Abstract:
An example sealing system includes a retainer for a gasket wherein the retainer protects the polished sealing surface of the seal gasket from scratches before assembly by suspending the gasket inside the retainer, regardless of orientation. A gap in the circumference of the retainer allows the retainer to flex open for insertion of the seal gasket. A small chamfer on the inner diameter of the retainer aids the insertion of the seal into the retainer. The gap in the circumference of the retainer also allows the retainer to compress to a smaller circumference for a tight fit inside the sealing counterbore. A groove in the inner diameter of the retainer includes a protruding portion for the seal to engage. The depth of this groove is configured to provide some clearance inside the retainer for the protruding edge of the seal during a complete compression of the retainer.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application is a Continuation-In-Part application of International Application No. PCT/US2011/063429, filed Dec. 6, 2011, designating the United States which claims the benefit of U.S. Provisional Application No. 61/420,268, filed Dec. 6, 2010; this application is also a Continuation-in-Part of U.S. application Ser. No. 13/312,156, filed Dec. 6, 2011, which claims the benefit of U.S. Provisional Application No. 61/420,268, all of which are hereby incorporated herein by reference in their entireties. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates generally to fluid couplings and more particularly to fluid couplings having seal assemblies including flexible gaskets and flexible retainers for those gaskets. 
       BACKGROUND 
       [0003]    Ring seals are typically annularly shaped, defining an axially aligned hole for gas or fluid passage, two axially opposed end surfaces, a radial inner surface and a radial outer surface. A simplistic ring seal has planar end surfaces and smooth circular radial inner and outer surfaces that define the inner diameter (ID) and outer diameter (OD) of the ring seal. However, it is common practice in the industry to utilize seals having different radial cross-sections to obtain varying sealing capabilities for different fluid flow environments. 
         [0004]    A commonly used ring seal is circular and has a radial cross-section of a “C” shape. These “C seals” are constructed with the open side of the C construction facing the center of the ring such as is described in U.S. Pat. No. 5,354,072, (“the &#39;072 patent”) or with the open side of the C facing away from the center of two mating surfaces are brought together with the C seal in the middle, where the C seal is compressed with the open side of the C cross-section closing during compression. The ductile properties of the seal permit plastic deformation to occur without damaging the mating surfaces. 
         [0005]    Additional seals that have been available include “V” seals, which are also circular, but instead of having a “C” cross-section, have a “V” cross-section with the low point of the V constructed to point either inwardly or outwardly towards the center of the seal. Other seals known in the art include “Z” seals and simple O-rings. These other types of seals are discussed, for example, in U.S. Pat. No. 6,708,985 (“the &#39;985 patent”). Both of the &#39;072 and &#39;985 patents are herein expressly incorporated by reference, in their entirety. Still another type of ring seal known in the industry is the “W” seal. Such a sealing system is disclosed, for example, in U.S. Pat. No. 7,140,647 (“the &#39;647 patent”), also herein expressly incorporated by reference, in its entirety. The “W” seal in the &#39;647 patent uses a snap ring situated on the inside of a retaining ring, identified in the patent as a guide, to retain the W-seal in the retainer and to keep the sealing surfaces on the W-seal or gasket protected from scratches. The &#39;647 patent retainer or guide also has a snap ring situated on its outside diameter to keep the retainer engaged in the ‘counterbore.’ 
         [0006]      FIGS. 1-4  illustrate a typical prior art W-seal  2 , comprising a retainer sleeve  2   a,  and a metal seal  2   b.  As discussed above, the assembly  2  further comprises an interior snap ring  2   c  and an exterior snap ring  2   d.  To accommodate these snap rings, there is provided a first Outside Diameter (OD) groove  2   e  on the outer surface of the retainer sleeve  2   a,  and an Inside Diameter (ID) groove  2   f  on the inner surface of the retainer sleeve  2   a.  Additionally, a second OD groove  2   g  is provided on the outer surface of the metal seal  2   b,  which corresponds to the ID groove  2   f,  wherein the second OD groove  2   g  and the ID groove  2   f  together accommodate the interior snap ring  2   c.  It should be noted that the cut in the ring and seal shown in  FIG. 2  is illustrative only, for the purpose of illustrating particular constructional features of the seal assembly. In actuality, both the seal and the retaining ring are circumferentially continuous and unbroken. 
