PP (Polypropylene) pipes are widely used in water supply, chemical, and industrial systems due to their excellent corrosion resistance and weldability. The main connection methods are based on thermal fusion welding, ensuring strong, leak-proof joints.
1. Socket Fusion Welding (Hot Melt Socket Welding)
Description
Socket fusion is the most common method for small-diameter PP pipes. The pipe and fitting are heated using a socket welding machine and then joined together.
Process Steps
Cut the pipe squarely and clean the surface
Heat the pipe end and fitting simultaneously using a socket heater
Insert the pipe into the fitting without rotation
Hold in position until cooled
Features
Simple operation
Low equipment cost
Reliable sealing
Applications
Small-diameter pipes (typically ≤ 110 mm)
Building water supply systems
2. Butt Fusion Welding
Description
Butt fusion is used for larger diameter pipes. The pipe ends are heated and then pressed together to form a strong joint.
Process Steps
Align and clamp the pipes
Face (trim) the pipe ends
Heat both ends using a heating plate
Remove the heater and apply pressure to join
Allow to cool under pressure
Features
High joint strength (same as pipe material)
Suitable for high-pressure systems
No additional fittings required
Applications
Large-diameter pipelines
Industrial and chemical systems
3. Electrofusion Welding
Description
Electrofusion uses special fittings with built-in heating wires. When electricity is applied, the fitting melts and bonds with the pipe.
Features
High precision and reliability
Suitable for complex or confined spaces
Easy to automate
Applications
Repair work
Underground pipelines
High-standard installations
4. Hot Air Welding (Extrusion Welding)
Description
Hot air or extrusion welding is mainly used for PP sheets or special structures rather than standard pipelines.
Features
Flexible for custom fabrication
Requires skilled operation
5. Key Advantages of PP Pipe Welding
Strong, leak-proof joints
Excellent chemical resistance
Long service life (up to 50 years)
No corrosion or scaling
6. Conclusion
Among all methods, socket fusion and butt fusion are the most widely used for PP pipes. The choice depends on pipe diameter, pressure requirements, and installation conditions.
