Abstract:
A multifunction cryogenic vacuum valve adapted to evacuate, seal off, and monitor vacuum levels and relieve cryogenic vacuum insulated systems is provided, wherein no thread sealant is necessary for the thermocouple threads.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to cryogenic systems and, more particularly, to a multifunction cryogenic valve adapted to evacuate, seal off, and monitor vacuum levels and relieve over-pressure for cryogenic vacuum insulated systems. 
         [0002]    Current evacuation valves for cryogenic vacuum insulated systems require additional components to make their valves function. The added components require additional space and clearance to operate; require more maintenance, spare parts, cleaning; and pose additional potential leak points and risk of breakage. The added components are needed to provide vacuum pump down, and monitoring of the vacuum, as well as an external operator and thermocouple isolation valve to evacuate and monitor the customers systems. Moreover, isolation valves require thread sealant on the thermocouple to keep the threads from leaking. Thread sealant is a concern in liquid oxygen systems because of the potential for ignition and fire. Thread sealant deteriorates after a period of time and requires replacement which makes it a maintenance requirement. 
         [0003]    As can be seen, there is a need for a multifunction valve adapted to evacuate, seal off, monitor vacuum levels and relieve over-pressure for cryogenic vacuum insulated systems, wherein no thread sealant is necessary. 
       SUMMARY OF THE INVENTION 
       [0004]    In one aspect of the present invention, a cryogenic vacuum valve includes a valve body forming a wide body cavity fluidly communicating with a narrower narrow body cavity; a valve plug defined by a circumferential surface dimensioned and adapted to snugly fit within the narrow body cavity; a top plug o-ring groove formed along an upper portion of the circumferential surface; a bottom plug o-ring groove formed along an lower portion of the circumferential surface so as to be spaced apart from the top plug o-ring groove, wherein the bottom plug o-ring groove is omega shape, and wherein the omega shape has a upper apex and a remaining portion; a thermocouple exposure slot formed along the circumferential surface so as to be disposed downward of the upper apex; and a thermocouple vacuum exposure hole formed through the valve body to fluidly communicate with the narrow body cavity, wherein the valve plug is movable from a go position to a stop position communicating the thermocouple vacuum exposure hole with the thermocouple exposure slot. 
         [0005]    In another aspect of the present invention, a cryogenic multi-function vacuum valve includes a valve body forming a wide body cavity fluidly communicating with a narrower narrow body cavity; a valve plug defined by a circumferential surface dimensioned and adapted to snugly fit within the narrow body cavity; a top plug o-ring groove formed along an upper portion of the circumferential surface; a bottom plug o-ring groove formed along an lower portion of the circumferential surface so as to be spaced apart from the top plug o-ring groove, wherein the bottom plug o-ring groove is omega shape, and wherein the omega shape has a upper apex and a remaining portion; a thermocouple exposure slot formed along the circumferential surface so as to be disposed downward of the upper apex; a thermocouple vacuum exposure hole formed through the valve body to fluidly communicate with the narrow body cavity; a cap rotatably mounted to an upper portion of the valve body, wherein the cap forms a central projection forming a cavity through which is secured a cap roll pin; and a valve shaft interconnecting the cap and the valve plug, wherein the valve shaft has an upper end operatively engaging the central projection, wherein the upper end forms a shaft cap pin slot adapted to operative engage the cap roll so that rotating the cap moves the valve plug between the go position and the stop position communicating the thermocouple vacuum exposure hole with the thermocouple exposure slot, wherein the go position comprises the thermocouple vacuum exposure hole being disposed downward of the remaining portion of the bottom plug o-ring groove, and wherein the go position comprises the thermocouple vacuum exposure hole being disposed downward of the remaining portion of the bottom plug o-ring groove. 
