Planning before cleaning
The tank is emptied, isolated from the process and assessed for residues, vapours, flammability, toxicity and atmosphere. Many out-of-service tanks are permit-required confined spaces. Where feasible, no-entry cleaning is selected, for example using fixed or remotely operated equipment.
Entry only with risk controls
Where entry is necessary, the procedure requires the applicable permit, atmospheric testing and continuous monitoring, ventilation, trained personnel, an attendant, communication and a prepared rescue plan. Used water and product residues are captured and managed according to their properties.