threads 146 with the fitting outer threads 144 until a hard stop is reached. As discussed above, in one embodiment, to fully engage the nut inner threads 146 with the fitting outer threads 144 may only require a rotation of around less than 180 degrees, and in some embodiments less than 135 degrees or around 120 degrees. The force on the fitting outer threads 144 and on the shoulder 172 of the fitting 1 12 presses first fitting 1 12 and second fitting 1 14 together to create a seal between the first fitting 1 12 and the second fitting 1 14 as shown. In the embodiment depicted, a seal such as o-ring 126 is disposed in first fitting 1 12 and serves to aid in sealing first fitting 1 12 to second fitting 1 14. Other embodiments may utilize another type of seal or may not utilize any type of seal whatsoever. [0053] At this point then, nut inner threads 146 are fully engaged (at a hard stop) with fitting outer threads 144 and connection system 200 may be locked by translating locking sleeve 102 along the center axis in a direction opposite from second fitting 1 14 until projections 150 of locking sleeve 102 align (along an axis substantially perpendicular to the central axis) with notches 166 on the rib 168. During this translation shoulders 1 19 of fingers 1 16 may transition from circumferential channel 122a to circumferential channel 122b and be captured in circumferential channel 122b. FIGURE 2C depicts the connection system 200 in such a locked position after such a translation, with the projections 150 of locking sleeve 102 aligned with notches 166 on the rib 168. The alignment of notches 166 and projections 150 serve to prevent rotational movement of locking sleeve 102, thereby preventing rotation of locking nut 104 engaged with locking sleeve 102 and disengagement of nut connection threads 146 on inner surface of locking nut 104 and outer threads 144 of fitting 1 14.

Additionally, as shoulders 1 19 of fingers 1 16 are captured in circumferential channel 122b translation of locking sleeve 102 is prevented.

[0054] Specifically, in one embodiment, a transition structure 178 is formed circumferentially on inner surface of locking sleeve 102 which may an area of lesser diameter configured to promote the transition of the shoulders 1 19 between circumferential channels 122. Such a transition structure 178 may be radiused to allow shoulders 1 19 of fingers 1 16 to travel more easily between circumferential channel 122a and circumferential channel 122b when locking sleeve 102 is translated into a locked position. Additionally, fingers 1 16 of locking nut 104 may be configured to deflect inward toward the central axis (e.g., when pressure is placed on shoulders 1 19) to assist in the transition of shoulders 1 19 over transition structure 178 when transitioning from circumferential channel 122a to circumferential channel 122b.

Retaining channels 122 may also have a wall opposite transition structure 178 which may be substantially perpendicular to the central axis to assist in retaining shoulders 1 19 in the retaining channel 122.

[0055] As shown then, embodiments of connection systems as disclosed herein may include a

locking feature that may be effectively utilized in coupling of fittings that cooperate to form a fluid flow passage. Other embodiments of such connection systems may equally effectively use such locking features in conjunction with a fitting that may serve as a cap to a second fitting. Such a connection system may be utilized in conjunction with certain processes or other instances where the second fitting needs to be capped or fluid tight. For example, certain purification cassettes such as those described in, for example, International Patent Application Nos. PCT/US2013/062744 and PCT/US2013/062743 both filed September 30, 2013 and U.S. Patent Application No. 14/043,620, entitled "Purifier Cassette" filed October 2, 2014, all of which are incorporated fully herein by reference, may have end caps that provide port fittings. These port fittings may need to be capped for certain processes such as autoclaving or for shipping in the cases where the purification cassettes are shipped in a pre- wet state.

[0056] Embodiments of a cap for use in such cases (among others) may utilize a connection

system as described above. FIGURES 3A and 3B are diagrammatic representations of one embodiment of a connector that may be used as a cap in such a connection system.

Specifically, FIGURE 3A depicts an exploded view of the connector while FIGURE 3B depicts a view of the assembled connector. Connector 300 includes cap 310 with a fitting 312 formed therein, a locking sleeve 302 and locking nut 304 formed annularly around central axis 390. Connector 300 may also include keepers 360 as discussed above..

