Kiln seal test is also called kiln pressure test. During normal production, the kiln calcination is operated under positive pressure, and the kiln pressure is below 35kPa, so the kiln reversing valve is the most important. The kiln sealing pressure test is often used to compare the sealing performance before and after the new kiln is completed and put into operation, and the sealing equipment such as the reversing valve is overseen and replaced. The test sequence is as follows: (1) the sealing test of the kiln before the new kiln is completed and put into operation 1. Before opening the kiln test, check all the equipment, especially check whether the Roots fan is lubricated and whether the manual turning can be easily turned, otherwise the fan should be checked whether it is dirty and rusty. If necessary, gasoline or other solvents can be used to remove rust and clean. 2. Check whether all process holes on the kiln, such as manhole cover, fire hole cover, access door, etc. are closed. 3. The kiln mode selection is set to the "open and test" state, the kiln channel pressure, combustion air pressure, cooling air pressure, the set value is 45kPa, the purpose is to prevent the alarm when the kiln pressure increases, and the spray gun pressure is generally not set above 45kPa. Check whether the combustion air release valve and cooling air release valve are closed, put the two φ1220 reversing valves on the pipe that closes the flue gas or chimney (that is, open the side that leads to the kiln), and manually open the two regulating butterfly valves on the cooling air pipe at the 6.8 meter platform. 5. Start the inverter fan and increase the speed to make the pressure 20kPa. If it is the first sealing test, it is required to check the connection of each weld and each flange, and carefully check whether the sealing of the reversing valve, release valve, feed valve, fire hole, discharge valve, explosion-proof disc, spray gun flange, combustion air, cooling air pipe and other parts on the kiln is normal.