         [0007]    Thus, each prior art W-seal requires four separate parts, including two snap rings and three formed grooves for accommodating those snap rings, resulting in manufacturing complexity and relatively high cost. Additionally, these snap rings have been found to make it substantially more difficult to remove the seal from the counterbore when desired, causing productivity problems and sometimes damage to the seal assembly. For instance, when the seals are used to connect two channels designed to carry very high purity gases such as in a silicon deposition environment, impurities introduced into the system by the seal can impact the performance of an entire system. For example, out-gassing of impurities from the surfaces exposed to the interior of the vacuum environment in the system can unacceptably pollute the system. Because known W-seals are made to have a tight slip fit between the seal  2   b  and the retainer sleeve  2   a  and between the retainer sleeve  2   a  and the counterbore, minor damage to the counterbore material and the retainer sleeve during installation and removal during maintenance can increase the amount of material exposed to the vacuum environment, thereby increasing the potential for introduction of excess impurities from out-gassing from that material. 
         [0008]    In one operation environment, gas and vapor handling equipment deliver reactant and inert gasses and vapors to a tool such as an epitaxial reactor, a plasma etcher, and the like, which are used in the manufacture of semiconductors. Such equipment includes gas sticks, which employ a semi-modular design and may be rapidly constructed and easily and quickly maintained. Maintenance would include replacement of active gas delivery and metering components along a gas flow path. Such active components may include valves, pressure regulators, mass flow meters and mass flow controllers. The active components are secured in a gas flow path through a substrate or substrate blocks by the use of block or face type connectors. 
         [0009]    The block connectors minimize contamination of the gas flow path by reducing the wetted surface. The wetted surface is the interior surface of a gas flow path that contacts the gas. The smaller the wetted surface that is presented the smaller the amount or likelihood that the surface will be contaminated with unwanted gas species during assembly during an initial build or during maintenance when the flow path is torn down. 
         [0010]    Some prior seals and retainers for face block systems may introduce unwanted contaminants via abrasion and physisorption and chemisorption on the seal surfaces. The existing face seal systems use a small area, sealing zone to reduce contamination by reducing the wetted area at the connector joint. This is done by making sure the sealing zone is essentially flat with no portions of one connector extending into the other connector as is common in less stringent applications. The threaded members holding the connector halves are positioned a substantial distance away from the flow path to avoid contaminating it with particulates generated during tightening or loosening of the connector bolts Likewise there is no threading along the outside of the flow path at the connector break of the type found in a garden hose. Such a “threaded pipe” construction might generate particulates in the immediate vicinity of the flow path during tightening. Despite this some problems remain. The W-seal is an example. 
         [0011]    The above described seal uses a retainer that cannot be characterized as “low force.” The snap ring on the outer surface or its retainer comes in sliding contact with the wall of the counterbore during assembly. Because a relatively large force is needed to set the seal and retainer, alignment problems can arise and the snap rings abrade the counterbore walls generating contaminating particulates. 
         [0012]    What is needed, for certain sealing system applications, is a seal system that affords certain functional advantages without the necessity and expense involved in employing snap rings, and which is preferably constructed to permit easy removal from the counterbore. 
       SUMMARY 
       [0013]    Pursuant to these various approaches, a ring sealing system suitable for applications such as a semiconductor manufacturing modular gas delivery system is described. 
         [0014]    More specifically, an example sealing system includes a retainer for a seal (also called a gasket) used to connect modular piping in a modular gas delivery system to the gas flow controlling components. The retainer design protects the polished sealing surface of the seal from scratches before assembly by suspending the seal inside the retainer, with some clearance around the seal regardless of orientation. Additionally, a slit or gap in the circumference of the retainer allows the retainer to flex open for insertion of the seal gasket. A small chamfer on the ID of the retainer, in certain aspects, aids the easier insertion of the seal into the retainer. A similar chamfer on an edge of the seal further aids this insertion process. 
