Method and apparatus for high pressure sealing

Abstract

The present technology generally relates to devices, systems and methods for providing a robust seal between surfaces in a pressurized system, such as a chromatography system. In particular, the devices, systems and methods relate to compliant and resilient components that can be reused and / or reinstalled even in a high pressure environment (e.g., 1000 psi or greater) while providing a pressure resistant sealing surface.

Description

[0001] Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 848,102 filed on May 15, 2019, the entire contents of which are hereby incorporated by reference herein. Technical Field

[0003] The present invention generally relates to devices, systems and methods for providing a secure seal between surfaces in a pressurized system (such as, for example, a chromatography system). Specifically, the devices, systems and methods relate to consumable parts that can be reused and / or reinstalled while still providing a pressure-resistant sealing surface. Background Art

[0004] Pressurized systems such as chromatography systems need to control the ability of fluid flow and pressure therethrough. Common is that pressure is greater than 500psi (e.g., 1000psi, 2000psi, 5000psi, etc.). In order to form enough pressure seals around moving parts (e.g., the injector of the needle or column in the back pressure regulator), consumable parts are used. In order to form a pressure seal, the consumable formed by the compliant material is fixed in place using torque. Although the torque manipulates the consumable and fixes it in place to form a tight seal, the torque may also have a harmful effect on the consumable. Specifically, during the installation of the consumable, the compliant consumable may be sheared, thereby producing scratches and impurities on the sealing surface. Depending on the degree of scratches and impurities, pressure control may be reduced to an unacceptable level. Therefore, the number of devices and / or the torque amount used are limited to ensure that the consumable can provide a pressure-resistant seal (e.g., 1000psi, 2000psi, etc.) during use. Summary of the invention

[0005] Provided herein are apparatus and methods for providing pressure-resistant seals between moving parts in a pressurized system. Embodiments of the present technology provide for multiple installation or positioning of sealing apparatus between moving components without compromising pressure control performance.

[0006] One aspect of the present technology relates to a method of installing a standoff between a first surface and a second surface in a pressurized system. The method comprises: (a) press-fitting the standoff into a housing that is connectable to the first surface; (b) sliding a threaded nut over the housing; (c) crimping an end of the nut to the housing to provide a rotationally disengageable connection between the housing and the nut that allows the nut to rotate freely about the standoff; and (d) securing the nut to the second surface. Due to the rotationally disengageable connection between the housing (containing the press-fit standoff) and the nut, the securing of the nut forms a pressure-resistant seal between the first surface and the second surface within the pressurized system via rotation of the nut without applying torque to the standoff.

[0007] Embodiments of this aspect of the present technology may include one or more of the following features. In certain embodiments, the first surface is the outlet of a back pressure regulator (BPR), and the second surface is the head of the BPR. The head includes a fluid inlet and a needle. In some embodiments, the support has a body defining a fluid flow path that extends substantially axially between an inlet external sealing surface and an outlet external sealing surface. The inlet external sealing surface is configured to have less elastic deformation than the outlet external sealing surface under the action of a force (e.g., axial compression) generated by the fixation of the nut. In an embodiment of the method, at least a portion of the inlet external sealing surface of the support is rounded.

[0008] Another aspect of the present technology relates to an elastomeric mount for sealing a surface in a pressurized system. The elastomeric mount includes a body defining a fluid flow path that extends substantially axially between an inlet exterior sealing surface and an outlet exterior sealing surface. The body includes an outer wall surface positioned between the inlet exterior sealing surface and the outlet exterior sealing surface. The inlet exterior sealing surface includes a deforming member that is configured to deform outwardly from the inlet exterior sealing surface toward the outer wall surface and away from an interior of the fluid flow path when the elastomeric mount is axially compressed. The outlet exterior sealing surface includes a sealing member that is configured to deflect inwardly from the outlet exterior sealing surface toward the fluid flow path when the elastomeric mount is axially compressed.

