NPSHa Calculator — Suction Lift
NPSH available when the pump draws water up from a well, sump or river below it.
Practical suction lift maxes out near 7–8 m at sea level for cold water — and loses ~1 m per 850 m of altitude. Buchholz' rule: put the pump low.
Formula
NPSHa Calculator — Suction Lift is a free suction lift npsh 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 NPSHa Calculator — Suction Lift
NPSH available when the pump draws water up from a well, sump or river below it. The calculation implements NPSHa = (P_atm(alt) − P_v(T))/ρg − lift − h_f (ANSI/HI 9.6.1; barometric formula). Practical suction lift maxes out near 7–8 m at sea level for cold water — and loses ~1 m per 850 m of altitude. Buchholz' rule: put the pump low.
How to use NPSHa Calculator — Suction Lift
- 1Enter Site altitude in m.
- 2Enter Vertical lift to pump eye in m.
- 3Enter Suction friction + foot valve in m.
- 4Enter Water temperature in °C.
- 5Read NPSH available instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use NPSHa Calculator — Suction Lift?
- ✓Implements the standard formula — NPSHa = (P_atm(alt) − P_v(T))/ρg − lift − h_f
- ✓Reference cited on-page: ANSI/HI 9.6.1; barometric formula
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Built-in engineering verdict flags out-of-range results instantly
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the NPSHa Calculator — Suction Lift use?+
It computes NPSHa = (P_atm(alt) − P_v(T))/ρg − lift − h_f, per ANSI/HI 9.6.1; barometric formula. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
Practical suction lift maxes out near 7–8 m at sea level for cold water — and loses ~1 m per 850 m of altitude. Buchholz' rule: put the pump low.
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 NPSHa Calculator — Suction Lift 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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