[0057] Here, cap 310 includes fitting 312 configured to mate or abut with a second fitting (not

shown) so that the cap may be connected to the second fitting in order to form a fluid tight seal between cap 310 and second fitting, in order to cap the second fitting. Again, the fittings may be complementary fittings that are configured to form a seal under axial force, such as a FlareMount™ fitting, Primelock® fitting, or other fitting known or developed in the art. In one embodiment a seal 326 such as a seal formed as a disc of material such as FEP of PFA or other type of gasket may be disposed within fitting 312 of cap 310.

[0058] Locking sleeve 302, locking nut 304 and fluid fitting 312 may be configured substantially as described above. In one embodiment, fitting 312 includes a first portion with an area of smaller diameter shaped so that the first portion passes through the portion of narrower diameter of the locking nut 304 while a second portion of the fitting 312 has a larger diameter (or other shaped footprint) than the area of narrower diameter. In this embodiment, the locking nut 304 and fitting 312 form complementary radial shoulders that are shaped and positioned to abut one another during use (e.g., a shoulder on the inner surface of locking nut 304 abuts an external shoulder on outer surface of fitting 312). In the particular embodiment depicted, the area of narrower diameter can comprise one or more fingers 386 with shoulders 388 formed at the end. These fingers 386 can deform towards the central axis of the locking nut and pass completely through the shoulder 340 of locking nut 304 and return substantially to their original shape to capture and retain shoulders 388 of the cap 310.

[0059] Connector 300 functions in use substantially as described above. In other words, the fitting

312 of cap 310 and a second fitting can be brought together and the locking sleeve 302 translated along the center axis until the projections of the locking sleeve 302 pass through the corresponding notches of a rib of the second fitting. When the end portion of the second fitting and the locking sleeve 302 are at the appropriate location, locking sleeve 302 can be rotated to fully engage the nut inner threads of locking nut 304 with the outer thread of the second fitting until a hard stop is reached to create a fluid tight seal between the fittings and cap a fluid passage of the second fitting. The locking sleeve 302 can then be translated in the opposite direction until the projections of the locking sleeve 302 align with corresponding notches of the rib of the second fitting, locking the connector 300 by preventing further rotational movement of locking sleeve 302 and locking nut 304 substantially ensuring that the fluid passage of the second fitting remains capped.

[0060] As may be realized after reading the above description, certain embodiments of a connector and connection system as discussed so far may entail two translational movements of a locking sleeve. A first translational movement along the central axis toward the second fitting to pass projections on the locking sleeve through corresponding notches on the rib of the second fitting and a second translational movement of locking sleeve away from the second fitting to align the projections with the corresponding notches in the rib on the second fitting. Thus, certain embodiments may require that both a translational force and a rotational force be applied simultaneously to a locking sleeve in order to engage the threads of the locking nut with the outer threads of a second fitting. Additionally, such embodiments may require initial alignment of projections on the locking sleeve with the complementary notches in the second fitting. In order to promote ease of coupling connectors in connection systems of this type it may be desire to limit the number or type of forces that may need to be applied to couple the fittings using such a connector. To that end, embodiments of connection systems as disclosed herein may utilize a "push to lock" connector. Such a push to lock connector may require only a single translational movement of the locking sleeve in order to join and lock the connector to a fitting.

[0061 ] FIGURES 4A and 4B are diagrammatic representations of one embodiment of a push to lock connector that may be used in a connection system. In particular, FIGURE 4A depicts an exploded view of the connector while FIGURE 4B depicts a view of the assembled connector. Connector 400 includes a fluid fitting 412 (which may be formed at the end of fluid tubing or as part of a cap, etc.), locking sleeve 402 and locking nut 404 formed annularly around central axis 490. Fluid fitting 412 provides a fluid flow passage open to the end of first fitting 412 and configured to mate or abut with a second fitting (not shown) so that the first fitting and the second fitting may be connected to form a continuous flow passage. Preferably, the fittings are complementary fittings that are configured to form a seal under axial force, such as a FlareMount™ fitting, Primelock® fitting, or other fitting known or developed in the art. While fitting 412 is illustrated as a female, in other embodiments, fitting 412 can be a male fitting and the second fitting a female fitting. One of the fittings can be part of an end cap of a cassette (e.g., as shown in FIGURE 7A), a fitting on a pressure transducer, a fitting on a liquid flow controller or other device.