[0009] Embodiments of this aspect of the present technology may include one or more of the following features. In some embodiments, the inlet external sealing surface is configured to have a smaller elastic deformation than the outlet external sealing surface when the elastic support is axially compressed. That is, the inlet external sealing surface may be made of different materials, contain different shapes or profiles, and / or have different thicknesses. In some embodiments, the deformation member on the inlet external sealing surface is a flange extending outward from the fluid flow path. The flange has a rounded outer profile. In certain embodiments, the size and shape of the fluid flow path are set to receive a needle for controlling the pressure through the elastic support. In other embodiments, the inner wall defining the fluid flow path is configured to substantially match the profile of the needle. In some embodiments, the sealing member on the outlet external sealing surface is a face seal. In certain embodiments, the outlet external sealing surface is configured to have a larger elastic deformation than the inlet external sealing surface when the elastic support is axially compressed. In other embodiments, the flange of the material surrounds the outlet of the fluid flow path. The flange has an angled profile. In certain embodiments, the outlet external sealing surface includes a flange extending from the body. Some embodiments are characterized by one or more protrusions on the side outer surface of the body. The one or more protrusions are adapted to provide an interference fit with the housing. Certain embodiments include one or more visual indicators (e.g., notches, color bars, etc.) to help place the elastomeric support in the housing. Some embodiments of the elastomeric support are suitable for use with a back pressure regulator. That is, some embodiments of the elastomeric support are fixed within the back pressure regulator. In some embodiments, the material forming the elastomeric support has a lower elastic modulus than the needle material (i.e., the material used to form the needle in the BPR). In certain embodiments, the material forming the elastomeric support has a lower elastic modulus than the housing material. In some embodiments, the material forming the elastomeric support has a lower elastic modulus than the head of the BPR.

[0010] The present technology has many advantages. For example, by eliminating the torque applied to the compliant support during installation, the support can withstand many installation and adjustment processes. In addition, the support of the present technology is less likely to be scratched or sheared, which leads to better sealing and pressure control due to the lack of impurities and gaps. In general, the support and installation method are more robust than conventional supports and methods. That is, the support of the present technology is elastic. In addition, some embodiments of the technology provide enhanced robustness and usability of the BPR because methods that reduce torque stress, shear and wear of the support can be used to customize and install components (e.g., supports).

[0011] Another advantage of the present technology is the construction of a compliant or resilient support. Specifically, embodiments of the support of the present technology are configured to have a portion that forms a rigid face seal and a portion that is intentionally deformed during installation. Therefore, the support of the present technology can provide better sealing and can be used in extreme pressure environments (e.g., higher than 1000psi, higher than 2000psi, higher than 3000psi, higher than 4000psi, higher than 5000psi, higher than 6000psi and greater). In addition, certain embodiments of the support provide a reduction in internal volume. That is, certain configurations or geometries of the support of the present technology are customized according to the internal geometry of a part of a pressurized system (e.g., a portion within a back pressure regulator (BPR), or a portion between two metal surfaces in an injector). Therefore, the internal volume of the system can be minimized, which generally improves performance due to a reduction in volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be more fully understood through the following detailed description taken in conjunction with the accompanying drawings.

[0013] Figure 1 An embodiment of a method of installing a mount between two surfaces in a pressurized system in accordance with an embodiment of the present technology is shown.

[0014] Figure 2 A needle-and-seat type backpressure regulator is schematically illustrated in accordance with an embodiment of the present technology.

[0015] FIG. 3A to FIG. 3C A method of connecting a support to a housing to provide a rotatably disengaged connection is schematically shown. In a first step, the support is press-fitted into the housing and the threaded nut is slid over the housing ( Figure 3A In the next step, the nut is aligned with the outer groove in the housing ( Figure 3B ). In a final step, the end of the nut is crimped to the housing to provide free rotation of the nut around the support, the support moving only in the axial direction when the nut is rotated ( Figure 3C ).

[0016] Figure 4 A conventional needle-standoff type back pressure regulator is schematically shown. The standoff used in this conventional BPR is within the prior art and is not in accordance with the present technology.

[0017] Figure 5 is a cross-sectional view of an embodiment of an elastic support according to the present technology. Figure 5 The support has a surface 550 that forms a face seal with an adjacent component and a deformable surface 520 that has a smaller elastic deformation than the surface 550 when the support is axially compressed. Figure 5 The support also has a geometry designed to reduce the internal fluid volume.

[0018] Figure 6 Schematically shows a finite element analysis of the total deformation of a mount according to the present technology. The outer black boundary 800 shows the undeformed state.

[0019] Figure 7 A finite element analysis of the sealing pressure on the inlet and outlet outer surfaces of a support in accordance with the present technique is schematically shown.

