Abstract:
A new and improved high pressure post valve used to control the flow of high pressure gas, e.g., oxygen, from a high pressure gas cylinder. More particularly, the improvements are directed to three different inventive embodiments: (1) manufacturing the post valve from cylindrical metal bar stock to contain a unitary valve body having an integral valve body seat ring for seating against gas cylinder structure, thereby preventing gas leakage between the valve body and the valve body seat ring; (2) providing the post valve with a valve actuator having an annular valve seat, surrounding a valve cavity, and disposing a deformable valve seat material in position to surround a gas inlet orifice for sealing contact with the annular actuator valve seat for sealing in an area surrounding the gas inlet orifice to prevent direct contact of high pressure inlet gas against the valve seat material; and (3) disposing of filter within a gas inlet orifice of the post valve to remove any solids entrained in the high pressure gas to prevent solids from contacting the valve actuator.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention is directed to a new and improved high pressure post valve used to control the flow of high pressure gas, e.g., oxygen, from a high pressure gas cylinder. More particularly, the improvements are directed to three different inventive embodiments: (1) manufacturing the post valve from cylindrical metal bar stock to contain a unitary valve body having an integral valve body seat ring for seating against gas cylinder structure, thereby preventing gas leakage between the valve body and the valve body seat ring; (2) providing the post valve with a valve actuator having an annular valve seat, surrounding a valve cavity, and disposing a deformable valve seat material in position to surround a gas inlet orifice for sealing contact with the annular actuator valve seat for sealing in an area surrounding the gas inlet orifice to prevent direct contact of high pressure inlet gas against the valve seat material; and (3) disposing a filter within a gas inlet orifice of the post valve to remove any solids entrained in the high pressure gas to prevent solids from contacting the valve actuator.  
       BACKGROUND  
       [0002]     A post valve is a valve that is used to control flow of fluid, typically gas, out of a high pressure container or cylinder. Post valves are, for example, common on high pressure oxygen cylinders, and typically have a hand crank mechanism that allows a person to manually open and close the valve to enable or disable the flow of gas from the cylinder. A seat ring is disposed between the valve body and the gas cylinder and either one or two elastomeric O-rings are placed on one or both sides of the seat ring to limit gas escaping from the gas cylinder between a gas cylinder-connecting threaded extension and the gas cylinder.  
         [0003]     During operation, the valve actuator is turned, using a handle, knob or other turning mechanism connected thereto, to open a valve orifice within the valve body to thereby allow gas to enter through a passageway within the threaded extension and to flow out of a gas cylinder outlet orifice to the valve actuator. The outlet orifice may be fluidly connected to a device that uses the gas within the gas cylinder, such as a torch or a breathing apparatus.  
         [0004]     In prior art post valves, the seat ring is created or machined as a separate part and is placed over a collar on the threaded extension before the post valve is attached to the gas cylinder. In the past, O-rings have been placed on both sides of the seat ring, or without an O-ring between the seat ring and the valve body, and the seat ring has been press fitted onto the collar of the threaded extension. In either case, there is some opportunity for high pressure gas within the gas cylinder to escape through the threaded engagement of the extension and the inner diameter of the seat ring. Further, the manufacturing of the seat ring apart from the valve body creates additional parts and results in a process that has additional manufacturing and assembly steps, which is undesirable.  
         [0005]     In a first embodiment of the high pressure post valve described herein, there is disclosed a method of manufacturing a post valve so that the seat ring is integrally formed thereon. The seat ring is integrally formed on the bottom side of the valve body with the gas cylinder-connecting threaded extension extending therefrom. This manufacturing procedure results in a post valve that provides no opportunity for gas to escape between the seat ring and the valve body. The manufacturing process includes starting with round metal bar stock, which is less expensive than the square or rectangular bar stock now used to machine the valve bodies, and cutting or etching away the outer diameter of the round metal stock to create the square or rectangular portions of the valve body The seat ring is turned or left to be circular. The threaded extension also is turned to the proper diameter. Thereafter, exterior holes (such as the outlet orifice) are created by side cuts or drill cuts. Next, the interior sections of the valve body are machined and the threads are cut into the threaded extension. Because this manufacturing process starts with the less expensive round bar stock, the entire manufacturing process is cheaper than the traditional process which starts with square or rectangular bar stock and uses a separate, press fitted or floating circular seat ring.  
