Abstract:
The present invention relates to a light weight check valve for use in bulk material transfers that incorporates a smooth, generally spherical interior cavity to minimize flow inefficiencies. The check valve is made from two portions: a body portion and a lid assembly which is removably mounted to the body portion. The gate valve, or poppet, is hingedly mounted to the lid assembly. Hence, when the check valve assembly is opened for inspection, by removing the lid assembly, the poppet is removed along with the lid assembly, to allow for easy inspection of the poppet.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority to provisional application Ser. No. 60/237,045 filed Oct. 2, 2000, entitled Plastic Swing Check Valve, and which is incorporated herein by reference. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not Applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    The present invention relates to an apparatus for allowing the transfer of bulk materials or fluids in containers, pipes or hoses, in one direction, but not in the opposite direction, and more particularly, to a lighter weight and more efficient swing check valve for use in the transfer of such materials or fluids.  
           [0004]    In the trucking industry, dry bulk materials and fluids (i.e., liquids and gasses) must regularly be transferred between truck trailer containers and either fixed storage containers or mobile containers, such as on ships planes or other trucks. In order to facilitate rapid transfer of the bulk materials and fluids, and to limit leakage, swing check valves are typically placed at the inlet ports on the containers. These valves have an internal pivoting gate, referred to as a “poppet,” that swings out of the way when the material flows in one direction, and drops in place to close the valve with a gasket seal when the material attempts to flow in the opposite direction. The valves are self-contained and require no external actuation other than the material flow itself.  
           [0005]    Conventional valves for most dry bulk trailer use are typically constructed of aluminum. Although lighter in weight than most metals, aluminum is significantly heavier than many materials, including plastics. In an application such as trucking, where large valves are required and carrying capacities are limited by loaded vehicle weight, any amount of weight reduction in the check valve directly results in greater load capacity, and thereby improved efficiency and reduced costs.  
           [0006]    In addition, when a bulk material or fluids (the transferred product) are transferred between storage containers, the transferred product must pass through the valve at a very rapid rate. Any irregularities (including irregularities due to pitting) in the shape of the check valve&#39;s inner surface will create turbulence in the material transfer that can slow the transfer. The greater the extent of the irregularities, the greater the turbulence and the greater the inefficiency in material transfer. Accordingly, it is desirable for the inner surface to be as spherical, smooth and free from pits and protrusions as possible. However, not only are the surfaces of the access port and poppet in a conventional check valve irregular in shape, conventional check valves exhibit burs and pits on the valve&#39;s inner surfaces from the casting process that finishing does not fully remove. These all result in undesirable excess turbulence during material flow.  
           [0007]    Furthermore, check valves require regular inspection and maintenance. Each valve has an access port for this purpose, generally located at the top of the valve. Complete inspection can only be accomplished by removing the access port, an external pivot pin assembly for the poppet, and then the internal poppet assembly. The same procedure must be followed to remove the poppet gasket for replacement, the most common maintenance and repair need on check valves. Because the gasket is typically glued to the poppet, the entire poppet assembly often must be replaced when the gasket fails.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention resides in a light weight check valve for use in bulk material transfers, and more particularly for use on truck trailer containers where the reduced weight over conventional metal valves provides efficiency benefits. The check valve is preferably made of an appropriate plastic which can withstand the bulk material or fluid passing through the check valve. Plastic is preferred due to the smooth surface that can be formed, and due to its ability to withstand pitting. Hence, the surface will remain smooth (i.e., will not become severely pitted, which can cause turbulent fluid flow through the valve). However, the check valve can also be made of other light weight materials. The poppet and access port in the present invention are configured such that when the check valve opens to allow air and material flow, the combined interior surfaces of the valve, excluding the inlet and outlet flow ports, mate smoothly against one another to form a nearly spherical shape. This, in combination with the smooth surface of the valve, reduces the amount of turbulence in the valve, increases flow efficiencies and enables increased flow rates.  