[0020] Figure 8 A needle-and-seat type back pressure regulator is schematically shown that is not configured to reduce internal volume.

[0021] Fig. 9 A needle-and-seat type back pressure regulator configured to reduce internal volume is schematically shown.

[0022] Fig.10 Three chromatograms showing the banding effects of various systems are provided. DETAILED DESCRIPTION

[0023] Certain exemplary embodiments will now be described so that the principles of the structure, function, manufacture and use of the apparatus and methods disclosed herein can be fully understood. One or more examples of these embodiments are shown in the accompanying drawings. It will be understood by those skilled in the art that the apparatus and methods specifically described herein and shown in the accompanying drawings are non-limiting exemplary embodiments, and the scope of the present invention is limited only by the claims. The features shown or described in conjunction with an exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.

[0024] Generally speaking, various aspects of the present technology relate to improved seals between two surfaces in a pressurized system (e.g., a system environment exceeding 1000psi). In some embodiments, improvements are achieved by removing the torque applied to a compliant member positioned at a sealing joint or minimizing the torque applied to a compliant member positioned at a sealing joint. In some embodiments, the compliant member is a support in a back pressure regulator. In other embodiments, the compliant member is a sealing ring between two metal surfaces in an injector of a chromatographic column.

[0025] Certain embodiments feature an elastomeric mount configured to provide a flat face seal on a lower pressure surface in a pressurized system and a displacement seal on a higher pressure surface in the pressurized system. The elastomeric mount is axially compressible such that a pressure-resistant seal can be formed between a face or end of the mount and a first surface and a second surface of the pressurized system without the use of torque on the mount. In certain embodiments, the displacement seal end of the mount is formed of a material that provides less elastic deformation during installation than the face seal end of the mount and / or has a shape / contour that provides less elastic deformation during installation than the face seal end of the mount.

[0026] See also Figure 1 , embodiments of the present technology are directed to methods of installing a support between a first surface and a second surface in a pressurized system. Figure 1 The illustrated method 100 can be used to install a support or other seal between two areas in a pressurized system, such as, for example, between a high pressure area and a low pressure area in a back pressure regulator (BPR), or between two metal surfaces within a sample injector of a chromatographic column. Because the method 100 utilizes a compliant or press-fit member that is disengaged from a housing as a sealing element, the installation method 100 eliminates the use of torque on the compliant seal. That is, when the support is disengaged from a fixed structure (e.g., a nut or threaded groove on the outside of the housing), the support only moves in an axial direction when the nut is rotated and fixed in place. Therefore, at least a portion of the method 100 can be repeated multiple times (e.g., step 140). The seal can be uninstalled and reinstalled multiple times without shearing or damaging the seal.

[0027] Method 100 includes four steps to install a support between a first surface and a second surface in a pressurized system. In step 110, the support or seal is press-fitted into a housing that can be connected to the first surface. Next, in step 120, a threaded nut is slid on the housing. In step 130, the end of the nut is crimped to the housing to provide a rotatably disengaged connection between the housing and the nut, which allows the nut to rotate freely around the support. Finally, in step 140, the nut is fixed to the second surface. Due to the rotatably disengaged connection, the fixing of the threaded nut to the second surface forms a pressure-resistant seal between the first surface and the second surface by the rotation of the nut. That is, because the connection is disengaged, no (or only very small) torque is applied to the support during the rotation of the nut. The support does not experience shearing, but only axial compression to form a high-pressure seal.

[0028] FIG. 3A to FIG. 3C A method 100 is shown for use in installing an elastomeric bearing within a BPR. For context, Figure 2 are provided as a reference for components and areas of the BPR. Note that Figure 2The embodiment of the present technology is shown. That is, Figure 2 The connected portion of the BPR 200 is shown after the installation method 100 has been performed to form a pressure-resistant seal between the first surface and the second surface.

