Forming large diameter straight seam welded pipe
molding methods are UOE molding method, a row of roll forming method (CFE), CE molding. For the most part of the molding process is the full-length steel pipe after welding diameter, in order to improve the quality of welded pipe. Large-caliber expanded production is an important process to ensure the quality of finished pipe.
Extension is a hydraulic or mechanical means to urge the pipe along the pipe wall radially outward pressure forming process. Compared with the mechanical hydraulic method, the equipment is simple and efficient and adopts the process of increasing several diameters in the longitudinal direction of the most advanced large-diameter pipe system in the world. The process is as follows: The radial expansion of the mechanical expansion section is used to enlarge the side of the crack, Longitudinal direction of the progressive realization of the plastic pipe in the process of deformation of the entire length. It is divided into five stages.
1. Initial full circle. Sections open until all segments are exposed to the tube wall, at this point in the radius of the steel within the steps of each point is almost the same, the initial round steel.
2. The nominal diameter of the stage. From the front position to reduce the speed until you reach the desired position, this position is in the finished pipe circumference quality requirements.
Three rebound compensation level. Begin the further low speed at the second phase until you reach the desired position, which is the previous pipe circumference required by the complex process design of the missile.