1. Pressure monitoring is fundamental. The total welding pressure must equal the drag pressure plus the theoretical welding pressure, with a pressure accuracy of 0.1 MPa. Whether the cylinder cross-sectional area is marked on the machine body is a crucial parameter for calculating welding pressure to ensure it conforms to national standards. Unstable pressure can lead to incomplete welds or excessively wide flanges.
2. Time control is critical. This includes flange rolling time, heat absorption time, switching time, gradual rise time, and cooling time, all of which must be strictly adjusted according to pipe specifications and ambient temperature. Too short a time results in incomplete weld penetration, while too long a time leads to carbonization.
3. Temperature control is essential. The heating plate temperature must be set according to the pipe grade: 215-235℃ for PE100 and 200-220℃ for PE80. Excessive temperature will cause carbonization, while insufficient temperature will result in incomplete welds. The heating plate should be calibrated regularly with a thermometer to ensure uniform temperature, with an error not exceeding ±5℃.
4. Equipment stability is fundamental. Regularly inspect components such as fixtures, milling cutters, and heating plates to ensure they function properly. Keeping the equipment clean and promptly replacing worn milling cutters and hydraulic oil can effectively extend equipment life and maintain welding accuracy. When the ambient temperature is below 5℃ or the wind speed is greater than 2m/s, preheating or windproof measures should be taken to avoid affecting welding quality.
Post-weld inspection of the rolled edges for uniformity, smoothness, and the absence of bubbles and shrinkage cavities is the most direct method for judging weld quality. Only by combining parameter control, equipment maintenance, and post-weld inspection can high-quality welded joints be consistently produced.
