After welding HDPE pipes, a visual inspection should be performed immediately after the weld has cooled to ambient temperature and is safe to touch. This is typically completed within 20 minutes to 1 hour after welding, depending on the pipe diameter, wall thickness, and ambient temperature.
Cooling to a touchable state is a fundamental prerequisite to avoid burns and ensure morphological stability. Small-diameter pipes (such as those below DN110) generally require at least 20 minutes of cooling before inspection, while larger-diameter or thick-walled pipes require longer.
The visual inspection should cover 100% of all weld joints, focusing on whether the rolled edges are full and uniform, whether there are misaligned joints, and whether there are defects such as cracks or porosity on the surface.
Although visual inspection can be performed earlier, non-destructive testing (such as ultrasonic or radiographic testing) and pressure testing must be performed 24 hours after welding to avoid the risk of delayed cracking, especially for high-density polyethylene (PE100) materials or critical engineering applications.
✅ Tip: Welding parameters and inspection results should be recorded simultaneously for each weld joint to ensure quality traceability and provide a basis for subsequent acceptance.
