Translations:Pumpen, Betriebs- und Regenwasserwerke/150/de

$V_{n}={\frac {0,33\times 4,2\ {\frac {m^{2}}{h}}\times (6\ bar+1)}{((6\ bar\ -2,5\ bar)\times {\frac {20}{h}}\times 1)}}=0,139\ m^{3}=139\ l$