Volume extraction systems require a large volume of air to be extraced and the level of vacuum is of lesser importance.
This means that a relatively large diamter pipe system is required.
If the pipe diameter was too small the flow resistance would increase and extraction capacity reduced. The pipe system 75 allows installationsup to 30 m with the WFE 4S uses in a stand alone system.
The pipe sections are designed to stick together and have internal sealing bushes.