Abstract:
A valve for controlling flow of a fluid exerting a fluid pressure. The valve has a body including a fluid passage for the fluid, and a valve seat positioned adjacent to the fluid passage at an orifice coaxial with the fluid passage. The valve seat includes a sealing gland defining a cavity therein, and the sealing gland has a support surface adjacent to the cavity and a resilient valve seat member within the cavity. The valve seat member includes a first pressure responsive surface adjacent to the orifice and a second pressure responsive surface substantially opposed to the first pressure responsive surface. The support surface includes a notch for positioning a portion of the support surface a distance apart from the second pressure responsive surface.

Description:
FIELD OF INVENTION 
     This invention relates to valve seals, and particularly pressurized valve seals. 
     BACKGROUND OF THE INVENTION 
     Valves typically employ a resilient seating material, such as an o-ring, about the perimeter of a port or aperture. The resilient seating material is intended to engage and be compressed by a movable valve sealing member to effect sealing of the port or aperture. The seating material is disposed and contained within a sealing gland, provided in the body of the valve. In order to achieve desirable sealing properties, the seating material must be sealingly engaged to the sealing gland both upstream and downstream of the point of sealing engagement between the valve sealing member and the seating material. Under some operating conditions, the seating member moves away from the sealing gland, creating a flow path, allowing fluid to leak through the port or aperture even though the valve sealing member is sealingly engaged to the seating material. Under these circumstances, sealing engagement of the valve sealing member to the seating material is ineffective in sealing the port or aperture. 
     To mitigate this problem, it is known to pressurize the cavity within the sealing gland, to thereby provide fluid pressure forces to act upon the seating material, opposing those fluid pressure forces acting on the seating material from within the fluid passage, and thereby mitigating loss of sealing engagement between the seating material and the sealing gland. An example of such a pressurized seal is disclosed in U.S. Pat. No. 5,474,104. 
     Valves with pressurized seals continue to experience problems with maintaining sealing engagement of the seating surface against the sealing gland. Because the seating surface is pressed into the cavity of the sealing gland, the seating surface is sealingly engaged to the sealing gland at multiple points, thereby creating multiple individual cavities between the seating surface and the sealing gland. It is believed that fluid introduced into the sealing gland, for purposes of pressurizing the seal, does not access these individual cavities. As a result, fluid pressure introduced into the sealing gland cavity is not necessarily effective in opposing the fluid pressure forces acting on the seating member from within the fluid passage, thereby potentially compromising the sealing of the seating member to the sealing gland. 
     SUMMARY OF THE INVENTION 
     In its broad aspect, the invention provides a valve for controlling a fluid which exerts a fluid pressure. The valve includes a body, which has a fluid passage and a valve seat defining an orifice. The valve seat includes a sealing gland having a support surface, and the support surface includes a notch. The valve seat also includes a resilient valve seat member disposed within the sealing gland. In addition, the body includes a valve sealing member disposed within the fluid passage and configured to seat against the valve seat member to effect sealing of the valve sealing member to the valve seat and thereby to close the orifice. The notch is configured to facilitate the application of the fluid pressure on the valve seat member to prevent leakage through the orifice and between the valve sealing member and the sealing gland when the valve sealing member is seated against the valve seat member. The valve seat member includes a first pressure responsive surface exposed to the fluid passage, and including a valve engaging surface portion. The valve engaging surface portion is configured to engage the valve sealing member to effect sealing of the valve sealing member to the valve seat. The valve seat member also includes a second pressure responsive surface configured to receive the application of the fluid pressure. The notch is positioned to face the second pressure responsive surface. Also, the notch is configured to facilitate the application of the fluid pressure on the second pressure responsive surface to counterbalance applications of forces on the first pressure responsive surface. 
     In another aspect, the first pressure responsive surface is located on the valve seat member substantially opposite to the second pressure responsive surface. 
