To optimise the performance of inlet separators, the FPSO required internal parts replacement. Taking place during a scheduled maintenance shutdown, component replacement required personnel to enter the confined space of the separators, thus requiring emptying, cleaning, and degassing. The existing plant had no valves or means to isolate the separators. Hot work carries additional risks, cost, and complexity offshore, and can be avoided using Izomax mechanical isolation systems. Isolation was critical due to the presence of hydrocarbons in the system. In this instance, the isolation needed to be performed on large 24” flanges. The required isolation of the separators from the rest of the system, including the riser, was not possible. The commonly used solutions utilise the flare system to bleed off all relevant systems after which the flare system can be gas freed. To ensure the entire system is free of gas using standard solutions, the shutdown period required for preparation time alone would be extended by between three and five days. The Izomax team focused on processes and technologies to avoid or mitigate such lengthy periods of time.