         [0015]    The gap in the circumference of the retainer also allows the retainer to compress to a smaller circumference, for a tight fit inside the sealing counterbore. A groove in the ID of the retainer includes a protruding portion for the seal to engage. The depth of this groove is configured such that with a complete compression of the retainer where the circumferential gap is completely closed, the protruding edge of the seal still has some clearance inside the retainer. This clearance, which acts as a stop to prevent the retainer from being overly compressed, ensures that the seal and retainer assembly will not jam during insertion of the assembly into the counterbore. 
         [0016]    The slit or gap in the circumference of the retainer allows for a larger tolerance in the machining on the OD of the retainer. With current designs, a slightly oversized OD will prevent insertion of the retainer and seal assembly into the counterbore because there is no room for compression. In one example of the retainer described herein, the retainer is free to close up to 0.010 inches. The gap in the circumference can be made larger and achieve the same results. 
         [0017]    There is a slight chamfer around the OD of the retainer for easier location of the retainer on the counterbore. The top half of the retainer has a slightly smaller OD for easy alignment of surface mount components. For instance, an installer can grasp this smaller OD and use the larger OD to engage a particular sealing point of multiple sealing points on the same block. 
         [0018]    In one example application, there is provided a ring seal assembly, which comprises an annular seal member having an inner diameter (ID) and an outer diameter (OD), and having an axial hole defined by the ID for fluid passage, wherein the OD of the seal member comprises a smaller OD portion and a larger OD portion. An annular retaining member is also provided, having an ID and an OD, wherein the ID of the retaining member is larger than the OD of the seal member. Advantageously, the ID of the retaining member comprises an axially cylindrical first portion and a second portion comprising a groove extending radially outwardly of the first portion for receiving and accommodating the larger OD portion of the seal, which extends radially outwardly into the groove. 
         [0019]    An additional feature in certain examples is the employment of a chamfer on at least one outside corner of the annular retaining member for easing installation of the retaining member into a counterbore. A chamfer may also be disposed on at least one inside corner of the annular retaining member for easing insertion of the sealing member into the retaining member. Yet another feature in certain examples is the inclusion of a load adjustment groove disposed on the seal member for improving the elastic response of the seal. 
         [0020]    In yet another aspect, there is provided a ring seal assembly, which comprises an annular seal member having an inner diameter (ID) and an outer diameter (OD), and having an axial hole defined by the ID for fluid passage. An annular retaining member has an ID and an OD, wherein the ID of the retaining member is larger than the OD of the seal member. A chamfer is disposed on at least one inside corner of the annular retaining member for easing insertion of the sealing member into the retaining member. Another chamfer is disposed on at least one outside corner of the annular retaining member for easing insertion of the retaining member into a counterbore. 
         [0021]    In still another aspect, a method for assembling a ring seal assembly includes radially expanding a retainer during insertion of a seal into the retainer to be supported by a groove in an inside surface of the retainer. The retainer expands at a slot or slots in the retainer&#39;s circumference. The retainer in certain examples includes a chamfer on an inside corner of the retainer, and the seal may include a chamfer on a seal outer corner to facilitate seal insertion. There is space around the seal to allow the retainer to compress around the seal during insertion of the retainer into a counterbore. For instance, a chamfer on an outside corner of the retainer guides the insertion by engaging the counterbore surface, which engagement slightly compresses the retainer at the slots with the slots restricting the compression such that the compression does not result in mechanical compression of the seal. After insertion into the counterbore, the retainer expands into the counterbore while supporting the seal for compression between elements defining the flow path. 
         [0022]    So configured, a retainer according to these teachings when used in a semiconductor manufacturing environment may act as shield to reduce abrasion and contamination of the seal during assembly with the retainer and while stored and being handled prior to and during assembly with a counterbore of a block, a handle to avoid contamination of the seal during assembly of the retainer and seal combination with a block, and a low force locator to avoid generating contaminants at the flow path adjacent the counterbore and spreading those contaminants throughout the downstream portion of the remainder of the flow, into a tool, and onto a semiconductor being processed. The low force retainer spreads the contact force at the counterbore wall along a larger surface reducing pressure and the likelihood of abrasion. 
         [0023]    In certain aspects, the retainer provides an outer handling jacket to avoid contacting the seal with any solids that could cling to the surface or even abrade it. Even small scratches on a mating surface of a seal increase the wetted area and provide additional sites for sorption of contaminating gasses and water vapor prior to assembly in a gas stick. 