[0062] In one embodiment a seal 426 such as an o-ring or other type of gasket may be disposed in annular shoulder 424 formed in fluid fitting 412. Seal 426 may serve to avoid wear and tear on certain types of fittings, including for example, fittings that utilize plastic-to-plastic contact such as FlareMount™ style fittings. Other embodiments a connector may be o-ringless, which may serve to improve contamination control and provide more reliable higher temperature operation

[0063] Fluid fitting 412 is at least partially received by locking nut 404. Specifically, locking nut 404 encircles the end portion of fitting 412 and is rotatable about central axis 490. The opening through the nut 404 can have areas of different diameter including an area of smaller diameter and an area of greater diameter. According to one embodiment, the opening of the locking nut 404 has an area of greater diameter at the first portion of locking nut 404 proximate fitting 412 and an area of narrower diameter at a second portion of locking nut 404 proximate the area of greater diameter, forming stepped shoulder 440.

[0064] According to one embodiment, fitting 412 can be shaped so that a first portion of the fitting passes through the portion of narrower diameter of the locking nut 404 while a second portion of the fitting 412 has a larger diameter (or other shaped footprint) than the area of narrower diameter. In this embodiment, the locking nut 404 and fitting 412 form

complementary radial shoulders that are shaped and positioned to abut one another during use (e.g., shoulder 440 on the inner surface of locking nut 404 abuts an external shoulder on outer surface of fitting 1 12). A set of locking nut threads 446 are disposed proximate to the end of lock nut 404 nearest fitting 412 and can be designed to engage the threads on a second fitting as will be discussed above.

[0065] Locking sleeve 402 includes a nut receiving area for receiving locking nut 404. Specifically, locking sleeve 402 may include one or more circumferential channels (not shown) formed on the inner surface of locking sleeve 402. A first circumferential channel may be disposed at an end of the locking sleeve 402 distal from the fitting 412 and a second circumferential channel may be disposed further toward fitting 412. Locking nut 404 has one or more fingers 416. Features 418 at the ends of fingers 416 may include raised shoulders 419 that are configured to be engaged with, and retained in, the circumferential channels formed on the inner surface of locking sleeve 402. In one embodiment, in a first position the raised shoulders 419 may be engaged with the first circumferential channel. When locking sleeve 402 is translated along center axis 490 in the direction of fitting 412, shoulders 419 are retained in the second circumferential channel and locking nut 404 is also translated along center axis 490. Locking nut 404 can thus be translated into a position where the shoulder 440 on the inner surface of locking nut 404 abuts an external shoulder on outer surface of fitting 412.

[0066] When locking sleeve 402 is translated further along center axis 490 in the direction toward the second fitting (in order, for example, to lock the first fitting 412 to the second fitting as will be discussed in more detail later herein) raised shoulders 419 at the end of fingers 416 may transition from the second circumferential channel to the first circumferential channel of locking sleeve 402 configured to receive the shoulders 419. The engagement of shoulders 419 in such a circumferential channel may serve to inhibit the translation or other movement of lock nut 404. In one embodiment, to aid in the transition of shoulders 419 between circumferential channels the inner of surface of locking sleeve 402 between the

circumferential channels may be radiused to form a transition structure.

[0067] One or more ribs 406 (e.g., three) are formed on the outer surface of locking nut 404 and project radially outward from the center axis 490. One or more complementary grooves 408 (e.g., three) are formed on the inner surface of locking sleeve 402 such that the ribs 406 on the locking nut 404 mate with the grooves 408 on the inner surface of the locking sleeve 402. The ribs 406 and grooves 408 thus cooperate to allow the locking sleeve 402 to translate (e.g., relative to the locking nut 404) along the center axis 490 while simultaneously serving to retain the ribs 406 within the grooves 408 such that locking sleeve 402 and locking nut 404 rotate around the center axis 490 as an assembly.

[0068] To aid in rotating locking sleeve 402 and locking nut 404 one or more features such as

channels or the like may be formed in outer surface of locking sleeve 402 in order to aid a human or machine (e.g., robot) in gripping locking sleeve 402. In some embodiments, grooves 408 or ribs 406 may extend less than the length of the locking sleeve 402 (e.g., in the case of grooves 408) or locking nut 404 (in the case of ribs 406) along the center axis 490 thereby serving to limit the distance along the center axis 490 locking sleeve 402 may translate relative to locking nut 404.

