The Method of HDPE Fusion Welding
Generally speaking, HDPE pipe is butt fused by applying heat to prepared pipe ends and then pushing the pipe ends together with a pre-determined force to make a permanent butt fusion joint.
It is a very simple process utilizing a properly sized butt fusion machine for the pipe size to be joined. The pipe is installed and clamped in the butt fusion machine with pipe supports on both ends of the machine to support the pipes on the machine center line. The pipe ends are then faced (machined) to mechanical stops to ensure clean, parallel pipe ends for the heating process. The pipe ends are then aligned using the clamps on the fusion machine. A temperature controlled heater is installed in the machine and the pipe ends are heated according to the butt fusion standard ASTM International F2620. Once the heating criteria is met, the heater is removed and the pipe ends are brought together at the pre-determined force. This force is held on the joint for the time required by the standard. At this point, the pipe can be removed from the machine and visually inspected before pulling down the pipeline.