Article 122 of the Safety and Technical Supervision Regulations for Pressure Vessels stipulates: "When there is pressure inside the pressure vessel, it is forbidden to repair it. For special production process, the bolts shall be tightened in temperate zone when necessary; Or emergency leakage needs to be stopped with pressure, the user must take effective operation requirements and protective measures according to the design regulations, and the operators should be trained professionally and operated with certificates, and approved by the technical director of the user. In actual operation, the safety department of the user unit should send someone to the site for supervision. "