Abstract:
A dual flow gas valve suitable for gas grills that allows a user to select the valve for use with gases of different heating values and to select one of a high flow position and a low flow position for each gas. The gas valve includes a body and an input passageway communicating with the body. In one embodiment, a rotational member in the body defines a first port communicating the input passageway with an interior chamber. The rotational member defines an additional passageway external to the rotational member. The rotational member may be rotated to a first position to activate high flow through the rotational member or may be rotated to a second position to activate the external, low flow, passageway.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of U.S. Provisional Patent Application No. 61/826,355 entitled “GAS VALVE WITH MULTI-FUEL CAPABILITY,” filed May 22, 2013, the contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a gas valve that may be easily modified to regulate gases having different heating values per unit volume. 
       BACKGROUND OF THE INVENTION 
       [0003]    The problem of how to address the use of multiple gas fuels on gas grills and similar cooking appliances has been addressed in a number of ways over the years. One problem is that two gases, such as propane and natural gas, have very different heating values per unit volume, i.e., propane has a heat value of around 2500 BTU/cubic foot and natural gas around 1000 BTU/cubic foot. It is desirable to avoid requiring two different valves, i.e., to use a single valve that may be modified to allow conversion from a low heating value gas requiring high volumetric flow to a high heating value gas requiring lower volumetric flow. A typical valve used for this application has a solid cone with an internal passage that is rotated inside a cast or forged body to align openings in the plug with openings in the side and end of the body to enable gas to flow at various volumetric flow rates. 
         [0004]    An early approach is outlined in Carlson, U.S. Pat. No. 4,020,870, in which the volume flow differential at high BTU/hr rates is handled by a change in the final orifice affixed to the exit end of the valve body and the volume rate differential at lower BTU/hr rates is handled by a screw coaxial with the cone that is advanced or retreated to block or open one of a pair of small holes used to meter flow. For high heating value gas the screw is set to have only one pair of holes open and for the low heating value gas the set screw is set to have both pairs of holes open. 
         [0005]    A further approach is outlined in Massey, U.S. Pat. No. 5,009,393, in which the volume flow differential for different gases at low BTU/hr rates is handled by an externally adjustable sleeve inside the rotating cone that opens or closes an additional low flow orifice, opening it for the low heating value gas and closing it for the low heating value gas. This sleeve is adjusted by a rotation driven by a tool inserted down a tubular valve stem as in the previously mentioned art. 
         [0006]    In Zhang, U.S. Pat. No. 7,458,386, this concept is taken further as the adjustable sleeve inside the rotating cone is used to change the low BTU/hr rates for the different gases and a new design of externally adjustable final orifice is used to change the high BTU/hr rate for the different gases. 
         [0007]    It should be understood that in all three cases above, two reconfigurations are required, one at the final orifice where it typically inserts into the burner, and one by adjustment with a tool inserted down the valve stem from the exterior of the appliance. 
         [0008]    A different approach is taken in Parrish, US Patent Application Publication No. 2008/0289615. A coaxial dual stage final orifice is constructed with the outer stage feed by a bypass on one side of the valve cone combined with a normal port feeding the inner stage. On the other side of the cone is a normal port that only feeds the inner stage. For high heating value gas, the side of the cone is used that feeds only the inner stage and for low heating value gas the side of the cone is used that feeds both the inner and outer stages. A limitation means is devised to allow reconfiguration of the valve to utilize either of the two sides of the cone, depending on the gas used. It will be appreciated that the intent of this design to be able to make the change over with only one reconfiguration which can in principle be done from the exterior of the appliance. 
         [0009]    In Hsiao, US Patent Application Publication No. 2009/0235988, the cone has two sets of large (high flow) and small (low flow) holes oppositely arranged with one set having a bypass hole provided that creates additional flow to a secondary final orifice placed alongside the normally configured final orifice, which is coaxial with the valve cone. For high heating value gas, the valve cone is rotated to engage the flow control holes that do not have the bypass hole located to cooperate with the flow control holes. For low heating value gas, the added flow required is obtained by rotating the cone to engage the flow control holes that have a bypass hole located to cooperate with them. At high flow rates the difference in flow is established by the addition of the bypass. At low flow rates it appears that the difference in flow is established by different sizing of the low flow holes. 
