The real work starts on the day a sprinkler system is commissioned: maintenance. NFPA 25 (Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems) defines in detail which check is carried out at which frequency. The operator's question is always the same: "What do I check this month?" This post summarizes the ITM tasks from weekly to five-yearly, in order and in field language.
Weekly Checks
- Dry pipe / preaction pressure gauge: Is the air pressure within the manufacturer's range, or has it drifted with day-night temperature swings?
- Control valve lock indicator: Does the tamper switch signal reach the panel?
Monthly Checks
- Wet pipe system pressure gauge: Within the normal operating range? If it has dropped, find out why.
- Control valves open and locked: A visual check is enough; no valve may be left closed.
- Jockey pump test: Does it start automatically on pressure drop, and is the stop pressure stable?
- Fire pump no-flow (churn) test: diesel pumps run at least 30 min, electric pumps at least 10 min; the frequency is weekly or monthly depending on pump type (weekly for diesel).
Quarterly Checks
- Alarm devices (flow switch, pressure switch): flow water through the test connection and verify the signal time at the panel.
- FDC (Fire Department Connection): Caps in place, threads clean, check valve leak-free.
- Hydrant visual inspection and lubrication: including body paint, cap gaskets and stem binding.
Annual Checks
- Main drain test: Open the main drain and measure the system pressure; if it drops by more than 10 psi (0.7 bar), investigate a blockage or a partly closed valve in the main.
- Dry valve partial trip test: the valve opens without the system filling completely with water; the mechanism is observed.
- Antifreeze concentration test: measured with a refractometer; never accept the mixture on paper.
- Fire pump annual flow test: the performance curve is plotted at 100% and 150% of capacity and compared with the manufacturer's curve.
- Visual sprinkler inspection: corrosion, paint, loading and obstructions.
- Hanger and seismic bracing check: looseness, rust or braces that have shifted angle.
Three-Year Checks
- Dry valve full trip test: the system fills completely with water, simulating a real fire.
Five-Year Checks
- Sprinkler laboratory test: samples from sprinklers older than 50 years are sent to an accredited laboratory; the upper limit is 75 years for standard sprinklers and 20 years for quick-response sprinklers.
- Internal pipe inspection: MIC (Microbiologically Influenced Corrosion) check.
- Gauge calibration or replacement: after 5 years the gauge is either verified or replaced.
- Tank internal inspection: coating condition and signs of oxidation.
Common Gaps in Turkey
- Weekly round only on paper: Nobody walks the site; checklist is just a signature.
- Fire pump runs skipped: without regular 30-minute runs the diesel batteries weaken, and in a real fire the pump may not start.
- Internal pipe inspection never performed: not a single pipe section has been opened, even on systems older than 15 years.
- No log book: without records neither the insurer nor the authority having jurisdiction can spot anomalies, and a claim may be refused after a fire.
Conclusion
ITM is the heart of the sprinkler system. If you want your system to still work in 20 years, every frequency from weekly to five-yearly has to be carried out with discipline. NFPA 25 Table 5.1 fits on one page — it should be on every facility manager's wall.
ITM schedule in MEP Calc
NFPA 25 frequency-based ITM calendar, reminders, and field log book.
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Download SprinkCalc on the App StoreCore reference: NFPA 25 Table 5.1 - ITM Frequencies. Original NFPA post: NFPA Today - ITM Frequencies.