Abstract: The causes of frequent jam and fracture of the tertiary air gate valve used are analyzed. By taking measures including increasing the opening of the tertiary air gate valve, changing the frame design of the tertiary air gate valve, laying protective bricks and removing the card slots on both sides, the tertiary gate valve has never been bent and broken again, and the stutter phenomenon has not occurred in the process of regulation. The replacement time of the tertiary air valve has been extended from the original maximum 6 months to 18 months, thus reducing cost and increasing efficiency.