         [0010]    The approach taken by Albizuri in U.S. Pat. Nos. 7,156,370, 7,641,470, 7,651,330, 7,950,834, 7,963,763, 7,967,005, and 8,092,212, is substantially different as the difference in flow rate for different gas at low flow rates is accomplished by two low flow holes accessed by turning the valve cone to two successive positions, the first accessing a low flow hole of relatively larger size for the lower heating value gas and the second accessing a low flow hole of relatively smaller size for the higher heating value gas, with various means defined to limit or define the valve cone rotation. The flow rate differential at the high flow condition is accomplished either by change of a removable final orifice or by the use of two orifices in series, when the larger sized orifice is placed interiorly relative to the smaller sized orifice such that when the smaller sized orifice, matched to the higher heating value gas, is removed the larger sized orifice, matched to the lower heating value gas, is exposed and functional. It would be understood that in this approach it is required to reconfigure the valve cone rotation definition and reconfigure the final orifice to achieve the desired conversion of gas type. 
         [0011]    Carvalho, in US Patent Application Publication No. 2013/0000624, defines another means of achieving the limitation of valve cone rotation described by Albizuri. 
         [0012]    May, in US Patent Application Publication No. 2011/0030501, likewise defines another means of achieving the limitation of valve cone rotation described by Albizuri. 
         [0013]    It should be evident that there are significant limitations in the prior art, taken individually and in groups. For example, Carlson, Massey, Zhang, Albizuri, Carvalho, and May all require two reconfigurations to be carried out to convert from one gas to another. In the case of Parrish, which only requires a single reconfiguration, the operation from OFF to HIGH to LOW flow is carried out in opposite rotational direction for the two different gas types, which may be confusing to the consumer and may violate product safety certification rules. In the case of Hsiao, which only requires a single reconfiguration, the double outlet in the low heating value gas case significantly complicates the design of the mating burner, which should ideally function for both gas types. Other disadvantages, such as manufacturing complexity, difficulty in determining which gas the valve is set for from external visual inspection, and difficulty in obtaining a linear change in flow from high rate to low rate present themselves in various of the prior art designs. 
       SUMMARY OF THE INVENTION 
       [0014]    The proposed valve of the invention has a rotating cone inside a body with ports in a plug. The valve has a body, wherein the ports in the plug and in the body are rotationally aligned to produce various flow rates. In the inventive valve, the final orifice used to regulate flow in the high flow case can be made in two different configurations in which a member extends into the body and further into the inside of the rotating cone. A seal is used to route flow though a bypass and orifice that is correctly sized for a low flow rate of different types of gas. 
         [0015]    As will be seen from the detailed description and specification there are several advantages of this device over prior the art. First, only one reconfiguration is required to convert from one type of gas to another since the orifice change will change both the low flow and high flow rates of the valve. Second, the valve rotation and arc of actuation will be entirely unchanged for two different gas types, which is not the case with the prior art designs that allow for single reconfiguration. Third, manufacture of the new inventive valve is possible with very straightforward techniques that will not pose a challenge to any manufacturer of such devices. For example, the final assembly of this valve consists of the same number of parts assembled in the same sequence as a standard non-convertible valve. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is an exploded view of the gas valve of the invention; 
           [0017]      FIG. 2A  is an enlarged perspective view of a tapered end of the rotatable conical insert in the gas valve shown in  FIG. 1 ; 
           [0018]      FIG. 2B  is an enlarged perspective view of a stepped end of the rotatable conical insert in the gas valve shown in  FIG. 1 ; 
           [0019]      FIG. 3  is a cross-sectional assembled view of the gas valve of  FIG. 1  shown in an OFF position; 
