The Energy Institute has released an updated version of its EL 1550 Handbook on Equipment Used for the Maintenance and Delivery of Clean Aviation Fuel. The revised volume takes into account industry developments since 2007’s first edition. In addition to an overview of good practices in the implementation and operation of fuel filtration systems, the handbook now contains five more chapters covering key topics such as the measurement and monitoring of differential pressure across a filter vessel, one of the primary means for detecting fuel contamination or the failure of a filtration system.