Abstract:
A clamp for securing a flexible sheet to the upper portion of a wall of a water tank includes a pair of thin, flexible strips spaced apart by a plurality of spacers near a top portion of the strips. At least one rod or threaded bolt extends through holes provided in the strips below the spacers. Nuts carried by the rod or bolt can be moved inwardly so as to deflect the flexible sheets inwardly thereby clamping the flexible sheet between the clamp and the tank wall.

Description:
BACKGROUND OF INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a water storage tank that can be assembled on a work site where there is a need for storing water. Also disclosed is a plurality of subcombinations that can be used in conjunction with known water storage tanks including a hydraulic hold down, a spout, a clamp, and wall joint structure as more fully disclosed herein. 
         [0003]    2. Description of Related Art 
         [0004]    In the oil and gas industry, water storage has become an issue due to the large amount of barrels of water required to perform drilling operations. Cost of transporting a large number of tanks to location, and logistical problems of having enough space at the well site to accommodate their positioning has forced the oil and gas industry to find a solution. The solution that has developed is the use of a single mobile erecting tank. These tanks eliminate a large fleet of storage vessels and the cost of transporting them to location. 
         [0005]    These large capacity tanks normally comprise 16 single panels that connect together side by side, forming in one embodiment a 122 ft. diameter tank with a height of 12 ft. After they are assembled a rubber sheet, plastic, or polypropylene sheet is positioned in the inside and the edges are laid over the top rail of the tank. These edges of the sheet are secured to the top rail by the use of c-clamps. 
         [0006]    The suction lines are then hung over into the tank and the tank is then filled with water. As the tank is filled, water forces the sheet into the lower inside corners of the tank. This can allow the sheet to be pinched or protrude under the wall of the tank causing a leak or tear of the rubber sheet. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present invention disclosed and claimed in this divisional application is a clamp specifically designed to secure the top layer sheet to the upper portion of the wall forming the tank which is the subject matter of the parent application. 
         [0008]    According to an embodiment of the invention, the clamp is formed by two thin strips of flexible material that are spaced apart by a plurality of spacers located at a top-portion of the strips. At least one threaded rod extends through apertures in the strips and carries nuts that can be moved inwardly against the strips and thereby deflecting the strips toward each other to create a clamping effect. 
         [0009]    While this discussion of a summary of the invention has been provided, it is understood that the invention of the present invention is defined by the claims included at the end of this specification. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0010]      FIG. 1  is a perspective view of a wall section of the water tank. 
           [0011]      FIG. 2  is a perspective view of a water tank formed by a plurality of the wall sections shown in  FIG. 1 . 
           [0012]      FIG. 3  is a perspective view of a hydraulic hold down according to an embodiment of the invention. 
           [0013]      FIG. 4  is a view taken along line A-A of  FIG. 3 . 
           [0014]      FIG. 5  is a cross-sectional view of the tank wall and bottom structure. 
           [0015]      FIG. 6  is a perspective view of a clamp according to an embodiment of the invention. 
           [0016]      FIG. 7  is a cross-sectional view taken along line  6 - 6  of  FIG. 6 . 
           [0017]      FIG. 8  is a perspective view of a spout according to an embodiment of the invention. 
           [0018]      FIG. 9  is a side view of the spout. 
           [0019]      FIG. 10  is a cross-sectional view of the spout attached to a wall section of the tank. 
           [0020]      FIG. 11  is a front view of one of the split rings shown in  FIG. 10 . 
           [0021]      FIG. 12  is a front view of a keeper ring as shown in  FIG. 10 . 
           [0022]      FIG. 13  is a cross-sectional view taken along line  13 - 13  of  FIG. 12 . 
           [0023]      FIG. 14  is a cross-sectional view of the joint between adjacent wall sections. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    An embodiment of the invention will now be discussed with reference to the figures. As shown in  FIG. 2 , a circular wall forming the storage tank  1  is formed by a plurality of individual curved wall sections  30  as illustrated in  FIG. 1 . Each wall section  30  includes a frame formed by a top  31 , a bottom  32 , vertical members  33  and thin walled portions  34 . One end of the wall section  30  includes a vertically extending plate  36  having apertures  37  therein and the opposite end of the wall section has a vertically extending plate  38  having a plurality of pins on  39  that are adapted to extend through the apertures  37  as shown in  FIG. 14 . 
         [0025]    Pins  39  may be secured within apertures  37  by a suitable fastening device such as a pin extending through a bore in pins  39 . Also a sealing gasket  12  may be placed over the vertically extending joint to prevent the final layer from being forced into the joint as will be described below. 
         [0026]    Channels  51  may be formed in the ground within the area defined by the circular wall to provide a drainage ditch. 
         [0027]    Prior to the wall sections being placed on the ground  101 , a circular ground mat of flexible water impermeable material  2  is positioned over the ground which has been leveled and cleared of debris to the extent necessary as shown in  FIG. 5 . Ground mat  2  extends a given distance outwardly from the circular wall  4 , for example two feet. This forms a protective barrier preventing damage to the final cover and prevents the ground from getting saturated which could cause a catastrophic failure of the grown under the tank. The mat  2  may be of any suitable thickness for example forty four mm and may be a polypropylene web reinforced sheet. The diameter of the sheet is selected to be slightly larger than the diameter of the tank, for example, the ground mat may extend a distance of 1-5 feet beyond the tank wall as shown in  FIG. 5 . 
