Hydraulics and Pneumatics A Technician’s and Engineer’s Guide

Abstract

Machines should work, people should think The IBM Pollyanna Principle Practically every industrial process requires objects to be moved, manipulated or be subjected to some form of force. This is generally accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics). Traditionally, pneumatics and hydraulics are thought to be a mechanical engineer’s subject (and are generally taught as such in colleges). In practice, techniques (and, more important, the fault-finding methodology) tend to be more akin to the ideas used in electronics and process control. This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems. It is intended for engineers and technicians who wish to have an insight into the components and operation of a pneumatic or hydraulic system. The mathematical content has been deliberately kept simple with the aim of making the book readable rather than rigorous. It is not, therefore, a design manual, and topics such as sizing of pipes and valves have been deliberately omitted. The second edition was updated to include recent developments such as the increasing use of proportional valves, and an expanded section on industrial safety. The third edition includes many changes based on suggestions from readers including a new chapter on sequencing applications and an appendix of hydraulic and pneumatic symbols. I would, in particular, like to thank Don MacDonald and Kerry Jones of IPS International (www.ips-international.com) for useful advice and the use of the simulation software described in Chapter 9. Andrew Parr Isle of Sheppey eap_minster@yahoo.co.uk