Patent Publication Number: US-9840367-B2

Title: Multi-function closure for a liquid containment tank

Description:
BACKGROUND OF THE INVENTION 
     Mobile and stationary bulk liquid containers or tanks come in many different sizes and shapes, and are used both above ground and below ground. These tanks typically require openings or porting to allow liquid to be introduced and removed from the tank, for venting of the tank, and for inspection of the tank interior. In some applications, government regulations require capture and containment of any spillage to avoid environmental issues. Also, contamination ingress is a concern in some applications. The various tank openings are separate and independent from one another. Each opening requires a lid or cap which can be removed as needed. The largest opening is a manway to accommodate scheduled, mandatory inspections and recertification of the tank. The fill ports are usually located in the top of a tank. A discharge port may also be located in the top of the tank for removal of fluid by suction or pumping. A vent port is also located in the top of the tank to displace air when liquid is added to the tank. Each port in these prior art tanks requires a seal to preclude leakage into or from the tank, with each seal providing an opportunity for leakage failure. 
     Therefore, a primary objective of the present invention is the provision of an improved closure for bulk liquid containment tanks. 
     Another objective of the present invention is the provision a closure for a liquid containment tank manway opening with multiple ports formed in the closure to accommodate liquid filling and discharge from the tank. 
     Yet another objective of the present invention is the provision a multi-functional closure for a liquid containment tank which minimizes the risk of liquid leakage into or out of the tank. 
     Still another objective of the present invention is the provision of a closure for a liquid containment tank manway opening having an anti-spill reservoir to capture spilled liquids being introduced to or removed from the tank. 
     Another objective of the present invention is the provision of a closure for a liquid containment tank which incorporates all the necessary ports required by the tank. 
     Yet another objective of the present invention is the provision of a closure for a liquid containment tank opening which can be used on a flat-walled or curved-walled tank. 
     A further objective of the present invention is the provision of a tank closure which can be used on mobile and stationary liquid containment tanks. 
     Another objective of the present invention is a closure for use on flat and curved wall liquid containment tanks. 
     Still another objective of the present invention is the provision of a closure for a liquid containment tank opening which protects and secures multiple openings in the closure and into the tank. 
     A further objective of the present invention is the provision of a closure for a bulk liquid containment tank inspection opening which is easy and economical to manufacture, and safe and durable in use in filling, emptying, and inspecting the tank. 
     These and other objectives will become apparent from the following description of the invention. 
     SUMMARY OF THE INVENTION 
     A multi-function closure is provided for a bulk liquid containment tank having an inspection opening in the top wall or top portion of the tank. The closure is mounted to the tank over the inspection opening. The closure includes a ring attached to the top or upper wall of the tank and extending around the inspection opening. The closure also includes a pan removably fastened to the ring and a lid pivotally connected to the pan for movement between open and closed positions. Multiple ports are formed in the bottom of the pan for the tank liquid functions, including filling the tank and removing liquid from the tank. The pan has a reservoir for capturing and collecting any liquid spills, and a drain to dispose of collected liquid. The pan and lid can be removed from the ring to provide access to the inspection opening for periodic inspections of the tank interior. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a liquid containment tank having the closure of the present invention, with the lid removed to show the multi-function features of the closure. 
         FIG. 2  is a perspective view of the closure with the lid in a closed position. 
         FIG. 3  is a perspective view of the closure with the lid in an open position. 
         FIG. 4  is an enlarged view of the pan with multiple ports. 
         FIG. 5  is a side elevation view of the closure, with the lid in an open position. 
         FIG. 6  is a bottom plan view of the closure, with the lid in the open position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The tank closure of the present invention is generally designated in the drawings by the reference numeral  10 . The closure  10  can be used on various size and shaped tanks, including a flat-walled and flat-top tank  12 , as shown in the drawings, or on curved wall or cylindrical tanks. The closure  10  is typically installed on the top of the tank, pursuant to governmental rules and regulations. 