         [0028]    A protective mat  3 , which can be made of felt, polypropylene, rubber, or various types of padding, may be laid on top of ground mat  2  within the wall of the tank as shown in  FIG. 5 . This adds an additional layer of protection from sharp objects that may come into contact with ground layer  2 . 
         [0029]      FIGS. 3 and 4  illustrate a novel hydraulic hold down according to an embodiment of the invention. A hydraulic hold down device  47  is formed with a horizontally extending planar portion  41 , a ninety degree bend portion  44  and vertically extending portion  42 . Extending along and attached to the bend portion  44  is an L-shaped reinforcing bar. Hydraulic hold downs  47  have a curvature that corresponds to the curvature of wall sections  30  so that they conform to the interface of walls  4  with protective mat  3  as shown in  FIG. 5 . A plurality of the hydraulic hold downs are placed within the tank so as to form a complete circle. The curvature of the hold downs is selected so as to form a circle having a diameter that corresponds to the diameter of the tank. 
         [0030]    By way of example, horizontal portion  41  may be about twelve inches in width and portion  42  may be two inches in height. The hydraulic hold downs also help to stabilize the side walls. 
         [0031]    Once the hold downs have been placed around the entire inner periphery of the tank wall, a protective strip  5  of material which may be felt, rubber, polypropylene, or any other protective material is placed on top of the hydraulic hold downs as shown in  FIG. 5 . The strip extends slightly beyond the horizontal and vertical portions of the hydraulic hold down as shown in  FIG. 5  so as to cover any sharp edges on the hydraulic hold downs. 
         [0032]    The next step in constructing the water tank is to position a flexible, circular floor sheet over the wall assembly so that it will cover the ground within the tank wall and extend upwardly and over the top portion of the tank wall as shown in  FIG. 5 . Circular floor sheet  8  will cover protective strip  5  and hold downs  47  and will form a fluid tight tank which includes side walls sections  30  and ground mat  2 . A suitable clamp which may be any known type of clamp is used to clamp the upper portion of the floor sheet  8  to the upper wall portion  9  as shown in  FIG. 5 . A clamping mechanism has been developed to clamp the upper portion of sheet  8  to the upper portion of side walls  30 . As shown in  FIGS. 6 and 7 , the clamp  60  includes two relatively thin strips  61  and  62  of flexible material such as sheet metal or plastic. Strips  61  and  62  may be slightly curved to conform to the curvature of wall portions  30  and are spaced apart by one or more spacers  63  at the top portion of each strip. Spacers  63  are welded or otherwise secured to strips  61  and  62 , and may be V-shaped. 
         [0033]    A plurality of threaded bolts or rods  64  extend through apertures formed in strips  61  and  62  at a position below where the spacers are located. Nuts  65  are positioned on each end of threaded bolts  64 . As the nuts are threaded inwardly, they will engage strips  61  and  62  which will cause the strips to flex inwardly and thus clamp sheet  8  to the upper portion of wall  8  when the clamps are positioned as shown in  FIG. 5 . Although two nuts are shown in  FIG. 7 , the clamp could include only one nut on either end of the rod or bolt  64 . 
         [0034]    Clamps  60  may be spaced around the top of tank wall  4  or they may completely cover the top portion of the wall. 
         [0035]    As shown in  FIG. 10 , a tubular fitting  70  is located in a side wall of the tank for easy filling and draining of the tank as needed. This is accomplished by the provision of a fitting for attachment to a fluid conduit for supplying or withdrawing water to and from the tanks As shown in  FIGS. 8 and 9 , tubular fitting  70  includes generally hollow cylindrical body portions  76 ,  74  and  72  with a beveled portion  73  between  72  and  74 . A circular flange  71  is located on an exterior end of the fitting. Fitting  70  is placed through an aperture located in a lower portion of a wall section as shown in  FIG. 10 . Fitting  70  also includes an annular groove  75  between flange  71  and body portion  72 . Suitable threads  95  may be provided on the outside surface of body portion  74  for connection to a water conduit. 
         [0036]    In order to form a water tight seal, a rubber seal  79  is positioned between the flange  4  and the inside surface of tank  4 . The rubber seal may consist of the portion of the floor sheet that extends upwardly along the inner tank wall or may be a separate circular ring member. A wall stiffening ring  99  is welded to the outside surface of the wall. Next a pair of split rings as shown in  FIG. 11  are positioned within groove  75  and are held in place by a keeper ring  83  shown in  FIGS. 12 and 13 . With the components positioned as shown in  FIG. 10 , the assembly is bolted together by bolts  98  that extend up to wall stiffening ring  99 . 
         [0037]    Rubber seal  79  may be a conventional circular seal. 
         [0038]    Wall stiffening ring  99  is a circular washer of stiff material and has a hole diameter so that it sits on outer surface  76  of the fitting  70 . 
         [0039]    The keeper ring  80  is illustrated in  FIGS. 12 and 13  and comprises an annular ring portion  81  having a plurality of apertures  82  formed therein. The ring  80  also includes a longitudinally extending flange  83  that extends at a right angle from ring portion  81 . Keeper ring  80  also has a centrally located opening  84  so that the ring may fit over the outside periphery of the tubular fitting. 
         [0040]    A split ring is shown in  FIG. 11  and includes an arcuate body portion  91  and a plurality of threaded apertures  92 . 
         [0041]    Two split rings are placed within the groove  75  of fitting  70  as shown in  FIG. 10   
         [0042]    Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims. 
         [0043]    Although an embodiment of the invention has been described, it is clear that other embodiments can be envisioned that fall within the scope of the invention as defined by the claims.