The following are the precautions in the use of HDPE butt fusion welding machine： 1. Connect the power of each part of the welding machine, and the power should be grounded. At the same time, ensure that the surface of the heating plate is clean and free of scratches. 2. Connect the pump station and the frame with hydraulic wires. Before connecting, check and clean up the dirtat the joint to prevent dirt from entering the hydraulic system and damage the hydraulic components; after the hydraulic wire is connected, the joint part should be locked to prevent the danger of the joint being opened during high-pressure work. 3. Clamp the pipes (pipe fittings) to be welded and fix them on the frame. When welding large-caliber pipes, it is best to use discarded pipe sections or special brackets to level up to protect the pipes and reduce friction during welding. . 4. Open the frame, insert the milling cutter, turn the locking knob, and fix the milling cutter on the frame. When starting the pump station, it should be carried out when the direction control handle is in the neutral position, and it is strictly forbidden to start under high pressure. 5. Start the milling cutter, close the fixture, and cut the end face of the pipe (pipe fitting). 6. When continuous cutting is formed, reduce the pressure, open the fixture, and close the milling cutter. This process must be carried out in the order of first reducing the pressure, then opening the fixture, and finally closing the milling cutter. 7. Remove the milling cutter, close the clamp, and check the gap at both ends of the pipe. When removing the milling cutter from the machine frame, avoid collision between the milling cutter and the end face, and re-milling if it has occurred; do not touch the milled end face or be contaminated by oil. 8. Check the concentricity of the pipe. When the gap between the two ends and the amount of misalignment cannot meet the requirements, the weldment to be welded should be re-clamped, milled, and the next step can be carried out after passing the test. 9. Check whether the temperature of the heating plate is appropriate. The red indicator light of the heating plate should be on or flashing. After the first light on the heating plate is turned on, it is best to wait another 10 minutes to use it to make the temperature of the entire heating plate uniform. 10. Test the drag pressure P0 of the system. The dragging pressure of each welding port needs to be measured; when the dragging pressure is too large, it can be solved by using short pads. 11. Place a heating plate with a suitable temperature on the rack, close the fixture, and set the system pressure P1. 12. When the protrusions between the pipes (pipe fittings) are uniform and the height reaches the requirement, reduce the pressure to P2 to approximate the drag pressure, and press the heat absorption timer button at the same time to start the heat absorption time. 13. After the endothermic time is reached, quickly open the fixture and remove the heating plate. When taking the heating plate, avoid collision with the molten end surface; if it has occurred, restart the entire welding process after the molten end surface has been completely cooled. 14. Quickly close the fixture, and evenly adjust the pressure to P3 within the specified time, while pressing the timer to cool down. 15. After the cooling time is reached, reduce the pressure to zero, open the fixture, and remove the welded pipe (pipe fitting). Before unloading the pipe, the system pressure must be reduced to zero; if the welding machine needs to be moved, the hydraulic wire should be removed, and dust-proof work at the joint should be done in time.