Mechanical expanding and hydraulic expanding characteristics

(1) the production of large diameter steel pipe aging rate. Because when you need to charge hydraulic expanding low-pressure water and then pressurized to achieve further boost when the steel yield. With the production of pipe diameter increases, the efficiency is greatly reduced, for example, pipe length 12m dollars, when 609.6mm (24in) diameter steel pipe hydrostatic expansion, 36 per hour, while the mechanical expanding, each Hour 28. Right 1067mm (42in) steel pipe, expanding the use of water pressure, 18 per hour, while 23 per hour when mechanical expanding. That mechanical expanding, not its efficiency and diameter size relationship, so relatively speaking diameter increases, the efficiency also high.

(2) easy to meet the stringent requirements of the inner diameter of the pipe. When laying long-distance pipelines, welded steel pipes installed in the field site, with an inner diameter of the base, the smaller inner diameter of the wrong side of two steel tube end after docking, transport resistance also smaller, so the pipe inner diameter of the dimensional accuracy requirements increasingly stringent, and the pressure outside the enlarged diameter of the die case is precisely controlled with pipe diameter, the inner diameter accuracy can not be guaranteed. Mechanical expanding head is inserted into the expanded diameter steel pipe were expanding, therefore, can control the pipe diameter size precision, regardless of wall thickness.

(3) good ovality. When the pressure expanding, because contact with the outer mold outer sleeve seam to the wall near the depression, the degree of damage to the oval steel tubes. When the expanding machine, as long as the weld head aligned with the enlarged diameter groove segments, expanded diameter when unconstrained weld area to form a smooth surface, thus effectively reducing the damage caused by the welded parts.

(4) the shape and size of the pipe end and high accuracy. Weld expanding effect when compared to both ends of the pipe need to push the conical indenter pressed against the head set in radial seal ring seal up, so steel tube end portion of the indenter in contact with the pipe flaring effect the tubular body portion inconsistent. The expanding does not have this phenomenon, good shape and size of the pipe end of the Field Installation and butt are favorable.

What is a steel pipe extrusion

The extrusion process is the heating of the ingot into the extruder barrel, the extrusion cylinder is placed at one end of the extrusion die, a pressure is applied to the other side, forcing the metal flow from the die orifice to produce a cross-section reduction, increasing the length plastic deformation method. Principle of the extrusion process, the first heated to a suitable temperature, to release the billet in the extruder barrel, extruder barrel at the end of the extrusion die is placed at the other end of the extruder barrel into the extruder barrel is slightly less than the pressing pressure washer, and then insert the shaft extrusion, extrusion shaft diameter smaller than the cylinder diameter 3 ~ 10mm. The pressure of the extruder through the extrusion axis, the metal billet is passed to the spacer, forcing the metal flow from the die hole, the hole size with the mold to obtain the shape of the same products. When the article is extruded hollow tube extrusion axis to an inner diameter of the pipe is determined by the punch pin. Wear larvae L needle is passed through the hollow shaft mounted on perforated extrusion systems extruder.

After the extruded steel pipe, first extrusion ingot axis by applying pressure to the pads, so that the metal tube full of extrusion, extrusion axis again after exiting some distance, then piercing needle to move forward through the ingot center and with the diameter of the extrusion die with a predetermined fit, is moved forward again after the extrusion axis, the pressure is transmitted to the billet forcing the annular gap between the metal of the mold formed by the punch pin hole and flows out to obtain the desired pipe. When the perforation, the central part of the metal billet to form a solid rod out from the die orifice to form the perforated first material. The degree of perforated material head size and full Extrusion ingots, diameter die hole piercing needle and relevant. At the end of extrusion, extrusion axis in the extrusion barrel remaining residual material that pressure more than the introduction of squeeze tube, by separating shears or hot saw the article and the pressure of more than cut off, and then by the separation mechanism will be pressed over the pad sheet separation, various tools and moving parts of the extruder to return the original state, the next pressing cycle.