For the common
titanium three-way pipe fittings, because of its small diameter, thin wall, and the requirements of parts under high pressure, to use casting method to manufacture not only casting difficult and its quality can not be guaranteed. If the use of two straight pipe welding forming, because the weld is the space intersecting line of two columns, blanking and welding operation are difficult to grasp, moreover the size of parts is small, can only be welded from the outside, its inner wall welding quality is not easy to maintain. Even if casting and welding can complete its shape manufacturing, because they inevitably have porosity and slag in the process, this and process defects are not allowed to exist for middle and high pressure pipelines.
Technicians proposed by forging or radial extrusion process made T solid bad material first, and then, again, the horizontal and vertical direction drilling method, but the experimental results show that titanium tee fitting quality is not easy to maintain, moreover, this process there is a machining process, low utilization rate of large equipment, metal materials needed more disadvantages.
Finally, decided to use the straight tube also extrusion forming, filling the straight tube blank into the mold cavity, upper and lower die die closed, and then with the same diameter size of the rod (2 pieces), from both sides at the same speed, the
titanium tube in the mold cavity under pressure at both ends must produce plastic deformation; Upsetting or extruding along a radial hole in a die.
Upsetting deformation is not possible because the tube is filled with incompressible packing, so the straight tube is extruded with the packing through a radial hole in the die under pressure. In order to prevent the extruded radial pipe from bursting under the internal pressure of the packing, a push rod is installed in the radial hole of the mold, and sufficient compressive stress is applied to the extruded radial branch pipe.
When the extruded branch pipe reaches the size requirement, the required titanium tee pipe fitting can be obtained by opening the mold and taking out the parts and clearing out the packing. The practice shows that the wall thickness of the three directions of the extruded tee pipe fitting is the same, the upsetting deformation is very small, and the height of the extruded part is 2 ~ 3 times of the pipe diameter. In addition, because the packing and titanium tube move synchronously in the cavity, the inner wall of the pipe fittings has no mechanical scratch, and the size and quality meet the requirements of the drawings.