[0069] Locking sleeve 402 can also include one or more locking features that may cooperate with complimentary locking features on the second fitting to prevent rotation of the locking sleeve 402 and locking nut 404 around the center axis 490, for example when the locking features are aligned. According to one embodiment, for example, locking sleeve 402 may include a set of inner projections 450 while the second fitting can comprises a rib spaced from the second fittings external threads that includes a set of notches. These inner projections 450 may, for example, be spaced 120 degrees apart. When the locking sleeve 402 is translated into a position such that the inner projections 450 are aligned (e.g., along an axis

substantially perpendicular to center axis 490) with the corresponding notches in the rib of the second fitting further rotation of the locking sleeve 402 around the center axis 490 is prevented, locking the first fitting to the second fitting. With brief reference to FIGURE 7B, for example, projections 450 may fit through notches 716 in rib 714.

[0070] In one embodiment, projections 450 may be disposed in a recessed ledge formed radially around the circumference of the inner surface of the locking sleeve 402. According to one embodiment then, the recessed ledge may have a greater diameter than inner surface of the locking sleeve 402 while projections 450 may be flush with the inner surface of locking sleeve 402. In this manner, the recessed ledge may be configured to accommodate the rib of the second fitting when projections 450 are aligned with the corresponding locking features of the rib. In some cases, the locking features can be configured so that only certain components may be connected, or may be only connected in certain positions (e.g., to ensure proper components are utilized together). For example, the inner projections 450 and corresponding notches can be altered in geometry, spacing, or other aspect for different fittings/connection nuts.

[0071 ] In operation, then the ends of first fitting 412 and a second fitting can be brought together and the locking sleeve 402 translated along the center axis 490, causing locking nut 404 to be translated as well, until the first fitting 412 and the second fitting are at the appropriate location. The nut inner threads 446 of locking nut 404 can then be engaged with the outer thread of the second fitting and locking sleeve 402 rotated to fully engage the nut inner threads 446 of locking nut 404 with the outer thread of the second fitting until a hard stop is reached to create a seal between the fittings. The locking sleeve 402 can then be translated in a direction along the central axis 490 toward the second fitting until projections 450 align with corresponding notches of the rib of the second fitting, locking the connector by preventing further rotational movement of locking sleeve 402 and locking nut 404.

Additionally, shoulders 419 of locking nut 404 may transition into the first circumferential channel on the inner surface of locking nut 402 preventing translation of locking nut 404 and locking sleeve 402.

[0072] As above, it will be helpful to an understanding of certain embodiments to discuss in more detail the use of embodiments of such a connector in a connection system. Moving on to FIGURES 5A, 5B and 5C, FIGURE 5A depicts one embodiment of a connection system in the unlocked and unengaged position, FIGURE 5B depicts the connection system in a rotated position with the threads fully engaged at a hard stop but unlocked and FIGURE 5C depicts the connection in a rotated and locked position. Turning first to FIGURE 5A, connection system 500 comprises locking sleeve 402, a locking nut 404 disposed in the nut receiving area of locking sleeve 402, a first fitting 412, and a second fitting 414. First fitting 412 provides a fluid flow passage open to the end of first fitting 412 proximate to locking sleeve 402 and locking nut 404, and second fitting 414 provides a fluid flow passage open to an end of second fitting 414 proximate to first fitting 412. First fitting 412 and second fitting 414 are configured to mate or abut so that the flow passages may be connected to form a continuous flow passage. As discussed, the fittings are complementary fittings that are configured to form a seal under axial force, such as a Primelock® fitting, FlareMount™ fitting or other fitting known or developed in the art.

[0073] Second fitting 414 may include an end portion 442 that is received through the locking

sleeve 402 and at least a portion of the locking nut 404. The received portion of second fitting 414 may include outer threads 444. Rib 468, including notches 466, is disposed on second fitting 414 proximate outer threads 444. A set of connection nut inner threads 446 on the inner surface of locking nut 404 are disposed proximate to the end of locking nut 404 and can be designed to engage the external threads 444 of second fitting 414. The nut inner threads 446 and external threads 444 may be multi-start threads as discussed above. Shoulders 419 of fingers 416 of locking nut 404 are captured in second circumferential channel 422b. Projections 450 on inner surface of locking sleeve 402 project radially inward from inner surface of locking sleeve 402 but are of greater diameter than the diameter of outer threads 444 of second fitting 414 such that projections 450 may clear external threads 444 when locking sleeve 402 is translated along the central axis.

