Pipe bending should be made with pipes with a positive wall thickness. The bending radius of the high-pressure steel pipe should be more than 5 times of the outer diameter, and the bending radius of other pipes should be 35 times larger than the outer diameter of the pipe; when the pipe is made of a pipe, the weld should be avoided; the stainless steel pipe should be cold-bent Processing and bending process, aluminum-manganese alloy pipe shall not be cold-bending for bending, and tube bending of other materials may be cold-bending or hot-bending.
High and medium alloy steel pipes shall not be watered during hot bending. Low-rise gold steel pipes are generally not suitable for watering. After hot bending, they should be slowly cooled in still air above 5 °C. When the bent pipe is processed by a hot bend pipe, the dry fine sand is always installed as required regardless of the pipe diameter.
The use of high-alloy steel pipes or non-ferrous metal pipes to make curved pipes should be mechanically used. When sanding pipes are used to make curved pipes, they must not be hammered. When the lead pipe is heated to make the bent pipe, it shall not be filled with sand. In addition to the case where the temperature of the bent pipe is maintained above 900 °C, the carbon steel pipe with a wall thickness greater than 19 mm shall be heat treated as specified after the bending of the carbon steel pipe.
When the bending process is hot bending, it will cause mechanical properties to change. Therefore, the hot bending temperature of the 20th steel pipe is preferably 800°C-900°C, and the heating temperature should not exceed 1000°C. The final bending temperature is not allowed. Below 800 ° C. When the 15MnV pipe is hot-bent, the hot bending temperature is preferably 950 °C ~ i000 °C, the heating temperature should not exceed 1050 °C, and the final bending temperature should not be lower than 800 °C.
High-pressure elbows must be carefully inspected during the processing, and there should be handover procedures between the various processes. After the elbow process is completed. Fill in the «High Pressure Pipe Processing Instructions» when expanding. Pipes that have been scrapped due to processing should be immediately painted and stored separately.