         [0006]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a front perspective view of an exemplary embodiment of the present invention; 
           [0008]      FIG. 2  is a rear perspective view of an exemplary embodiment of the present invention; 
           [0009]      FIG. 3  is an exploded view of an exemplary embodiment of the present invention; 
           [0010]      FIG. 4  is a detailed reverse exploded view of an exemplary embodiment of the present invention; 
           [0011]      FIG. 5  is a section view of an exemplary embodiment of the present invention; 
           [0012]      FIG. 6  is a section view of an exemplary embodiment of the present invention; 
           [0013]      FIG. 7  is a detailed section view of an exemplary embodiment of the present invention; 
           [0014]      FIG. 8  is a detailed section view of an exemplary embodiment of the present invention; 
           [0015]      FIG. 9  is a detailed section view of an exemplary embodiment of the present invention; 
           [0016]      FIG. 10  is a section view of an exemplary embodiment of the present invention; 
           [0017]      FIG. 11  is a section view of an exemplary embodiment of the present invention; 
           [0018]      FIG. 12  is a section view of an exemplary embodiment of the present invention; 
           [0019]      FIG. 13  is a section view of an exemplary embodiment of the present invention; 
           [0020]      FIG. 14  is a perspective view of an exemplary embodiment of the present invention; 
           [0021]      FIG. 15  is a perspective view of an exemplary embodiment of the present invention; 
           [0022]      FIG. 16  is a section view of an exemplary embodiment of the present invention; 
           [0023]      FIG. 17  is a perspective view of an exemplary embodiment of the present invention, illustrating turning an exemplary embodiment of a valve cap 45 degrees and lifting the connected assembly upward; 
           [0024]      FIG. 18  is a section view of an exemplary embodiment of the present invention; 
           [0025]      FIG. 19  is a section view of an exemplary embodiment of the present invention; and 
           [0026]      FIG. 20  is a section view of an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0028]    Broadly, an embodiment of the present invention provides a multifunction cryogenic valve adapted to evacuate, seal off, monitor vacuum levels and relieve over-pressure in cryogenic vacuum insulated systems. 
         [0029]    Referring to  FIGS. 1 through 20 , the present invention may include a multifunction cryogenic valve  10  adapted to evacuate, seal off, monitor and relieve cryogenic vacuum insulated systems. The multifunction cryogenic valve  10  may include a valve body  16  forming a tubular wide body cavity  68  fluidly communicating to a narrower narrow body cavity  70  via a conical transition as illustrated in  FIGS. 19 and 20 . The wide body cavity  68  may extend from the conical transition to a top portion, wherein the top portion forms a top opening. The top portion may form a body o-ring groove  88  near an outer periphery thereof and a sunken top recess inward from the outer periphery. The body o-ring groove  88  may be dimensioned to snugly receive a body o-ring  42 ; and the sunken top recess may form a top o-ring groove  90  for snugly receiving a top o-ring  46 , as illustrated in  FIG. 3 . 
         [0030]    It should be understood, that the valve body  16  forms the body cavities  68 ,  70  along a shared longitudinal axis, wherein each cavity  68 ,  70  is concentric about, though consecutively along. As a result, terminology such as “upward”, “downward”, “upper”, “lower”, “top”, “bottom” is reference relative to positioning about the longitudinal axis, and not necessarily as relative to the force of gravity. 
         [0031]    The multifunction cryogenic valve  10  may also provide a valve top  14  dimensioned and adapted to be snugly received within the top opening so that a top flange portion may be supported by the sunken top recess, as illustrated in  FIG. 13 . The top flange portion may form at least one wrench hole  96  for installation purposes. The valve top  14  may have a tubular projection adapted and dimensioned to extend from the top flange portion into the wide body cavity  68 . Said tubular projection may form peripheral threading  74  to securely engage operating body cavity threading  76 . Said tubular projection forms a top shaft hole  98 , wherein at least one peripheral shaft ring groove is formed along its circumference, each dimensioned to snugly receive a shaft o-ring  34 . 
         [0032]    The multifunction cryogenic vacuum valve  10  may also provide a valve plug  20  adapted and dimensioned to frictionally engage the narrow body cavity  70 . A centrally disposed plug shaft hole  108  may be formed in a plug shaft that extends upwardly from the center of a body of the valve plug  20  so as to project toward the wide body cavity  68 . The plug shaft hole  108  may form a plug pin hole  100 . The body of the valve plug  20  may form spaced-apart top and bottom plug o-ring grooves  102 ,  104 , each dimensioned to snugly receive top and bottom plug o-rings  40 ,  38 , respectively. The bottom plug o-ring  104  and thus the snugly-fitting bottom plug o-ring  38  may be omega-shaped, as illustrated in  FIG. 3 . The omega shape may include an upward projecting segment  39 , whose upper apex is elevated above a majority of the remaining portion of the bottom plug o-ring  38 . The body of the valve plug  20  may form a thermocouple exposure slot  106  along a circumferential surface thereof, as illustrated in  FIG. 4 . The thermocouple exposure slot  106  is disposed to align with the upward projecting segment  39 . 