         [0006]     Another serious disadvantage of extant post valves for connection to a high pressure gas supply is that sometimes when the valve is opened, high pressure gas carries solid particulate materials into a valve cavity of the valve actuator (such as metal particles or dust from the gas cylinder). These high speed particles strike against the polymeric valve seat sealing material, thereby creating sufficient heat to ignite the valve seat material. This is potentially very dangerous to a patient receiving oxygen, and to those surrounding the high pressure gas cylinder.  
         [0007]     Typical in the prior art, the actuator is coupled to a valve seat, typically made of brass, disposed in a valve chamber. Longitudinal movement of the actuator causes the valve seat to move toward or away from a conical gas inlet orifice. When the valve seat is moved away from the gas inlet orifice, gas under high pressure enters into the valve chamber through a passageway within the threaded extension and through the gas inlet orifice. The actuator valve seat includes a circular cavity. Valve seating material, typically a polymer or elastomeric material, is disposed within the cavity and, when the post valve is closed, comes into sealing contact with the conical gas inlet orifice to prevent gas from entering into the valve chamber. The polymer or elastomeric material is used at the seating surface of the orifice because it is softer than brass and thus provides a better seal. However, when the actuator is turned to cause the valve seat to move away from the orifice, gas under very high pressure flows through the orifice and comes into direct contact with the valve seat material  42 . Impurities in the gas, such as particles, will hit the valve seat material directly at very high speeds. In some cases, the energy in these particles is enough to cause ignition of the valve seat material, which may lead to the combustion of the post valve and down stream components.  
         [0008]     As disclosed herein in the second embodiment, the improved valve design includes the valve seat material  50  disposed to surround the gas inlet orifice. In this configuration, the bottom surface of the annular ring comprising the actuator valve seat provides sealing contact with the valve seat material in an area surrounding, and preferably below, the inlet orifice so that impurities within the gas flowing at high speeds through the orifice first hit a metal surface in the valve cavity, which has a much higher ignition temperature than the valve seat material. This configuration reduces the likelihood of impurities within the gas causing ignition with the post valve.  
       SUMMARY  
       [0009]     In brief, the high pressure post valve disclosed here, in the first embodiment, provides a tight seal to a high pressure gas cylinder by including an integral gas cylinder sealing ring in a monolithic valve body formed from circular bar stock. In a second embodiment, the high pressure post valve includes a valve actuator having an annular valve seat, surrounding a valve cavity, and having a deformable valve seat material disposed in position to surround a gas inlet orifice for sealing contact with the annular actuator valve seat for sealing in an area surrounding the gas inlet orifice to prevent direct contact of high pressure inlet gas against the valve seat material.  
         [0010]     Accordingly, one aspect of the apparatus and methods of a first embodiment disclosed herein is to provide a high pressure post valve, and a method of manufacturing the high pressure post valve, that includes a monolithic valve body formed from round metal bar stock, to form an integral, round valve body seat extending radially outwardly from the valve body for seating against gas cylinder structure with less gas leakage.  
         [0011]     Another aspect of the apparatus and methods of a second embodiment disclosed herein is to provide a high pressure post valve having an annular valve seat and valve seat material surrounding, and preferably disposed below the valve inlet orifice to prevent any direct contact of high pressure gas directly against the valve seat material.  
         [0012]     Still another aspect of the apparatus and methods disclosed herein is to provide a high pressure post valve having a filter material disposed within a gas flow conduit for removing any solid contaminants contained in the high pressure gas flowing through the post valve. 