     In yet another aspect, the invention provides a valve for controlling a fluid exerting a fluid pressure. The valve has a body, which includes a fluid passage and a valve seat defining an orifice. The valve seat includes a sealing gland, a resilient valve seat member disposed within the sealing gland, and including a notch, and a valve sealing member disposed within the fluid passage and configured to seat against the valve seat member to effect sealing of the valve sealing member to the valve seat, and thereby to close the orifice. The notch is configured to facilitate the application of the fluid pressure on the valve seat member to prevent leakage through the orifice and between the valve sealing member and the sealing gland when the valve sealing member is seated against the valve seat member. Also, the valve seat member includes a first pressure responsive surface, exposed to the fluid passage, and including a valve engaging surface portion, in which the valve engaging surface portion is configured to engage the valve sealing member to effect sealing of the valve sealing member to the valve seat. The valve seat member also includes a second pressure responsive surface configured to receive the application of the fluid pressure. The notch is configured to facilitate the application of the fluid pressure on the second pressure responsive surface to maintain engagement of the valve seat member to the sealing gland upstream of the valve engaging surface. 
     In yet another aspect, the invention provides a valve for controlling a fluid exerting a fluid pressure. The valve includes a body having a fluid passage and a valve seat defining an orifice. The valve seat includes a sealing gland including a cavity, and a resilient valve seat member disposed within the sealing gland. The body also includes a valve sealing member disposed within the fluid passage and configured to seat against the valve seat member to effect sealing of the valve sealing member to the valve seat and thereby to close the orifice. The sealing gland includes two or more spaced apart apertures configured to distribute fluid pressure within the cavity to act upon the valve seat member to prevent leakage through the orifice when the valve sealing member is seated against the valve seat member. The spaced apart apertures are configured to facilitate the application of the distributed fluid pressure on the valve seat member to prevent leakage through the orifice and between the valve sealing member and the sealing gland when the valve sealing member is seated against the valve seat member. 
     In yet another of its aspects, the valve seat member includes a first pressure responsive surface exposed to the fluid passage, and including a valve engaging surface portion. The valve engaging surface portion is configured to engage the valve sealing member to effect sealing of the valve sealing member to the valve seat. In addition, the valve seat member also includes a second pressure responsive surface configured to receive the application of the distributed fluid pressure. The spaced apart apertures are configured to facilitate the application of the distributed fluid pressure within the cavity on the second pressure responsive surface to maintain engagement of the valve seat member to the sealing gland upstream of the valve engaging surface portion. 
     In another aspect, the invention provides a valve for controlling flow of a fluid exerting a fluid pressure. The valve has a body including a fluid passage for the fluid, and a valve seat positioned adjacent to the fluid passage. The valve seat includes a sealing gland having a sealing gland defining a cavity therein. The sealing gland has a support surface thereon adjacent to the cavity. The valve seat also includes a resilient valve seat member disposed and supported within the cavity. The valve seat member includes a first pressure responsive surface adjacent to the orifice and a second pressure responsive surface substantially opposed to the first pressure responsive surface. In addition, the support surface includes a notch for positioning a portion of the support surface a predetermined distance apart from the second pressure responsive surface. The body further includes a valve sealing member disposed in the fluid passage and movable between an engaged position, in which the valve sealing member is seated on the valve seat to block fluid flow through the orifice, and an open position, in which fluid flow through the orifice is permitted. Also, the body includes a resilient member for urging the valve sealing member into the engaged position. The fluid passage includes an upstream portion disposed upstream of the valve sealing member when the valve sealing member is in the engaged position, and a downstream portion disposed downstream of the valve sealing member when the valve sealing member is in the engaged position. The valve sealing member is urged into the open position by the fluid in the upstream portion. Also, the body includes a communication channel for fluid communication between the downstream portion and the cavity in the sealing gland, so that fluid pressure in the cavity acts upon the second pressure responsive surface to urge the valve seat member to seal the orifice when the valve sealing member is in the engaged position. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The embodiments of the present invention are described below with reference to the accompanying drawings in which: 
