Tests were conducted with a trickle valve attached to a 100-mm-diameter dipleg to determine the effect of trickle valve operation with aerated and unaerated diplegs, immersed and unimmersed diplegs, and the effect of the flapper weight on dipleg operation. It was found that the solids flux through the dipleg was not a function of the flapper weight when aeration was used for both immersed and unimmersed trickle valves. Unimmersed, unaerated trickle valves were found to be able to operate at higher solids fluxes than immersed trickle valves. The best way to aerate trickle valves was to add aeration at the midpoint of the mitered section of the valve.