I would say first thing is to make sure your blowdown valves are open and that there in no (0) presure in the tank. Then uncap your product lines, carefully making sure there is also no (0) pressure. then hook up your product hose(s) to the plant (tank)mor silo. Now open your line air wide open, close your blowdowns, hook up your hot air to the blower, and your ready to power up the blower. This is done in this order to ensure that the line your going to unload into is not plugged to start with (like by the last driver). Once you determin that the product line is clear, and your blowdowns are now closed, oper your airators (bottom air into the tank), if you have top air and the product unloads with it open it, you can use them together most of the time, just remember if you open the top air wide open the bottom will stop working. run it up tp 10 - 15 pounds, open the line air wide open, then open the product valve slowly, wait a few minutes let it equalize, should settle in around 12 pounds.
When the tank pressure gauge drops to zero you should be empty, if your unloading and your line air pressure starts to drop before your empty close the ariator (or top air) a notch see if it satbilizes.