     
    
       [0013]     The above and other aspects and advantages of the post valves and methods of manufacturing the post valves described herein will become more apparent from the following detailed description, taken in conjunction with the drawings, wherein  
         [0014]      FIG. 1  is a side view of a prior art post valve connected to a high pressure gas cylinder;  
         [0015]      FIG. 2  is a perspective, partially exploded view, of the prior art post valve of  FIG. 1 , showing a separate valve body seat ring;  
         [0016]      FIG. 3  is a side view of the post valve described herein;  
         [0017]      FIG. 4  is a cross-sectional view of the post valve of  FIG. 3 , taken along the line  4 - 4  of  FIG. 3 ;  
         [0018]      FIG. 5  is a partial, cross-sectional view of a valve seat portion of the prior art post valve of  FIG. 1 ; and  
         [0019]      FIG. 6  is a partial, cross-sectional view of the valve seat portion of the post valve of  FIG. 4 . 
     
    
     DETAILED DESCRIPTION  
       [0020]     In the first embodiment of the high pressure post valve described herein, there is disclosed a method of manufacturing a post valve so that the seat ring is integrally formed thereon. The seat ring is integrally formed on a lower end of the valve body with a gas cylinder-connecting threaded extension extending therefrom. This manufacturing procedure results in a post valve that provides no opportunity for gas to escape between the seat ring and the valve body. The manufacturing process includes starting with round metal bar stock, which is less expensive than the square or rectangular bar stock now used to machine the valve bodies, and cutting or etching away the outer diameter of the round metal bar stock to create square or rectangular portions of the valve body. The seat ring is turned or left to be circular. The threaded extension also is turned to the proper diameter. Thereafter, exterior holes (such as the outlet orifice) are created by side cuts or drill cuts. Next, the interior sections of the valve body are machined and the threads are cut into the threaded extension. Because this manufacturing process starts with less expensive round bar stock, the entire manufacturing process is cheaper than the traditional process which starts with square or rectangular bar stock and uses a separate, press fitted or floating circular seat ring.  
         [0021]     As shown in  FIG. 1 , post valves  10  are threadedly connected to a high pressure gas cylinder  12 . Known post valves  10  ( FIGS. 1 and 2 ) include a valve body  14 , a valve actuator  16  and a threaded extension  18  that is threadedly connected to port  19  of the gas cylinder  12 . A seat ring  20  is disposed between the valve body  14  and the gas cylinder  12  and either one or two O-rings  21  are placed on one or both sides of the seat ring  20  in prior art post valves, as shown in  FIG. 2 , to limit gas escaping from the gas cylinder  12  between the threaded extension  18  and the gas cylinder  12 .  
         [0022]     During operation, the valve actuator  16  is turned, using a handle, knob or other turning mechanism (not shown) connected thereto, to open a valve orifice within the valve body  14  to thereby allow gas to enter through a passageway within the threaded extension  18  (as illustrated by the arrow in  FIG. 1 ) and to escape out of an outlet orifice  22 . The outlet orifice  22  is fluidly connectable to a device that uses the gas within the tank  12 , such as a torch or a breathing apparatus (not shown).  
         [0023]      FIG. 2  illustrates a prior art post valve  10  after the valve actuator  16  has been assembled onto the valve body  14 , but before the seat ring  20  is press-fitted thereon. As illustrated, the seat ring  20  is created or machined as a separate part and is placed over a collar  23  on the threaded extension  18  before the post valve  10  is attached to a gas cylinder. In the past, O-rings have been placed on both sides of the seat ring  20 , or as illustrated in  FIG. 2 , the seat ring  20  has been press fitted onto the collar  23  of the threaded extension  18  without an O-ring between the seat ring  20  and the valve body  14 . In either case, there is some opportunity for gas within the gas cylinder  12  to escape through the threaded engagement of the extension  18  and the inner diameter of the seat ring  20  in the prior art valve shown in  FIG. 2 . Further, the manufacturing of the seat ring  20  apart from the valve body  14  creates additional parts and results in a process that has additional manufacturing and assembly steps, which is undesirable.  
