Technologies for Manufacture of Pipe Tees

As a kind of pipe fittings, stainless steel tees are also called as pipe tees or tee joint pipe fittings. They are mainly applied to connect main pipes and branch pipes. There are equal tees and reducing tees. Just as the name suggests, the ends of equal tees are of the same sizes. For reducing tees, the ends connect with main pipes are of the same size while the ends connect with branch pipes are smaller. At present, technologies used to produce seamless pipe tees primarily contain hydro-bugling and thermal forming. 

 

 

In this process, branch pipes bulging out through the axial compensation of metal materials. First, filling liquids into tube blanks which have the same diameters with pipe tees. And then, using the lateral horizontal cylinders of hydraulic machines to press tube blanks. Under this circumstance, tube blanks become smaller after squeezing and pressure of liquids in them will growth. Once the internal pressures meets the required limitation for expanding pipe tees, the metallic materials will give birth to branch pipes under the dual functions of lateral cylinders and pressures of liquids. 

 

This technology can produce pipe tees in just one step which proves to be high efficient. Thicknesses of main pipes and shoulders are increased. Nevertheless, the equipment used for this technology have large tonnages. In current China, this technology are mainly used to manufacture pipe tees with standard thicknesses and sizes smaller than DN400. The suitable materials for this technology are steels of relatively low cold hardening tendency, such as low carbon steel, low alloy steel and stainless steel as well as some nonferrous metal like iron, aluminum and titanium, etc. 

 

 

First, pressing tube blanks into the similar sizes of pipe tees and make a hole on the position of branch pipes. Second, putting the tube blanks into forming dies after heating and install. Trimming dies should also be put into the tube blanks in this step. Under the function of pressure, tube blanks are compressed radially. During this process, metals flow toward the position branch pipes and finally form branch pipes under the stretch of trimming dies. 

 

The whole manufacture process are finished with the radial compression of tube blanks and stretch of branch pipes. Different from hydro-bugling, metals in this technology are compensated through radial movement. That is why thermal forming is also called as radial compensation technology. The equipment required in this technology have relative smaller tonnages. With ow carbon steel, alloy steel and stainless steel are all suitable for this technology. For pipe tees with big diameters and thick walls, this technology is the most commonly used one.