Plan Review and Approvals

Acceptance testing quick reference

All tests per NFPA 13, Chapter 27. Confirm AHJ requirements before scheduling — some jurisdictions add tests or modify criteria.

Test	Requirement	Duration	Acceptance Criteria
Hydrostatic (wet pipe)	200 psi or 50 psi above max working pressure, whichever is greater	2 hours	No visible leaks, no pressure drop
Hydrostatic (dry pipe)	200 psi or 50 psi above max working pressure	2 hours	No visible leaks, no pressure drop
Air test (dry/preaction, pre-2019)	40 psi	24 hours	Max 1.5 psi drop
Air test (dry/preaction, 2019+)	System operating pressure	2 hours	Max 3 psi drop
Main drain test	Fully open main drain, record static and residual	N/A	Compare to original flow test data
Inspector's test	Open most remote inspector's test connection	N/A	Waterflow alarm activates within 90 seconds
Trip test (dry valve)	Trip the dry valve	N/A	Water to inspector's test in 60 seconds
Trip test (preaction)	Activate detection and trip valve	N/A	Water delivery per system design
Alarm test	Activate all alarm devices	N/A	All alarms received at FACP and central station
Antifreeze test	Verify solution concentration	N/A	Concentration within listed range (refractometer)

Hydrostatic test pressure must be maintained for the full 2 hours. If the system cannot hold pressure, do not attempt to compensate by re-pumping during the test. Find and fix the leak.

Test preparation checklist:

[ ] All piping complete and supported
[ ] All heads installed (or test plugs in place with AHJ approval)
[ ] FDC connections capped
[ ] Gauges installed at riser and at test location
[ ] Drain path established for inspector's test
[ ] FACP and monitoring in place for alarm tests
[ ] AHJ and/or third-party inspector scheduled

FM Global vs. NFPA 13 — key differences

Projects with FM Global insurance often have requirements that exceed NFPA 13. Identify FM involvement early.

Requirement	NFPA 13	FM Global
Governing documents	NFPA 13 standard	FM Data Sheets (DS 2-0, 3-26, 8-9, etc.)
Design density	Per standard tables/curves	Often higher than NFPA 13, especially for storage
Storage protection	Chapters 20-26	DS 8-9 — frequently more conservative
Water supply safety margin	10 psi typical practice	May require 15-25 psi margin depending on data sheet
Component approval	UL Listed	FM Approved (separate listing)
Sprinkler heads	Any UL listed head meeting design	FM Approved heads required — not all UL heads are FM Approved
Rack storage	In-rack per NFPA 13 tables	DS 8-9 may require additional in-rack levels
Hydraulic calculations	NFPA 13 methodology	Same methodology, but higher demand points
Inspection frequency	NFPA 25	FM may require more frequent inspections
Plan review	AHJ review	FM engineering review in addition to AHJ

FM Approved is not the same as UL Listed. A head can be UL Listed but not FM Approved. Always verify component approval status when FM Global is the insurer.

Common plan review rejection reasons

Rejection Item	Resolution
Flow test data expired (> 12 months)	Obtain new flow test per NFPA 291
Hydraulic calc summary missing or incomplete	Include demand point, supply curve, safety margin, and node-by-node results
Head spacing exceeds listing	Verify against cut sheet; add or relocate heads
Obstruction rules not addressed	Apply Section 8.5.5; show obstruction analysis on plans
Seismic bracing missing in required zone	Add bracing per Section 18.5; show on plans with calculations
Hanger spacing exceeds table	Add hangers per Table 9.2.1
Inadequate water supply	Increase pipe sizes, reduce friction loss, or request fire pump
Wrong hazard classification	Provide occupancy documentation; re-classify per Chapter 5
Missing alarm device details	Show all waterflow switches, tamper switches, and FACP connections
Plans not signed/sealed	Obtain required professional signature per state licensing requirements
No commodity classification for storage	Classify per NFPA 13 Section 5.6; document on plans
Design area not shown on plans	Outline the hydraulically most remote area with dimensions

