Pipe material selection plays a critical role in refrigerant piping design. Different materials have different thermal conductivity, corrosion resistance, and pressure ratings, which affect the design of the piping system. For example, copper pipes are commonly used in refrigeration systems due to their high thermal conductivity and resistance to corrosion. However, copper pipes may not be suitable for systems using refrigerants with high acidity, such as ammonia. In such cases, stainless steel or other corrosion-resistant materials may be required. The pipe material selection must also meet the pressure ratings and temperature requirements of the system.