[0029] Specifically, Figure 2 An enlarged view of the connection between the head portion 240 (high pressure portion) and the outlet 230 (located in the low pressure portion) is shown. Generally speaking, the outlet 230 is located in the housing 260. Fluid flow within the BPR 200 enters through the inlet port 205, is controlled by the movement of the needle 210 positioned in the seal 204 through the support 215, and flows out of the BPR through the outlet 230. In order to form a pressure-resistant seal within the regulator 200 and maintain the seal, the nut 265 is rotatably fixed (i.e., twisted) to the head 240 (e.g., a second surface in the BPR) until the housing 260 contacts the second surface on the head 240. In the devices and methods of the prior art, the support between the high pressure portion and the low pressure portion is directly connected to the nut or threaded housing. When the outlet portion is fixed to the head of a conventional device, the housing and the support rotate together, thereby generating high shear forces acting at the end of the support. Therefore, conventional supports deteriorate during installation.

[0030] However, Figure 2 The standoff 215 is shown not coupled to the nut 265. That is, the standoff 215 is rotatably disengaged from the nut 265, thereby allowing a more direct connection between the head 240 and the outlet 230 (e.g., minimizing the internal volume) and preventing undesirable shearing of the standoff during an installation event. Figure 4 and Figure 2 For comparison, a conventional BPR 400 connection is shown using a standoff 415 connected directly to the housing 460. Figure 4 4, a head 440 is secured directly to a threaded housing 460 to provide a connection to an outlet 430 located in the low pressure portion of the system. Fluid flows through the BPR 400 through the inlet 405. The flow of fluid is controlled by axial movement of the needle 410 located in the seal 404, with the tip 406 positioned in the seat 415. The seat 415 is located within the housing 460, which has a threaded outer surface 465 that is directly connected to the head 440. When the housing 460 is twisted into the head 440 to form a seal, the ends 416 and 417 of the seat 415 are sheared.

[0031] Specifically, the components of the BPR 200 may be constructed and mounted using the following techniques to minimize internal volume and reduce shear forces on the mount 215 as compared to conventional mounts installed in conventional BPRs or other pressurized equipment. FIG. 3A to FIG. 3C2, wherein the support 215 is first press-fit into the housing 260. See the support 215 having a press-fit connection with the opening in the housing 260. That is, the support 215 has an interference fit with the opening in the housing 260. The threaded nut 265 slides over the housing 260, as shown. Figure 3A To provide a rotatably disengaged connection between the housing and the nut, the nut is positioned over one or more external grooves 262 in the housing 260, such as Figure 3B As shown, the end 270 of the nut 265 is crimped to the housing 260, as shown Figure 3C This type of connection allows the nut 265 to rotate freely about the housing 260. Thus, when the housing 260 containing the outlet 230 is installed in the head portion 240 (see Figure 2 ), which can be tightened / secured by rotation as needed without any shearing effect on the support 215. That is, when the nut 265 is rotated and tightened to form a pressure seal with the head 240, the support 215 does not rotate, but moves axially toward the needle 210. This mounting and support design allows for a more stable connection because the support 215 does not experience shear. Therefore, the housing 260 can be removed and reinstalled multiple times without damaging the support 215. For example, compared to the support 415 during installation, the scratches and particles (if any) generated during installation are minimal. Both scratches and particles can lead to a degraded or poor seal because gaps are created by scratches (removed material) within the support and particles that collect and accumulate along the sealing surface.

[0032] Generally speaking, the present technology also relates to an elastic support or seal that can provide an improved pressure-resistant connection between two different pressure areas (e.g., a high pressure portion and a low pressure portion) within a system. Embodiments of the elastic support or seal can be used in conjunction with the methods of the present technology. In addition, the elastic support or seal can be used to improve the seal by customizing the geometry, shape and / or material of the support / seal to meet environmental requirements. For example, since the support / seal is typically located at the interface between the high pressure zone and the low pressure zone, each end of the support and seal of the present technology is constructed with its environmental placement in mind. That is, in an embodiment used in conjunction with a BPR, one end of the support interacts with the tip of the needle 210 and is exposed to the high pressure, while the opposite end of the support interfaces with the outlet 230 and is on the low pressure side of the regulator. In order to address these needs and eliminate excess fluid paths within the support, the support 215 has Figure 5The customized geometry shown. The first end 520 of the support 215 located at the end (high pressure side) that intersects with the needle is formed to have a compliant surface that is angled and sized to allow the needle 210 to be positioned within a range of axial positions therein. In certain embodiments, this portion of the internal geometry of the support includes a surface 525 that closely matches the contour of the needle 210 to provide a tight connection and allows the flow path FF to be customized for the range of needle displacements through this first portion of the support. The first end 520 is compliant and deformable, especially during installation, to allow the support 215 to be correctly positioned with the head portion 240. The internal geometry of the support transitions from a cone or angled volume to a narrower customized right cylinder at point 530 to meet the needs of the low pressure side. The opposite end 550 of the support (which is the side of the support that intersects with the outlet 230) includes a small flange (e.g., chamfer) 540 with a face seal. Using finite element analysis, it was found that a small flange or chamfer 540 on the end 550 helps control deformation within the inner diameter of the support during use. In this embodiment, the flange 540 has an angled (i.e., non-rounded) profile and extends from the outlet external sealing surface 550. In other embodiments, the flange 540 can be rounded. When the support 215 is axially compressed, the angled profile of the flange 540 deflects inwardly from the outlet external sealing surface 550 toward the fluid flow path (FF) extending between the surfaces 520 and 550.

