Silicon carbide Liquid-lifting pipe is mainly used for low-pressure casting of aluminum products, especially cars, motorcycles and other components of low-pressure casting machine. Under working conditions, it is placed in a closed aluminum melting furnace with a die-casting machine and directly contacted with the metal solution at a temperature of about 700℃. The aluminum die casting machine applies a certain air pressure to the aluminum melt surface every 3-5 minutes, From the Liquid-lifting pipe to the mold cavity for casting to achieve its automation and continuity. Aluminum filling process has 0.8 ~ 1 / 2 pressure, requiring liquid pipe has excellent thermal shock fatigue resistance, excellent corrosion resistance, high strength and relatively-good air tightness.