Over recent years there have been substantial changes in those industries which are concerned with the design, purchase and use of special purpose (ie critical, high-revenue) rotating equipment. Key personnel have been the victims of early retirement or have moved to other industries: contractors and end-users have reduced their technical staff and consequently have to learn complex material 'from scratch'. As a result, many companies are finding that they are devoting unnecessary man hours to the discovery and explanation of basic principles, and having to explain these to clients who should already be aware of them. In addition, the lack of understanding by contractors and users of equipment characteristics and operating systems often results in a 'wrong fit' and a costly reliability problem. Forsthoffer's Rotating Equipment Handbooks: Auxiliary Systems deals with types, function and application of each major system type, (lubrication, control, liquid and gas seal, cooling, buffer gas and pump flush) component selection and design of reservoirs, pump systems, control valves and instrumentation, coolers/filters and transfer valves, design audits and troubleshooting of systems and components, maintenance, key reliability indicators, system condition monitoring and much more. Forsthoffer's Rotating Equipment Handbook: Auxiliary Systems is the forth title in the five volume set. The volumes are: 1. Fundamentals of Rotaing Equipment; 2. Pumps; 3. Compressors; 4. Auxiliary Systems; 5. Reliability Optimization through Component Condition Monitoring and Root Cause Analysis'.