[0033] Using finite element analysis, the stress state around the end of the support 215 was studied and the local stress state was found to be at an acceptable level. Figure 6 The results of the deformations on the support caused by the installation are shown. Figure 6 As can be seen in the , the outlet outer sealing surface 550, which forms the top face seal, experiences the greatest degree of deformation. Without being bound by theory, it is believed that the shape or amount of material present on the outlet outer surface 550 creates a rigid seal, resulting in deformation coaxial with the load and without deformation into the fluid flow path of the support. It should be noted that during FEA, changing the angle of the inner chamfer on this surface changes the degree of deformation entering the flow path. The inlet outer surface 520 shows the shape change in response to the applied axial deformation. The outer black boundary 800 shows the undeformed state, while the inner shaded portion shows the shape of the support after the load is applied. As shown in Figure 6520 deforms so that material overflows beyond its initial boundaries. Without being bound by theory, it is believed that surface 520 changes shape because it is more flexible than surface 550 because it does not contain material (e.g., see gap 810, thereby forming a rounded lip / flange 527). Flange 527 deforms outwardly toward surface 580. By changing the angle of the inner chamfer that defines the opening to the fluid flow path, the degree of outward deformation can be changed. That is, in this embodiment, if the inner chamfer has a steep angle (e.g., vertical), the deformation outward to edge 580 will be less than the deformation outward to a shallower angle (e.g., more horizontal). Figure 7 Results using FEA for sealing pressure are shown. Specifically, the sealing pressure on the raised structure 540 on the surface 550 and the rounded lip 527 on the surface 520 were studied. For the boundary conditions applied, both the raised structure 540 and the lip 527 were able to seal up to 31,307 psi.

[0034] Generally speaking, the outlet external sealing surface 550 is configured to have greater elastic deformation than the internal external sealing surface 520 when the support is axially compressed. That is, the material, shape configuration and / or thickness of the features extending from the outlet external sealing surface provide less resistance to deformation than the inlet external sealing surface. For example, the outlet external sealing surface 550 may include an angled flange 540 that will deflect inwardly and will deform more than the flange 525 extending from the inlet external sealing surface 520. The flange 525 extends outward from the fluid flow path (see the angled edge of the fluid flow path FF near the end 520, which extends outward toward the side outer surface 580). In addition to expanding outwardly, the flange 525 also includes a rounded outer profile 527. When the support 215 is axially compressed, the rounded outer profile 527 is easily deformed and will deform outward from the inlet external sealing surface 520 toward the outer surface 580 and away from the interior of the fluid flow path FF. Although Figure 5 The support 215 is shown with a rounded profile flange extending from its inlet outer surface to provide a deformation member for the support, but other structures or materials may be used in addition to or in place of the rounded profile flange. For example, a different material that is more deformable than the inner portion of the surface 520 may be used on a portion of the surface 520 corresponding to the position of 527, rather than including a rounded profile. Additionally or alternatively, rounded flanges or protrusions of different sizes extending from the surface 520 may be used as the deformation member. In fact, any deformation member that is configured to deform outwardly toward the outer surface or side outer surface 580 and away from the internal fluid flow path FF may be used.

