Chemical dosing pump sizing
Size a metering pump from water flow, target dose and stock solution strength — output in L/h with a duty-point check against the 20–80% stroke rule.
Results
| Required pump output | 0,3 L/h |
|---|---|
| Solution consumption per day (24 h) | 7,2 L |
| Duty point on selected pump | 6% of capacity |
A duty point of 6% is below the 20–80% band where solenoid pumps dose repeatably. Use a smaller pump, or dilute the stock solution to raise the duty point.
Formula used
q = Q × D ÷ C
C (g/L) = strength (% w/v) × 10
duty (%) = q ÷ q_max × 100
- q
- required pump output, L/h
- Q
- water flow being dosed, m3/h
- D
- target dose, mg/L (= g/m3)
- C
- active concentration of stock solution, g/L
- q_max
- selected pump's maximum output, L/h
Percentage strength is taken as weight-per-volume (% w/v). For chemicals supplied by weight (% w/w), multiply by the solution density first. The 20–80% duty band is the usual guidance for a solenoid metering pump set by stroke length; a pump that trims its output by stroke frequency, or one running under an external 4–20 mA or pulse signal, has its own turndown, so check the model's own stated minimum before sizing to this band.
Equipment for this duty
Send the water analysis and duty point, and the branch confirms exact selections, pricing and lead times — usually within one working day.
Request a quoteResults are indicative engineering estimates based on standard formulas and typical assumptions. They are not a design service; confirm any design against a full water analysis and the relevant manufacturer’s data.