The application of China's PE-RT pipelines in the field of hot and cold water pipes in buildings has developed rapidly, and raw materials have also been further developed. In 2002, the industry standard "PE-RT Pipeline System for Hot and Cold Water" was released, but the industry standard was based on the German standard "PE-RT" pipe - general quality requirements. And "heat-resistant polyethylene (PE-RT) pipe - size", both standards are based on the performance indicators of type I PE-RT materials. With the development of materials, the performance index of type II PE-RT materials has been much higher than that of the first generation materials. The international standard ISO22391 "PE-RT pipe system for hot and cold water" has also been revised and updated. , increased the requirements for Type II PE-RT pipes. 
With the development of materials, PE-RT tubes are upgraded to PE-RTII tubes, which are classified into three types according to their comonomers:
1. Copolymer of ethylene and octene - heat resistant polyethylene (C2+C8);
2. Copolymerization of ethylene and hexene - heat resistant polyethylene (C2+C6);
3. Heat-resistant polyethylene (C2+C4) copolymerized with ethylene and butene
At present, (PE-RT II type pipe) material has been introduced, which is suitable for industrial and civil building hot and cold water piping systems, drinking water systems, thermal pre-embedded pipes, ground radiant heating systems and high-temperature ground source heat pump systems, especially in the north. It is applied to the secondary pipe network of urban heating system-PE-RT II type prefabricated direct buried insulation pipe.