Water Tank

Abstract

A cylindrical upstanding water tank is formed from a plurality of rows of corrugated curved panels bolted edge to edge with a liner extending over the cylindrical wall and support surface to contain the water within the tank. An access opening is formed in one panel of the cylindrical wall and includes a frame with a rectangular planar front flange and a rearwardly extending flange welded into the hole. Liner retention straps surround the hole to fasten an edge of the liner around the hole. An access cover plate is bolted to the front flange of the frame and carries a hoop strength plate which fastens to studs at the rear of the plane so that the plates are removable to allow service access to the interior of the tank.

1 . A water tank comprising:
 a plurality of rows of curved panels of corrugated sheet metal with horizontally extending corrugations where the panels of each row are bolted end edge to end edge to form a cylindrical wall portion and where the wall portions formed by the rows are stacked and bolted top edge to bottom edge to form a cylindrical wall extending from a bottom edge of the cylindrical wall mounted on a support surface to a top edge of the wall for containing water;   a liner extending over the cylindrical wall and support surface to contain the water within the tank;   and an access opening in the cylindrical wall comprising:   a frame welded into a hole formed in one of the curved panels;   a liner retention system surrounding the hole to fasten an edge of the liner around the hole;   and an access cover plate arranged to be fastened to the frame so as to be removable therefrom to allow access to the interior of the tank inside the liner by a person for service within the interior.   
     
     
         2 . The water tank according to  claim 1  wherein the frame is rectangular with two upstanding side posts and two horizontal connecting rails. 
     
     
         3 . The water tank according to  claim 2  wherein the frame includes a front planar flange onto which the access cover plate is fastened and a rearwardly extending flange which is welded to the panel at an edge of the hole and wherein the rearwardly extending flange of each of the connecting rails is deep enough in a direction into the hole such that a horizontal curved edge of the panel is welded onto the flange across its full width while being spaced from the front flange across its full width. 
     
     
         4 . The water tank according to  claim 3  wherein the curved edge of the panel is welded on the inside surface and on the outside surface to the flange. 
     
     
         5 . The water tank according to  claim 1  wherein the frame includes a front flange onto which the access cover plate is fastened and a rearwardly extending flange which is welded to the panel at an edge of the hole. 
     
     
         6 . The water tank according to  claim 1  wherein there is provided a hoop strength coupling plate extending across the hole at the frame for transferring hoop loads from the panel across the frame, the hoop strength coupling plate being removable. 
     
     
         7 . The water tank according to  claim 6  wherein the frame includes a front flange onto which the access cover plate is fastened and a rearwardly extending flange which is welded to the panel at an edge of the hole and wherein there is provided a rear flange at each side of the frame extending inwardly across the hole and wherein the hoop strength coupling plate is connected to each of the rear flanges for transferring the hoop loads therebetween. 
     
     
         8 . The water tank according to  claim 6  wherein the hoop strength coupling plate is removable with the cover plate. 
     
     
         9 . The water tank according to  claim 6  wherein the hoop strength coupling plate is carried on the cover plate for removal therewith. 
     
     
         10 . The water tank according to  claim 1  wherein the cover plate is sealed to the frame by a sealing strip to prevent escape of the water from the interior of the tank through the hole. 
     
     
         11 . The water tank according to  claim 10  wherein there is provided a hoop strength coupling plate extending across the hole at the frame for transferring hoop loads from the panel across the frame, the hoop strength coupling plate being removable and wherein the hoop strength coupling plate is not sealed to the frame so that water enters between the hoop strength coupling plate and the cover plate. 
     
     
         12 . The water tank according to  claim 6  wherein the hoop strength coupling plate is arranged to transfer hoop loads to the frame by studs connected between the hoop strength coupling plate and the frame. 
     
     
         13 . The water tank according to  claim 12  wherein the hoop strength coupling plate has holes at side edges thereof arranged to engage studs on the frame. 
     
     
         14 . The water tank according to  claim 13  wherein the studs comprise shear bolts where a hole in either the frame or the plate engages over a head of the shear bolt. 
     
     
         15 . The water tank according to  claim 1  wherein the cover plate is bolted to a front flange of the frame. 
     
     
         16 . The water tank according to  claim 1  wherein the liner retention system is fastened to the inside surface of the wall portion. 
     
     
         17 . The water tank according to  claim 16  wherein the liner retention system includes a pair of parallel upright straps bolted to the panel on either side of the hole and a pair of parallel horizontal straps bolted to the panel above and below the hole. 
     
     
         18 . The water tank according to  claim 17  wherein the upstanding straps are corrugated similarly to the panels.