           [0020]      FIG. 4  is a cross-sectional perspective assembled view of the gas valve of  FIG. 1  shown in a HIGH FLOW position; 
           [0021]      FIG. 5  is a cross-sectional perspective assembled view of the gas valve of  FIG. 1  shown in a LOW FLOW position; 
           [0022]      FIG. 6  is a cross-sectional perspective assembled view of the gas valve of  FIG. 1  shown in a MEDIUM FLOW position; 
           [0023]      FIG. 7  is a cross-sectional perspective assembled view of the gas valve of  FIG. 1  shown from a perspective approximately aligned with a gas input passageway; 
           [0024]      FIG. 8A  shows an alternate embodiment of the gas valve of  FIG. 1 , wherein a longitudinal slot is formed in the valve body rather than in the conical insert, wherein the gas valve is shown in an OFF position; 
           [0025]      FIG. 8B  shows the gas valve of  FIG. 8A , wherein the gas valve is shown in a HIGH FLOW position; 
           [0026]      FIG. 8C  shows the gas valve of  FIG. 8B , wherein the gas valve is shown in a LOW FLOW position; 
           [0027]      FIG. 8D  shows an enlarged perspective view of a second embodiment of the rotatable conical insert of the gas valve of  FIGS. 8A-8C  having an extension protruding from a tapered end; 
           [0028]      FIG. 9A  is an alternate embodiment of the gas valve of  FIG. 1  wherein the conical insert is provided with a first hole and a second hole for selecting between flow conditions, wherein the gas valve is positioned in an OFF position; 
           [0029]      FIG. 9B  is an alternate embodiment of the gas valve of  FIG. 9A , wherein the gas valve is positioned in a HIGH FLOW position; 
           [0030]      FIG. 9C  is an alternate embodiment of the gas valve of  FIG. 9A , wherein the gas valve is positioned in a LOW FLOW position; 
           [0031]      FIG. 10A  shows a perspective view of an exit end of an alternate embodiment of the gas valve of  FIG. 1 , wherein the orifice member is configured with alternate locations for a low flow orifice and a low flow bypass; 
           [0032]      FIG. 10B  shows a perspective view of a plug end of an alternate embodiment of the gas valve of  FIG. 1 , wherein the orifice member is configured with alternate locations for a low flow orifice and a low flow bypass; 
           [0033]      FIG. 11  is an alternate embodiment of the gas valve of  FIG. 1  wherein the orifice member has an alternate configuration with respect to threads and the sealing member; 
           [0034]      FIG. 12  is an alternate embodiment of the gas valve of  FIG. 1  wherein the orifice member is secured by an orifice cap. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    Referring now to  FIGS. 1-7 , shown is a gas valve  10  of the invention. Gas valve  10  includes valve body  12 . Valve body  12  has a gas source connector portion  14  and a body portion  16 . Body portion  16  defines primary passageway  17  having a threaded end  18  and a component end  19 . Primary passageway  17  has an exit section  20 , a tapered section  21 , a component section  22 , and an input orifice  23  ( FIGS. 3-7 ). Component end  19  preferably defines flange  24 . Flange  24  preferably defines a plurality of fastener orifices  26  ( FIG. 1 ). Gas source connector portion  14  defines gas input passageway  28  ( FIGS. 3-7 ) that communicates with tapered section  21  of primary passageway  17  through input orifice  23 . Tapered section  21  defines internally tapered surface  29 . Exit section  20  defines internal threads  30 . 
         [0036]    Rotatable conical insert  60  is received in component end  19  of valve body  12 . As shown in an enlarged view in  FIGS. 2A and 2B , conical insert  60  has a tapered end  62  having tapered outer surface  64 . Conical insert  60  additionally has stepped end  66  defining stepped outer surface  68 . Tapered outer surface  64  is matingly received within internally tapered surface  29  of tapered section  21  of primary passageway  17  ( FIGS. 3-7 ). Conical insert  60  defines first blind hole  70  ( FIG. 2A ) defining first bottom surface  72  ( FIGS. 3-7 ) and cylindrical surface  74 . First blind hole  70  is defined on tapered end  62  of conical insert  60 . Second blind hole  76  ( FIGS. 2B ,  4 - 6 ) defines second bottom surface  78 . Second blind hole  76  is defined on stepped end  66  of conical insert  60 . Second blind hole  76  additionally defines key slot  80  ( FIGS. 2B ,  4 ). Conical insert  60  defines high flow hole  82  that communicates tapered outer surface  64  with cylindrical surface  74  of first blind hole  70 . 
