Understanding the 'joints' in plastic piping systems - fittings

Pipe fittings are key components for connecting pipelines, changing direction, and controlling flow distribution. Understanding common types of pipe fittings is helpful for system design and maintenance:

Classified by function:

Connection: direct, flexible joint, flange, etc., used to connect straight pipe sections.
Steering: Bend (90 °, 45 °), used to change the direction of the pipeline.
Diversion: three-way, four-way, used to divert or merge fluids.
Variable diameter: direct/elbow for reducing diameter, used to connect pipes of different diameters.

Classified by connection method:

Solvent bonding: mainly used for PVC/CPVC pipes, using specialized adhesive to form a permanent seal.
Hot melt docking/socket: mainly used for PE/PP pipes, it melts and integrates the base material at the interface through heating, with high connection strength.
Threaded connection: Process internal or external threads on the pipe fittings for easy installation and disassembly, and pay attention to sealing.