[0035] In addition to deformation and sealing features, the support 215 of the present technology may include other structures or features on the outer surface. For example, Figure 5The support 215 in the embodiment includes a protrusion 560 on its side outer surface 570. The protrusion 560 extends radially and improves the interference fit of the support 215 in the retainer 260. In addition to the protrusion, the side outer surface may also include a visual aid to help place the support in the retainer. Figure 5 In FIG. 5 , the support 215 includes a visual aid 580 (eg, a notch) that corresponds to the location of the transition portion 530 in this embodiment. Figure 5 The visual aid 580 in the housing indicates the end that is inserted into the housing (e.g., to assist the user in properly placing the support 215). Figure 5 The embodiment shown uses notches or cutout grooves, but other visual aids are possible. For example, color changes or color bands or stripes can be used instead of notches. In addition, other patterns besides notches can also be used to visually mark the desired orientation or position of the support.

[0036] The support 215 can be made of a single material, graded materials, or multiple materials. That is, the support 215 can be formed of a single piece (e.g., a single material or graded materials), or it can be a two-piece structure, where each piece is formed of a different material and bonded together. Figure 5 In the illustrated embodiment, the support 215 is a one-piece piece formed of a single compliant material such as a polyimide-based plastic (e.g., Vespel). The difference in elastic deformation between the inlet and outlet external sealing surfaces is caused by the structures and features on those surfaces. In other embodiments, the difference in elastic deformation is caused by grading the materials (the inlet surface 520 has a smaller elastic deformation than the outlet 550). That is, additives can be incorporated into the material forming the support so that the surface 520 has a smaller elastic deformation characteristic than the surface 550. In other embodiments (not shown), the support 215 can be made of two different materials bonded together (such as at the location of the transition portion 530) to provide a difference in elastic deformation characteristics between the surfaces 520 and 550. The one or more materials forming the support 215 are typically compliant materials that are elastic under axial compression. The support 215 will be compressed between metal or rigid surfaces that define high pressure and low pressure areas when installed. Furthermore, in embodiments within a BPR, the support will be exposed to the needle 210, which moves in, out, and along the flow path FF, with its tip possibly hitting the transition portion 530 to control the flow of fluid therethrough. To provide resilience under these operating conditions, the material forming the resilient support will typically have a lower elastic modulus than the material forming the needle. Furthermore, to ensure the resilience of the support 215 during multiple installation events, the material used to form the support will have a lower elastic modulus than the housing material and a lower elastic modulus than the material forming the head of the back pressure regulator.

[0037] Generally speaking, the support / seal described herein and the method for being installed in the pressurized system provide enhanced pressure sealing ability.Therefore, the present technology can be used stably in high pressure system (for example, with 1000psi or greater combination).This advantage is particularly attractive for use in the BPR for controlling the pressure change in the chromatographic system.The support of the present technology also helps to eliminate the untouched volume by reducing the internal volume and increase or enhance the performance of pressure control.The untouched volume is the accessible part of the fluid flow, but not in the main solvent flow path used in the chromatographic separation.The part of the solvent flow can diffuse into the untouched volume or diffuse out the untouched volume at an irregular rate, thereby causing the spectral band widening.The spectral band widening reduces the quality of separation, and can cause wide and potentially overlapping chromatogram peaks.In the present technology, the support in the BPR can be customized to reduce the internal volume in the BPR.For example, at least a portion of the fluid flow path FF extending through the support can be precisely customized for the external shape of the pin in the BPR. Another portion of the fluid flow path FF (the portion above transition 530) is sized to provide a narrower restriction, which also reduces the length of the fluid path, thereby eliminating internal volume. Examples 1 and 2 below illustrate the improved performance of a BPR utilizing standoffs in accordance with the present technology.

[0038] Example 1

[0039] Figure 8 A backpressure regulator 1300 that has not been configured for reducing internal volume (i.e., a standard commercial raw material BPR) is shown. The backpressure regulator 1300 includes an inlet 1305, a seal 1304, a needle 1310, a support 1315, and an outlet 1330. The needle 1310 and the support 1315 define a restriction 1316 where the needle 1310 will meet the support 1315 at one extreme of the range of motion of the needle 1310. The backpressure regulator 1300 also includes an internal volume that can be occupied by a mobile phase fluid flow when the backpressure regulator is used for chromatographic separation. The head volume 1306 (55.0 μL) includes the portion of the fluid flow from the inlet upward to the seal 1304, along the needle 1310, and to the support 1315. The seal volume 1307 (25.0 μL) is close to the seal 1304. The support volume 1318 (34.1 μL) is located within the support 1315. An outlet volume 1335 (19.8.1 μL) is located downstream of the support 1315 at the outlet 1330. The total internal volume of these components is 134 μL (excluding the 109 μL of the sealed volume 1307).