           [0009]    Further, the poppet assembly and access port are coupled internally so that both can be removed as a single unit for easy and rapid inspection of the entire valve. A simple seal such as an O-ring, or preferably a Quad-Ring® (available from Minnesota Rubber of Minneapolis, Minn.), located on the rim inside the valve against which the poppet closes, forms the poppet seal. In contrast to conventional check valves, this Quad-ring seal can be easily and rapidly replaced when necessary.  
           [0010]    The present invention is readily adaptable to virtually any size check valve, and can readily be combined with numerous interfaces for connection to a variety of containers, pipes and hoses.  
           [0011]    Additional features of the present invention will be in part apparent and in part pointed out hereinafter. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a perspective view a first embodiment of a fully assembled check valve of the present invention;  
         [0013]    [0013]FIG. 2 is a perspective view of the check valve with the lid assembly removed;  
         [0014]    [0014]FIG. 3 is a bottom view of a lid gasket;  
         [0015]    [0015]FIG. 4 is a perspective view of the seal mount;  
         [0016]    [0016]FIG. 5 is a cross-sectional view of the seal mount;  
         [0017]    [0017]FIG. 6 is a cross-sectional view of the fully assembled check valve with the gate closed, as viewed from the center of the valve toward the input side of the valve  
         [0018]    [0018]FIG. 7 is a side elevational view of a lid assembly of the check valve;  
         [0019]    [0019]FIG. 8 is a perspective view of the lid assembly;  
         [0020]    [0020]FIG. 9 is a bottom plan view of the lid assembly;  
         [0021]    [0021]FIG. 10 is a perspective view of a pin used to in lid assembly;  
         [0022]    [0022]FIG. 11 is a perspective view of a poppet of the check valve;  
         [0023]    [0023]FIG. 12 is a cross-sectional view of the poppet;  
         [0024]    [0024]FIG. 13 comprises a top plan view of a seal-ring used in conjunction with the poppet;  
         [0025]    [0025]FIG. 13A is a cross-sectional view of the seal ring;  
         [0026]    [0026]FIG. 14 is a top plan view of a spring for the poppet;  
         [0027]    [0027]FIG. 14A is a side elevational view of the spring;  
         [0028]    [0028]FIG. 15 is a perspective view of the a second embodiment of the check valve, when fully assembled;  
         [0029]    [0029]FIG. 16 is a perspective view of the lid gasket for the second embodiment.  
         [0030]    [0030]FIG. 17 is a cross-sectional view of the fully assembled check valve of FIG. 15 with the gate closed, as viewed from the center of the valve toward the input side of the valve;  
         [0031]    [0031]FIG. 18 is a side elevational view of the lid assembly of the check valve of FIG. 15;  
         [0032]    [0032]FIG. 19 is a cross-sectional view lid assembly taken along line B-B of FIG. 18 showing of the hinge area of the lid assembly;  
         [0033]    [0033]FIG. 20 is a perspective view of the lid assembly of the check valve of FIG. 15;  
         [0034]    [0034]FIG. 21 is a bottom plan view of the lid;  
         [0035]    [0035]FIG. 22 is a cross-sectional view of the lid assembly taken along line A-A of FIG. 21;  
         [0036]    [0036]FIG. 23 is an end elevational view of the lid assembly;  
         [0037]    [0037]FIG. 24 is a perspective view of the poppet for the check valve of FIG. 15;  
         [0038]    [0038]FIG. 25 is a side elevational view of the poppet;  
         [0039]    [0039]FIG. 26 is an additional side view of the lid in the second embodiment; and  
         [0040]    [0040]FIG. 27 is a cross-sectional view of the lid assembly taken along line B-B of FIG. 26 showing the hinged connection of the poppet to the lid.  
