This is a paper presented at the Twenty-Ninth International Pump Users Symposium in 2013. API 682 is the leading document for mechanical seals in petrochemical, chemical, and pipelines services worldwide. It has combined the aspects of seal design, testing, standardization, and applications to provide the users and OEMs alike with a common source of information for mechanical seals. As seal technology has advanced, the standard has expanded to incorporate new seal designs, materials, seal selection guidance, and piping plans. This document covers major changes introduced in the fourth edition.