[0040] Fig. 9A backpressure regulator 1400 that has been constructed to reduce internal volume is shown. The backpressure regulator 1400 contains the same basic components: the backpressure regulator 1400 includes an inlet 1405, a seal 1404, a needle 1410, a support 1415, and an outlet 1430. The needle 1410 and the support 1415 define a restriction 1416 where the needle 1410 will meet the support 1415 at one extreme of the range of motion of the needle 1410. The backpressure regulator 1400 also includes an internal volume that can be occupied by the flow of mobile phase fluid when the backpressure regulator is used for chromatographic separation. The head volume 1406 includes the portion of the fluid flow from the inlet upward to the seal 1404, along the needle 1410, and to the support 1415. The seal volume 1407 is adjacent to the seal 1404. The support volume 1418 is within the support 1415. The outlet volume 1425 is located downstream of the support 1415 at the outlet 1430 .

[0041] The back pressure regulator 1400 is configured to reduce internal volume. That is, the relationship and positioning of the various BPR components have been tailored to reduce internal volume (e.g., to minimize unswept volume). It should be understood that although Fig. 9 The BPRs shown have been customized in a number of ways, but BPRs do not need to be customized in a Fig. 9 Each of the approaches shown is tailored to achieve at least some advantages over commercially available BPRs. By positioning the inlet 1405 proximate to the support 1415 and providing the inlet 1405 perpendicular to the needle 1410 to reduce the length of the flow path to the needle 1410, the head volume 1406 has been reduced to 39.4 μL (a 28% reduction). The seal 1404 is positioned closer to the support 1415. The seal volume 1407 is not reduced in the back pressure regulator 1400, as shown. By reducing the length of the support 1415 and shaping the support 1415 so that its internal volume is closer to the shape of the needle 1410, the support volume 1418 has been reduced to 9.3 μL (a 73% reduction). The restriction 1416 is configured to define a sharp point at the interface of the conical portion and the cylindrical portion of the support 1415. The outlet volume 1430 has been reduced to 1.9 μL (a 90% reduction) by connecting the outlet 1430 directly to the flow path from the support 1415 . Figure 8 and Fig. 9The comparison also provides an example of reducing volume by reducing the cross-sectional area at the interfaces between BPR components. The seat volume 1418 and the outlet volume 1425 are reduced by minimizing the cross-sectional area at the outlet 1430, and the seat 1415 is configured so that it is no larger than the size of the flow path. The total internal volume of the backpressure regulator 1400 is 76 μL, a 44% reduction compared to the backpressure regulator 1300, or 51 μL (53% reduction) excluding the sealing volume. In general, the interfaces between components in an unmodified backpressure regulator may have larger areas than the flow paths within the components, and reducing these areas may reduce the volume within the backpressure regulator.

[0042] Example 2

[0043] Fig.10 The significant reduction in band distortion effects achieved using the BPR 1400 is shown. Fig.10 Chromatograms are provided for three different BPR designs, and the effects on peak broadening and tailing are shown. Trace 1501 is a peak measured from a sample that did not pass through a single flow path that contained both a backpressure regulator and a detector. That is, trace 1501 is a peak measured from a sample measured from a system having a split flow interface design, in which make-up solvent is provided to the BPR and the detector is split from a streamline extending directly from the column. Because the sample associated with the split flow interface design is not affected by the amount of unswept volume in the BPR, the sample associated with trace 1501 does not experience any sample band spreading—see area 1510. Trace 1501 is sharp and symmetrical, with a half-width of approximately 1.22. Trace 1502 is a peak measured in accordance with the same method, except that the sample was passed through a backpressure regulator without the present technique (i.e., using a backpressure regulator). Figure 8 1502) shows a significantly broadened peak compared to trace 1501 (compare the half width of trace 1501, 1.22, to the half width of 1502, 3.22), and it exhibits considerable tailing and some shoulders in region 1515. Trace 1503 is also a flow splitter interface using the BPR interface design but includes BPR 1400 (which is configured in accordance with the present technology to have a reduced internal volume). Fig. 9 , and described in Example 1). Trace 1503 is a sharp, symmetrical peak that is more closely aligned with trace 1501 (compare the half width of trace 1501 of 1.22 to the half width of trace 1503 of 1.65), and has significantly less broadening and shoulder in region 1520 than in trace 1502.

