Abstract:
A flow control device is disclosed. The flow control device comprises a pressure reducing valve. The pressure reducing valve comprises a valve body having at least an inlet port on a high side and an outlet port on a low side and having walls defining a regulating chamber, the outlet port in fluid communication with the regulating chamber. A diaphragm assembly is provided having a diaphragm and a stem for engaging the diaphragm. The stem has a base and a connecting arm. The diaphragm engages the main valve at a perimeter thereof so as to partially enclose the regulating chamber. A valve controlled opening cooperating with the connecting arm of the stem is located between the inlet port and the regulating chamber. The valve controlled opening is adapted to adjustably restrict flow of gas between the inlet port and the regulating chamber responsive to movement of the connecting arm.

Description:
This application claims the benefit of and incorporates by reference U.S. Patent Application Ser. No. 61/366,307, filed Jul. 21, 2010. 
    
    
     FIELD OF THE INVENTION 
     Flow control devices; namely, a pressure reducing valve. 
     BACKGROUND OF THE INVENTION 
     Pressure reducing valves are used to allow high pressure fluid supply lines or compressed gas tanks to be reduced to safe, usable pressures for various applications. A pressure reducing valve may be part of a gas pressure regulator, for example, a pressure regulator, to match the flow of gas through the valve to the demand placed on it. 
     SUMMARY OF THE INVENTION 
     A pressure reducing valve comprising a valve body having at least an inlet port on a high side and an outlet port on a low side and having walls defining a regulating chamber, the outlet port in fluid communication with the regulating chamber. A diaphragm assembly is provided having a diaphragm and a stem for engaging the diaphragm. The stem has a base and a connecting arm. The diaphragm engages the main valve at a perimeter thereof so as to partially enclose the regulating chamber. A valve controlled opening cooperating with the connecting arm of the stem, is located between the inlet port and the regulating chamber. The valve controlled opening is adapted to adjustably restrict the flow of gas between the inlet port and the regulating chamber responsive to movement of the connecting arm. A main spring is provided for engaging the diaphragm and urging it toward valve controlled opening. The base of the stem includes a lower surface that is channeled so as to assist the flow of gas from the valve controlled opening to the regulating chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are cross-sectional views of the pressure reducing valve in an open (gas flowing) position;  FIG. 1A  through Section A-A,  FIG. 1B  through Section B-B. 
         FIG. 1C  is a top elevational view of the valve body. 
         FIGS. 1D and 1E  are detailed views of the valve seat;  FIG. 1D  in an open position;  FIG. 1E  in a closed (gas not flowing) position. 
         FIGS. 2A and 2B  are exploded side perspective views of the pressure reducing valve;  FIG. 2A  from the top;  FIG. 2B  from the bottom. 
         FIG. 3  is an exploded side perspective view from above the diaphragm assembly. 
         FIG. 4  is a bottom side perspective view of the stem. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1A ,  1 B,  1 C,  1 D, and  1 E as well as  FIGS. 2A and 2B , illustrate various views of Applicants&#39; pressure reducing valve  10 . Pressure reducing valves are known in the gas flow control industry for stepping down or reducing a high pressure gas to a set lower pressure at an outlet port. For example, compressed gas cylinders, when full, can provide for compressed gas up (for example, 3000 psi of CO 2 ) to a pressure reducing valve  10 , such as illustrated. This valve will in turn provide a step down pressure at an outlet of, for example, 160 lbs. The pressure reducing valve  10  allows gas under pressure to flow through the valve from the high end to the low end when the pressure at the low end drops below its set pressure, here, for example, 160 lbs. 
     Turning now to the general construction of Applicants&#39; pressure reducing valve  10 , it is seen to have a valve body  12 , typically made of brass. A bonnet assembly  14  is threadably engaged to the valve body in a gas sealing manner. 
     Turning back to the valve body  12 , it is seen to have a threaded gas inlet port  16  for engaging the high side pressure source, typically a high pressure compressed gas tank for holding a compressed gas, such as CO 2 . Valve body  12  also includes a high side pressure gauge port  18  or gauge for measuring the high side source pressure. As the tank (not shown) is depleted through feeding the downstream device or system (not shown), pressure from the source will drop. Gauge port  18  is for a gauge to measure the high side (source) pressure. Outlet port  22  is provided in valve body  12  for supplying a downstream device at a regulated set or reduced pressure, here, for example, 160 lbs. Also included in valve body  12  is an outlet gauge port for indicating the working pressure, that is for an outlet pressure gauge (not shown), to provide an indication of the regulated outlet pressure, here, typically about 160 lbs., for example. 
