Abstract:
A pressure vessel that includes a housing having separable portions is provided. A seal is provided in a groove formed between the separable portions. A retaining mechanism is provided for retaining the seal in the groove, wherein the seal is prevented from obstructing a passageway formed between the separable portions when the separable portions have not been properly compressed against each other.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to pressure vessels, and more particularly, to a sealing arrangement utilized in a pressure vessel, such as a filter. 
       BACKGROUND OF THE INVENTION 
       [0002]    One type of conventional pressure vessels, such as swimming pool filters, include two separable units in order to allow for repeated access to the interior of the pressure vessel for cleaning or replacement, etc. A clamp is utilized to secure the separable units to each other. These pressure vessels are generally equipped with a seal between the separable units in order to prevent leakage when the pressure vessel is properly assembled. The seal is typically designed to maintain its integrity up to the structural limits of the clamp. In this manner, when the clamp is not properly assembled, the seal will maintain its integrity and prevent leakage, while the clamp will be stressed beyond its structural mechanical limits. This could create an unsafe condition if the clamp is not properly assembled or if the pressure vessel is overpressurized, the pressure vessel could separate forcefully, without any visual indication. 
         [0003]    Accordingly, it would be desirable to provide a pressure vessel that has a visual indication when the clamp is not properly secured or if the pressure vessel is overpressurized. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention relates to a pressure vessel that includes a housing having separable portions, which are moveable from a first position to a second position. In the first position, the separable portions are substantially retained against each other. In the second position, a passageway is formed between the separable portions. The passageway is sized to allow fluid to pass therethrough. A seal is provided in a groove formed between the separable portions. A retaining mechanism is provided for retaining the seal in the groove, wherein the seal is prevented from obstructing the passageway. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    For a more complete understanding of the present invention, reference is made to the following Detailed Description of the Invention, considered in conjunction with the accompanying drawings, in which: 
           [0006]      FIG. 1  is a perspective view of a filter according to the present invention; 
           [0007]      FIG. 2  is a cross-sectional view, taken along section line  2 - 2  and looking in the direction of the arrows, of a portion of the filter shown in  FIG. 1 ; 
           [0008]      FIG. 3  is a cross-sectional view similar to the view shown in  FIG. 2 , showing the filter in a deformed condition when the clamp is not properly secured to the filter or when the filter becomes over-pressurized; 
           [0009]      FIG. 4A  is a perspective view of the gasket and the metal ring utilized in the filter shown in  FIG. 1 ; 
           [0010]      FIG. 4B  is a cross-sectional view, taken along section line  4 B- 4 B and looking in the direction of the arrows, of the gasket and metal ring shown in  FIG. 4A ; 
           [0011]      FIG. 5  is a top view of the clamp utilized with the filter shown in  FIG. 1 ; 
           [0012]      FIG. 6  is a perspective view of a main segment utilized in the clamp shown in  FIG. 5 ; 
           [0013]      FIG. 7  is a perspective view of another main segment utilized in the clamp shown in  FIG. 5 ; 
           [0014]      FIG. 8  is a perspective view of a connecting segment utilized in the clamp shown in  FIG. 5 ; 
           [0015]      FIG. 9  is a perspective view of a bolt utilized in the clamp shown in  FIG. 5 ; 
           [0016]      FIG. 10  is a perspective view of a hinge pin that can be utilized in the clamp shown in  FIG. 5 ; 
           [0017]      FIG. 11  is a perspective view of another hinge pin that can be utilized in the clamp shown in  FIG. 5 ; 
           [0018]      FIG. 12  is a perspective view of an insert utilized in the clamp shown in  FIG. 5 ; 
           [0019]      FIG. 13  is a perspective view of a nut utilized in the clamp shown in  FIG. 5 ; and 
           [0020]      FIGS. 14A-E  are cross-sectional views showing alternative embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The present invention is described in connection with a filter adapted for removing particulate matter from a fluid stream. It should be understood, however, that the present invention can be used with other pressure vessels that employ a gasket, an o-ring, or other sealing materials. 
         [0022]      FIG. 1  illustrates a filter  10  having an upper housing portion  12  and a lower housing portion  14  removably and sealably attached to the upper housing portion  12 . The upper and lower housing portions  12 ,  14  facilitate assembly and maintenance of the filter  10 . 
         [0023]    A clamp  16  is used to secure the upper portion  12  of the filter  10  to the lower portion  14  of the filter  10 . While the present invention will be described in connection with the clamp  16 , it should be understood that the present invention can be used with other types of clamps, or in some other conventional manner for retaining and compressing the upper and lower portions  12 ,  14  to each other. 
         [0024]    The filter  10  includes an inlet  18  for receiving fluid to be filtered and an outlet  20  for discharging filtered fluid from the filter  10 . An air relief valve  22  is provided for removing the air from the filter  10 . 