         [0041]    Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0042]    A first embodiment of a assembled check valve A is shown in FIG. 1. The check valve is preferably made of a plastic which can withstand the materials or fluids which flow through the check valve. In particular, preferably the plastic will withstand pitting due to corroding effects of the material which passes through the check valve so that the inner surfaces of the check valve will remain smooth. A preferred plastic is a polyamide (such as Grilon PVZ-5H available from EMS-Chemie (North America), Inc. of Sumter, N.C.) combined with Nylon and with impact modifiers. Other preferably light weight materials which will withstand the environment to which they are subjected and which will withstand pitting can be used as well.  
         [0043]    The check valve A includes a hollow body  1  and a lid assembly  2  fixedly attached to the body  1  by six bolts  3 . A thin, flat gasket  12  forms a seal between the body  1  and the lid assembly  2 . The body  1  comprises a generally spherical shape that transforms into two parallel, generally square shaped, fitting plates  6   a  and  6   b  at opposite ends of the body  1 . Each fitting plate  6   a,b  has an end face  9 , generally flat perimeter faces  10 , and a thickness equal to approximately one tenth the overall length of the body  1 . Brass nut inserts  11  are imbedded in the end faces  9  at each of the eight corners of the fitting plates  6   a  and  6   b  to facilitate ready attachment between the valve A and containers, pipes, hoses or other external devices to which the valve A can be attached.  
         [0044]    The fitting plates  6   a  and  6   b  have an input port  4  and an output port  5 , respectively to allow dry bulk material or fluids to flow through the input port  4 , through the body  1 , and through the output port  5 . The input port  4  and output port  5  are coaxial, each having equal diameters and a circular rim  8  located at the end faces  9 , perpendicular to the central axis of the ports  4  and  5 . A circular groove  7 , concentric with the ports  4  and  5 , is formed in each end face  9  of the fitting plate  6 . The groove  7  has an inner diameter slightly greater than that of the rim  8 , and a depth and outer diameter configured to accommodate standard compression Quad-ring seals (available from Minnesota Rubber of Minneapolis, Minn.) for sealing the valve to, for example, a container or a supply hose.  
         [0045]    To minimize cost and weight, the bodies of the fitting plates  6   a  and  6   b  comprise webbed members between the outer edges of the groove  7 , the supporting rings about the brass nut inserts  11 , and each of the sidewalls supporting the perimeter faces  10 .  
         [0046]    The body  1  defines a cavity C (FIG. 2), wherein the bottom half of the cavity C comprises a smooth, elongated hemispherical surface  13  truncated at the ports  4  and  5 . The surface  13  ends with ledges  14  at the approximate mid-height of each side of the body  1  between the ports  4  and  5 . The ledges  14 , thereupon extend radially a short distance beyond the surface  13 , and run laterally along the length of the interior of the body  1  from the input port  4  to the output port  5 . Sidewalls  16  of the cavity C extend vertically from both of the ledges  14  to a horizontal rim  17  at the top of the body  1 , that is coplanar with the uppermost perimeter faces  10  of the ports  4  and  5 .  
         [0047]    The inlet and outlet ports  4  and  5  are defined by circular surfaces  15  extending axially from the cavity C. A detent is formed in the cavity C above surfaces  15 . The detent if formed by a curved surface  18  that runs laterally from an approximate 45 degree arc, centrally located along the top of the outermost perimeter of the circular surface  15 , toward the fitting plate  6   a  for approximately half the length of the input port  4 . Another sidewall  19  rises vertically, from the edge of the surface  18  opposite the ledge  15 , to the rim  17 . Two parallel sidewalls  20  rise vertically from the lowermost edges of the surface  18  to the rim  17 , each being perpendicular to, and intersecting, the sidewall  19  along their outermost edges.  
         [0048]    Two end faces  21 , coplanar with one another and parallel to the end face  9  of the fitting plate  6   a,  join the faces  20 , the ledge  15 , the sidewalls  16  and the rim  17  in the cavity C, on either side of the input port  4 . Each face  21 , on its respective side of the port  4 , extends from the innermost edge of the face  19 , to an arc of the circular ledge  15  that runs between the intersections of the ledge  15  with the face  20  and the sidewall  16 , to the edge of the sidewall  16  that runs vertically from the point on ledge  14  nearest the port  4  to the rim  17 , and to rim  17 .  
