Before sand blasting, a series of inspections shall be conducted for each mechanism in the sand blasting system. If some damages are found, including the wear of sand blasting pipe and sand blasting rod, they should be replaced and repaired immediately, and they cannot be put into use. The operator shall also check each limit switch and replace it immediately in case of damage. Dalian sandblasting and shot blasting processing, ventilation and power on to check the compressed air source. Close the switches in the power cabinet and the circuit breaker in the electric control cabinet. When the pressure of compressed air is about 0.8MPa, open the ball valve and gate valve of each gas circuit.