         [0024]    The face type connectors when properly assembled should not have a seal touching anything other the mating beads of the flow path defining elements. This avoids contaminating the flow path by scraping a seal along a tight counterbore during assembly. The seal in this approach should be in registration with the beads during connector closure. In some aspects, an example retainer of these teachings solves these problems by allowing the seal to “float” slightly. The seal only has very low forces applied to it by the retainer. The low forces avoid abrasion of the seal by the interior of the retainer and abrasion of the retainer by the seal. This avoids introducing particulates into the flow path. 
         [0025]    These and other benefits may become clearer upon making a thorough review and study of the drawings and the following detailed description. In these accompanying drawings, like reference numerals designate like parts throughout the figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is an isometric view of a prior art W-seal; 
           [0027]      FIG. 2  is an isometric view of the W-seal shown in  FIG. 1 , wherein a circumferential portion has been removed to illustrate a cross-section of the seal; 
           [0028]      FIG. 3  is a cross-sectional view of the prior art W-seal shown in  FIGS. 1 and 2 ; 
           [0029]      FIG. 4  is an exploded view of the prior art W-seal shown in  FIGS. 1-3 ; 
           [0030]      FIG. 5  is a top view of one example a retaining ring constructed in accordance with various principles of the invention; 
           [0031]      FIG. 6  is a cross-sectional view of the retaining ring shown in  FIG. 5 ; 
           [0032]      FIG. 7  is a detailed cross-sectional view of the portion of  FIG. 6  denoted by the letter A; 
           [0033]      FIG. 8  is an isometric view of the retaining ring of  FIGS. 5-7 ; 
           [0034]      FIG. 9  is a top view of a modified example retaining ring constructed in accordance with various principles of the invention; 
           [0035]      FIG. 10  is a cross-sectional view of the retaining ring shown in  FIG. 9 ; 
           [0036]      FIG. 11  is a detailed cross-sectional view of the portion of  FIG. 10  denoted by the letter B; 
           [0037]      FIG. 12  is an isometric view of the retaining ring of  FIGS. 9-11 ; 
           [0038]      FIG. 13  is a top view of an example seal gasket constructed in accordance with various principles of the invention; 
           [0039]      FIG. 14  is an elevation of the gasket shown in  FIG. 13 ; 
           [0040]      FIG. 15  is a cross-sectional view of the gasket shown in  FIGS. 13 and 14 ; 
           [0041]      FIG. 16  is a detailed cross-sectional view of the portion of  FIG. 15  denoted by the letter C; 
           [0042]      FIG. 17  is an isometric view of the gasket shown in  FIGS. 13-16 ; 
           [0043]      FIG. 18  is a top view of a modified example seal gasket constructed in accordance with various principles of the invention; 
           [0044]      FIG. 19  is an isometric view of the gasket shown in  FIG. 18 ; 
           [0045]      FIG. 20  is an elevation of the gasket shown in  FIGS. 18 and 19 ; 
           [0046]      FIG. 21  is a cross-sectional view of the gasket illustrated in  FIGS. 18-20 ; 
           [0047]      FIG. 22  is a cross-sectional view illustrating an example retaining ring and gasket in an assembled state constructed in accordance with various principles of the invention; 
           [0048]      FIG. 23  is a cross-sectional view similar to  FIG. 22  illustrating the assembled seal after it has been fully installed and compressed to its operational status; 
           [0049]      FIG. 24  is an isometric view of another example seal constructed in accordance with various principles of the invention; 
           [0050]      FIG. 25  is a side view of another example seal constructed in accordance with various principles of the invention; 
           [0051]      FIG. 26  is a side view of another example seal constructed in accordance with various principles of the invention; 
           [0052]      FIG. 27  is a perspective view of an example retainer constructed in accordance with various principles of the invention; 
           [0053]      FIG. 28  is a top view of an example fluid flow system constructed in accordance with various principles of the invention; 
           [0054]      FIG. 29  is a cross-sectional view taken through lines  29 - 29  of  FIG. 28 ; 
           [0055]      FIG. 30  is a cross-sectional view taken through lines  30 - 30   FIG. 29 ; 
           [0056]      FIG. 31  is an exploded isometric view of the fluid sealing system shown in  FIGS. 28-30 ; 
           [0057]      FIG. 32  is an enlarged exploded isometric view of the portion of the system illustrated in  FIG. 31  denoted by the letter E; 
       
    
    
       [0058]    Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein. 