         [0037]    Referring now particularly to  FIG. 2A , tapered outer surface  64  defines partial circumferential transition slot  84  that partially encircles conical insert  60  wherein an outer edge of slot  84  is a first distance  86  from tapered end  62  of conical insert  60 . Transition slot  84  has a deep end  88  that is proximate to high flow hole  82 . Transition slot  84  additionally has shallow end  90 . Transition slot  84  decreases in depth from high flow hole  82  to shallow end  90 . Shallow end  90  preferably terminates at a zero depth, i.e., terminates at tapered outer surface  64 . The graded transition slot  84  defines a medium flow area  91 . Conical insert  60  further defines longitudinal slot  92  that terminates at first distance  86  from tapered end  62  of conical insert  60 . Longitudinal slot  92  has an exit end  96  that communicates with tapered end  62  of conical insert  60 . Exit end  96  of longitudinal slot  92  has a first depth  98 . 
         [0038]    Referring back to FIGS.  1  and  3 - 7 , shaft  110  is received within second blind hole  76  of conical insert  60 . Shaft  110  is provided with key  112  ( FIGS. 1 ,  4 ) for locating in key slot  80  of second blind hole  76  of conical insert  60 . Key  112  is for facilitating rotation of conical insert  60  with shaft  110 . Spring  120  is received in second blind hole  76  of conical insert  60 . Spring  120  is located between second bottom surface  78  of second blind hole  76  and shaft  110  for urging tapered outer surface  64  of conical insert  60  into sealing contact with internally tapered surface  29  of valve body insert  12 . Spring  120  additionally facilitates a press-to-turn feature when a user attempts to rotate shaft  110 . Spring  120  presses shaft  110  outwardly, which results in key  112  being pressed against an inner surface of cover plate  130 . In a preferred embodiment, inner surface of cover plate  130  is provided with detents so that shaft  110  must be pressed inwardly against the force of spring  120  to release key  112  to allow rotation of shaft  110 . Lesser detents are preferably provided on inner surface of cover plate  130  around shaft  110  to provided tactile feedback as shaft  110  is rotated and as key  112  passes over inner surface of cover plate  130 . The lesser detents may be positioned to alert a user when one of low, medium and high flow positions are achieved. Other detent positions may also be provided. 
         [0039]    Cover plate  130  defines shaft orifice  132  for receiving shaft  110 . Cover plate  130  is affixed to flange  24  on component end  19  of valve body  12  with fasteners  134  received within fastener orifices  26  of flange  24 . 
         [0040]    Orifice member  140  has an exit end  142  defining an exit orifice  143  and a plug end  144  connected together with an extension portion  146 . Orifice member  140  defines interior passageway  148  (see, e.g.,  FIGS. 3 and 4 ) that passes through extension portion  146  and communicates exit end  142  with plug end  144 . Exit end  142  defines exit portion  150  adjacent to threaded portion  152 . Threaded portion  152  is provided for threaded engagement with internal threads  30  of exit section  20  of valve body  12 . Plug end  144  is received within first blind hole  70  of conical insert  60 . Extension portion  146  further defines low flow orifice  154  (FIGS.  1  and  3 - 7 ) that communicates interior passageway  148  with an exterior surface of extension portion  146 . 
         [0041]    Sealing member  160 , such as an O-ring, is received on plug end  144  of orifice member  140  for sealingly engaging cylindrical surface  74  of first blind hole  70  of conical insert  60 . 
         [0042]    In  FIG. 1 , shown is an exploded view of gas valve  10  the invention. Valve body  12  has a gas source connection portion  14  to allow connection to a gas source such as a gas tube manifold of typical sort. Conical insert  60 , that rotates inside valve body  12 , is held into place and is rotated by a typical valve stem assembly that includes spring  120  and a rotatable and axially movable shaft  110  with a key  112  for transmitting rotation to the conical insert  60 . In addition, fasteners  134  are shown that are received in fastener orifices  26  of valve body  12  to hold the valve stem assembly in place. Orifice member  140  is shown disassembled, attaching to valve body  12  with threaded portion  152 . Orifice member  140  is shown with extension portion  146  and a plug end  144 , for mounting sealing member  160 , such as an O-ring. Orifice member  140  also has an exit portion  150  that is configured to allow rotation of orifice member  140  and contains exterior orifice  143  for gas flow into a burner. 
