Butt Fusion Machines
Butt fusion is a thermofusion process which involves the simultaneous heating of the ends of two pipe/fitting components which are to be joined, until a molten state is attained on each contact surface. The two surfaces are then brought together under controlled pressure for a specific cooling time and a homogeneous fusion joint is formed. The resultant joint is fully resistant to end loads and has comparable performance under pressure to the pipe itself.
An electrical heater plate is used to raise the temperature of the pipe ends to the required fusion temperature. Butt-fusion can be used to join both PE80 and PE100 materials for pipe sizes of 90mm and above of the same SDR.
The butt welding machines used to weld PE pipes have controls to ensure the welding parameters are strictly adhered to. The following parameters are controlled:
heater plate temperature
ovality and alignment
heat soak time
Electrofusion is a simple method of joining PE pipes in circumstances where butt fusion is not practicable, such as where valves, elbows, and tees must be added. Prefabricated fittings are used, incorporating an electrical heating coil which melts the plastic of both the fitting and the pipe, causing them to fuse together.