     Turning back to bonnet assembly  14 , and with reference to  FIGS. 1A ,  1 B,  2 A, and  2 B, it is seen to include a bonnet housing  15 , with an interior dimensioned to receive a main spring  24  which resides therein. A removed end of the main spring  24  is in contact with an outer surface of a diaphragm assembly  26  and a near end to adapter  44 . Diaphragm assembly  26  is generally circular and has an outer perimeter which is sandwiched between valve body  12  and bonnet housing  15  as seen in  FIG. 1A . Diaphragm assembly  26  includes a stem  30  engaged therewith and will move along the longitudinal axis of the valve  10  as the diaphragm flexes. Stem  30  includes connecting arm  30   a , which may have gussets  30   i . Arm  30   a  has a centrally located orifice  28   a  of an orifice screw  28 , which orifice screw is threadably secured into the body as seen in  FIG. 1A  with an O-ring  36  sealing orifice screw  28  to valve body  12 . 
     It is seen in detail view in  FIGS. 1D and 1E , how connecting arm  30   a , typically cylindrical, moves freely in orifice  28   a  of orifice screw  28 . Moreover, it is seen that orifice screw  28  includes a downward depending lip  28   b , around orifice  28   a.    
     Adjacent the removed end of connecting arm  30   a  is located a cylindrical movable seal  32 , which is urged against the removed end of connecting arm  30   a  by a seal spring  34 . Moreover, it is seen that seal  32  is dimensioned to be received within seal cavity  28   c  of orifice screw  28 , which sealed cavity has threaded walls  28   d  of orifice screw  28 . Stem  30  is seen to have a connecting arm channel  30   b  running longitudinally on an exterior surface therethrough from the removed end of connecting arm  30   a  through diaphragm assembly  26  as illustrated in  FIG. 1A . Connecting arm channel  30   b  provides for pressure relief when one adjusts output or working pressure. 
     Turning back to bonnet assembly  14 , it is seen in  FIGS. 1A and 1B  that bonnet assembly  14  is dimensioned to substantially enclose main spring  24  and to locate main spring  24  adjacent an upper surface of the diaphragm assembly  26  as illustrated. Bonnet housing  15  includes a relief hole  17  for relief of pressure above the diaphragm assembly  26  (see  FIG. 2A ). An adjusting screw  21  is provided to selectively adjust pressure spring  24  applied to the upper surface of diaphragm  48 . Bonnet assembly  14  also includes washer  38 , which is sandwiched between the diaphragm assembly upper surface and the removed end of main spring  24  to prevent direct contact and abrasion of the diaphragm assembly by the main spring. Washer  40  is also provided and can be placed between the bonnet housing  15  and the main body  12 , along with the outer perimeter of the diaphragm assembly as illustrated, such that when threadably engaging the bonnet housing  14  to valve body  12 , a tight pneumatic seal is provided by compressing these elements between the bonnet housing  15  and the main body  12 . 
     A regulating chamber  46  is seen, which is defined in part by sidewalls  12   a  and cross walls  12   b  of the valve body and by the underside of the diaphragm assembly  26 . The regulating chamber  46  includes outlet ports  46   a / 46   b / 46   c  in the main body  12 . Outlet port  46   a  provides fluid communication between the regulating chamber  46  and gauge port  20 . Outlet port  46   b  provides fluid communication between the regulating chamber  46  and outlet port  22  (see  FIG. 1B ). Outlet port  46   c  provides fluid communication between the regulating chamber  46  and a safety or blowout prevention valve (not shown). 
