The problem
Fire sprinkler systems rely on accurate pressure readings to ensure everything works as designed during a fire. But sprinkler gauges don’t last forever. They must either be replaced or tested every five years—and potentially be recalibrated or replaced after the test.
If gauges are expired, their readings may be incorrect, potentially compromising system performance when it matters most. Out-of-date gauges can also trigger a deficiency tag during inspection, leading to extra costs and inconvenience.
Why this matters
NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems sets specific requirements for gauge maintenance, because malfunctioning gauges can lead to incorrect system pressure readings—and sprinkler systems that fail in a fire.
13.2.4.2* Gauges shall be replaced every 5 years or tested every 5 years by comparison with a calibrated gauge.
13.2.4.3 Gauges not accurate to within 3 percent of the full scale shall be recalibrated or replaced. [NFPA 25: 2023]
Many people ask, “Do I need to do this five years after installation or five years after the gauge was manufactured?” Recent editions of NFPA 25 aren’t particularly clear on this, but the 2014 edition of the NFPA 25 Handbook was:
The 5-year period is based on the installed date as opposed to the manufacture date of a gauge, so it is acceptable to mark the installed date with a permanent marker on a label or on the body of a gauge when it is originally installed or calibrated.
In any case, expired gauges not only may result in inaccurate pressure readings; they can also lead to a system deficiency tag during your next inspection!
The fix
To stay compliant and safe, building owners need to either test or replace expired sprinkler gauges:
Option 1: Testing
A fire protection pro obtains a verifiably calibrated test gauge, inserts it into a system connection (ideally, a dedicated gauge test valve), and takes pressure readings. Then, the process is repeated for each system gauge to be tested, and the subsequent readings on the system gauges are compared to the calibrated test gauge.
If the reading on any gauge is not “within 3 percent of the full scale,” it must be recalibrated or replaced. Testing can be costly and inconvenient, especially if recalibration or replacement is still required afterward.
Option 2: Replacement
Many owners skip testing and simply replace gauges outright—often, an efficient move, as new gauges are affordable and readily available. NFPA 25 acknowledges this approach, stating, “In many cases, replacement might be more economical than testing.”
Buyer’s guide
Choosing a sprinkler gauge involves several considerations:
- System type & pressure: Match the gauge to your system type and what it’s measuring (air or water) and the necessary pressure range—QRFS gauges span from -30 to 300 PSI.
- Accuracy: Choose gauges with at least ±3/2/3% range-based accuracy.
- Certifications: UL Listed or FM Approved gauges are not required by NFPA standards, but these “listings” indicate high quality.
Need help? Contact QRFS.
Product recommendations
Find sprinkler gauges & more at QRFS
If you need fire protection parts, check out our selection of:
- Sprinkler gauges
- Both sprinkler and flow testing gauges
- Flow testing kits and equipment
- Other testing and monitoring solutions
Have questions or need help placing an order? Contact us!
FAQs
When does the 5-year replacement period start—at manufacture or installation?
It starts at installation, though it’s not necessarily a bad idea to replace unused gauges that have been sitting unused in a box for many years.
Can I test my sprinkler gauge instead of replacing it?
Yes, but testing requires employing a professional who uses a calibrated test gauge to conduct a comparison process with each gauge that’s assessed. And if a gauge is off by 3% or more, it must still be recalibrated or replaced. It’s usually simpler to just buy new ones.
What happens if my gauges are expired?
Your system may be tagged with a deficiency during inspection, and the system pressure readings may not be reliable, potentially leading to problems during an emergency.
Do I need a listed gauge?
NFPA 13 doesn’t require “listed” gauges, instead stating they must only be “approved” [by the authority having jurisdiction]. However, UL Listed or FM Approved gauges (either one counts as a “listing” to NFPA) are a strong sign of product quality.
