The four-way tees at Shitong have opposing dimensions; the main tee of the tapered tees has opposing dimensions, while the branch tee dimensions are 10mm smaller than the main tee. The stainless steel four-way tee is a pipe fitting used at pipe branch points. For four-way tees made of seamless pipes, the current commonly used processes are hydraulic expansion and hot pressing forming. The hydraulic expansion of the hydraulic expansion four-way tee is a forming process that involves expanding the branch pipe through axial compensation of the metal material.

The process involves using a hydraulic press to inject a liquid into a billet with the same diameter as the four-way pipe. The billet is then simultaneously compressed by the press's two horizontal side cylinders. As the billet is compressed, its volume decreases, causing the liquid inside to increase in pressure. When the pressure reaches the level required to expand the four-way branch, the metal material flows and expands into the branch under the combined pressure of the side cylinder and the liquid inside the billet.

The four-way hydraulic bulging red art can be formed in one go, offering high production efficiency; the thickness of the main and shoulder walls of the four-way has been increased.