         [0025]    Referring to  FIG. 2 , the upper portion  12  of the filter  10  includes a flange  24  having a tapered surface  26 , while the lower portion  14  of the filter  10  includes a flange  28  having a tapered surface  30 . The flange  24  includes a substantially cylindrical outer wall  32  with an end  34 , and the flange  28  includes a substantially cylindrical outer wall  36  with an end  38 . The flanges  24 ,  28  are retained and compressed against each other via the clamp  16  such that the end  34  of the flange  24  is adjacent to the end  38  of the flange  28 . 
         [0026]    With reference to  FIGS. 2-4B , a seal material, such as an annular gasket  40 , is seated in an opening, such as the groove  42 , between the flange  24  of the upper portion  12  of the filter  10  and the flange  28  of the lower portion  14  of the filter  10  so as to form a substantially fluid-tight seal between the upper portion  12  and the lower  5  portion  14 , when the upper portion  12  and the lower portion  14  are properly compressed toward each other. The gasket  40  can be made from any suitable elastomeric material, such as rubber, or rubber compound. 
         [0027]    A retaining means, such as a seal support ring  44 , is attached to the gasket  40  along the perimeter of the gasket  40 . More particularly, the support ring  44  is substantially embedded in the gasket  40 . A portion  46  of the support ring  44  extends from the outer periphery of the gasket  40 . The support ring  44  is sized to limit the outward expansion of the gasket  40  for reasons to be discussed hereinafter. The support ring  44  can be formed from a rigid metal and/or alloy, such as AISI  304  stainless steel. 
         [0028]    With reference to  FIG. 5 , the clamp  16  includes a set of main segments  48 ,  50  and a connecting segment  52 . The main segments  48 ,  50  and the connecting segment  52  are secured to each other to form a cylindrical band clamp. Each of the three segments  48 ,  50 ,  52  has a C-shape cross-section. The main segment  48  is identical to the main segment  50 . The clamp  16  can be fabricated from cast aluminum, cast stainless steel or other suitable material. 
         [0029]    Referring to  FIG. 6 , the main segment  48  includes a curved section  54  with a bolt pad  56  extending radially outwardly from one end  58  and a pair of outer tongues  60  extending from an opposite end  62 . The bolt pad  56  includes an opening  64  therethrough for receiving a fastener, such as a tangential bolt  66  (see  FIG. 9 ). The bolt pad  56  is positioned relative to the curved section  54  such that the opening  64  extends in a horizontal direction. Each of the outer tongues  60  includes an aperture  68  for receiving a fastener, such as a hinge pin  70   a  (see  FIG. 10 ). The apertures  68  are aligned in a vertical direction and are positioned perpendicular to the opening  64  of the bolt pad  56 . 
         [0030]    Likewise, as shown in  FIG. 7 , the main segment  50  includes a curved section  72  with a bolt pad  74  extending radially outwardly from one end  76  and a pair of outer tongues  78  extending from an opposite end  80 . The bolt pad  74  includes an opening  82  therethrough for receiving a fastener, such as the tangential bolt  66  (see  FIG. 9 ). The bolt pad  74  is positioned relative to the curved section  72  such that the opening  82  extends in a horizontal direction. Each of the outer tongues  78  includes an aperture  84  for receiving a fastener, such as the hinge pin  70   a  (see  FIG. 10 ). The apertures  84  are aligned in a vertical direction and are positioned perpendicular to the opening  82  of the bolt pad  74 . The use of a pair of outer tongues  60 ,  78 , rather than a single tongue, on the first and second main segments  48 ,  50  serves to increase the strength and durability of the clamp  16 . 
         [0031]    With reference to  FIG. 8 , the connecting section  52  includes a curved section  86  with an inner tongue  88  extending from one end  90  and an inner tongue  92  extending from an opposite end  94 . Each of the inner tongues  88 ,  92  includes an aperture  96 ,  98 , respectively, for receiving a fastener, such as the hinge pin  70   b  (see  FIG. 11 ). The inner tongue  88  is sized to be received within the outer tongues  60  of the main segment  48 , and the inner tongue  92  is sized to be received within the outer tongues  78  of the other main segment  50 , as will be described in further detail hereinafter. 
         [0032]    To assembly the clamp  16 , the main segments  48 ,  50  are positioned relative to each other such that the bolt pads  56 ,  74  are adjacent to each other, as illustrated in  FIG. 5 . The connecting segment  52  is positioned between the two main segments  48 ,  50 . In this manner, the inner tongue  88  of the connecting segment  52  is situated between the outer tongues  60  of the main segment  48 , and inner tongue  92  of the connecting segment  52  is situated between the outer tongues  78  of the other main segment  50 . 
