It must also be realized that a 75 mm bore pipeline for a conveying distance of 500 m is not likely to be a realistic option. It is used here only for illustration purposes to avoid the introduction of additional variables. The air only pressure drop has to be taken into account in every pipeline because that value of the pressure drop is not available for conveying material. If it is high little will be left to convey material. Air only pressure drop is considered in detail in Chapter 10 and is applied in subsequent chapters.