The four-way has the equal diameter and the different diameter, and the connecting ends of the equal-diameter four-way are all the same size; the main-shaped connecting tube of the different-diameter four-way has the same size, and the connecting tube has a smaller connecting tube size than the main connecting tube.
The welded four-way four-way is a type of pipe used for the branch of the pipe. For the production of four-way pipe with seamless pipe, the current commonly used processes are hydraulic bulging and hot press forming.