         [0033]    The multifunction cryogenic vacuum valve  10  may also provide a valve shaft  18  extending from an upper end to a lower end, wherein the lower end is dimensioned and adapted to be snugly received through the top shaft hole  98 , through a lumen of a body spring  32 , extending into the wide body cavity  68  so as to be at least partially received within the plug shaft hole  108 . Thereby, forming an annular space between the valve shaft  18  and the circumference of the body cavity  68 . The valve shaft  18  may be periscope shaped, wherein the upper end may form a generally rectangular shape, as illustrated in  FIG. 13 . The lower end may form an elongated shaft plug pin slot  94  dimensioned to slidably receive a plug roll pin  58  to ride therein, as illustrated in the Figures. The upper end may form a step-shaped shaft cap pin slot  92 . 
         [0034]    The multifunction cryogenic vacuum valve  10  may also provide a cap  12  having a body portion and, extending from the body portion, an annular ring dimensioned and adapted to snugly receive a portion of the top portion, as illustrated in  FIGS. 5 and 13 . The body portion may form a central projection  91 , wherein the central projection  91  and the annular ring are separated by a space, as illustrated in  FIG. 6 . The central projection  91  may form a cap shaft slot  86  dimensioned to receive the upper end of the valve shaft  18 . A narrow cap pin hole  80  may be formed in the central projection  91  so as to generally align with the shaft cap pin slot  92 , wherein a cap roll pin  56  is dimensioned to slidably be received through both, as illustrated in  FIG. 10 . 
         [0035]    The annular ring may form diametrically opposing wide cap pin holes  78  that generally align with the narrow cap pin hole  80 , wherein a pair of cap hole pins  54  are dimensioned to slidably and securely be received into the wide cap pin holes  78 . The annular ring may form a cap outer slot  82  extending along a periphery thereof, wherein a wider cap outer slot opening  84  may be disposed generally midpoint along the cap outer slot  82 , as illustrated in  FIGS. 2 and 12 . A body pin  64  may be disposed along a periphery of the valve body  16 , for example, protruding from a formed body pin hole  110 , wherein the body pin  64  is adapted and dimensioned to ride along the cap outer slot  82  when the cap  12  rotates about the portion of the top portion, as illustrated in  FIG. 12 . 
         [0036]    A lower portion of the valve body  16  may form a thermocouple threaded hole  112  fluidly communicating to the narrow body cavity  70  via a thermocouple. A thermocouple seal  36  may be disposed in the thermocouple threaded hole  112  so as to operatively engage the thermocouple vacuum exposure hole  114 . The thermocouple vacuum exposure hole  114  may be disposed along the lower portion of the valve body  16  so as to sufficiently align with the thermocouple exposure slot  106 . 
         [0037]    A side body opening  72  may be formed into the valve body  16 . A tubular valve flange  66  may be provided so as to be operatively welded by a fillet weld  138 , such as a TIG weld, along a periphery of side body opening  72 . The valve flange  66  may provide on one end flange threading  124  and a flange o-ring groove  122 , the groove  122  being dimensioned to snugly receive a flange o-ring  44 . 
