Ensuring Fire Safety: Key Insights on NFPA Standards and Compliance

• Extension fittings: The 2016 version has a new definition for this term. These adapters are frequently used to modify how a sprinkler that has been installed in finished walls and ceilings fits in the end. This updated definition complements the addition of new specifications for these fittings in Section 6.4.8. A single extension fitting may be used, provided it satisfies the requirements listed in Section 6.4.8 (multiple extension fittings are not allowed to be linked).
• K-8 or smaller sprinklers are required (6.4.8.1).
• Merely light and common hazard occupancy (6.4.8.2)
• The extension fitting’s internal diameter needs to match the sprinkler’s nominal inlet diameter (6.4.8.3).
• Extension fittings (6.4.84 and 6.4.8.4.1) longer than two inches are to be indicated.
• Extension fittings beyond 2 inches need to be factored into the hydraulic computations.

The extension fitting needs to be specified and taken into account in the hydraulic calculations because the required distance in the scenario as indicated is 3 inches. I haven’t looked into the availability of 3-inch listed extension fittings.

• Revamping: When “revamping” a system, (1) 8.15.20.4 (for pipe schedule systems) and (8.15.20.5) (for hydraulic design systems) permit the use of a 1/2-inch nipple up to a maximum length of 4- inches. This would include lowering a sprinkler to match the height of the ceiling. The following requirements would have to be fulfilled.
• Verification of the required flow rate through calculation. According to the annex (A.8.15.20.5.2), this isn’t meant to be a comprehensive hydraulic analysis.
• Where seismic design is necessary, breasts attached to an armover that have a diameter of less than one inch are not allowed.
• 

Many recessed, flush, and concealed sprinklers are tested and listed as an assembly with either their escutcheons or cover plates. These components might be required for the assembly to trap heat to activate the sprinkler; without them, the sprinkler might not turn on as expected and hence the items should be present.

Not deemed a deficiency per NFPA 25, standard escutcheons on pendent sprinklers extending below the ceiling (those not recessed, flush, or concealed) tend not to influence sprinkler activation or performance.

NFPA 13 does not provide an exception for outdoor closets on decks and balconies, unlike NFPA 13R. Every closet must have sprinklers

Installing the FDC upstream of the PRV also has no actual advantage. One doesn’t worry about the FDC’s pressure. These flows in parallel cause the pressures to not compound; rather, the flow at any given pressure is raised. Therefore, the responding fire fighters will not overpressurize the system as long as the maximum pressure rating of the system is recorded on the FDC signs.

The third reason is the possibility of failure of pressure reduction valves, therefore prohibiting the responding fire brigade from charging the system from the outside. Though NFPA 13 (2013) Section 8.16.1.1.3 forbids shutting off valves between each system and the FDC, the intention is to not install any components that could stop the fire fighters from charging the system.

Although NFPA 13 allows sizing the pump that exceeds the system rated pressure and providing a reduction valve downstream, NFPA 20 actually forbids doing so. Although the installation of the PRV is allowed since it is located downstream of the fire pump discharge isolation valve, care should be taken with a pump with high discharge pressure.

Section 4.17.8 specifies a specified indication gate or butterfly valve to be fitted on the side of the pump discharge check valve pertaining to the fire prevention system. This part especially allows a gate or butterfly valve and does not ask for a globe style valve.

Approved indication valves that are not outside screw and yoke (OS&Y) type are allowed since the manual comments on this part state that isolating valves on the discharge side of the fire pump do not affect the operation of the pump.

Although it seems a listed and indicating globe valve might be fitted on the fire pump discharge piping as it would not be expected to influence the pump’s operation, the requirements of the body of the standard clearly stipulate that just listed gates or butterfly valves may be utilized.

You could want to suggest, per Section 1.5, an equivalency method. I’m not sure why the standard would forbid using a listed and indicating globe valve on the fire pump discharge piping. Finding a listed globe valve that indicates, as in my experience most globe valves have a non- Rising stem and are not indicating type valves, could prove challenging. Going back to at least the 1976 edition of NFPA 20, this need seems to be unaltered.

