Storage tank

Abstract

A storage tank includes an exterior cover extending over at least a portion of the bottom wall of the tank, but does not cover or enclose the entire tank. The exterior cover is sealed to the tank around the portion of the bottom wall to contain any leakage through the bottom wall portion.

1 . A storage tank comprising: 
 a bottom wall and    an exterior cover extending over at least a portion of the bottom wall, but not covering the entire tank, and sealed to the tank around the bottom wall portion to contain any leakage through the bottom wall portion.    
   
   
       2 . The tank according to  claim 1  wherein the tank includes side or end walls and said exterior cover extends partially over the side or end walls.  
   
   
       3 . The tank according to  claim 1  wherein said tank comprises a generally cylindrical elongated shape having a length and a perimeter and said tank is adapted to be installed horizontally, said exterior cover extending at least substantially along the length and partially along the perimeter of said tank.  
   
   
       4 . The tank according to  claim 3  wherein said tank comprises a right cylindrical shape having a longitudinal axis and said exterior cover extends between about 5 degrees and about 35 degrees along the perimeter of the tank as measured from the longitudinal axis.  
   
   
       5 . The tank according to  claim 1  wherein said tank comprises a generally cylindrical elongated shape having opposite ends and being closed at each end by a tank head, such that one of the tank heads defines the bottom wall and said cover extends at least substantially over the entire bottom wall.  
   
   
       6 . The tank according to  claim 1  wherein said tank comprises a generally rectangular shape and said cover extends at least substantially over the entire bottom wall of said tank.  
   
   
       7 . The tank according to  claim 1  wherein said cover is sealed to the bottom wall of the tank.  
   
   
       8 . The tank according to  claim 1  wherein said tank and cover are made of steel and the cover is sealed to the tank by a weld.  
   
   
       9 . The tank according to  claim 1  wherein said tank includes a sensing apparatus to detect the presence of liquid between the bottom wall and the cover.  
   
   
       10 . The tank according to  claim 9  wherein said sensing apparatus comprises a monitoring pipe communicating between the bottom wall and cover.  
   
   
       11 . The tank according to  claim 10  wherein the sensing apparatus further includes an aperture in either the bottom wall of the tank or the exterior cover, said aperture communicating between the bottom wall and cover, and the monitoring pipe being in sealed communication with the aperture, such that contents leaking through the bottom wall portion can migrate between the tank and cover to the aperture and into the monitoring pipe for detection.  
   
   
       12 . A storage tank comprising: 
 an upper access opening in the tank for receiving a measuring rod, which measuring rod contacts a bottom wall of the tank generally at a contact area; and 
 a striker plate located on the exterior of the tank and overlying at least the contact area, but not covering the entire tank, said striker plate being sealed to the tank around the contact area.  
   
   
   
       13 . The tank according to  claim 12  wherein the tank includes side or end walls and said striker plate extends partially over the side or end walls.  
   
   
       14 . The tank according to  claim 12  wherein said tank comprises a generally cylindrical elongated shape having a length and a perimeter and said tank is adapted to be installed horizontally, said striker plate extending at least substantially along the length and partially along the perimeter of the tank.  
   
   
       15 . The tank according to  claim 14  wherein said tank comprises a right cylindrical shape having a longitudinal axis and said striker plate extends between about 5 degrees and about 35 degrees along the perimeter of the tank as measured from the longitudinal axis.  
   
   
       16 . The tank according to  claim 12  wherein said tank comprises a generally cylindrical elongated shape having opposite ends and being closed at each end by a tank head, such that one of the tank heads defines the bottom wall and said striker plate extends at least substantially over the entire bottom wall.  
   
   
       17 . The tank according to  claim 12  wherein said tank comprises a generally rectangular shape and said striker plate extends at least substantially over the entire bottom wall.  
   
   
       18 . The tank according to  claim 12  wherein said striker plate is sealed to the bottom wall of the tank.  
   
   
       19 . The tank according to  claim 12  wherein said tank and striker plate are comprised of steel and said striker plate is sealed to said tank by a weld.  
   
   
       20 . The tank according to  claim 12  wherein said tank includes a sensing apparatus to detect the presence of liquid between the bottom wall and the striker plate.  
   
   
       21 . The tank according to  claim 20  wherein said sensing apparatus comprises a monitoring pipe communicating between the bottom wall and striker plate.  
   
