Ceramic fiber pipes are not typically used for water supply systems due to their high porosity and potential for contamination. They are more commonly used in high-temperature applications such as insulation for industrial furnaces. For water supply systems, materials like PVC, copper, or stainless steel are preferred due to their durability, resistance to corrosion, and safety for potable water. These materials are designed to meet health and safety standards for drinking water, unlike ceramic fiber pipes which may not be suitable for such applications.