         [0024]     In accordance with the first embodiment of the post valve described herein, the seat ring  20  is integrally formed as a unitary part of the valve body  14 . The new post valve  25  is illustrated in  FIG. 3  where it can be seen that the valve body seat ring  20  is integrally formed on a lower end of the valve body  14  above the threaded extension  18 , extending downwardly therefrom. This manufacturing procedure results in a post valve  25  that provides no opportunity for gas to escape between the seat ring  20  and the valve body  14 . The manufacturing process includes starting with round metal bar stock, which is less expensive than the square bar stock now used to machine the valve bodies  14  of  FIGS. 1 and 2 , and cutting or etching away each of the sections thereon to create a predominantly square or rectangular cross-sectional shape to the valve body  14 . The seat ring  20  is turned for constant diameter or left to be circular. Generally, if turning or other metal removal process is needed to provide a constant diameter to the seat ring  20 , less than 10% of the material of the seat ring  20  is removed, preferably less than about 5% of the seat ring material. The threaded extension  18  is also turned to the proper diameter. Thereafter, the exterior holes (such as the outlet orifice  22 ) are created by side cuts or drill cuts. Next, the interior sections of the valve body  14  are machined and the threads are cut into the threaded extension  18 . Because this manufacturing process starts with less expensive round bar stock, the entire manufacturing process is cheaper than the traditional process which starts with square or rectangular bar stock and uses a separate circular seat ring  20 .  
         [0025]     Accordingly, the high pressure post valve  25  of the first embodiment described herein comprises a monolithic valve body  14  having an internal aperture  26  for receiving the valve actuator  16  for internal connection and seating within the valve body  14 . The valve body  14  has an integral threaded extension  18  for threadedly connecting the valve body  14  to the gas cylinder  12 , and the threaded extension  18  includes a gas inlet orifice  32  in alignment with the internal aperture  26  for the passage of high pressure inlet gas to the valve actuator  16 . The valve body  14  includes an integral, circular valve body seat  20  including a lower, planar valve body seating surface  29  disposed above and extending radially outwardly from the threaded extension for seating the valve body  14  against the gas cylinder outlet opening  19 . In accordance with a preferred embodiment, the valve body  14  is formed from round metal bar stock.  
         [0026]     The post valve  25  is manufactured by forming metal round bar stock (not shown) to provide a monolithic valve body  14  including the internal aperture  26  for receiving the valve actuator  16 . The valve body  14  has predominantly planar side surfaces  27  and an integral circular threaded extension  18  for connection to the high pressure gas cylinder  12 . The valve body  14  includes an integral, circular valve body seat  20  extending radially outwardly from the valve body  14  between the threaded extension  18  and the planar side surfaces  27  for seating the valve body  14  against gas cylinder  12  structure surrounding the gas cylinder outlet opening  19 . The threaded extension  18  includes a gas inlet orifice  32  in alignment with the internal aperture  26  in which the actuator  16  is connected within the valve body  14  for the passage of inlet gas to the value actuator  16 .  
         [0027]     The fabrication method becomes much simpler when starting with metal round stock, as described hereinafter.  
         [0028]     The round metal stock is continuously fed by an automatic bar feeder. First or chuck side process: The front end work is very similar to conventional machining: center drilling, turning, boring, thread milling, side cut drilling and tapping. The valve is then oriented by the machine and a flat is milled on the first side (⅞″ side). The valve is indexed 90° and another flat is milled along with side-work (center drilling, side cut drilling and tapping). The valve is indexed 90° and another flat is milled on the third side (⅞″ side). The valve is indexed 90° and the final flat is milled a long with side-work (center drilling, side cut drilling and forming). A secondary spindle (sub-spindle) then grasps the valve, both a primary spindle (chuck) and the secondary spindle rotate in synchronization and the part is cut to length as the sub-spindle pulls away from the primary spindle (chuck). Simultaneously the part in the sub-spindle and the part in the chuck start to be machined. Second or sub-spindle side process: The back end work is very similar to conventional machining; center drilling, turning, thread milling and side cut drilling. The machined complete part is then transferred into a parts catcher.  