         [0043]    Rotatable conical insert  60  is shown in more detail in  FIG. 2  where critical design features are shown in greater detail. It will be readily understood with reference to  FIGS. 3-7  that the conical insert  60  defines first blind hole  70 , which forms part of a gas pathway leading to the output, i.e., to exit orifice  143  of gas valve  10 . Arranged around the circumference of the conical insert  60  is first a high flow hole  82 , which admits gas into first blind hole  70  when high flow hole  82  is aligned with input orifice  23  of gas input passageway  28 . Next there is a transition slot  84  cut into the circumference of conical insert  60 , which reduces the flow of gas into first blind hole  70  as conical insert  60  is rotated so that high flow hole  82  no longer aligns directly with input orifice  23 . In this configuration, gas flows through gas input passageway  28 , through input orifice  23 , and enters transition slot  84 , whereupon the gas flows to the high flow hole  82 . However, flow is reduced due to the progressive reduction in area in transition slot  84 . Longitudinal slot  92  extends downward along the outside surface of conical insert  60 . The function of longitudinal slot  92  will become clear as we describe the operating modes of gas valve  10  are described as follows. 
         [0044]    In  FIG. 3 , we show a section of gas valve  10  in the OFF position. In this case, gas input passageway  28  in valve body  12  is aligned with a section of tapered outer surface  64  of conical insert  60  that has no opening. In this case, no gas can flow in any path to the exit orifice  143 . It will be noted in this assembly view that the plug end  144  on extension portion  146  of orifice member  140  extends into first blind hole  70  of conical insert  60  and that the sealing member  160  forms a sealing surface with respect to the inside diameter or cylindrical surface  74  of first blind hole  70 . 
         [0045]    In  FIG. 4 , we show a section of gas valve  10  in the HIGH position. We see the effect of rotating conical insert  60  so that high flow hole  82  is aligned with input orifice  23  of gas input passageway  28  of valve body  10 . In this case, gas flows through gas input passageway  28 , through input orifice  23 , and through high flow hole  82  into an interior space defined by first bottom surface  72  of first blind hole  70  and sealing member  160  on plug end  144  of orifice member  140 . From there the gas flows down interior passageway  148  of orifice member  140  and then flows through exit orifice  143  defined to produce the maximum flow rate for that type of gas. 
         [0046]    In  FIG. 5 , we show a section of gas valve  10  in the LOW position. We see the effect of rotating conical insert  60  so that input orifice  23  of gas input passageway  28  is aligned with longitudinal slot  92  so that the gas is traveling through longitudinal slot  92  to an annular space defined by an outer diameter of extension portion  146  of orifice member  140  and the corresponding coaxial inner diameter of portion of exit section  20  of primary passageway  17 . The gas then flows through the low flow orifice  154  in the side of the extension portion  146  into the interior passageway  148  of the orifice member  140  and then out through the exit orifice  143  with flow rate defined by the area of the low flow orifice  154 . 
         [0047]    By inspection of  FIG. 2 , and with reference to  FIGS. 3-7 , it will be seen that in an intermediate position of conical insert  60 , which we might call the MEDIUM position of the valve, it will be possible for input orifice  23  of gas input passageway  28  to align at a place along transition slot  84  so that all the gas travels along transition slot  84  through high flow hole  82  into the interior space defined by first bottom surface  72  of first blind hole  70  and sealing member  160  on plug end  144  as previously described. 
         [0048]    It also can be seen in  FIGS. 6 and 7 , which depict gas valve  10  at slightly different rotations, that it might be possible to design gas valve  10  so that there is a position in which input orifice  23  of gas input passageway  28  might be partially aligned with transition slot  84  (best seen in  FIG. 7 ) and partially aligned with longitudinal slot  92  so that gas flow is split along the two paths described above with regard to the MEDIUM and LOW positions, providing a further ability to design the flow rate as a function of rotation of conical insert  60  to change as smoothly as possible from HIGH to MEDIUM to LOW. This is further illustrated in  FIG. 7  where we look through a sectioned view of gas valve  10  along gas input passageway  28  and see part of the transition slot  84  exposed as well as part of longitudinal slot  92 . 
         [0049]    In one alternate embodiment, longitudinal slot  92  is relocated from conical insert  60  to valve body  12 . Longitudinal slot  92  may further be formed by a combination of features found on conical insert  60  and on valve body  12 . Referring now to  FIGS. 8A-8D , alternate gas valve  210  is shown in an OFF ( FIG. 8A ), HIGH FLOW ( FIG. 8B ), and LOW FLOW ( FIG. 8C ) position. In  FIG. 8A , it can be seen that valve body slot  292 , formed in valve body  212 , is blocked from communication with gas input passageway  228  by extension  293  on tapered end  262  of conical insert  260 . Additionally, gas input passageway  228  is blocked from communicating with an interior space defined by plug end  144  of orifice member  140 , and first blind hole  270 , i.e., by first bottom surface  272  and cylindrical surface  274 . Therefore, valve  210  is an “OFF” position, since no gas can flow into interior passageway  148  and out of exit orifice  143  of orifice member  140 . 
         [0050]      FIG. 8B  shows alternate gas valve  210  in a HIGH FLOW configuration, wherein conical insert  260  is rotated so that high flow hole  282  communicates with gas input passageway  228 . Gas is, therefore, able to flow through gas input passageway  228 , through high flow hole  282  and into plug end  144  of orifice member  140  before passing through interior passageway  148  and out exit orifice  143 . Gas may also be able to flow through low flow orifice  154  in the same manner as explained with regard to  FIG. 8C . 
         [0051]      FIG. 8C  shows alternate gas valve  210  in a LOW FLOW configuration, wherein conical insert  260  is rotated so that gas is able to pass through valve body slot  292  and into primary passageway  217  and low flow orifice  154  and through interior passageway  148  where the gas exits through exit orifice  143  of orifice member  140 . Gas input passageway  228  is blocked from communicating with an interior space defined by plug end  144  of orifice member  140 , and first bottom surface  272  and cylindrical surface  274 . Therefore, all flow passing through exit orifice  143  must pass through low flow orifice  154 . 
         [0052]    In an additional alternate embodiment, conical insert  60  may be replaced with conical insert  360  having a first flow hole  382   a  ( FIG. 9B ) and a second flow hole  382   b  ( FIG. 9C ) rather than a single high flow hole  82  ( FIGS. 2 and 4 ) as discussed in the embodiment of  FIGS. 1-7 . Referring now to  FIGS. 9A-9C , alternate gas valve  310  is shown in an OFF ( FIG. 9A ), HIGH FLOW ( FIG. 9B ), and LOW FLOW ( FIG. 9C ) position. In  FIG. 9A , it can be seen that conical insert  360  is positioned such that no communication exists between gas input passageway  328  and an interior space defined by plug end  144  of orifice member  140 , and first blind hole  370 , i.e., first bottom surface  372  and cylindrical surface  374 . Gas flow is, therefore, blocked from passing through orifice member  140  and exit orifice  143 . 
         [0053]      FIG. 9B  shows alternate gas valve  310  in a HIGH FLOW configuration, wherein conical insert  360  is rotated so that a first flow hole  382   a  ( FIG. 9B ) communicates gas input passageway  328  with an interior space defined by plug end  144  of orifice member  140 , and first bottom surface  372  and cylindrical surface  374 . Gas is, therefore, directed through first flow hole  382   a,  into interior passageway  148  and out exit orifice  143 . 
         [0054]      FIG. 9C  shows alternate gas valve  310  in a LOW FLOW configuration, wherein conical insert  360  is rotated so that a second flow hole  382   b  communicates gas input passageway  328  and an annular space defined by an inside of primary passageway  317  and an outside of extension portion  146  of orifice member  140 . Gas is, therefore, directed through low flow orifice  354 , into interior passageway  148  and out exit orifice  143 . 