         [0049]    A gasket groove  22  extends along the rim  17  at the edge of the cavity C in the body  1 . The gasket groove  22  is sized and shaped to accommodate a ridge  12   a  (FIG. 3) on one side of the gasket  12  (FIG. 3). The cross-sectional dimensions of the groove  22  and the gasket ridge  12   a  are such that the gasket ridge  12   a  fits snugly into the groove  22  when the gasket  12  is placed atop the body  1  of the valve A.  
         [0050]    A seal mount  23  (FIGS. 4 and 5) is positioned in the ports  4  and  5  to mount a seal in the ports  4  and  5 . The seal is circular in plan and having generally square in crosssection (FIG. 5). The seal mount  23  comprises a cylindrical inner surface  24  with a diameter equal to the diameter of the input port  4 , a cylindrical outer surface  25  with a diameter equal to the outer diameter of the port surface  15 , and a back face  26  and a front face  27 , such that the surfaces  24  and  25  are concentric. A circular groove  28 , shaped and sized to hold a seal ring (such as a Quad-Ring® seal available from Minnesota Rubber of Minneapolis, Minn.), runs the full circumference of the front face  27 . Another groove  29 , having a generally square cross-section, runs the full circumference of the outer cylindrical surface  25 . The seal mount  23  is secured in the ports  4  and  5  with the back face  26  against the port surface  15 . The seal is then received in the seal mount groove  28 .  
         [0051]    The lid assembly  2  (shown in detail in FIGS.  7 - 12 ) comprises a lid  30 , two bushings  31 , two pins  32 , a poppet  33 , and a spring  35 . A seal plate  36  at the top of the lid  2  (FIGS. 7 and 8), having a thickness approximately equal to that of the sidewalls  16  of the body  1 , generally conforms in shape to the top of the body  1  without the end plates  6   a  and  6   b,  having an input end  36   a  and an exit end  36   b.  Six ears  37  surround the seal plate  36 , each having a central bore  38  with a diameter slightly larger than that of the bolts  3  to allow the bolts to turn freely in the bores  38  with little or no lateral or angular movement.  
         [0052]    Rising from the center of the seal plate  36  is a dome  39 , having a height approximately three times that of the seal plate  36 , and a radius slightly larger than the cross-sectional radius of the centermost section of the elliptical portion of the cavity C. The dome  39  is positioned on the seal plate  36  such that it contains a diameter d, running perpendicular to the input and exit ends  36   a  and  36   b,  that bisects the seal plate  36 . Descending perpendicularly from the seal plate  36  is a hollow cylindrical neck  40 , being concentric with, and having an outer diameter approximately equal to that of, the dome  39 . Also descending perpendicularly from the seal plate are two ears  41 , both parallel to and approximately one half the radius of the dome  39  from the diameter d. The ears  41  are each connected in part to the side of the neck  40 , have a height less than that of the sidewalls  20  of the cavity C, and a thickness equivalent to that of the seal plate  36 . The dimensions and locations of the ears  41  are such that the ears  41  can readily fit between the sidewalls  20  of the detent above the inlet  4 .  
         [0053]    Through each of the ears  41  runs a bore  42 , having a central axis parallel to the seal plate  36  and perpendicular to the diameter d, each bore  42  being axially aligned with one another and having a diameter generally equal to the outer diameter of the bushings  31 . Above the ears  41 , a structural member  43  rises from the seal plate  36 , and extends along an ascending plane to a plane above and parallel with the seal plate  36  to intersect with the dome  39  at approximately half the height of the dome  39 , therein providing additional structural support for the ears  41 .  
         [0054]    Descending from the neck  40  of the lid  2  is a generally dome shaped body  44 , having outer walls  45  shaped to conform to, and fit snugly within, the sidewalls  16  of the cavity C, and further shaped such that their lowest edges abut against, for the full length of, the ledge  14  of cavity C. Beneath the dome  39  and inside the neck  40  and body  44  (FIG. 9), the lid  2  houses an interior dome  47  that opens to expose a portion of the underside of the seal plate  36  and the inner faces of the ears  41 . For added strength, a rib  46  spans the center of the inner dome  45  from between the ears  41  to the inner surface of the neck  40  opposite the ears  41 .  
