GB/T 28799.5 - 2020 is the fifth part of the standard for heat-resistant polyethylene (PE) (PE-RT) piping systems for hot and cold water. This part focuses on system suitability and specifies methods for testing and evaluating PE-RT piping systems, covering aspects such as connection Reliability, temperature and pressure resistance performance, etc., simulating the actual operating conditions of the system. Through these specifications, it can be judged whether the PE-RT piping system is suitable for hot and cold water installation and use, providing a scientific basis for the design, construction and acceptance of the system, and ensuring the safe and stable operation of the system.