News From NFPA: Modifying Sprinkler Systems In Existing Facilities

By Jonathan R. Hart, PE

With many companies rethinking how their workplace spaces will be utilized post-pandemic, a substantial number will undergo renovations or redesigns. Add this to normal tenant fit outs, which includes shell area in constructed buildings, and you can find sure to be a large number of existing sprinkler techniques requiring adjustments to adequately protect redesigned areas. This frequently raises the question in regards to what level the sprinkler system should be brought up up to now with the most recent standard, if the operational system must be recalculated, and how substantial the tests of the modified program should be. Fortunately, the 2019 edition of NFPA 13, Standard for installing Sprinkler Techniques dedicated the chapter to certain requirements for these situations for the very first time and that information may carry to the soon-to-be-issued 2022 edition.

Change Of Make use of/Occupancy

For the purpose of this dialogue, we will concentrate on situations where in fact the occupancy or even use classification of the area isn’t being changed. Where this is the case a far more complex analysis is probable necessary to determine the influence of changes to create densities, regions of operation, and many other possible modifications.  NFPA 25, Regular for the Inspection, Assessment, and Upkeep of Water-Based Fire Defense Systems  areas responsibility on the dog owner for ensuring an assessment be conducted within these instances, a lot of which exceed the reconfiguration of work place where in fact the space protected will probably remain a lighting hazard occupancy.


Whenever a building is going through a renovation or perhaps a remodel of its room the removal or add-on of walls, partitions, and ceilings make a difference the potency of the originally designed sprinkler program negatively. In these instances, many sprinklers should often be added or relocated to be able to appropriately protect the reconfigured space.

This will not necessarily suggest that the complete system should be reevaluated to ensure full compliance with the most recent edition of the specifications. Actually, portions of the prevailing system that aren’t subject to the adjustments can be viewed as previously approved beneath the retroactivity clause of  NFPA 13, Standard for installing Sprinkler Techniques  , nor have to be evaluated. Whenever adjustments or additions are created to an existing system, enough of the prevailing system must be pointed out on the plans to create all conditions very clear for the AHJ to judge. This means that among the first steps used these instances ought to be to gather just as much of the existing programs and calculations, as can be acquired. A far more complex analysis could be required for the complete system if the initial design basis can’t be confirmed.

Hydraulic Calculations

While some possess argued that minimal modifications shouldn’t impact the machine demand significantly sufficient to require calculations, NFPA 13 will require calculations be provided to verify that the operational system design circulation rate will undoubtedly be achieved. Prior editions of the typical included an annex notice indicating that it had been not really the intent to need a full hydraulic evaluation of the prevailing sprinkler system, as well as the new sprinkler design. This take note has been taken out in latest editions. This still will not necessarily need a full group of hydraulic calculations especially if the modifications are created in a area of the system that’s not probably the most hydraulically challenging. In cases like this the modified part of the system could be hydraulically calculated back again to the branch range or riser to the stage where authentic calculations are accustomed to show that the look flow rate could be fulfilled.  This is simply not entirely clear in reading the typical especially minus the previous annex note to indicate so it’s certainly worth checking with the neighborhood AHJ to find out what they’ll accept for these instances.

Hydrostatic Examining

Recently installed sprinkler systems should be hydrostatically examined to check on for leaks at a stress of at the very least 200 psi (14 bar) for an interval of at the very least 2 hours. When current systems are modified in a way that the ongoing function affects significantly less than 20 sprinklers, the operational system only requires testing at the machine working pressure. Where in fact the modification affects a lot more than 20 sprinklers, that part of the system should be isolated and examined at 200 psi (14 bar) for just two 2 hrs. If the brand new work can’t be isolated, the testing can be achieved at system working pressure if the adjustments involved a lot more than 20 sprinklers even. In general, current portions of the operational program need not be subjected to a fresh hydrostatic test.

Impressive A Balance

Many structures are routinely undergoing adjustments that can effect the fire sprinkler program and need modification of the machine to adequately guard the space since it evolves. The provisions for current program modifications in NFPA 13 are designed to ensure that the area has adequate coverage, the machine demand could be met, and the workmanship of the work enough has already been completed well. This is designed to strike the correct balance between making certain the noticeable changes aren’t simply ignored, not throwing the complete latest regular out, and stating everything must be raised to those specifications.

Hart is really a technical business lead and principal fire security engineer for the Nationwide Fire Safety Association (NFPA). This short article originally made an appearance on the NFPA weblog .

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