         FIG. 1  is a sectional elevation view of an embodiment of the valve of the present invention; 
         FIG. 2  is a detailed sectional elevation view, partly cut-away, of the valve seat area of the valve illustrated in  FIG. 1 ; 
         FIG. 3  is a plan view of the valve illustrated in  FIGS. 1 and 2 , taken along the lines  3 — 3  in  FIG. 2 ; 
         FIG. 4  is a sectional elevation view of another embodiment of the valve of the present invention; 
         FIG. 5  is a detailed sectional elevation view, partly cut-away, of the valve seat area of the valve in  FIG. 4 ; 
         FIG. 6  is a plan view of the valve illustrated in  FIGS. 4 and 5 , taken along the lines  6 — 6  in  FIG. 5 ; 
         FIG. 7  is a sectional elevation view of another embodiment of the valve of the present invention; 
         FIG. 8  is a sectional elevation view, partly cut-away, of the valve seat area of the valve illustrated in FIG.  7 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 ,  3 , in one embodiment, the present invention provides a valve  10  comprising a body  12  including a fluid passage  14 , a valve seat  16 , and a communication channel  18 . The valve seat  16  includes a sealing gland  20  and a resilient valve seat member  22  disposed and supported within a cavity  24  of the sealing gland  20 . The sealing gland  20  has a support surface  26  including a notch  28 . The notch  28  defines a channel which forms part of the cavity  24 . The communication channel  18  effects communication between the fluid passage  14  and the cavity  24 , and, therefore, the notch  28 , through an aperture  30  provided in the sealing gland  20 . In this respect, the communication channel  18  provides a means for effecting communication between the cavity  24  and a source of fluid pressure (in this case, the fluid passage). 
     The body  12  is made of a material which is significantly harder than the material of construction of the valve seat member  22 . The valve seat member  22  is made of a resilient material, such as an elastomeric rubber, for example, nitrile rubber. In turn, the body is made of steel, such as stainless steel, brass, or a hard polymer. 
     A valve sealing member  32  is disposed within the passage  14 . The valve sealing member  32  is configured to seal against the valve seat  16 . In this respect, the valve sealing member  32  is configured to seat against the valve seat member  22  which is disposed within the sealing gland  20  of the valve seat  16 . 
     The valve sealing member  32  can be of the form which is biassed to close an orifice  35  defined by the valve seat  16 . In this respect, the valve sealing member  32  can be urged into engagement with the valve seat member  22  by a resilient member  33 , such as a compression spring. The valve sealing member  32  is unseated by fluid pressure upstream of the valve sealing member  32  (ie. in a direction opposite from the direction in which the force imparted by the resilient member acts upon the valve sealing member  32 ). It is understood that the present invention is not limited to such spring-loaded, one way valves. For example, the present invention may be incorporated in solenoid-actuated valves and pintle valves. 
     The valve seat member  22  includes a first pressure responsive surface  34  and a second pressure responsive surface  36 . The first pressure responsive surface  34  is exposed to the fluid passage. The second pressure responsive surface  36  is configured to receive application of a fluid pressure from within the cavity  24 , and is opposite the first pressure responsive surface  34 . 
     The first pressure responsive surface  34  is configured to engage the valve sealing member  32  to effect sealing of the valve sealing member  32  to the valve seat  16 . The first pressure responsive surface  34  receives application of forces from the valve sealing member  32  (when the valve sealing member  32  engages the first pressure responsive surface  34 ) and the fluid pressure forces in the fluid passage  14 . The first pressure responsive surface  34  includes a valve engaging surface  38 , configured to engage the valve sealing member  32 . 
     Sealing of the valve sealing member  32  to the valve seat  16  requires that the valve seat member  22  bridge the gap across the sealing gland  20  upstream  40  of the valve engaging surface  38 . In this respect, the valve seat member  22  is maintained engaged to the sealing gland  20  upstream  40  of the valve engaging surface  38  of the first pressure responsive surface  34 . 
     The valve seat member can be in the form of an o-ring or any other compliant seal of various cross-sectional shapes. 
     To maintain the necessary engagement between the valve seat member  22  and the sealing gland  20 , a fluid pressure is introduced into the cavity  24  of the sealing gland  20  to act upon the second pressure responsive surface  36 . In this respect, this fluid pressure opposes or counterbalances the above-described forces acting on the first pressure responsive surface  34  such that the valve seat member  22  remains engaged to the sealing gland  20 . 
