This part of ISO 15748 applies to the planning, design and configuration of potable water supply systems on ships, stationary or floating marine structures and inland waterway crafts. This part of ISO 15748 serves to determine the quantity of potable water to be carried on board, the capacity of the pressurized reservoirs and water heaters, the pumping capacity, etc. NOTE In accordance with ISO 15748-1 plastic pipes are permitted but are rarely used at present due to the restrictive conditions laid down by the classification societies. Pressure losses in plastic pipes have not yet been included in ISO 15748 owing to their limited applicability.