[0074] In operation then, the ends of first fitting 412 and second fitting 414 are brought together and locking nut threads 446 formed on the inner surface of locking nut 404 engage outer threads 444 on second fitting 414. As may be realized after a review of the disclosure herein, in embodiments of a push to lock connector 400 as disclosed, projections 450 on locking sleeve 402 do not have to pass through notches 466 of rib 468 before the threads 446 on locking nut 404 and external threads 444 on the second fitting 414 are engaged. Thus, in such embodiments, projections 450 may not be able to serve as alignment features.

Accordingly, in one embodiment, alignment marks may be made on the outer surface of locking sleeve 402 to assist in aligning thread starts of threads 446 on locking nut 404 and external threads 444 on the second fitting 414. These marks may be dots, arrows, line or other visual indicators and may, or may not, be features that aid in gripping locking sleeve 402.

[0075] Turning to FIGURE 5B, locking sleeve 402 is can now be rotated to a hard stop position. As discussed above, locking ribs (not shown) formed on outer surface of locking nut 404 are engaged with corresponding grooves (not shown) on inner surface of locking sleeve 402. Thus, the rotation of locking sleeve 402 serves to rotate locking nut 404 engaging the nut inner threads 446 with the fitting outer threads 444 until a hard stop is reached. As discussed above, in one embodiment, to fully engage the nut inner threads 446 with the fitting outer threads 444 may only require a rotation of less than 180 degrees or less than 135 degrees and in some embodiments may only require a rotation of around 120 degrees. The force on the fitting outer threads 444 and on the shoulder 472 of the fitting 412 presses first fitting 412 and second fitting 414 together to create a seal between the first fitting 412 and the second fitting 414 as shown. In the embodiment depicted, a seal such as o-ring 426 is disposed in first fitting 412 and serves to aid in sealing first fitting 412 to second fitting 414. Other embodiments may utilize another type of seal or may not utilize any type seal whatsoever.

[0076] At this point then, nut inner threads 446 are fully engaged with fitting outer threads 444 at a hard stop. Projections 450 on locking sleeve 402 may be aligned along the central axis with notches 466 on rib 468 but separated from the notches 466. The connection system may then be locked by translating locking sleeve 402 along the center axis in a direction toward second fitting 414 until projections 450 of locking sleeve 402 align (along an axis

substantially perpendicular to the central axis) with notches 466 on the rib 468. During this translation shoulders 419 of fingers 416 may transition from circumferential channel 422b to circumferential channel 422a and be captured in circumferential channel 422a. FIGURE 5C depicts the connection system 500 in such a locked position after such a translation with the projections 450 of locking sleeve 402 aligned with notches 466 on the rib 468. The alignment of notches 466 and projections 450 serve to prevent rotational movement of locking sleeve 402, thereby preventing rotation of locking nut 404 engaged with locking sleeve 402 and disengagement of nut connection threads 446 on inner surface of locking nut 404 and outer threads 444 of fitting 414. A recessed ledge formed in locking sleeve 402 is configured to accommodate the rib 468 of the second fitting 414 when projections 450 are aligned with the corresponding notches 466 of the rib 468. Additionally, as shoulders 419 of fingers 416 are captured in circumferential channel 422a translation of locking sleeve 402 is prevented. [0077] Specifically, in one embodiment, a transition structure 478 is formed circumferentially on inner surface of locking sleeve 102 which may an area of lesser diameter than the circumferential channels 422 configured to promote the transition of shoulders 419 between circumferential channels 422. Such a transition structure 478 may be radiused to allow shoulders 419 of fingers to travel more easily between circumferential channel 422b and circumferential channel 422a when locking sleeve 402 is translated into a locked position. Additionally, fingers 416 of locking nut may be configured to deflect inward toward the central axis (e.g., when pressure is placed on shoulders 419) to assist in the transition of shoulders 419 over transition structure 478 when transitioning from circumferential channel 422b to circumferential channel 422a. Circumferential channels 422 may also have a wall opposite transition structure 478 which may be substantially perpendicular to the central axis to assist in retaining shoulders 419 in the circumferential channel 422.

