Tanks can be used to hold materials as diverse as milk, water, waste, petroleum, chemicals, and other hazardous materials, all while meeting industry standards and regulations.[1] Storage tanks are available in many shapes: vertical and horizontal cylindrical; open top and closed top; flat bottom, cone bottom, slope bottom and dish bottom. Large tanks tend to be vertical cylindrical, with flat bottoms, and a fixed frangible or floating roof, or to have rounded corners transition from the vertical side wall to bottom profile, in order to withstand hydraulic hydrostatic pressure.