AHJ submittal requirements

Minimum submittal per NFPA 13 Chapter 29:

Item	Required Content
Floor plans	All piping with sizes, head locations, hanger locations, brace locations, valve locations
Riser diagram	Valve arrangement, trim, component identification, connection to water supply
Hydraulic calculations	Complete node-by-node, with summary and supply/demand graph
Water supply data	Flow test with static, residual, and flow; date and location
Cut sheets	Every head, valve, and device used in the system
Material list	Pipe type, fitting type, hanger type, and quantities
System description	Hazard classification, design criteria, occupancy type, building construction
Seismic data	Seismic design category, bracing calculations, brace locations (if applicable)

Supplemental items that reduce review time:

Cover sheet with project info, contractor license, and point of contact
Code edition and any local amendments referenced
Previous review comments with responses (for re-submittals)
Color-coded revisions for re-submittals

Acceptance testing procedures

Hydrostatic test — step by step

Close the main control valve
Connect test pump to the system (through FDC or test connection)
Fill system completely — all air must be vented from high points
Pump to test pressure (200 psi or 50 psi above max WP)
Close pump valve and record gauge reading
Wait 2 hours
Record final gauge reading
Walk all piping looking for visible leaks
Pass: no visible leaks and no pressure drop on gauge
Document results on test certificate

Temperature changes during testing affect pressure readings. A 10F temperature increase can raise pressure by approximately 10 psi in a closed system. Account for ambient conditions when evaluating results.

Main drain test

Record static pressure at the system gauge
Fully open the main drain valve
Wait for pressure to stabilize (minimum 30 seconds)
Record residual pressure
Close drain valve
Compare static and residual to the original flow test data
A significant drop from original values indicates a water supply problem

Inspector's test (wet systems)

Open the inspector's test connection at the hydraulically most remote point
Start a timer when the valve opens
Waterflow alarm must activate within 90 seconds
Verify alarm signal is received at the FACP
Verify alarm signal is transmitted to the central monitoring station
Close the test connection
Verify the system resets properly

As-built documentation requirements

Per NFPA 13, as-built drawings must reflect actual installed conditions. This is a code requirement, not optional.

As-built drawings must show:

[ ] All installed piping with actual sizes (including any field changes)
[ ] All sprinkler head locations as installed
[ ] All valve locations with identification numbers
[ ] All hanger and brace locations as installed
[ ] Any deviations from the approved plans — clearly marked
[ ] Actual pipe lengths if they differ from approved plans
[ ] Any field-routed piping not shown on original plans

As-built documentation package:

Document	Recipient
As-built drawings	Building owner and AHJ
Hydraulic calculations (updated if design changed)	Building owner and AHJ
Test certificates (hydrostatic, alarm, drain)	Building owner and AHJ
Contractor's material and test certificate (NFPA 13 form)	Building owner and AHJ
Sprinkler head and device cut sheets	Building owner
Spare head cabinet inventory	Building owner
Operating instructions for valves and devices	Building owner

The spare head cabinet must contain a minimum of 6 spare heads for systems with under 300 heads, 12 for 300-1000, and 24 for over 1000 heads. Include a sprinkler wrench for each head type. This is an NFPA 13 requirement, not a suggestion.

Inspection, testing, and maintenance handoff

At project closeout, the installing contractor should provide the building owner with:

Item	Purpose
NFPA 25 summary	Inspection, testing, and maintenance schedule for all system components
Valve location chart	Quick reference for emergency shutdowns
Spare head cabinet location	So maintenance staff can find it
Fire pump operation manual	If applicable — includes test procedures
Monitoring company contact info	Central station and local alarm company
Contractor contact info	For service, repairs, and warranty issues

Many building owners do not understand their NFPA 25 obligations. A brief handoff meeting explaining the inspection schedule prevents system neglect and potential liability for the installing contractor.