The failure of lockhopper valves in coal gasification processes has long been a significant problem resulting in costly premature terminations of gasification experiments. Few successful investigations have determined the major causes of such failures. The purpose of the present investigation is to identify possible failure mechanisms of lockhopper ball valves and to establish some fundamental analytical methods from which mathematical models of such failure mechanisms may be developed. In addition, the present work involves some recommendations of various basic experimental procedures that may also aid in the identification of failure mechanisms. 43 references, 7 figures.