PP-R EF fittings, also known as PP-R electric fusion fittings, are polypropylene pipe connectors with built-in electric heating wires. After being powered on, the internal resistance wire heats up and melts the contact surface between the pipe and the fitting, forming an integrated sealed joint after cooling. It is mainly used for large-diameter or critical pipeline systems that require high connection reliability. Compared with common hot-melt socket connections, the quality of electric fusion connections is more stable and less affected by human operation factors.