NFPA 25 worksheet
Hydrant Flow and Water Supply Worksheet
A water supply worksheet for hydrant pitot flow, static and residual pressure, available flow at required residual, and sprinkler demand comparison.
hydrant flow water supply worksheet3 workflow phases6 linked tools4 required inputs
Workflow phases
3
Ordered job steps
Linked calculators
6
Tools used by the worksheet
QA gates
3
Review checkpoints
Worksheet input matrix
Trace each required value to its source before running linked calculators.
| Group | Field | Source | Required | Used for |
|---|---|---|---|---|
| Field test basis | Static pressure | Hydrant flow test record | Required | Supply curve and available flow |
| Field test basis | Residual pressure | Hydrant flow test record | Required | Supply curve and available flow |
| Field test basis | Pitot pressure | Field pitot reading | Conditional | Hydrant discharge flow |
| Comparison basis | Required residual pressure | Project demand or AHJ basis | Required | Available flow at residual |
| Comparison basis | System demand | NFPA 13 hydraulic worksheet or system demand calculator | Conditional | Demand comparison |
| Comparison basis | Test date and location | Field report | Required | Record traceability |
Worksheet workflow
Run phases in order so the worksheet answers the full job intent, not only one formula.
| Phase | Objective | Actions | Linked tools | Acceptance gate |
|---|---|---|---|---|
| 1. Record hydrant test | Capture field readings and confirm the test basis before calculations. | Record static pressure, Record residual pressure, Record pitot and outlet data | Field readings belong to the same test event and outlet condition. | |
| 2. Calculate available water | Estimate available flow at the required residual pressure. | Enter measured flow, Enter static and residual pressures, Set required residual, Review available flow | Available flow is reported at the same residual pressure basis used for demand comparison. | |
| 3. Prepare demand comparison | Hand water supply data to sprinkler demand or pump selection workflows. | Compare available flow to sprinkler demand, Flag narrow supply margin, Send result to pump sizing if needed | Supply point and demand point are both retained with GPM and pressure basis. |
Worksheet QA gates
Use these gates before the worksheet result is used for design coordination or review.
| Gate | Check | Evidence |
|---|---|---|
| Test consistency | Static, residual, and flow values are from one test record. | Field test basis input group |
| Residual basis | Available flow is calculated at the required residual pressure. | Available water output |
| Demand comparison | Demand and supply are compared using compatible pressure and flow assumptions. | Demand comparison phase |
Records to keep
1Hydrant flow test calculation
2Available flow at required residual
3Water supply curve point
4Demand comparison record
Related calculators and references
Authority records
Document jurisdiction, AHJ, submittal, inspection, or edition-basis records before final project reliance.
Engineering disclaimer
NFPA in USA provides engineering workpapers, calculation checks, and reference tables for project screening and coordination. Final design decisions, code interpretations, submittals, and acceptance records must be completed by qualified professionals and verified against the adopted code, project criteria, listings, and Authority Having Jurisdiction requirements. This site does not issue signed or sealed engineering documents.FAQ
What is the hydrant flow and water supply worksheet for?+
It organizes a complete preliminary engineering check across inputs, linked calculators, reference tables, QA gates, and retained deliverables.
Can this worksheet replace a sealed calculation package?+
No. It is a structured screening and coordination worksheet. Final design, code interpretation, and submittal documents must be reviewed by qualified professionals and the AHJ.
Why use a worksheet instead of a single calculator?+
A single calculator answers one formula. A worksheet follows the job workflow, keeps input sources visible, links the required tools, and records the review gates before project use.