Power Plant Instrumentation and Control Handbook

2. Control Valve Types

2.0. Introduction

It is indeed a big task to select the control valve best suited for a particular application. Control valves that work in power plants might not be appropriate for process plants like refineries and paper plants. In this clause we discuss the types of valves normally encountered in a power plant; however, some special types of valves might also be discussed, depending on their application. Since in power plants there are many applications where cavitation and/or flashing fluid might occur, a term C_d (= C_v/d²) as defined in figure VI/1.2-1 is very useful for calculating the pressure 

TABLE VI/2.0-1

Valve Selection Guide (3)

Feature	Ball	Butterfly	Digital	Globe (1)	Globe (2)	Saunders
Maximum pressure class common (lb) ...