Calculations based on a maximum allowable flow rate of 3m/s unless a lower flow rate is known.
Input data required: Number of cistern inlets and their respective diameters "D", width "l" and % open area of slot, weir thickness "Cw" and unobstructed vertical deptth of wier sill upstream face "Uw"
Select "Calculate" and total maximum flow rate "Q", air gap "A", head over weir "h" and weir slot height "Ow" are automatically calculated.
Results valid for single or multiple inlet arrangements if the following conditions are met. Calculate
"h" = head over Weir at Total Maximum Flow.All dimensions in mm | Acceptable Weir Sizes | Validation Criteria see above | ||||
l Weir Width |
Ow (4) Weir Height |
h | 1 | 2 | 3 | |
Unrestricted Weir. (No insect screen) | ||||||
Weir Width l increased to account for insect screen obstruction | ||||||
Slot Height Ow increased to account for insect screen obstruction |