This image shows a consistent level tank with an internal overflow. The internal overflow tube must be at least two times the diameter of the largest supply pipeline. If the largest dimension of the tank is less than 3 feet, the overflow tube must end at least one diameter of the largest supply pipeline but no less than 4 inches above the floor. If the largest dimension of the tank is greater than 3 feet, the overflow tube must end at least one diameter of the largest supply pipeline but no less than 6 inches above the floor. The air break above the flood level must be at least two times the diameter of the largest return pipeline. The size of the vent pipe must be the size of the largest return pipeline or larger. Raw milk well at the bottom of the tank must be at a level below the bottom of the tank.