This book examines the full spectrum of compressor types, how they operate, how to control them, and how operating conditions can significantly impact their performance. Discussed in detail are the influence of pressure, temperature, molecular weight, specific heat ratio, compression ratio, speed, vane position, and volume bottles. The various methods of throughput control are also addressed; including discharge throttling, suction throttling, guide vane positioning, volume bottles, suction valve unloaders, and speed control, as well as how each of these control methods affects compressor life. Compressor surge is defined and discussed in detail, along with the available types of instrumentation (controllers, valves, pressure and temperature transmitters), and which of these are most suitable for controlling surge. Case studies are included to illustrate the principles covered in the text.