The PVC tubes used for our pneumatic tube systems have a very low production tolerance in terms of dimensions and surface. The tubes are connected to each other using couplings. Around 95% of the tubes used today are made of PVC due to its relatively simple processing. In certain, mostly public buildings, e.g. hospitals, the use of stainless steel pipe or halogen-free pipe is mandatory. Approximately 70% of newly installed pneumatic tube systems are also retrofitted into existing buildings.