All four-way tees at Sintong 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 piping fitting used at pipe branch points. For four-way tees manufactured using seamless pipes, the current commonly used processes are hydraulic expansion and hot pressing. The hydraulic expansion of the hydraulic expansion four-way tee is a forming process that expands the branch pipe by compensating axially the metal material.

The process involves using a hydraulic press to inject liquid into a billet with a diameter equal to that of the four-way pipe. The billet is then uniformly squeezed 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 pressure within the billet.

The four-way hydraulic expansion 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.