These days’ manual calculations are rarely done; software is now available to speedup the process and removes human error. The primary aim of the software is to size the pipework to ensure it runs full of water as quickly as possible to induce a syphonic action as the water column drops in the main vertical section of the pipe system. On buildings of several stories negative pressure of –800 mbar frequently occurs providing a high level of suction at the outlets.
Calculation software is frequently linked to a drawing package, which provides a diagram of the proposed installation, together with the hydraulic calculations.