[0078] Similarly to what was described above with respect to FIGURES 3A and 3B, embodiments of a push to lock connector may be utilized to provide a fluid tight cap for port fittings or the like. FIGURES 6A-6C are diagrammatic representations of one embodiment of a connector that may be used as a cap in such a connection system. Specifically, FIGURE 6A depicts an exploded view of the connector while FIGURES 6B and 6C depict views of the assembled connector. Connector 600 includes cap 610 with a fitting 612 formed therein, a locking sleeve 602 and locking nut 604 formed annularly around central axis 690.

[0079] Here, cap 610 includes fitting 612 configured to mate or abut with a second fitting (not

shown) so that the cap may be connected to the second fitting in order to form a fluid tight seal between cap 610 and second fitting to cap the second fitting. Again, as discussed, the fittings may be complementary fittings that are configured to form a seal under axial force, such as a FlareMount™ fitting, Primelock® fitting, or other fitting known or developed in the art. In one embodiment a seal 626 such as a seal formed as a disc of material such as FEP of PFA or other type of gasket may be disposed within fitting 612 of cap 610.

[0080] Locking sleeve 602, locking nut 604 and fluid fitting 612 may be configured substantially as described above with respect to the embodiment of FIGURES 5A, 5B and 5C. In one embodiment, fitting 612 includes a first portion with an area of smaller diameter shaped so that the first portion passes through the portion of narrower diameter of the locking nut 604 while a second portion of the fitting 612 has a larger diameter (or other shaped footprint) than the area of narrower diameter. In this embodiment, the locking nut 604 and fitting 612 form complementary radial shoulders that are shaped and positioned to abut one another during use (e.g., a shoulder on the inner surface of locking nut 604 abuts an external shoulder on outer surface of fitting 612). In the particular embodiment depicted, the area of narrower diameter can comprise one or more fingers 686 with shoulders 688 formed at the end. These fingers 686 can deform towards the central axis of the locking nut and pass completely through the shoulder 640 of locking nut 604 and return substantially to their original shape as can be seen with reference to FIGURE 6C to capture and retain shoulders 618 of the cap 610 as can be seen with reference to FIGURE 6C.

[0081 ] Connector 600 functions in use substantially as described above. In other words, the fitting

612 of cap 610 and a second fitting can be brought together. When the end portions of the first fitting and the second fitting are at the appropriate location (e.g., when the threads of locking nut 604 are in contact with the outer threads of the second fitting) locking sleeve 602 can be rotated to engage the nut inner threads 646 of locking nut 604 with the outer threads of the second fitting until a hard stop is reached to create a fluid tight seal between the fittings and cap a fluid passage of the second fitting. The locking sleeve 602 can then be translated in the direction of the second fitting until the projections 650 of the locking sleeve 602 align with corresponding notches of the rib of the second fitting, locking the connector by preventing further rotational movement of locking sleeve 602 and locking nut 604

substantially ensuring that the fluid passage of the second fitting remains capped.

Additionally, the translation of the locking nut serves to transition the shoulders 619 of the fingers 616 of the locking nut 604 into a circumferential channel formed on the inner surface of the locking sleeve 602 preventing translation of the locking sleeve 602.

[0082] It may now be helpful to discuss embodiments of fittings with which embodiments of a

connector as discussed above may be utilized. Looking then at FIGURES 7A-7C, diagrammatic representations of another embodiment of an end cap 700 that provides port fittings for a cassette or other device are depicted. End cap 700 comprises a base 702, a first port fitting 710 and a second port fitting 720. Although two port fittings are shown, devices with one port fitting opposing ports or more than two port fittings may be used. The port fittings may be externally threaded as shown by threads 712 and 722. The port fittings may be threaded in the same or opposite directions.

[0083] The port fittings may include locking features that, in cooperation with corresponding locking features of a connector, facilitate locking of the port fitting to the connector. The locking features may also be configured so that the start of threads 712 cannot engage

corresponding threads of the connector unless the corresponding features of the fitting and connector align or mate.

[0084] According to one embodiment, for example, a set of locking features may include notches that align with inner projections of a connection nut (e.g., inner projections a locking sleeve as depicted in FIGURES 1 -6). To this end, in the embodiment illustrated, an annular locking rib extends radially outward from each port fitting as shown by port ribs 714 and 724. Each locking rib may include spaced locking notches at the periphery of the rib. For example, rib 714 includes spaced notches 716 and rib 724 includes spaced notches 726. The spaced notches may be arranged so that when a complementary locking feature (e.g., a projection) in a connector is aligned with the notch 726 (e.g., along an axis perpendicular to the center axis) the locking feature on the connector inhibits movement of the projection along the axis of alignment, inhibiting rotation of the locking sleeve and preventing disengagement of the connector.