         [0055]    In a further embodiment, as shown in  FIG. 10 , low flow orifice  154  may be replaced with bypass orifice  454  and relocated to plug end  444  of orifice member  440  as low flow orifice  482 . High flow or bypass orifice  454  is located on a longitudinal wall of orifice member  440  between plug end  444  and exit portion  450 . Therefore, to achieve HIGH FLOW, the positioning of conical insert  60 , when using orifice member  440  is the reverse of the position of conical insert  60  in the embodiment shown in  FIGS. 1-7 , i.e., is the LOW FLOW position of conical insert  60  of  FIGS. 1-7 . Similarly, to achieve LOW FLOW, the positioning of the conical insert  60 , when used with orifice member  440 , is the reverse of the position of conical member  60  in the embodiment shown in  FIGS. 1-7 , i.e., is the HIGH FLOW position of conical member  60  when used with the embodiment of  FIGS. 1-7 . 
         [0056]    In a further embodiment, internal threads  30  of valve body  12  are relocated to an inside surface of tapered end  62  of conical insert  60 . Referring now to  FIG. 11 , shown is an alternate embodiment wherein orifice member  540  has a plug end  544  provided with threads  551  for engaging internal threads  530  of conical insert  560 . Sealing member  561 , such as an O-ring, is located on sealing portion  552 , adjacent to exit portion  550 . Exit orifice  543  is defined by exit portion  550 . Low flow orifice  554  is defined by a longitudinal wall of orifice member  540  between exit portion  550  and plug end  544 . 
         [0057]    In an additional embodiment, i.e., alternate gas valve  610 , shown in  FIG. 12 , orifice member  640  is secured within valve body  612  by orifice cap  662 , which is threadably received on external threads  630  on threaded end  618  of valve body  612 . In the embodiment of  FIG. 12 , exit orifice  643  is formed in orifice cap  662  rather than formed in an exit portion  150  of orifice member  140 , as shown in the embodiment of  FIGS. 1-7 . Orifice member  640  defines low flow orifice  654 . 
         [0058]    It should now be appreciated how simple it is to change the configuration of gas valve  10 ,  210 ,  310 ,  610  from a high heating value gas to a low heating value gas. All that is required is to have two separate orifice members  140 ,  440 ,  540 , i.e., a first orifice member and a second orifice member. In the case of the low heating value gas, the low flow limiting orifice  154 ,  354 ,  482 ,  654  and exit orifice  143 ,  643  of orifice member  140 ,  440 ,  540 , and orifice cap  662  may be sized relatively larger than the orifice corresponding to orifices  154 ,  354 ,  482 ,  654 , and to exit orifice  143 ,  643  on a substitute orifice member  140 ,  440 ,  540 , and orifice cap  662  for a high heating value gas. 
         [0059]    It can also be appreciated that some distinguishing feature can be machined or stamped into some part the orifice member  140 ,  440 ,  540 ,  640  and orifice cap  662  to differentiate between two orifice members for two types of gas. Other means of differentiating might include but are not limited to markings, such as different colors, materials or markings. 
         [0060]    It will now be understood how this invention uses many easy to replicate features of current valve art but adds a unique and novel feature of an orifice member  140 ,  440 ,  540 ,  640  that seals into the interior of rotating conical insert  60 ,  260 ,  360 ,  560  of a standard gas valve, thus allowing change of both high and low flow rates for different types of gas with only the replacement of the orifice member  140 ,  440 ,  540 ,  640  and orifice cap  662  required. 
         [0061]    It should further be appreciated that the sealing member  160 ,  561  is simply a means of providing a seal which could be provided by an O-ring or by other means known to the art, including even a precision machined fit on plug end  144 ,  444 ,  544  of the orifice member  140 ,  440 ,  540 ,  640  into first blind hole  70 ,  270 ,  370  of the rotatable conical insert  60 ,  260 ,  360 ,  560 . This could be accomplished by omission of the O-ring and reconfiguration of plug end  144 ,  444 ,  544  for sealing into a minimal clearance fit with the inside diameter or cylindrical surface  74 ,  274 ,  374  of first blind hole  70 ,  270 ,  370 . 
         [0062]    Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.