       DETAILED DESCRIPTION 
       [0059]    Referring now more particularly to  FIGS. 5-30 , wherein the terms “lower” and “upper” are with respect to the figures only and not necessarily with the orientation of the sealing assembly in an actual installation, there is shown in  FIGS. 22 and 23  an example ring seal assembly  10  including a retainer or retaining ring  12  surrounding, in circumferential fashion, an annular gasket or seal  14 . As illustrated in  FIG. 22 , the seal  14  comprises a center hole  16  and an annular body element  18 . The retainer  12  is also annular in construction and comprises an annular body element  20  defining a center hole  22  into which the seal  14  is inserted. The retainer material should have sufficient elastic properties to allow expansion and compression as described herein and recover its original shape and be machined or otherwise formed into the described shapes; such materials may include metal, polymer, or any other suitable material. The seal material should have an elastic property to allow compression and spring back for good sealing along an axial flow path when compressed between elements that define the flow path. In a seal used in a wafer fabrication environment where high purity of the gases passing through the flow path is required, materials such as  316  double melt stainless steel, nickel, HASTELLOY (available from Central States Industrial Equipment &amp; Service, Inc.), and AL-6XN (available from Central States Industrial Equipment &amp; Service, Inc.) are exemplary suitable materials. 
         [0060]    In the illustrated example of  FIGS. 22 and 23 , the outer diameter (OD) of the retaining ring  12  is stepped, having a smaller OD portion  24  and a larger OD portion  26 . A retainer ID groove  28  is disposed on the ring  12 , within the larger OD portion  26 . An outer chamfer  30  is disposed on each corner on the OD of the retainer  12 . Inner chamfers  32  are disposed on the lower corners of the ID of the retainer  12 . 
         [0061]    The seal  14  comprises a substantially cylindrical ID  34  surrounding and defining the center hole  16 . The OD of the seal  14  comprises a smaller OD portion  36  and a larger OD portion  38 . In certain approaches, between these two portions  36 ,  38  is disposed a load adjustment groove  41  (see, for example,  FIGS. 18-21 ), or, in another approach, bores  40  (see, for example,  FIGS. 13-16  and  25 ). The load adjustment groove  41  or bores  40  provide a elasticity to the seal  14  that facilitates a sealing engagement with the fluid path defining elements. For example, the load adjustment groove  41  or bores  40  increase the elasticity of the seal  14 . This improved elasticity better distributes the forces applied by the beads of the flow path defining elements during the sealing process. The beads may not be axially aligned, and in such a situation, the seal having insufficient elasticity may deform in a manner applying excess transverse forces to the beads, which can result in a poor sealing effect and/or damage the beads such that they cannot from a new seal after being reset. The seal elasticity provided by the load adjustment groove  41  or bores  40  at least partially better manages these forces to alleviate these potential adverse results during the sealing process. The bores  40  may have a variety of depths or shapes other than those illustrated and can be tailored to a given application. 
         [0062]      FIG. 23  illustrates the ring seal assembly  10  in an installed configuration. As illustrated, the seal assembly  10  is disposed within a gas or fluid flow path  42 , wherein the fluid flow moves in the direction of the arrow  44 . Defining the fluid flow path  42  are a component  46  and a base block  48 . A component counterbore  50  is machined into the component  46 , while a complementary base block counterbore  52  is machined into the base block  48 . It is noted that the outer chamfers  30  are advantageously designed to permit easy insertion of the retaining ring  12  into the counterbores  50 ,  52 . The inner chamfers  32  facilitate ready insertion of the seal  14  into the center hole  22  of the retainer  12 . 
         [0063]    Upon installation of the seal assembly  10  into the flow path  42 , the component  46  and base block  48  are compressed axially about the seal assembly  10 , causing a sealing bead  54  to engage the seal  14 , as illustrated in  FIG. 23 . It is noted that, even when fully compressed, the retainer  12  remains spaced from the walls defining the counterbore  50 ,  52 , as shown in  FIG. 23 , allowing continued play between the retainer  12  and the counterbore  50 ,  52 . 