     The condition of the valve seen in  FIGS. 1A and 1B  is open. That is to say, gas pressure is flowing through the valve from high to low by entering valve body  12  at inlet port  16  and passing up through orifice  28   a  into regulating chamber  46  and out through port  46   b  and outlet port  22 . In this “open” position, seal  32  is maintained off or spaced away from circular lip  28   b  of orifice screw  28 , thus allowing gas to flow through the valve. In this condition, a device downstream of outlet port  22  is consuming gas from the high pressure source. However, when demand downstream decreases or ceases, then back pressure will develop until pressure in regulating chamber  26  is sufficient to raise the stem up as seen in  FIG. 1E , a sufficient distance, such that seal  32  is now seated on lip  28   b  and gas can no longer flow through valve  12 . Seal  32  may be comprised of a stainless steel housing  32   a  dimensioned to receive a durable seat  32   b  made from a synthetic or other suitable material. Seat  32   b  is dimensioned to make contact with lip  28   b  when the valve is in a closed position. 
       FIG. 3  illustrates the elements of the diaphragm assembly  26 . Diaphragm assembly  26  is seen to include four cooperating elements: stem  30 , diaphragm  48  (preferably convoluted), piston  50 , and nut  52 . The advantage of the convoluted diaphragm is that it typically does not stretch, after repeated use, like a flat diaphragm does. Moreover, it is seen that nut  52  may engage threaded arm  30   c  of stem  30 , which is dimensioned to pass through central hole  48   a  of diaphragm  48  and central hole  50   a  of piston  50 . Threaded nut  52  will sandwich piston  50  so that it is seated within the space created by convoluted portion  48   b  of diaphragm  48 . Moreover, it may be seen that there is typically a recessed portion  50   b  on the upper surface of piston  50  dimensioned to receive washer  38  as seen in  FIG. 2A . 
     One of the novel features of Applicants&#39; present device is in the structure and function of stem  30 . Stem  30  is seen to transmit changes in the diaphragm position to the seat. Moreover, it is seen that connecting arm  30   a  is dimensioned to be generally cylindrical (and may be slightly tapered) and received through circular orifice  28   a  with an annular gap “G” therebetween (see  FIG. 1D ). This annular gap will allow gas to pass therethrough when seal  32  is displaced or lifted off lip  28   b . It is noted that a tight gap will be more restrictive of flow than a wide gap. Gaps may be preferably about 0.035″/side or a range of 0.020″ to 0.050.″ 
     With further reference to  FIGS. 1A ,  1 B,  3 , and  4 , it is seen that connecting arm  30   a  projects downward from the underside of stem  30  and, along the longitudinal axis thereof, threaded arm  30   c  projects upward. An outwardly extending lateral base  30   d  extends from the longitudinal axis that lays between the removed ends of the stem. Base  30   d  is seen to have a flat, first or upper surface  30   f  and a channeled, second or lower surface  30   e . When diaphragm assembly  26  is together, it is seen that upper surface  30   f  lays adjacent the lower surface of diaphragm  48 . When the gas is flowing through opening  28   a , the seal being off the lip, channeled lower surface  30   e  lays near, on, adjacent or next to the typically flat top surface of orifice screw  28  (see  FIG. 1D ). 
     Turning now to channeled lower surface  30   e , it is seen to have a central recess  30   g  surrounding the base of the connecting arm  30   a , that is, where the connecting arm  30   a  joins base  30   d . Central recess  30   g  may be circular and may have a diameter typically greater than the diameter of orifice  28   a . Further, it is seen that, typically, a multiplicity of radial channels  30   h  extend outward from the outer perimeter of central recess  30   g  to the outer perimeter of the base. The radial channels  30   h  may be straight (shown), curved (not shown), or any other suitable shape. Typically there are more than one radial channels, preferably three or four equally spaced. 
     The channeled structure of the lower surface, including the central recess and the multiplicity of radial channels (preferably more than one), tends to generate unobstructed gas flow at a given pressure differential between inlet port  16  and outlet port  22 . It has been found that at some pressure differentials, as much as 20% more gas flow is generated when using the recessed sections or channels of the lower surface, rather than a plane or flat lower surface. 
     It is shown that the channeled lower surface generates more gas flow. Applicants disclose an arrangement with a recess and three channels. However, any number of channels, in any arrangement, will work. Moreover, while a recess is preferred, radial channels alone will work. 
     Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. On the contrary, various modifications of the disclosed embodiments will become apparent to those skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover such modifications, alternatives, and equivalents that fall within the true spirit and scope of the invention.