Temperature and pressure ratings are critical factors in piping material selection for HVAC systems, as they directly impact the safety and performance of the system. Piping materials must be able to withstand the maximum operating temperatures and pressures of the system, as well as any potential pressure surges or temperature fluctuations. For example, refrigerant lines in HVAC systems may require piping materials with high temperature ratings to handle the hot gas discharge from compressors. Similarly, piping materials used in high-pressure applications like hydronic systems must be able to withstand the maximum operating pressure.