Water Main Flushing Calculator
Flow, time and water volume to flush a main at scouring velocity for the required pipe volumes.
Open the hydrant until you've passed n pipe volumes at scouring velocity AND chlorine residual stabilises. Plan dechlorination before it hits a stream.
Formula
Water Main Flushing Calculator is a free main flushing for pump engineers, plumbers and plant designers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Water Main Flushing Calculator
Flow, time and water volume to flush a main at scouring velocity for the required pipe volumes. The calculation implements Q = A·V_flush; V_water = A·L·n; t = V/Q (AWWA C651 — disinfecting water mains). Open the hydrant until you've passed n pipe volumes at scouring velocity AND chlorine residual stabilises. Plan dechlorination before it hits a stream.
How to use Water Main Flushing Calculator
- 1Enter Main diameter in mm.
- 2Enter Length to flush in m.
- 3Enter Pipe volumes to pass (AWWA C651: ≥ 3 volumes).
- 4Enter Flushing velocity in m/s (≥ 0.9 m/s (3 ft/s)).
- 5Read Required flow, Flush time, Water used instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Water Main Flushing Calculator?
- ✓Implements the standard formula — Q = A·V_flush; V_water = A·L·n; t = V/Q
- ✓Reference cited on-page: AWWA C651 — disinfecting water mains
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Water Main Flushing Calculator use?+
It computes Q = A·V_flush; V_water = A·L·n; t = V/Q, per AWWA C651 — disinfecting water mains. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
Open the hydrant until you've passed n pipe volumes at scouring velocity AND chlorine residual stabilises. Plan dechlorination before it hits a stream.
Can I use this for pump selection?+
Use it to establish the duty (flow, head, NPSH, power) and then pick a pump whose curve passes through that point near best efficiency. The tool gives you the engineering numbers a supplier will ask for.
Is the Water Main Flushing Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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