Within the boiler, piping and pressure vessel industry, pressure relief devices are considered one of the most important safety components. These Devices are literally the last line of defense against catastrophic failure or even lose of life. Written in plain language, this fifth book in the ASME Simplified series addresses the various codes and recommended standards of practice for the maintenance and continued operations of pressure relief valves as specified by the American Society of Mechanical Engineers and the American Petroleum Institute. Covered in this book are: preventive maintenance procedures, methods for evaluation of mechanical components and accepted methods for cleaning, adjusting and lubricating various components to assure continued operation and speed performance as well as procedures for recording and evaluating these items.