The connection methods between cast iron tees and pipelines include direct welding (commonly used) flange connection, threaded connection, and socket connection. Commonly used pipe fittings in pipeline installation, used to connect the outside of bent pipes. Cast iron tee materials include cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, etc. 1. Classification of cast iron tees 1. Classification of cast iron tees: reducing tees, Y-shaped tees, high-pressure tees, etc. 1. Material classification: carbon steel, cast steel, alloy steel, stainless steel, copper, aluminum alloy, etc. Cast iron tee technology is a pipe fitting used for pipeline branching. At present, the commonly used processes for manufacturing cast iron with seamless steel pipes include hydraulic bulging and hot pressing forming.

The process of hydraulic bulging involves injecting liquid into a billet with the same diameter as a cast iron tee using a dedicated hydraulic press. The pipe blank is simultaneously squeezed by two horizontal oil cylinders of the hydraulic press. After extrusion, the volume of the billet decreases, and the liquid pressure inside the billet increases as the volume of the billet decreases. When the pressure required for the expansion of the cast iron three-way branch pipe is reached, the liquid in the side cylinder and pipe blank is made of metal material under the dual action of pressure, and the branch pipe flows and expands along the inner cavity of the mold. One time hydraulic bulging of cast iron tees results in high production efficiency, increasing the wall thickness of the main pipe and the shoulder wall thickness of the cast iron tees.

Due to the large equipment tonnage required for the seamless cast iron tee hydraulic bulging process, it is currently mainly used in the manufacturing of standard wall thickness cast iron tees below DN400 in China. The applicable forming materials include low-carbon steel, low-alloy steel, and stainless steel with low cold work hardening, including non-ferrous metal materials such as copper, aluminum, titanium, etc.

The hot pressing forming of cast iron tees is to flatten a billet larger than the diameter of the cast iron tee to the size of the cast iron tee diameter, and open a hole at the position of the drawn branch pipe. After heating, the billet is placed into a forming mold, and the mold for drawing the branch pipe is installed on the billet; Under pressure, the pipe blank is radially compressed. The entire process is composed of radial compression of the pipe blank and pulling of the branch pipe. Unlike hydraulic bulging cast iron tees, the metal of hot pressed cast iron tees is compensated through the radial movement of the billet, hence it is also known as the radial compensation process.

Due to the use of pressed cast iron tees after heating, the equipment tonnage required for material forming is reduced. Hot pressed cast iron tees have wide material adaptability and are suitable for low carbon steel, alloy steel, and stainless steel materials; Especially for large-diameter thick walled cast iron tees, this forming process is usually used.

The process of connecting cast iron tees is also the same. There is a mold with a straight bottom and flange holes on top. After inserting the pipeline, fix it with a hydraulic cylinder, fill both sides with liquid, and expand inward. Squeeze the tube into a "convex" shape, then remove the protruding part from the appropriate position and punch it into the groove. It must be shot twice. Due to work hardening during the processing, heat treatment is also required, which is the production process of cast iron tee fittings.