ABSTRACT
In this chapter we will discuss the various types of valves and flow measurements used on gas pipelines. The design and construction codes for valves, materials of construction, and application of the different types of valves and their performance characteristics will be explained. The importance of flow measurement in a gas pipeline and the accuracy of available instruments, codes, and standards used will be discussed. Various American National Standards Institute (ANSI), American Petroleum Institute (API), and American Gas Association (AGA) formulas used in connection with orifice meters will be reviewed. Since a small error in measurement in gas flow in a pipeline can translate to several thousand dollars of loss of revenue, it is important that industry strives to improve upon measurement methods. Accordingly, gas transportation companies and related industries have been researching better ways to improve flow measurement accuracy. For a detailed discussion of gas flow measurement, the reader is referred to the publications listed in the Reference section.
