Distillation columns allow separation of fluid mixtures based on their boiling points. As vapors rise through the column, different components will condense at different temperatures and accumulate for withdrawal. Distillation columns will have a wide range of temperatures throughout. Fluids, especially at the lower end can be dirty and cause coating and plugging of equipment. Overfill is a risk especially during plant start-up and before equilibrium is reached between the liquid and gas flow. If an overfill occurs, process media typically ends up in the flare system for hydrocarbons with the risk of a dangerous incident / explosion.