How to Purchase a Replacement Fire Sprinkler Gauge

Valin 11/2/2018
How to Purchase a Replacement Fire Sprinkler Gauge

The most important thing to look for when replacing a pressure gauge for a fire sprinklers is Underwriters Laboratory (UL) listed and Factory Mutual (FM) approved certification for fire protection sprinkler service.

If you maintain a commercial fire sprinkler system you may be familiar with The National Fire Protection Association (NFPA), which publishes NFPA 25, Standard for Inspection, Testing and Maintenance of Water-Based Fire Protection Systems. This 100-page document contains the rules, regulations and procedures for performing proper maintenance on systems.

How to Purchase a Replacement Fire Sprinkler Gauge

NFPA 25 specifies testing the accuracy of the gauges weekly or monthly and replacing or recalibrating pressure gauges at five-year intervals. Excerpts from the code are shown in Table 1.

Table 1 - NFPA 25 Pressure Gauge Inspection and Testing Requirements
Frequency Item Code No. NFPA Code Description
Weekly Gauges - Dry, Preaction & Deluge 2-2.4.2 Gauges on dry, pre-action, and deluge systems shall be inspected weekly to ensure that normal air and water pressures are being maintained.
Monthly Gauges - Wet Pipe Systems 2-2.4.1 Gauges on wet pipe sprinkler systems shall be inspected monthly to ensure that they are in good condition and that normal water supply pressure is being maintained.
5-Years Gauges 2-3.2 Gauges shall be replaced every 5 years or tested every 5 years by comparison with a calibrated gauge. Gauges not accurate to within 3 percent of the full scale shall be recalibrated or replaced.
 
Recalibrating fire sprinkler gauges, as referenced in section 2-3.2, is not generally recommended. The cost of gauge recalibration is five or six times the cost of gauge replacement.

NFPA 25 is a widely used national consensus standard that has been adopted in 37 states (as of 2008) with proposed or pending legislation in many more jurisdictions. It has been accepted by the American National Standards Institute (ANSI) as an American National Standard. In addition, numerous communities have adopted NFPA 25 as a referenced standard in their building codes, which are enforced by local inspection authorities and many insurance companies require the buildings they insure to have sprinkler systems that comply with this nationally recognized standard.

The job of selecting replacement gauges for a fire sprinkler system is relatively straightforward. Fire sprinkler gauges are available in two standard pressure ranges. A pressure range of 0-300 psi is used on wet pipe systems where water is available to sprinkler heads, while a 0-80 retard to 250 psi pressure range is used on dry systems where lines are filled with air pressure until activation. All fire sprinkler gauges have 1/4″ lower connections (on the bottom of the gauge) and all brass wetted parts.

If the brand of pressure gauge specified in your fire protection sprinkler system is not available, a UL-listed and FM approved pressure gauge of the same psi may be substituted.