     As perhaps best illustrated in  FIG. 2 , the notch  28  is deliberately formed in the support surface  26  of the sealing gland  20 , and functions as a channel to effect distribution of fluid pressure through the cavity  24 , the fluid pressure being introduced into the cavity  24  through the aperture  30  in the sealing gland  20 . In this respect, the notch  28  and the valve seat member  24  are co-operatively configured so that the valve seat member  22  is not capable, upon deformation, of sealing the channel defined by the notch  28 . The notch  28  is provided to mitigate against the risk that the valve seat member  22  engages the sealing gland  20  and impedes distribution of fluid pressure through the cavity  24 . By impeding distribution in this manner, the effectiveness of the introduced fluid pressure in opposing or counterbalancing the above-described forces being applied to the first pressure responsive surface  34  would be compromised. 
     In this respect, the notch  28  opposes the second pressure responsive surface  36  of the valve seat member  22 , and is configured to facilitate application of a fluid pressure on the valve seat member  22 , and specifically the second pressure responsive surface  36  of the valve seat member  22  to prevent leakage through the orifice  35  when the valve sealing member  32  is seated against the valve seat member  22 . Similarly, the notch  28  is also configured to facilitate the application of the fluid pressure on the valve seat member  22  to prevent leakage through the orifice  35  and between the valve sealing member  32  and the sealing gland  20  when the valve sealing member  32  is seated against the valve seat member  22 . The notch  28  is also configured to facilitate application of the fluid pressure on the second pressure responsive surface  36  to counterbalance the application of the above-described forces on the first pressure responsive surface  34  of the valve seat member  22 . 
     In one embodiment, the notch  28  is characterized by a depth of at least 0.00254 millimeters (100 microinches). In another embodiment, the depth of the notch is at least 0.0254 millimeters (0.001 inches). Preferably, the notch  28  is characterized by a depth of from 0.508 millimeters (0.020 inches) to 0.762 millimeters (0.030 inches). 
     Referring to  FIGS. 4-6 , in another embodiment, the present invention provides a valve  110  comprising a body  112  including a fluid passage  114 , a valve seat  116 , and a communication channel  118 . The valve seat  116  includes a sealing gland  120  and a resilient valve seat member  122  disposed and supported within a cavity  124  of the sealing gland  120 . The resilient valve seat member  122  includes a notch  128  opposing a support surface  126  of the sealing gland  120 . The notch  128  defines a channel which forms part of the cavity  124  of the sealing gland  120 . The communication channel  118  effects communication between the fluid passage  114  and the cavity  124 , and, therefore, the notch  128 , through an aperture  130  provided in the sealing gland  120 . In this respect, the communication channel  118  provides a means for effecting communication between the cavity  124  and a source of fluid pressure (in this case, the fluid passage  114 ). 
     The body  112  is made of a material which is significantly harder than the material of construction of the valve seat member  122 . The valve seat member  122  is made of a resilient material, such as an elastomeric rubber, for example, nitrile rubber. In turn, the body is made of steel, such as stainless steel, brass, or a hard polymer. 
     A valve sealing member  132  is disposed within the passage  114 . The valve sealing member  132  is configured to seal against the valve seat  116 . In this respect, the valve sealing member  132  is configured to seat against or engage the valve seat member  122  which is disposed within the sealing gland  120  of the valve seat  116 . 
     The valve sealing member  132  can be of the form which is biased to close an orifice  135  defined by the valve seat  16 . In this respect, the valve sealing member  132  can be urged into engagement with the valve seat member  122  by a resilient member  133 , such as a compression spring. The valve sealing member  132  is unseated by fluid pressure upstream of the valve sealing member  132  (i.e. in a direction opposite from the direction in which the force imparted by the resilient member acts upon the valve sealing member  132 ). It is understood that the present invention is not limited to such spring-loaded, one way valves. For example, the present invention may be incorporated in solenoid-actuated valves and pintle valves. 
     The valve seat member  122  includes a first pressure responsive surface  134  and a second pressure responsive surface  136 . The first pressure responsive surface  134  is exposed to the fluid passage  114 . The second pressure responsive surface  136  is configured to receive application of a fluid pressure, and is opposite the first pressure responsive surface  134 . 
     The first pressure responsive surface  134  is configured to engage the valve sealing member  132  to effect sealing of the valve sealing member  132  to the valve seat  116 . The first pressure responsive surface receives  134  application of forces from the valve sealing member  132  (when the valve sealing member  132  engages the first pressure responsive surface  134 ) and the fluid pressure forces in the first fluid passage  114 . The first pressure responsive surface  134  includes a valve engaging surface  138 , configured to engage the valve sealing member  132 . 
     Sealing of the valve sealing member  132  to the valve seat  116  requires that the valve seat member  122  bridge the gap across the sealing gland  120  upstream  140  of the valve engaging surface  138 . In this respect, the valve seat member  122  is maintained engaged to the sealing gland  120  upstream  140  of the valve engaging surface  138  of the first pressure responsive surface  134 . 
     The valve seat member  122  can be in the form of an o-ring or any other compliant seal of various cross-sectional shapes. 
     To maintain the necessary engagement between the valve seat member  122  and the sealing gland  120 , a fluid pressure is introduced into the cavity  124  of the sealing gland  120  to act upon the second pressure responsive surface  136 . In this respect, this fluid pressure opposes or counterbalances the above-described forces acting on the first pressure responsive surface  134  such that the valve seat member remains engaged to the sealing gland  120 . 
     As perhaps best shown in  FIG. 4 , the notch  128  is deliberately formed in the second pressure responsive surface  136  of the valve seat member  122 , and functions as a channel to effect distribution of fluid pressure throughout the cavity  124 , the fluid pressure being introduced into the cavity  124  through the aperture  130  in the sealing gland  120 . The notch  128  is configured so that the valve seat member  122  is not capable, upon deformation, of collapsing the notch  128 . The notch  128  is provided to mitigate against the risk that the valve seat member  122  engages the sealing gland  120  and impedes distribution of fluid pressure throughout the cavity  124 . By impeding distribution in this manner, the effectiveness of the introduced fluid pressure in opposing or counterbalancing the above-described forces being applied to the first pressure responsive surface  134  would be compromised. 
     In this respect, the notch  128  opposes the support surface  126  of the sealing gland  120 , and is configured to facilitate application of a fluid pressure on the valve seat member  122 , and specifically the second pressure responsive surface  136  of the valve seat member  122 , to prevent leakage through the orifice  135  when the valve sealing member  132  is seated against the valve seat member  122 . Similarly, the notch  128  is also configured to facilitate the application of the fluid pressure on the valve seat member  122  to prevent leakage through the orifice  135  and between the valve sealing member  132  and the sealing gland  120  when the valve sealing member  132  is seated against the valve seat member  122 . The notch  128  is also configured to facilitate application of the fluid pressure on the second pressure responsive surface  136  to counterbalance the application of the above-described forces on the first pressure responsive surface  134  of the valve seat member  122 . 
     In one embodiment, the notch  128  is characterized by a depth of at least 0.00254 millimeters (100 microinches). In another embodiment, the depth of notch  128  is at least 0.0254 millimeters (0.001 inches). Preferably, the notch  128  is characterized by a depth of between 0.508 millimeters (0.020 inches) and 0.762 millimeters (0.030 inches). 
     Referring to  FIGS. 7 and 8 , in another embodiment, the present invention provides a valve  210  comprising a body  212  including a fluid passage  214 , a valve seat  216 , and first and second communication channels  218   a ,  218   b . The valve seat includes a sealing gland  220  and a resilient valve seat member  222  disposed and supported within a cavity  224  of the sealing gland  220 . The sealing gland  220  includes first and second spaced apart apertures  230   a ,  230   b  communicating with the first and second communication channels  218   a ,  218   b , respectively. The communication channels  218   a ,  218   b  effects communication between the fluid passage  214  and the cavity  224 , thereby providing a means for effecting communication between the cavity  224  and a source of fluid pressure (in this case, the fluid passage  214 ). 
     The body  212  is made of a material which is significantly harder than the material of construction of the valve seat member  222 . The valve seat member  222  is made of a resilient material, such as an elastomeric rubber, for example, nitrile rubber. In turn, the body is made of steel, such as stainless steel, brass, or a hard polymer. 
