Butt fusion is the most common method of fusing HDPE pipes. Butt fusion joins two ends of thermoplastic pipes. Thermoplastics are types of polymers that become pliable and moldable when heated and solidified when cooled. Common thermoplastics used in butt fusion include high-density polyethylene (HDPE), polypropylene (PP), and polyvinyl chloride (PVC). The prepared and faced ends of the pipes are heated using a specialized heating tool or a heating plate. The temperature is carefully controlled to reach the melting point of the thermoplastic material without causing degradation. This is accomplished with butt fusion machine equipment. For larger pipes, a butt fusion welding machine is used to allow precise control of several additional factors, including:
- Alignment
- Surface squareness and cleanliness
- Heat soak time
- Heater plate temperature
- Bead width
- Interfacial pressure
- Cooling time
Butt fusion has several advantages in the piping industry:
- Leak-free Joints: Since butt fusion creates a seamless and homogenous joint, it minimizes the risk of leaks.
- High Strength: The fusion process creates a joint that is as strong as the original pipe, maintaining the overall integrity of the pipeline.
- Longevity: Butt-fused joints are known for their durability and resistance to corrosion, making them suitable for various applications.
Butt fusion is commonly used in the installation of water and gas distribution systems, industrial piping, and other applications where the benefits of a strong, leak-free joint are critical. The technique is widely accepted in the industry and is considered a reliable method for joining thermoplastic pipes.