         [0029]     In accordance with the second embodiment of the post valves described herein, the post valve  25  provides an improvement to the valve seating arrangement used inside the valve body  14  of the post valve  25 .  FIG. 4  illustrates a cross-sectional view longitudinally through the post valve  25  of  FIG. 3 . As is typical in the art, the actuator  16  is coupled to a valve seat  30 , typically made of brass, disposed in a valve chamber  31 . Movement of the actuator  16  (e.g., turning of the actuator  16 ) causes the valve seat  30  to move toward or away from a conical gas inlet orifice  32 . When the valve seat  30  is moved away from the gas inlet orifice  32 , gas under high pressure enters into the valve chamber  31  through a passageway  34  within the threaded extension  18  and through the gas inlet orifice  32 .  
         [0030]      FIG. 5  illustrates a known valve seat mechanism  30  while  FIGS. 4 and 6  illustrate the improved design of the second embodiment described herein. As shown in  FIG. 5 , the prior art valve seat  30  includes an annular ring  40  which forms a circular cavity within the valve seat  30 . Valve seating material  42 , typically a polymer or elastomer, is disposed within the cavity and, when the post valve is closed, comes into sealing contact with the conical gas inlet orifice  32  to prevent gas from entering into the chamber  31 . This prior art design is prone to spontaneous ignition or auto-ignition of the valve seat material  42  during operation. In particular, when the actuator is turned to cause the valve seat  30  to move away from the orifice  32 , gas under very high pressure flows through the orifice  32  and comes into direct contact with the valve seat material  42 . Impurities in the gas, such as solid particles, will hit the valve seat material  42  directly at very high speeds. In some cases, the energy in these particles in enough to cause spontaneous ignition of the valve seat material  42 , which may lead to the melting of the post valve and result in a substantial fire hazard.  
         [0031]     The improved valve design  25 , described herein, includes a polymeric or elastomeric sealing material  50  disposed to surround the gas inlet orifice  32 . In this configuration, the bottom surface of the annular ring  40  provides sealing contact with the sealing material  50  in a closed loop surrounding and preferably below the gas inlet orifice  32 . Furthermore, a valve cavity  41 , defined by the annular ring  40  and an upper, interior valve seat surface  54 , does not have any ignitable, elastomeric material therein so that the interior valve seat surface  54  of the valve seat body  30 , subject to direct contact with high pressure gas by virtue of being in longitudinal alignment with the gas inlet orifice  32 , is formed of metal and not subject to ignition. In the configuration of  FIG. 6 , impurities within the gas flowing at high speeds through the orifice  32  first hit the metal surface  54  of the valve chamber, which, in the preferred embodiment, is made of brass having a much higher melting temperature than the valve seat material  50 . This configuration reduces the likelihood of impurities within the gas causing auto ignition within the post valve, since there is no direct contact of high pressure gas with the sealing material  50  (the sealing material  50  is not in longitudinal alignment with an upward extension of the cross-sectional area of the gas inlet orifice  32 ).  
         [0032]     As best shown in  FIGS. 3 and 4 , the valve body  14  includes external apertures  33  that act as locating devices for alignment of a gas regulator device (not shown) that attaches to valve  25 . The separation distance between apertures  33  is defined by Compressed Gas Association (CGA) industry standards. Adjacent to apertures  33  is the gas outlet passage  22 . Surrounding the outlet passage  22  is a circular groove  37  useful in receiving and locating a seal device that is a part of gas regulators well known in the medical gas industry and constructed according to CGA standards. Outlet passage  22  is located in accordance with the position of apertures  33 , also in accordance with CGA standards.  