   
       22 . A fuel storage tank comprising: 
 a generally cylindrical elongated shape including a perimeter, a length, a bottom wall and opposite ends;    a tank head attached to each end of said tank to close the ends;    an external plate covering at least a portion of the bottom wall, extending at least along the length of the tank and stopping short of an attachment area of each head, and sealed to the tank to enclose the bottom wall portion.    
   
   
       23 . The tank according to  claim 22  wherein said tank comprises a right cylindrical shape having a longitudinal axis and said external plate extends between about 5 degrees and about 35 degrees along the perimeter of the tank as measured from the longitudinal axis.  
   
   
       24 . The tank according to  claim 22  wherein said external plate is sealed to the bottom wall of the tank.  
   
   
       25 . The tank according to  claim 22  wherein said tank, tank heads and external plate are made of steel and each of the tank heads are attached to the tank by a weld, and said external plate is sealed to the tank by a weld.  
   
   
       26 . The tank according to  claim 22  wherein said tank includes a sensing apparatus to detect the presence of liquid between the bottom wall and the external plate.  
   
   
       27 . The tank according to  claim 26  wherein said sensing apparatus comprises a monitoring pipe communicating between the bottom wall and external plate.  
   
   
       28 . The tank according to  claim 27  wherein the sensing apparatus further includes an aperture in either the bottom wall of the tank or the external plate, said aperture communicating between the bottom wall and the external plate, and the monitoring pipe being in sealed communication with the aperture, such that contents leaking through the bottom wall portion can migrate between the tank and external plate to the aperture and into the monitoring pipe for detection.  
   
   
       29 . A fuel storage tank comprising: 
 a top wall and a bottom wall;    an opening in the top wall for receiving a measuring rod, which measuring rod contacts the bottom wall of the tank generally at a contact area;    an external plate covering at least a portion of the bottom wall including the contact area, but not covering the entire tank, said external plate sealed to the tank around the bottom wall portion to contain any leakage through the bottom wall portion;    an aperture in either the bottom wall of the tank or the external plate, said aperture communicating between the bottom wall and external plate; and    a monitoring pipe being in sealed communication with the aperture, such that contents leaking through the bottom wall portion can migrate between the tank and external plate to the aperture and into the monitoring pipe for detection.    
   
   
       30 . The tank according to  claim 29  wherein said tank comprises a cylindrical elongated shape having a perimeter, a length and opposite ends, and a tank head attached to each end to close the ends and said external plate extending substantially along the length of the tank and partially along the perimeter.  
   
   
       31 . The tank according to  claim 30  wherein said external plate extends substantially along the length of the tank stopping short of an attachment area of each tank head.  
   
   
       32 . The tank according to  claim 30  wherein said external plate extends partially over the tank heads.  
   
   
       33 . The tank according to  claim 30  wherein said tank comprises a right cylindrical shape having a longitudinal axis and said external plate extends between about 5 degrees and about 35 degrees along the perimeter of tank as measured from the longitudinal axis.  
   
   
       34 . The tank according to  claim 29  wherein said tank comprises a generally cylindrical elongated shape having opposite ends and being closed at each end by a tank head, such that one of the tank heads defines the bottom wall and said external plate extends at least substantially over the entire bottom wall.  
   
   
       35 . The tank according to  claim 29  wherein said tank comprises a generally rectangular shape and said external plate extends at least substantially over the entire bottom wall of said tank.  
   
   
       36 . The tank according to  claim 29  wherein said external plate is sealed to the bottom wall of the tank.  
   
   
       37 . The tank according to  claim 29  wherein said tank and external plate are made of steel and the external plate is sealed to the tank by a weld.  
   
   
       38 . The tank according to  29  wherein the aperture is in the bottom wall of the tank.  
   
   
       39 . The tank according to  29  wherein the aperture is in the external plate.  
   
   
       40 . The tank according to  claim 29  wherein said external plate covers a portion of the tank up to a selected depth.  
   
   
       41 . The tank according to  claim 40  wherein said depth is less than or equal to about 6 inches (15.2 cm).  
   
   
       42 . A tank comprising: 
 a top wall, a bottom and a height which is measured from the bottom wall to the top wall;    an external cover sealed to the tank to contain any leakage through the bottom wall, wherein the cover covers at least all portions of the tank that are in contact with fluid of a selected depth within the tank without covering or enclosing the entire tank, which depth is less than or equal to about one-half the height of the tank.    
   
   
       43 . The tank according to  claim 42  wherein the depth is less than or equal to about 6 inches (15.2 cm).  
   
   
       44 . A storage tank comprising: 
 an upper tank wall portion and a lower tank wall portion;    an external cover defining a leakage containment area in the lower tank wall portion only.