         [0038]    The present invention may include a relief valve assembly  150 . The relief valve assembly  150  may include a relief valve poppet  52  sandwiching a relief valve body  26  against the one end of the valve flange  66 , and held in place by a coupling nut  24  providing inner threading  126  and a retainer slot  128 . The relief valve body  26  may form a body portion forming a centrally disposed relief valve body center hole  134  surrounded by a plurality of relief valve body exhaust holes  136 , wherein a retainer ring  130  may be formed along the periphery of said body portion, wherein the retainer ring  130  operatively engages the retainer slot  128 . A body portion of the relief valve poppet  52  may form at least one tether slot  120  and a relief valve o-ring groove, said groove being dimensioned to snugly receive a relief valve o-ring  28 . A relief valve poppet shaft  116  may be centrally disposed and extend from the body portion of the relief valve poppet  52 . The relief valve poppet shaft  116  may form a relief valve pin hole  118  dimensioned to slidably receive a relief valve roll pin  30 . The relief valve poppet shaft  116  may extend through the relief valve body center hole  134 , wherein a relief valve spring  60  is disposed, so that the relief valve roll pin  30  is held in place by the relief valve washer  62 , as illustrated in  FIG. 9 . 
         [0039]    Evacuation and Seal Off: 
         [0040]    To evacuate a system, the relief valve assembly  150  may be removed and allowed to hang from its tether cable  48  operatively engaging the at least one tether slot  120  by means of a tether crimp  50 . A user may attach evacuation equipment to the valve flange  66  by way of a coupling tube  22  forming a peripheral retainer ring  132  and a second coupling nut  140  having threading  142  and a second retainer slot  144 , as illustrated in  FIG. 14 , wherein the second retainer slot  144  operatively engages the retainer ring  132 , as illustrated in  FIG. 16 . The user then starts his pump and when the vacuum level is satisfactory, the cap  12  is lifted and shifted to the left and rotated up 90 degrees to the vertical position, whereby the cap roll pin  56  rides along the shaft cap pin slot  92 , as illustrated in  FIG. 20 . This enables the pump to begin pumping on the annular space between the inner vessel and the outer shell. Once a satisfactory vacuum level has been reached the cap  12  is rotated down to the closed position which seals off the systems vacuum annular space. 
         [0041]    Vacuum Monitoring: 
         [0042]    Vacuum level monitoring can be accomplished any time the present invention is in the closed position, wherein the cap  12  is down. The bottom plug o-rings groove  104  and thus the bottom plug o-ring  38  enable the thermocouple to be exposed when the top of the bottom plug o-ring  38  rises above the thermocouple exposure hole  114 , as illustrated in  FIGS. 6 and 7 . This is accomplished by turning the cap  12  90 degrees to a thermocouple stop position where it is secured with the body pin  64  riding within and along the cap outer slot  82 , as illustrated in  FIG. 12 . When in the thermocouple stop position, the thermocouple hole  114  communicates with the exposure slot  106  as a result of the upward projecting segment  39  of the bottom plug o-ring  38  disposed relative to the thermocouple hole  114 , as illustrated in  FIG. 7 . The multifunction cryogenic vacuum valve  10  can stay in this position for as long as the user requires, since the system is still sealed off with the top plug o-ring  40 . If the vacuum level is satisfactory, the cap  12  is turned 90 degrees back the other way—to a thermocouple go position—causing the bottom plug o-ring  38  to transition below the thermocouple hole  114  and providing a two o-ring—top and bottom plug o-rings  40 ,  38 —seal to maintain a more reliable vacuum seal off. This position is the standby or normal position and the cap  12  is secured to the assembly by the body pin  64  riding within the along the cap outer slot  82 . 
         [0043]    Pressure Relief: 
         [0044]    Pressure relief is required if there is a leak in the inner vessel and the cryogen begins to expand in the narrow body cavity  70 . The present invention provides for over pressure relief by the incorporation of the relief valve assembly  150  mounted on the flange  66 . When there is an increase in the annular pressure within the narrow body cavity  70  above a predetermined threshold the valve plug  20  rises on the valve shaft  18  by way of the plug roll pin  58  riding along the elongated shaft plug pin slot  94 , as illustrated in  FIG. 9 . The predetermined threshold specified by the user through the selection of a predetermined body spring  32  and relief valve spring  60 . This allows the relief valve assembly  150  to be exposed to the overpressure and it will push the relief valve poppet shaft  116  of the relief valve assembly  150  open and vent the over pressure to atmosphere. When the pressure is reduced to the design pressure the relief valve assembly  150  will close to maintain system cleanliness and integrity. This relief action will continue for as long as required until the over pressure is corrected. 
         [0045]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.