Translations:Pumpen, Betriebs- und Regenwasserwerke/74/en

All possible operating points of a pump are shown on the operating characteristics curve (known as a pump curve or throttle curve) as a Q-H diagram, wherein the pressure is usually expressed as a meter water column (1 bar corresponds to approximately 10 m water column). The operating point of the pump is where the pump curve intersects the system characteristic curve. Each individual fixture has its own system characteristic curve together with the corresponding piping system. This also includes the system characteristic curve resulting from different combinations of fixtures. This results in various different operating points for the pump. In order to avoid calculating all system characteristic curves, the critical fixture demand is determined below, which must be optimally supplied even when several different fixtures are simultaneously operated. The operating point determined in this way should be close to, but below, the pump curve. The chosen pump should optimally supply the system without needing to be oversized and therefore consuming too much electricity.