Water Supply Analysis NFPA 13

Hydrant flow test analysis on the N^1.85 curve. Static and residual readings go in; available pressure and available flow come out.

WHAT IT CALCULATES
- Available pressure at a required flow on the N^1.85 supply curve
- Available flow at a required pressure
- Safety margin between the available and the required pressure
- Adequate or inadequate verdict against the system demand
- Available supply compared against sprinkler or standpipe demand

CODE REFERENCES BUILT IN
- N^1.85 curve from the Hazen-Williams relationship between flow and friction loss
- Flow test practice used with NFPA 13 design and AWWA distribution work

HOW IT WORKS
Enter static pressure, residual pressure and the flow at which the residual was read. You get available pressure or flow at any point on the curve.

CORE FEATURES
- Works 100 percent offline, no signal needed on site
- US or metric units: psi and gpm, or bar and L/min
- Calculation history you can reopen and reuse
- PDF export for submittals and field records
- Light and dark themes
- English and Spanish
- Material Design 3 interface

TYPICAL USES
- Checking a layout on site before the pipe goes up
- Verifying a contractor submittal during plan review
- Sizing during a bid walk without pulling the code book out of the truck
- Backing a field decision with a PDF you can attach to the job file
- Studying for NICET certification

WHAT THE PDF REPORT INCLUDES
- Every input you entered
- The calculated results with units
- Date and time of the calculation

OPTIONAL PRO UPGRADE - $2.99 ONE-TIME IN-APP PURCHASE
The following features require a separate one-time in-app purchase. They are not required to use the calculator:
- Unlimited saved calculation history
- PDF export of results
- Dark theme
- Ad-free experience

WHO IT IS FOR
- Fire protection engineers and system designers
- Sprinkler fitters and installers
- Fire inspectors and AHJ plan reviewers
- Contractors preparing bids and submittals
- NICET candidates and fire protection students

ACCURACY NOTE
Results are a design aid, not a stamped design. Verify against the edition of the standard adopted in your jurisdiction and confirm with the authority having jurisdiction.

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