         [0055]    Each of the bushings  31  is coaxially mounted in one of the ears  41  (FIG. 6), such that the outermost faces of the opposing bushings  31  are flush with the outermost faces of the ears  41 . The pin  32  extends through the bushings  31 , such that the ends of the pin  32  are generally flush with the outermost faces of the ears  41  and the pin  32  may rotate freely within the bushings  31 . Numerous straight knurls  47  (FIG. 10) score the full circumference of the pin  32 , each parallel to the central axis of the pin  32  and running the length between the innermost faces of the bushings  31 , the knurls being distanced slightly from the bushings  31  so as not to hinder the free rotation of the pin  32  within the bushings  31 .  
         [0056]    A sleeve member  48  of the poppet  33  (FIG. 11) attaches the poppet  33  to the pin  32 , the poppet  33  being held fixedly to the pin  32  by the knurls  47 , such that the poppet  33  and the pin  32  rotate in unison about the pin&#39;s central axis within the bushings  31 . From the sleeve  48 , the poppet transitions into a flat outer ring  49  that surrounds a dome  50 . Rising above and spanning across the convex side of the dome  50  are six structural ribs  51 , each radiating from the center of the dome  50  to the outer edge of the outer ring  49 . On the opposite side of the poppet  33  from the ribs  51  (FIG. 12), a channel  52 , having a rectangular cross-section with a horizontal tongue  53  midway up the innermost side of the rectangle, is formed about the full circumference of the front face of the outer ring  49 .  
         [0057]    The channel  52  has a depth, and inner and outer diameters equal to the same dimensions of the ring-shaped brass insert  34  (FIG. 13). The insert  34  has a small channel  54 , located on the inner edge of the insert  34  (FIG. 13 a ), having dimensions equal to the dimensions of the tongue  53  on the poppet  33 , such that the tongue  53  is received in the channel  54 . When the insert  34  is pressed into the channel  52  of the poppet  33  with sufficient force, the tongue  53  seats snugly into the channel  54  in the insert  34  to secure the insert  34  in place on the poppet  33 .  
         [0058]    The spring  35  (FIG. 14), comprised of a single, contiguous, stainless steel spring wire, is generally U-shaped, having a generally U-shaped base  55  having legs  55   a  and residing in a plane p, a coil  56  located at the end of each leg  55   a,  and pair of parallel tails  57  extending from the double coils  56  to the top of the spring  35 . The coils  56  share a common central axis, and have an inner diameter slightly greater than the outer diameter of the pin  32 . The base legs  55   a  each have a bend  58 , of approximately 45 degrees, located between the base of spring  35  and each double coil  56 . The bend  58  raises the double coils  56  above the plane p containing the base  56 . The tails  57  extend from the double coils  56  perpendicularly back toward, and through the plane p. The spring  35  is thus configured to enable the coils  56  to fit around, and rotate freely about, the pin  32 , while the base  55  presses against the rib  51  of the poppet  33 , nearest the sleeve  48 , and the tails  57  press against that portion of the underside of the seal plate  36  between the ears  42 .  
         [0059]    The body  1 , lid assembly  2 , and poppet  33  of the check valve A are all constructed of a light weight plastic material, such as a polyamide available from EMS-Chemie under the name Grilon PVZ-5H with 50% G.F. Nylon and an impact modifier. This material, and others like it, provide adequate strength for the check valve, along with the advantages of having a lighter weight than metals, including aluminum, and smoother member surfaces.  
