ToF detector needs constant supply with gas mixture and also place to exhaust used gas. It is going to consist of 12 identical parts that would create a dodecahedron around main part of the MPD, each of which is going to be supplied with gas separately with specially dedicated gas system.
The system is designed to be an assembly of a few lesser modules of which mine to work with was a gas returning module. It is important to avoid exhaust used gas into the atmosphere due to environment-harmful component of the gas - Tetrafluoroethane. Thus the module have to collect it and enforce closed feedback loop flow controlled with input pressure.