This document provides recommended methods and describes associated equipment and test setups to assist in understanding and conducting pressure drop tests on fuel system components. Background information and suggestions are provided as means of improving accuracy and repeatability of test results. Although written specifically for fuel system components@ the methods@ equipment and suggestions presented herein apply equally to pressure drop tests of other liquidhandling devices. Purpose: The purpose of conducting a pressure drop test on a component is to establish the energy (pressure) loss resulting from flowing liquid into one port and out of another under stated conditions such as flow rate@ attitude@ degree of valve opening@ flow direction@ fluid density@ viscosity and temperature. Resulting pressure drop data may be used to predict or compare relative pressure drop of similar devices or to make various system analyses in conjunction with pressure drop data of associated piping and other components.