1. It is used for connecting pipes of all specification which have the same materials and the same SDR system. 2. It possesses reliable connectivity, high interface strength, good airtight performance, and stable welding performance. 3. It is easily welded and operated, and conveniently used. 4. It is not easily affected by changes in environment temperature or human factors. 5. The hidden spiral heating wires buried inside can effectively resist oxidation and rust corrosion, ensuring stable welding performance. 6. The cost of equipment investment and maintenance is low.