[0044] Embodiment 2 demonstrates that embodiments of the present technology significantly reduce or eliminate the band broadening caused by the back pressure regulator, thereby allowing separation quality comparable to separations performed in split flow interface designs. Thus, users can achieve the advantages associated with back pressure regulators, such as good pressure control at a reasonable cost and robust and wear-resistant operation, without sacrificing separation quality by implementing the methods, apparatus, and mounts of the present technology.

[0045] Those skilled in the art will appreciate the additional features and advantages of the present invention based on the above-described embodiments. Therefore, the present invention is not limited by what has been specifically shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.

Claims

1. An elastic support for sealing a surface in a pressurized system, the elastic support comprising: a body defining a fluid flow path extending substantially axially between an inlet exterior sealing surface and an outlet exterior sealing surface, the body including an exterior wall surface positioned between the inlet exterior sealing surface and the outlet exterior sealing surface; the inlet outer sealing surface including a deformation member configured to deform outwardly from the inlet outer sealing surface toward the outer wall surface and away from the interior of the fluid flow path when the resilient support is axially compressed; The outlet exterior sealing surface includes a sealing member configured to deflect inwardly from the outlet exterior sealing surface toward the fluid flow path when the resilient seat is axially compressed, wherein the sealing member includes a flange extending from the body.

2. The resilient support according to claim 1, wherein the inlet outer sealing surface is configured to have a smaller elastic deformation than the outlet outer sealing surface when the resilient support is axially compressed.

3. The elastomeric mount of claim 1, wherein the deformable member on the inlet outer sealing surface comprises a flange extending outwardly from the fluid flow path and having a rounded outer profile.

4. The elastomeric mount of claim 1, wherein the fluid flow path is sized and shaped to receive a needle for controlling pressure through the elastomeric mount.

5. The resilient mount of claim 4, wherein an inner wall defining the fluid flow path is configured to substantially match a contour of the needle.

6. The elastomeric mount of claim 1, wherein the sealing member on the outlet exterior sealing surface comprises a face seal.

7. The resilient support of claim 1, wherein the outlet outer sealing surface is configured to have a greater elastic deformation than the inlet outer sealing surface when the resilient support is axially compressed.

8. The elastomeric mount of claim 7 wherein a flange of material surrounds the outlet of the fluid flow path, the flange having an angled profile.

9. The elastomeric mount of claim 1, wherein a side outer surface of the body includes one or more protrusions adapted to provide an interference fit with the housing.

10. The elastomeric mount of claim 1, wherein a side exterior surface of the body includes one or more visual indicators adapted to aid in placement of the elastomeric mount in a housing.

11. The elastomeric support of claim 1, wherein the elastomeric support is fixed within a back pressure regulator.

12. The elastic support according to claim 4, wherein a material forming the elastic support has a lower elastic modulus than a needle material.

13. The elastic mount of claim 9, wherein a material forming the elastic mount has a lower elastic modulus than a material of the housing.

14. The resilient mount of claim 11, wherein a material forming the resilient mount has a lower elastic modulus than a head portion of the back pressure regulator.

15. A method for installing an elastic bearing according to any one of claims 1 to 14 between a first surface and a second surface of a pressurized system, the method comprising: press-fitting the resilient support into a housing connectable to the first surface; sliding a threaded nut on the housing; crimping an end of the nut to the housing to provide a rotationally disengageable connection between the housing and the nut, the connection allowing the nut to freely rotate about the resilient mount; as well as The nut is secured to the second surface, wherein the securing of the nut forms a pressure-resistant seal between the first surface and the second surface via rotation of the nut without applying torque to the resilient mount due to the rotatably disengageable connection.

16. The method of claim 15, wherein the first surface is an outlet of a back pressure regulator and the second surface is a head of the back pressure regulator, the head containing a fluid inlet and a needle.

17. The method of claim 15, wherein at least a portion of the inlet outer sealing surface is rounded.

Images