         [0060]    In use then, when seal mount  23  is properly seated on the port surface  15  in the cavity C of the valve A, a seal of appropriate dimensions is properly seated in the groove  28  of the seal mount  23 , and the lid assembly  2  is properly and fully placed within the body  1  of the valve A, the front face of insert  35  on the poppet  33  will align concentric to and flush with the seal in the seal mount  23 . This is the “closed” position for valve A. The spring  35  imparts a force against the ribbed side of the poppet  33  that maintains the poppet in the “closed” position.  
         [0061]    When a sufficiently strong counter force is applied to the concave side of the dome  50  of the poppet  33 , such as when bulk material is being directed through the inlet port  4  of the valve A, the poppet swings up against the inner dome  45  of the lid  30 . The shape of the concave side of the poppet  33  in conjunction with the exposed walls of the inner dome  45  of the lid  30  and the elongated hemispherical surface  13  in the body  1 , combine to form a generally spherical cavity through which the bulk material passes inside the valve A. This shape creates much less turbulence than the shapes of conventional swing valves and thereby offers greater transfer efficiency and throughput velocities. Should the flow of material begin to reverse for any reason, the poppet  33  will quickly return to, and remain in, the “closed” position to prevent the possibility of any such backflow.  
         [0062]    Finally, because the lid  30 , the bronze bushings  31 , the pin  32 , the poppet  33 , and the brass insert  34  all comprise a single unitized lid assembly  2 , the entire core of the check valve A can be quickly and readily examined by simply removing the lid assembly  2  from the body  1 . This exposes the Quad-ring seal in the seal mount for ready examination and replacement, as well as facilitating rapid examination and maintenance of the lid assembly  2  itself.  
         [0063]    A second embodiment of the check valve A′ is shown in FIGS.  15 - 25 . The check valve A′ is substantially similar to the check valve A of FIG. 1. It includes a body  101  identical to the body  1  of valve A. A lid assembly  102  closes the body  101 . The lid assembly  102  is slightly different from the lid assembly  2 . The lid assembly  102  includes a seal plate  136  having a perimeter sized and shaped to close the open top of the body  101 . A series of ears  137  surround the seal plate  36 . The ears have holes  138  through which bolts pass to secure the lid assembly  102  to the body  101 .  
         [0064]    A gasket  112  is positioned on the upper edge of the body walls, and the seal plate  136  is placed on top of the gasket. The gasket  112  thus forms a fluid tight seal between the body  101  and the seal plate  136 . The gasket  112  is corresponds in shape to the circumferential shape of the body walls. The gasket  112  includes a rib  112   a  which fits in a groove in the upper edge of the body wall and a plurality of ears  112   b  which correspond in size, shape, and position to the ears of the seal plate  136 . Hence, the bolts pas through the gasket ears when the cover assembly  102  is secured to the body  101 . The gasket  112  also includes legs  112   c  which are positioned effectively at the four corners of the gasket  112 . The gasket legs  112   c  help locate the gasket  112  on the body  101 .  
         [0065]    A dome  139  rises up from the center of the seal plate  136 . The dome  139  has a radius slightly larger than the cross-sectional radius of the centermost section of the elliptical portion of the cavity C. The dome  139  is positioned on the seal plate  136  such that it contains a diameter d, running perpendicular to the input and exit ends  136   a  and  136   b,  that bisects the seal plate  136 . A plurality of intersecting ribs  139   a  extend over the outer surface of the dome  139 .  
         [0066]    A cylindrical neck  140  descends from the seal plate  136 . The neck  140  is concentric with, and has an outer diameter approximately equal to that of, the dome  139 .  
         [0067]    A pair of opposed ears  141  also descend from the seal plate  136 . As best seen if FIGS. 19 and 25, the ears  141  have a circumferential wall  141   a  defining a pocket  141   b  with a floor  141   c.  A central opening  142  is formed in the pocket floors  141   c.  The openings  142  of the opposed ears  141  are aligned with each other.  
