Laboratory Drainage TechnologyHow does vacuum drainage work? The system works under vacuum with vacuum valves. This means the pipework is permanently under negative pressure. Immediately waste water needs to be led away the vacuum valve of the collection tank opens and the waste water is transported to the central waste water tank in the machine room. The vacuum valve closes when all the waste water has been safely sucked into the vacuum pipeline network. A welcome side effect is that the damp, at all events polluted air at the point where the waste water collects is sucked out with the waste water. Thereby odour problems are simultaneously reduced or avoided altogether.