ABSTRACT
In this chapter we will discuss the properties of gases that influence gas flow through a pipeline. We will explore the relationship of pressure, volume, and temperature of a gas and how the gas properties such as density, viscosity, and compressibility change with the temperature and pressure. Starting with the ideal or perfect gases that obey the ideal gas equation, we will examine how real gases differ from ideal gases. The concept of compressibility factor, or gas deviation factor, will be introduced and methods of calculating the compressibility factor using some popular graphical correlation and calculation methods explained. The properties of a mixture of gases will be discussed, and how these are calculated will be covered. Understanding the gas properties is an important first step toward analysis of gas pipeline hydraulics.
