There should be limits placed on the fill rates based upon type of roof (steel, aluminum) and the low-leg setting. Filling too fast can cause product to splash through wells in the roof and onto the deck plate. Typically it is recommended to fill the tank slower initially until it is floating before opening-up to full rate. If this is not an option then using a diffuser and deflector plate is an option. Typically a good velocity to use is 3 ft/sec.