         [0033]    Fastening devices are used to secure adjacent segments. More particularly, the tangential bolt  66  is extended through an insert  100   a  ( FIGS. 5 and 12 ) and through the openings  64 ,  82  ( FIG. 6 ) in the bolt pads  56 ,  74  so as to secure the main segments  48 ,  50  to each other. In this position, the bolt  66  is tangent to the clamp  16 . Another insert  100   b  ( FIG. 5 ) is placed on a shaft  102  ( FIG. 9 ) of the inserted bolt  66  and an associated self-centering nut  104  ( FIG. 13 ) is fastened to the bolt  66 , thereby tightening the bolt  66  onto the clamp  16 . The bolt  66  and the nut  104  are preferably made of dissimilar materials to prevent galling. The inserts  100   a,    100   b  are designed to provide a wear surface. The bolt  66  and the nut  104  each have a spherical surface to aid in alignment and prevent bolt bending, and are designed to be installed with wrenches. 
         [0034]    The hinge pin  70   b  ( FIG. 11 ) is used to attach the connecting segment  52  to the main segment  48 , and another hinge pin  70   b  is used to attach the connecting segment  52  to the main segment  50 . The hinge pin  70   b  is inserted through the outer tongues  60  of the main segment  48  and the inner tongue  88  of the connecting segment  52 , and the hinge pin  70   b  is inserted through the outer tongues  78  of the main segment  50  and the inner tongue  92  of the connecting segment  52  such that the pins  70   b  are perpendicular relative to the clamp  16 . The hinge pin  70   b  has a hollow end  106   b  to allow for swedging. Alternatively, the hinge pin  70   a  ( FIG. 10 ) could be used in connection with a snap ring. The hinge pin  70   a  has a groove  106   a  to receive a snap ring. 
         [0035]    In operation, the clamp  16  is secured to the upper portion  12  of the filter  10  and the lower portion  14  of the filter  10 . Fluid to be filtered is delivered into the filter  10  through the inlet  18  (see  FIG. 1 ). When the clamp  16  is properly secured to the filter  10  as shown in  FIG. 2 , the flange  24  of the upper portion  12  of the filter  10  and the flange  28  of the lower portion  14  of the filter  10  are retained and compressed against each other. In this position, the gasket  40  will form a substantially fluid-tight seal between the upper portion  12  and the lower portion  14  of the filter  10 . Thus, the filter  10  will operate without any leakage of fluid. 
         [0036]    When the clamp  16  is not properly secured to the filter  10  (such as when the clamp  16  is manually secured to the filter  10 ) or when the filter  10  becomes over-pressurized, the flange  24  of the upper portion  12  of the filter  10  and the flange  28  of the lower portion  14  of the filter  10  will not be properly retained and compressed against each other, as shown in  FIG. 3 . In such circumstances, the upper portion  12  of the filter  10  and the lower portion  14  of the filter  10  could separate such that a gap G or passageway is form between the end  34  of the flange  24  of the upper portion  12  of the filter  10  and the end  38  of the flange  28  of the lower portion  14  of the filter  10 . A gap G 1  or passageway could also form between the gasket  40  and the flange  24 . 
         [0037]    Conventionally, a gasket would move and expand into the gap formed between the flanges, thereby preventing any fluid from leaking. This may cause the buildup of the pressure in the filter, which may cause the upper portion and the lower portion to become unstable and volatile. 
         [0038]    Because the support ring  44  serves to limit the outward expansion of the gasket  40 , the gasket  40  is prevented from expanding into the gap G formed between the flange  24  of the upper portion  12  and the flange  28  of the lower portion  14  of the filter  10 , thereby permitting fluid to flow around the gasket  40  and through the gap G formed between the flanges  24 ,  28  (as indicated by the arrows in  FIG. 3 ), and leak out of the filter  10 . Thus, the filter  10  will operate while leaking, thereby preventing the buildup of pressure by providing a slow and safe release of pressure without the clamp  16  disengaging. Such leaking also provides a visual indication that the clamp  16  is not properly secured. Accordingly, the support ring  44  prevents the development of an unsafe condition. 
         [0039]    It should be noted that the present invention can have numerous modifications and variations. For instance, the present invention can be used with other retaining means that serve to limit the outward expansion of the gasket  40 .  FIG. 14A  shows a retainer  144  that is connected to certain portions of the gasket  1407  while  FIG. 14B  illustrates a retainer  244  that is connected to the gasket  240 .  FIG. 14C  illustrates a retainer  344  connected to the gasket  340 , while  FIG. 14D  shows a retainer  444  connected to two sections of the gasket  440 .  FIG. 14E  shows a retainer  544  connected to the gasket  540 . 
         [0040]    It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.