Instrumentation and Control Systems, 3rd Edition

Chapter 6

Correction Elements

Abstract

This chapter gives a discussion of the correction elements used with control systems, including pneumatic and hydraulic systems with directional and flow control valves and electrical systems with motors. Case studies are included.

Keywords

Correction elements; pneumatic and hydraulic systems; electrical systems

Outline

• 6.1 Introduction 137
  • 6.1.1 The Range of Actuators 138
• 6.2 Pneumatic and Hydraulic Systems 138
  • 6.2.1 Current to Pressure Converter 138
  • 6.2.2 Pressure Sources 138
  • 6.2.3 Control Valves 139
  • 6.2.4 Actuators 140
• 6.3 Directional Control Valves 141
  • 6.3.1 Sequencing 143
  • 6.3.2 Shuttle Valve 145
• 6.4 Flow Control Valves 146
  • 6.4.1 Forms of Plug 147
  • 6.4.2 Rangeability and Turndown 149
  • 6.4.3 Control Valve ...