         [0064]    The retainer  12  extends axially substantially above and below the seal  14 . So configured, even when compressed, the upper and lower surfaces of the seal  14 , which are highly polished, are protected from damage such as scratching to preserve optimal seal integrity. 
         [0065]    With reference now to  FIGS. 5-21  and  25 , various embodiments of each of the retainer  12  and seal  14  are illustrated. It should be noted that any of the retainer examples and seal examples may be employed, as shown in  FIGS. 22 and 23 , within the scope of these teachings, with a caveat that specific complementary features and dimensions of each element should be coordinated to fit together appropriately. The specific dimensions shown in the figures are exemplary only. 
         [0066]    With respect to  FIGS. 5-8 , one example retaining ring  12  is shown. As illustrated, a slot or gap  56  is configured to facilitate fixation of the retainer  12  and seal  14  within the counterbore. The radial slot  56  passes completely through the wall of the retainer  12  for its entire axial length, thereby making it feasible to temporarily spread the slot (gap)  56  elastically. This spreading of the gap  56  enlarges the effective diameter of the center hole  22  sufficiently to accept the larger outside diameter portion  38  of the seal  14 , and to easily position the retainer inside diameter groove  28  over the larger outside diameter portion  38  of the seal  14 . This arrangement thus allows the seal  14  to effectively float within the confines of the retainer  12  and reduces scraping of the seal  14  and the retainer  12  during positioning of the seal  14  in the retainer  12 . The angles of the various chamfers may be defined according to a given application with an example angle being about forty-five degrees. 
         [0067]      FIGS. 9-12  illustrate a somewhat modified example retaining ring  12 . The primary difference between this example and that of  FIGS. 5-8  is the utilization of a retaining ring having a stepped OD. The retainer  12  includes a retainer outer surface having a first outer diameter  24  and a second outer diameter  26  with the first outer diameter  24  being smaller than the second outer diameter  26 . The retainer  12  further includes a retainer inner diameter of the center hole  22 , the inner diameter being stepped to define a groove  28  in an inner surface of the retainer  12  inside and opposite of the retainer outer surface&#39;s second outer diameter  26 . The groove&#39;s diameter is larger than the retainer&#39;s center hole  22  ID and smaller than the second outer diameter  26 . 
         [0068]      FIG. 22  illustrates another example retainer  12 , in this case having a hook-like edge feature to facilitate identification of the orientation of the retainer and removal of the retainer from a counterbore. In this example, the first outer diameter  24  of the retainer  12  defines a step  25  radially inward from the first outer diameter  24  to a third outer diameter  27  that is smaller than the first outer diameter  24 . The step  25  is configured to facilitate engagement with a member to extract the second outer diameter  26  from a counterbore. 
         [0069]      FIG. 27  illustrates yet another example retainer  12 , in this case having three partial slots  57  defined in the second outer diameter  26 . These slots  57  operate like the slot  56  that fully splits the retainer  12  in that the slots  57  allow for elastic expansion of the retainer  12  during insertion of the seal and for elastic compression of the retainer  12  during insertion of the assembly into a counterbore. Although three slots  57  are illustrated, the number of slots  57  can be tailored to a given application. 
         [0070]      FIGS. 13-17  illustrate an example seal having a smaller OD portion  36  and a larger OD portion  38  and having a plurality of bores  40  spaced and disposed in each of the smaller OD portion  36  and the larger OD portion  38 . The ring shaped seal  14  includes top  35  and bottom  37  surfaces configured to be compressed when in a sealing configuration. A stepped outer diameter is defined between the top  35  and bottom  37  surfaces with a first outer diameter  36  being smaller than the second diameter  38 . A plurality of bores  40  are defined in at least two rows in one or both of the first outer diameter  36  and the second outer diameter  38 . The plurality of bores  40  are sufficient to effect resiliency in the seal  14  in response to compression of the seal  14  on the top  35  and bottom  37  surfaces. The bores  40  in the example of  FIGS. 12 and 13  circumferentially alternate so that only one is shown in  FIG. 12 . 