[0085] The spaced notches may also be arranged so that a complementary locking feature in a connector may pass through the notches only when threads 712 and 722 are properly aligned with threads of the connection system. For example, the notches may be arranged to align with inner projections of a locking sleeve when the locking sleeve or locking nut within the locking sleeve nut is in a specific angular position. Furthermore, in one embodiment, the locking sleeve may not be able to rotate until the projections pass through the notches. Thus, the locking features of the fitting and connection system (on the locking sleeve in this example) may also prevent rotation of the locking sleeve until the threads are properly positioned relative to each other.

[0086] The port rib 714 may be set back from the start of port fitting external threads 712 a selected distance such that the start of threads 712 cannot engage corresponding threads of the connection system unless the locking features pass through alignment notches 716.

Similarly, port rib 724 may be set back from the start of port fitting external threads 722 a selected distance such that the start of threads 722 cannot engage corresponding threads of a connector unless the locking features pass through notches 726.

[0087] FIGURES 8A and 8B are diagrammatic representations of one embodiment of a purification cassette 800 having a first end cap 804 and a second end cap 806 providing port fittings, (e.g., one or more of first port fitting 808, second port fitting 810, a third port fitting 812 and fourth port fitting 814). Depending on the configuration of purifier cassette 800, any of the one or more ports may act as an inlet port, an outlet port, a vent port, drain port or other type of port. In some cases, the ports may be placed so that the purifier cassette can be reversed.

[0088] As depicted in FIGURE 8A, the port fittings may include port fitting external threads to

engage with threads of a manifold or other component. Additionally, a port fitting may include a radially projecting port rib (e.g., radial rib 830 and radial rib 832) extending from a surface of the end cap and set back from the respective port openings. Radial rib 830 and radial rib 832 may be used as a locking or alignment feature and help ensure a sealed connection as discussed above.

[0089] The end caps may include features such as alignment holes, rails, guide channels or the like to engage with complementary features on a manifold assembly to help ensure proper placement of the purifier cassette or other device. In the embodiment of FIGURE 8A, end cap 804 includes alignment hole 834 and end cap 806 includes alignment hole 836 open to the front of cassette 800 to receive guide pins of a manifold (e.g., such as alignment knobs or marks). Alignment holes 834/836 can receive corresponding guides of a manifold to vertically position and hold cassette 1 100. End cap 804 may further include an alignment opening 840 and end cap 806 may include alignment opening 842. According to one embodiment, alignment opening 840 is axially aligned with the opening of port fitting 808 and alignment opening 842 is axially aligned with the opening of a port fitting. Alignment opening 840 and alignment opening 842 may receive an alignment post or the like.

[0090] Although specific embodiments have been described, these embodiments are merely

illustrative, and not restrictive of the invention. The description herein of illustrated embodiments of the invention, including the description in the Abstract and Summary, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein (and in particular, the inclusion of any particular embodiment, feature or function within the Abstract or Summary is not intended to limit the scope of the invention to such embodiment, feature or function). Rather, the description is intended to describe illustrative embodiments, features and functions in order to provide a person of ordinary skill in the art context to understand the invention without limiting the invention to any particularly described embodiment, feature or function, including any such embodiment feature or function described in the Abstract or Summary. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the invention in light of the foregoing description of illustrated embodiments of the invention and are to be included within the spirit and scope of the invention. Thus, while the invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of embodiments of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the invention.

[0091 ] Reference throughout this specification to "one embodiment", "an embodiment", or "a

specific embodiment" or similar terminology means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment and may not necessarily be present in all embodiments. Thus, respective appearances of the phrases "in one embodiment", "in an embodiment", or "in a specific embodiment" or similar terminology in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any particular embodiment may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the invention.

[0092] In the description herein, numerous specific details are provided, such as examples of

components and/or methods, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that an embodiment may be able to be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, components, systems, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention. While the invention may be illustrated by using a particular embodiment, this is not and does not limit the invention to any particular embodiment and a person of ordinary skill in the art will recognize that additional embodiments are readily understandable and are a part of this invention.

[0093] It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. Additionally, any signal arrows in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise specifically noted.

[0094] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component.