The above suggests that sprinklers should be placed beneath the two ductwork blockages in your design

The language in more recent versions of NFPA 13 clarifies that if barriers larger than 4 feet in width are near the ground, extra coverage is not needed. NFPA 13 (2022 edition) Section 9.5.5.3.1.5 specifies that “Sprinklers shall not be required below noncombustible obstructions over 4 feet (1.2 m) where the bottom of the obstruction is 24 inches (600 mm) or less above the floor or deck.”

This modification was justified by the restricted fuel loads under the obstacle and the difficulty of installing and servicing fire sprinklers given the limited space. That justification allows one to argue to the authority having jurisdiction (AHJ) that the lower duct—two feet above the air handling unit—follows the same logic.

Steel pipe must comply with Section 16.3.1, 16.3.2, 16.3.3, or 16.3.4. Since this is an or statement, only one of the sections applies, not all of them. Pipes listed in Table 7.3.1.1 that do not require listings are covered in Section 16.3.2. The minimum wall thickness required to join the pipe with rolling groove fittings or welding is outlined in Section 7.3.1.1. Since there is no specific listing for the pipe types specified in Table 7.3.1, this section provides basic prescriptive requirements for that installation.

Minimum criteria for threaded pipes are set in Section 16.3.3.

Finally, Section 16.3.4 allows the use of specially mentioned pipe and specifies that the pressure constraints and wall thickness for steel pipe expressly listed in line with Section 7.3.3 should be allowed to be in line with the pipe listing standards. Section 16.3.4 applies, not 16.3.2 since the installed pipe is listed; so, the installation needs to to follow the manufacturer’s guidelines in compliance with the listing.

Section 11.2.3.2 of NFPA 13, 2013 edition is particular to the application of the density area design approach, which requires a minimum design area of 1,500 square feet. Applying Section 11.2.3.2.3 would thus begin with a base design area of 1,500 square feet and apply the quick response sprinkler reduction to that area.

Section 11.2.3.3 offers the specifications for the room design technique, which may be relevant in this situation. Using the room design approach does not allow a rapid response area reduction.

Guideline for tags (where utilized) found in NFPA 25 – Annex G “While NFPA 25 does not mandate system status tagging, it is desirable that a certain level of consistency exist between programs,” notes explanatory comments in NFPA 25.

NFPA 13’s Section 8.4.6.1 calls for a draft curtain separating ESFR sprinklers from standard response sprinklers only. Not normal response sprinklers, quick response sprinklers call for no draft curtain. Between ESFR sprinklers and quick reaction sprinklers, there is no need for  draft curtains. Although ESFR sprinklers and quick response sprinklers could have somewhat different RTIs—one might be 40 while the other is 45 for example—there is no reason to be concerned about such minute variations

The draft curtain separating standard response sprinklers from ESFR sprinklers addresses the issue that a fire under the standard response sprinklers will open ESFR sprinklers remotely from the fire prior to opening standard response sprinklers over the fire.

That worry disappears when both of the two different kinds of sprinklers have a quick response. Small differences in RTI would still not allow an ESFR sprinkler remote from the fire to open before the rapid response sprinklers above the fire.

The horizontal distance between the sprinkler and the fire, the vertical distance between the sprinkler and the fire, the distance of the sprinkler below the ceiling, the conductivity between the sprinkler and the water-filled piping, and the size of the fire are among the several factors influencing the time when a sprinkler opens. With all these factors, the minor variation between two distinct kinds of rapid response sprinklers has no bearing.

The answer is generally no. The issues remain the same even if the references address the valves typically in the open state. Water has to reach the area of the system experiencing a fire incident. Should water be directed through one of these other valves during a fire emergency, there could not be enough where it is required. Therefore, it becomes crucial to monitor them in their regular state.

• Section 10.2.8.1 calls for Standard Spray Pendent (SSP), Upright (SSU), and Sidewall: 18 inches
• Extended Coverage (EC): Section 11.3.7 – 18 inches

Control Mode Special Application (CMSA): Section 13.2.9, 36 inches

• Section 14.2.12, Early Suppression Fast Response (ESFR), 36 inches

There are also a few other factors:

• The particular sprinkler manufacturer could have different distances from top of storage to deflector.
• Some of the storage design applications (Chapters 20 and 24) specify maximum storage height and maximum ceiling / roof heights (typically, a greater distance from storage to ceiling requires more density); hence, sometimes there is a balance between maintaining the minimum distances but not getting too far away so as to increase the density.
•