The literature on spinning cones as pumps and degassers is reviewed. Experiments on a spinning cone rig designed to measure spinning cone-pumping rates are described. A large number of experiments were carded out, measuring pumping rates as a function of cone angle and immersion depth. Cone half angles were from 15 to 60degrees. Most of the tests were done with water but a number of runs were carried out with 75% by volume glycerol solution. This changed the viscosity and fluid density. An equation is proposed to predict the volumetric pumping rate (Q) of a cone in terms of its geometry and the physical properties of the fluids. Experiments with gassed fluids indicate that the liquid pumping rate of a spinning cone is independent of any gas present. It was also found that both outside and inside surfaces of the cone contribute equally to the fluid pumping process. The effectiveness of spinning cones as a degasser and/or level controller have been tested in mechanically agitated baffled vessels using cones mounted on the agitator shaft at the liquid surface. Under gassed conditions and with surfactants added to the liquid, the spinning cone was shown to be effective in controlling the level and reducing the gas voidage over a wide range of operating conditions. The effectiveness of the cone as a defoamer appears to scale at equal tip speed, suggesting that shear rate is the dominant mechanism. Tests were done on 2 ft (0.61 m) and 3 ft (0.914 m) diameter stirred tanks.