         [0033]     The valve actuator  16  includes a rotatable stem  55  that is held within the internal aperture  26  with an externally threaded bonnet  57  that mates with internal threads within an interior surface of the valve body  14 . Actuator stem  55  is operatively positioned with respect to the actuator valve seat body  30 , having the annular ring seat  40  extending therefore, for sealing contact against the valve seat material  50 . Rotation of the actuator stem upwardly or downwardly enables or restricts gas flow, respectively, from the valve inlet orifice  32  to the outlet passage  22 . Disposed within threaded aperture  49  in an exterior wall of the valve body  14  is a threaded plug  51  that secures an over-pressure rupture disk.  
         [0034]     Accordingly, the high pressure post valve  25  of the second embodiment comprises the valve body  14  having an internal aperture  26  for receiving a valve actuator  16  for internal connection and seating within the valve body  14 , wherein the valve body  14  has a threaded extension  18  for threadedly connecting the valve body  14  to the gas cylinder  12 , the threaded extension including a gas inlet orifice  32  in alignment with the internal aperture  26  for the passage of high pressure inlet gas to the valve actuator  16 .  
         [0035]     The valve actuator includes an annular valve seat  40  surrounding a valve cavity  41 , the valve seat  40  being disposed at a lower end of the value actuator  16  and longitudinally movable within the internal aperture  26  in the valve body  14  by manipulation of the valve actuator  16  to open and close the valve inlet orifice  32 .  
         [0036]     The valve body  14  also includes valve seat material  50  adjacent to surrounding, and preferably below the gas inlet orifice  32  such that longitudinal movement of the annular valve seat  40  in sealing contact with the valve seat material  50  to close the valve provides sealing of the valve cavity  41  in an area surrounding, and preferably below the gas inlet orifice  32 , and such that longitudinal movement of the valve seat  40  to open the valve  25  prevents any direct contact of high pressure inlet gas against the valve seat material  50 .  
         [0037]     The high pressure post valve  25  of this second embodiment is manufactured by forming a valve body  14  to include an internal aperture  26  for receiving the valve actuator  16  and a threaded extension  18  for connection to the high pressure gas cylinder  12 , wherein the threaded extension  18  includes a gas inlet orifice  32  in alignment with said internal aperture  26  for the passage of inlet gas to the valve actuator  16 .  
         [0038]     The valve actuator then is connected to said valve body  14 , within the internal aperture  26 , e.g., by threaded attachment. The valve actuator  16  includes an annular valve seat  40  surrounding a valve cavity  41 , said valve seat  40  disposed at a lower end of the valve actuator  16 . The valve seat  40  is longitudinally movable within the internal aperture  26  in the valve body  14  by manipulation of the valve actuator  16  to open and close the valve inlet orifice  32 .  
         [0039]     The valve body  14  also includes valve seat material  50  adjacent to, surrounding, and preferably below the gas inlet orifice  32  such that longitudinal movement of the annular valve seat  40  in sealing contact with the valve seat material  50  to close said valve  25  provides sealing of the valve chamber  41  in an area surrounding the gas inlet orifice  32 , and longitudinal movement of the valve seat  40  to open the valve  25  prevents any direct contact of high pressure inlet gas against the valve seat material  50 .  
         [0040]     In accordance with a third embodiment, the high pressure post valve includes a filter, such as a sintered bronze filter  60 , disposed within the gas inlet orifice  32  (instead of or in addition to the annular valve seat surrounding the gas inlet orifice  32 ) to trap any solid contaminants. The filter can be press-fitted into the gas inlet orifice  32  within the threaded extension  18  to prevent any solids from contacting valve seat material disposed in alignment with the gas inlet orifice  32 , thereby avoiding combustion. When the filter  60  is disposed in the gas inlet orifice  32 , e.g., by press-fitting or by threaded connection (not shown), the valve actuator  16  can contain valve seat material within the valve cavity  41  (as in prior art post valves) since the filter will remove the problematic solid contaminants.