     The closure  10  has three primary components, a ring  14 , a pan  16 , and a lid  18 . The ring  14  is welded or otherwise fixed to the top wall of the tank so as to extend around an inspection opening in the tank  12  used for periodic inspections of the tank interior. The ring  14  has an annular vertical lip  20  extending into the inspection opening of the tank  12 , and an annular horizontal flange  22  residing on top of the tank  12 . A gasket may be provided between the horizontal flange  22  and the upper tank wall. The ring  14  provides the transition between the tank and the pan  16 , whether the tank is flat-walled or curved wall. 
     The pan  16  is removably attached to the flange  22  of the ring  14  in any convenient manner, such as by a plurality of nuts and bolts  26 . The pan  16  includes a bottom wall  28  and a side wall  30  which form a cavity or reservoir  32  for capturing liquids spilled during filling or discharge of the tank  12 . 
     The lid  18  is pivotally connected to the pan  16  for movement between a closed position, shown in  FIG. 2 , and an open position, shown in  FIG. 3 . The lid includes a top wall  34  and a side wall  36 . The diameter of the side wall  36  is slightly larger than the diameter of the pan side wall  30 , so that the lid  18  overlays the pan  16  when in the closed position. The pivotal connection between the pan  16  and lid  18  can be formed in any known and convenient manner, such as a hinge  38  with a substantially horizontal pivot axis  40 . The pan  16  and lid  18  each include a tab  42 ,  44 , respectively, which overlay each other when the lid  18  is closed. The tabs  42 ,  44  each have a hole for receipt of a padlock (not shown), so that the lid  18  can be locked in the closed position to prevent unauthorized access to the interior of the closure  10 . 
     The pan  16  has a plurality of ports formed in the bottom wall  28 . The ports provide multi-functionality for the closure  10 . For example, a first inlet port  46  is provided for introducing liquid into the tank  12 . A removable cap  48  is provided for the port  46 , and can be threaded or otherwise connected in any known manner. Preferably, the cap  48  is vented. A second inlet port  50  may be provided in the pan  16  to allow filling of the tank  12  from two separate liquid sources, to speed up the filling process. The port  50  may be provided with a cam lock coupling  52  which accepts a mating nozzle on the end of a fill hose. The cam lock coupling  52  provides a sealed connection so as to preclude spillage during filling of the tank  12 . 
     A third port  54  may be provided in the bottom  28  of the pan  16 , with a depth gauge  56  mounted therein. The depth gauge  56  includes a float  57  extending downwardly into the tank  12 . The depth gauge  56  allows the level of liquid in the tank  12  to be monitored. A fourth port  58  in the pan  16  forms a liquid discharge outlet. For example, the tank  12  may include an internal pump (not shown) connected to a anti-syphon valve  60  mounted to the port  58 , with a hose  62  leading from the valve  60  to discharge liquid from the tank  12 . 
     The pan  16  may also include a pair of plugs  64 ,  66 . The plug  64  is removably threaded into a reclamation port  68  which allows any “clean” liquid spilled into the reservoir  32  to be directed back into the tank  12 . The plug  66  is removably threaded into a 6 th  port in the pan  16  to drain any “dirty” spillage from the reservoir  32  into a bucket or can via a drain line  70  for disposal. 
     With the closure  10  of the present invention, the tank  12  only has one opening, the inspection opening, formed therein, with the remaining functional ports  46 ,  50 ,  54  and  58  being formed in the pan  16 . Thus, only one seal is required for the tank  12 . Appropriate seals may be provided on the inside of the pan  16  for the ports  46 ,  50 ,  54 , and  58  and the cap  48 , cam lock coupling  52 , depth gauge  56 , and syphon valve  60 . 
     The closure  10  meets all the general Canadian design requirements for a registered, UN Standard Mobile IBC, including the fill port(s) being located in the top of a tank, a discharge port in the top of the tank, venting in the top of the tank, and a manway for the scheduled, mandatory inspections and recertification of the tank. The lid  18  protects the various ports, and secures unauthorized access when the lid  18  is locked to the pan  16 . 
     Accordingly, the closure  10  achieves at least all of the stated objectives of the present invention. 
     The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives.