Fire Hose Smooth-Bore Nozzle Flow
Discharge from a smooth-bore fire nozzle: Q = 29.7·d²·√P (NFPA form).
The fireground constant every pump operator memorizes: a 1" tip at 50 psi throws 210 gpm. Inputs deliberately stay in US units to match NFPA practice.
Formula
Fire Hose Smooth-Bore Nozzle Flow is a free smooth bore nozzle for process, mechanical and water engineers — 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 Fire Hose Smooth-Bore Nozzle Flow
Discharge from a smooth-bore fire nozzle: Q = 29.7·d²·√P (NFPA form). The calculation implements Q(gpm) = 29.7 · d² · √P (d in inches, P in psi) (NFPA / IFSTA Pumping Apparatus Driver-Operator Handbook). The fireground constant every pump operator memorizes: a 1" tip at 50 psi throws 210 gpm. Inputs deliberately stay in US units to match NFPA practice.
How to use Fire Hose Smooth-Bore Nozzle Flow
- 1Enter Tip diameter in in (Hand line 15/16"–1¼"; master stream 1⅜"+).
- 2Enter Nozzle pressure in psi (Hand lines 50 psi; master streams 80 psi).
- 3Read Discharge, Discharge instantly — no submit button needed.
Why use Fire Hose Smooth-Bore Nozzle Flow?
- ✓Implements the standard formula — Q(gpm) = 29.7 · d² · √P (d in inches, P in psi)
- ✓Reference cited on-page: NFPA / IFSTA Pumping Apparatus Driver-Operator Handbook
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Fire Hose Smooth-Bore Nozzle Flow use?+
It computes Q(gpm) = 29.7 · d² · √P (d in inches, P in psi), per NFPA / IFSTA Pumping Apparatus Driver-Operator Handbook. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
The fireground constant every pump operator memorizes: a 1" tip at 50 psi throws 210 gpm. Inputs deliberately stay in US units to match NFPA practice.
Does this work for any fluid?+
Yes — density and viscosity are inputs (with common fluids suggested in the field hints), so the same physics applies to water, oils, gases and process fluids. Compute always runs in SI internally, so unit mix-ups can't corrupt the result.
Is the Fire Hose Smooth-Bore Nozzle Flow 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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