         [0071]      FIGS. 18-21  illustrate a somewhat modified example of the gasket or step seal  14 . The primary difference, other than with respect to certain dimensions, between the two examples is that in the  FIG. 18  example a single circumferential load displacement groove  41  is employed, instead of the bores  40  of  FIGS. 13-17 . The groove  41  is defined between the first outer diameter  36  and the second outer diameter  38  sufficient to effect resiliency in the seal  14  in response to compression of the seal  14  on the top  35  and bottom  37  surfaces. 
         [0072]      FIG. 25  illustrates an example seal  14  having a step between a smaller OD portion  36  and a larger OD portion  38 , but having no groove or bores.  FIG. 26  illustrates another example seal having a stepped OD, comprised of smaller OD portion  36  and larger OD portion  38 . In this example, a portion  43  of the smaller OD portion  36  adjacent the larger OD portion  38  includes bores  40  distributed around the perimeter of the portion  43 . Although the example of  FIG. 26  shows the portion  43  as having a smaller OD than that of the smaller OD portion  36 , the portion  43  may have an OD co-extensive with that of the smaller OD portion  36 . The seal  14  of  FIG. 26  further includes a chamfer  39  disposed on a edge of the outer diameter portion of the seal  14 . The chamfer  39  is configured to facilitate placement of the seal  14  in the retainer by reducing the load needed to slide the seal  14  into the retainer. The chamfer  39  may be place on any outside edge that may engage the retainer during insertion of the seal  14  into the retainer. 
         [0073]    Referring once again to  FIG. 23 , it is noted that there is play between the seal and the retainer, even when assembled. The reason for this is to ensure that when the retainer compresses, it does not hit the seal, because otherwise it would not be able to be compressed to a dimension smaller than the counterbore, which would affect seal integrity. The split or slot  56  facilitates this feature because it serves as the stop to control the amount of compression of the retaining ring  12 . Upon compression, the ring  12  compresses until the two surfaces defining the slot engage one another. Also illustrated in  FIG. 23 , the larger OD portion  38  of the stepped seal is captured top and bottom by the retainer  14  in its relaxed or pre-compression position. There is no interference between the retainer and the elastic response modifying portions (perforations or load adjustment groove  40 ) of the seal. 
         [0074]    In still another approach,  FIG. 24  illustrates an annular seal  114  defining an aperture  116  with an inner diameter  134 . The seal  114  defines no perforations or groove and has a single OD  118  between a top surface  160  and a bottom surface. In one example, this seal  114  (or a similar seal with a single OD  118  that defines a groove or bores) can be inserted into a retainer  12  as described herein to provide a sealing assembly with benefits similar to those discussed above with respect to  FIGS. 22 and 23 . 
         [0075]      FIGS. 28-32  illustrate an example ring seal assembly  110  in a typical sealing environment, wherein a fluid flow path  142  to be sealed is defined by a component  146  and a base block  148 , which are attached by bolts  182  or other suitable means. The seal  110  is adapted to be fitted within the space formed by the component counterbore and corresponding base block counterbore and to form a leak-tight fluid connection therein, via sealing beads  154 . 
         [0076]      FIGS. 31 and 32  illustrate the process of snapping the metal seal assembly into the seal port counterbore to install the seal. A method of assembling a ring-shaped retainer having at least one slot and a ring seal includes engaging the ring seal against a chamfer on an inside edge of the retainer to spread the retainer and sliding the seal into proximity with a retainer groove on an inside portion of the retainer. The retainer relaxes at least partially when the seal ring is in the groove such that the retainer in a relaxed state surrounds the right seal without clamping the ring seal. To position the seal assembly  110  in the counterbore, the retainer is squeezed with the seal retained in the groove, and the squeezed retainer is positioned relative to a counterbore. The retainer is released to effect placement of the retainer in the counterbore. The retainer inside diameter groove  28  supports the seal  14  and locates the seal at the center of the fluid path  142 . 
         [0077]    While this invention has been described with respect to various specific examples, it is to be understood that various modifications may be made without departing from the scope thereof. Therefore, the above description should not be construed as limiting the invention, but merely as an exemplification of preferred embodiments thereof and that the invention can be variously practiced within the scope of the following claims.