     A valve sealing member  232  is disposed within the passage  214 . The sealing member  232  is configured to seal against the valve seat  216 . In this respect, the valve sealing member  232  is configured to seat against or engage the valve seat member  222  which is disposed within the sealing gland  220 . 
     The valve seat member  222  includes a first pressure responsive surface  234  and a second pressure responsive surface  236 . The first pressure responsive surface  234  is exposed to the fluid passage  214 . The second pressure responsive surface  236  is configured to receive application of a fluid pressure from within the cavity  224 , and is opposite the first pressure responsive surface  234 . 
     The first pressure responsive surface  234  is configured to engage the valve sealing member  232  to effect sealing of the valve sealing member  232  to the valve seat  216 . The first pressure responsive surface  232  receives application of forces from the valve sealing member  232  (when the valve sealing member  232  engages the first pressure responsive surface  234 ) and the fluid pressure forces in the fluid passage  214 . The first pressure responsive surface  234  includes a valve engaging surface  238 , configured to engage the valve sealing member  232 . 
     Sealing of the valve sealing member  232  to the valve seat  216  requires that the valve seat member  222  bridge the gap across the sealing gland  220  upstream  240  of the valve engaging surface  238 . In this respect, the valve seat member  222  is maintained engaged to the sealing gland  220  upstream  240  of the valve engaging surface  238  of the first pressure responsive surface  234 . 
     The valve seat member can be in the form of an o-ring or any other compliant seal of various cross-sectional shapes. 
     To maintain the necessary engagement between the valve seat member  222  and the sealing gland  220 , a fluid pressure is introduced into the cavity  224  of the sealing gland to act upon the second pressure responsive surface  236 . In this respect, this fluid pressure opposes or counterbalances the above-described forces acting on the first pressure responsive surface such that the valve seat member  222  remains engaged to the sealing gland  220 . 
     The first and second spaced apart apertures  230   a ,  230   b  are formed in the sealing gland  220  and are each configured to act as a means for introducing fluid pressure into the cavity  224 . In this respect, the first and second apertures  230   a ,  230   b  function as first and second means for introducing fluid pressure into the sealing gland cavity  224 . Introducing fluid pressure into the cavity  224  at different points within the sealing gland  220  functions as a means for effecting distribution of fluid pressure through the cavity  224 . The multiple points of introduction are provided to mitigate against the risk that the valve seat member  222  engages the sealing gland  220  to form multiple isolated cavities and thereby impeding distribution of fluid pressure through the cavity  224 . By impeding distribution in this manner, the effectiveness of the introduced fluid pressure in opposing or counterbalancing the above-described forces being applied to the first pressure responsive surface  234  would be compromised. 
     In this respect, the first and second means for introducing fluid pressure into the sealing gland cavity  220  are configured to facilitate application of a fluid pressure on the valve seat member  222 , and specifically the second pressure responsive surface  236  of the valve seat member  222 , to prevent leakage through an orifice  235  when the valve sealing member  232  is seated against the valve seat member  222 . Similarly, the first and second means are also configured to facilitate the application of the distributed fluid pressure on the valve seat member  222  to prevent leakage through the orifice  235  and between the valve sealing member  232  and the sealing gland  220  when the valve sealing member  232  is seated against the valve seat member  232 . The first and second means are also configured to facilitate application of the fluid pressure on the second pressure responsive surface  236  to counterbalance the application of the above-described forces on the first pressure responsive surface  234  of the valve seat member  222 . It is understood that the invention is not limited to the provision of only first and second means for introducing fluid pressure into the sealing gland cavity, and further such means may be provided to effect distribution of fluid pressure within the sealing gland cavity  224  with a view to opposing forces applied to the first pressure responsive surface  234  and maintaining the necessary engagement between the valve seat member  222  and the sealing gland  220   
     Although the disclosure describes and illustrates preferred embodiments of the invention, it is to be understood that the invention is not limited to these particular embodiments. Many variations and modifications will now occur to those skilled in the art. For definition of the invention, reference is to be made to the appended claims.