         [0068]    A truncated dome shaped body  144  descends from the neck  140 . The dome shaped body  144  has arced side walls  145  ending with a flat, vertical face  145   a  shaped to conform to, and fit snugly within, the sidewalls  16  of the cavity C, and further shaped such that their lowest edges abut against, for the full length of, the ledge  14  of cavity C. The dome shaped body  144  has an inner surface  147  which defines a radius corresponding to the radius defined by the lower portion of the cavity in the body  101 . For added strength, a rib  146  spans the center of the inner dome  147  from between the ears  141  to the inner surface of the neck  140  opposite the ears  141 . The dome shaped body, in conjunction with the lower section of the valve body cavity C defines a substantially spherical chamber when the cover assembly  102  is mounted on the body  101 , with entrance and exit ports through which fluid material flows.  
         [0069]    As seen in FIG. 25, a pin  132  extends through each of the ear holes  142 . In FIG. 25, two pins are used, which of which extends into the space between the ears  141 . However, a single pin, which spans the distance between the ears  142  (such as used in the valve A) can also be used. The pin  132  includes a slot  132   a  extending across the potion of the pins  132  in the ear pockets  141   b.    
         [0070]    The poppet  133  is pivotally mounted to the lid assembly  102  by means of the pins  132 . The poppet has a main, generally circular body  133   a  with a sleeve member or arm  148 . The arm  148  has a hole  148   a  into which the pins  132  extend. The pins  132  are sized to be frictionally received in the sleeve hole  148   a.  Hence, the pins  132  act as axles for the poppet  133 , and rotate in the ear holes  142  as the poppet  133  is pivot relative to the dome shaped body  144 .  
         [0071]    The poppet body  133   a  includes a flat outer ring  149  from which the sleeve member  148  extends. The ring  149  surrounds a dome  150 . Rising above and spanning across the convex side of the dome  150  are structural ribs  151 , each radiating from the center of the dome  150  to the outer ring  149 . On the opposite side of the poppet  33  from the ribs  51  (FIG. 12), a channel  52 , having a rectangular cross-section with a horizontal tongue  53  midway up the innermost side of the rectangle, is formed about the full circumference of the front face of the outer ring  49 .  
         [0072]    A torsion spring  135  is received in the pockets  141   b  of the ears  141 . The torsion spring is journaled about the each pin  132  and includes a coil  135   a  having ends  135   b  and c. The end  135   b  of the spring  135  is bent to be received in the pin slot  132   a,  and the end  135   c  extends outwardly from the coil to engage the under side of the lid assembly  102 , as seen in FIG. 26.  
         [0073]    The poppet  133  is shown in its down position in FIG. 26, in which position, the poppet would close the inlet port into the valve body  101 . As can be appreciated, when the poppet  133  is rotated counterclockwise (with respect to FIG. 26) into the cavity, the end  135   b  of the torsion spring  135  will engage the underside of the lid  136 . The interaction of the spring, as such a point, between the pins  132  (which are engaged by the spring) and the lid  136 , will create a spring force which will urge the poppet  133  back to the position shown in FIGS. 26 and 27.  
         [0074]    As can be appreciated, in both embodiments of the check valve, the lid assembly and the body define complementary cavities, such that, when the lid assembly is mounted to the body, they form a spherical chamber through which the flowable material passes. Further, the walls of the body and the lid assembly are formed such that there is a smooth transition on the chamber wall between the body and the lid assembly. Hence, the flowable material is presented with a substantially smooth surface to reduce the potential of turbulence within the valve, and increase throughput through the valve. Lastly, the lid assembly, to which the poppet is hingedly mounted) in both embodiments, is removably mounted to the body. Thus, by removing the bolts or screws which secure the lid assembly to the body, the lid assembly and poppet can be removed. This makes for easy inspection (and replacement if necessary) of the poppet and its associated seals.  
         [0075]    As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. For example, although the valve lid assembly  2  and body  1  are preferably made from plastic, they can be made from other materials as well. Additionally, the inner surface or wall of the lid assembly and body can be coated with a material which will resist pitting, if a different material is required for the exterior surfaces of the check valve. This will produce a valve in which the walls of the chamber are lined with a material which will substantially resist pitting.