PT ALVA PRIMA VALVE -HOSE - EXPASION JOINT PNEUMATICS
This tutorial briefly describes the basic components of different types of linear and rotary action control valves available for use in steam and water systems.
Use the quick links below to take you to the main sections of this tutorial:
The printable version of this page has now been replaced by The Steam and Condensate Loop Book
View the complete collection of Steam Engineering Tutorials
Introduction to Electric / Pneumatic Controls
Block 6 of The Steam and Condensate Loop considers the practical aspects of control, putting the basic control theory discussed in Block 5 into practice.
A basic control system would normally consist of the following components:
All of these terms are generic and each can include many variations and characteristics. With the advance of technology, the dividing line between individual items of equipment and their definitions are becoming less clear. For example, the positioner, which traditionally adjusted the valve to a particular position within its range of travel, can now:
Take input directly from a sensor and provide a control function.
Interface with a computer to alter the control functions, and perform diagnostic routines.
Modify the valve movements to alter the characteristics of the control valve.
Interface with plant digital communication systems.
However, for the sake of clarity at this point, each item of equipment will be considered separately.4242424