Discussion on Internal Punching Process for Friction-welded Oil Drill Pipe

Based on the technical requirements for removal of the internal welding ring of the oil drill pipe,the field production experience,and basic structure of the internal punching system,realization of all the functions of the system are discussed,including power,balancing,driving,punching and positioning. And accordingly relevant reference scheme is proposed. Also elaborated here in the paper are the main technical requirements and process tips of each individual unit of the system. Moreover summarized are the work-piece positioning requirement,the pre-punching and post-punching check requirements,and related major inspection/measurement methods. The actual application result shows that the onetime success rate of the internal punching operation can be improved by means of adopting a reasonable system structure and properly controlling of various key elements associated with the internal punching process.