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I am working in a warehouse with an existing ESFR system at the ceiling level. The new tenant is going to have manufacturing occupancies below, with no high-piled storage. We are utilizing the 2025 edition of NFPA 13.
There is a lot of ductwork being added to the spaces, and a question has come up regarding round and square ducts between 24 and 48" wide/diameter, and if protection is required below. For example, there is a series of (5) 42" Ø fabric ducts (Ductsox) running across a space. The top of the ductwork is approximately 6' below the deflectors of the 16.8K ESFR sprinklers overhead. When looking at section 14.2.10.3.4, I am interpreting the rules as follows - If a fixed obstruction is larger than 24" wide, and it isn't placed in accordance with table 14.2.10.2.1(a), it will require supplemental sprinklers regardless of the distance below the ESFR sprinklers. Obstructions over 48" will still always require supplemental sprinklers, and obstructions less than 24" won't need supplemental sprinklers if they can comply with one of the options 2-6 in 14.2.10.3.4. The confusion comes in with the reference to Table 14.2.10.2.1(a). Others in my office are interpreting the rules to mean that since the obstruction is greater than 31" below the deflectors, it would be acceptable to omit supplemental sprinklers underneath. I am of the belief that Table 14.2.10.2.1(a) doesn't apply at all since the obstruction is greater than 31" down from the deflectors - Since they don't comply with any of the other options in 14.2.10.3.4, supplemental sprinklers should be installed below obstructions between 24" and 48" wide when spaced more than 31" below the deflectors. What is your take on this? Are sprinklers required for obstructions between 24-48" wide when more than 31" below the deflectors? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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When a new fire pump controller is installed or replaced, is an acceptance test required?
I suppose I know the answer, but I am looking for a code basis. Thank you. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Assuming a jurisdiction requires sprinkler pipe to be bonded to the building grounding system, would a sprinkler system fed from a fire pump be considered bonded since it is attached to the pump which is already grounded?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe In sub-grade parking garages, with PRV fire hose valves/floor controls - for testing purposes, would you connect a PRV fire hose valve to the express drain via hose and pump vertically to get to the exterior grade to discharge? Are there any issues with this method during testing to consider? PRV floor control would be hard piped to the express drain and utilize the same pathway to the exterior. Then at the bottom of the express drain has a ball valve, acting as an auxiliary drain only. It can discharge to a gravity drain system, whether storm or sanitary, whatever your local AHJ permits. Or is everyone trying to discharge into a gravity drain at the bottom of the stairs and hoping to not flood anything? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  What is your method for determining whether to use a tree, looped, or gridded sprinkler system?
I would think that in most cases, a tree-shaped layout is sufficient, but I'm curious to your take as to why you'd choose otherwise. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Have 5 stories of parking with about 15 levels of residential floors above. For an enclosed, heated/conditioned garage we can use a wet system.
If we're using Extra Hazard Group 2 with high temp sprinklers or 11.2k sprinklers, which reduces our design area we know we need to account for "0.40 gpm/sqft x 2,000 sq.ft. = 800 gpm demand" at least. A PRV floor control valve like a 2-1/2" Zurn ZW5004 tops out at 500 gpm per the data sheet. Would it be possible to utilize two of these floor controls from different stairs and have an interconnected system on those levels? Or would it be better to utilize to try and separate the garage level sprinkler system from the standpipe for those levels and use a master pressure reducing valve station on ground level to feed the 5 garage levels? Would a redundant pressure reducing valve at a master pressure reducing valve station be necessary if the sprinkler feed is separated from the standpipe feed for those levels? Or could I just use a grooved 6" pilot-operated PRV like a Cla-Val 90G-21 (listed for 1763 gpm) before a floor control on garage levels? (a combined sprinkler/standpipe configuration) Lots to this, appreciate the feedback in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When calculating overhead systems with in-rack sprinklers, how much in-rack demand is added to the calculations?
I assume all in-racks within the most remote area, but want to ask to be sure I'm getting this right. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe As an AHJ, I would like to ask what other AHJ's enforce for sprinklers in R-3 Occupancies when home health or Boarding Care businesses open facilities in single-family homes?
Please explain your reasoning as well as thresholds like 5 or more, etc. We're evaluating what our requirements and/or enforcement should be. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe TL;DR:
How can surge/water hammer forces be managed in very tall high-rise fire protection system using a single high-pressure pump (~365 psi) without exceeding equipment ratings or NFPA limits? Question: Trying to pre-plan in my mind for some upcoming pretty tall highrises where design teams would like to utilize 1 pump in lieu of a high/low multi-pump set up. I'm coming up with a couple of challenges. For the sake of the problem lets assume the static pressure at the fire pump discharge flange is 365 psi. I'm concerned that fire pump starting methods might create shockwaves/water hammer in high-pressure standpipes whether it be at the start of the pump like across-the-line or end of the curve spike like a wye-delta closed might see. How concerning is creating surge forces that exceed coupling/PRV valve/Pressure Relief Valve listed ratings? First reaction for many like me has always been to utilize soft-start but electrically with generators soft-start has a much higher load that has to be accounted for in the generator sizing because of the electrical engineers have to size them as across-the-line because of the bypass & 600% FLA. Maybe they just have to suffer on their design for FPs to be what it needs to be, but am trying to be accommodating where it makes sense. Is the general method to rely on a main relief valve in these high-pressure systems? NFPA 14 limits us to 400 psi but I'm not finding pressure relief valves that are listed high enough for the static pressure of the system i.e. cal-val at 300 psi, Victaulic at 350 psi. Is anyone utilizing anything like an Amtrol Surge-Trol Tank type products? Maybe VFD controllers to flatten/lower the static pressure? Some additional concerns in my mind are PRV hose valves have a 400 psi rated value and some couplings for example Victaulic might be rated at 365 psi. I know there are higher rated couplings on the market, like 500 psi, but if my static pressure on the system is 365 psi, I could see a surge force exceeding the rated values (zero math to support that claim). I'm struggling to quantify the possible surge force values in the design phase and how to handle that. Reading SFPE Handbook of Fire Protection Engineering 5th edition Water Hammer section pg 1407, it's focused mostly on the closing of valves, and still wrapping my head around if those equations can be applicable/same for pump starting forces. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I'm working on an office fit-up, which is being fed from a dry system in an industrial facility.
I've already talked to them about providing a wet system, but that is not what they want to do. So, we've got a dry system feeding pendent sprinklers coming down to an acoustic ceiling. When using pendents on a dry system, we need to provide return bends. Does a return bend have to be for only one sprinkler, or could there be multiple heads on a single return bend? I'm picturing the pipe extending up from the main, then across horizontally, with multiple drops coming off of the horizontal. Is this an allowed approach? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When hanging a 6-inch Schedule 10 pipe via trapeze hangers, the trapeze material is a 2.5-inch Schedule 40 pipe spanning 6 feet 6 inches. I’ve been instructed to use 3/8 rod and beam clamps for the trapeze hangers and then a heavy-duty 2.5-inch ring with a 1/2 button going down to the 6-inch pipe. The job is based on NFPA 2019. The table for NFPA 13 17.2.1.1 states that rods must be 1/2 for 6-inch pipe. I’ve been instructed that we are basing our decision on the following rule, which means we do not need to use a 1/2inch rod for the trapeze hangers themselves, only for going from the trapeze to the 6-inch pipe. 17.2.1.2 Rods of smaller diameters than indicated in Table 17.2.1.1 shall be permitted where the hanger assembly has been tested and listed by a testing laboratory and installed within the limits of pipe sizes expressed in individual listings. Is this correct? Is 3/8-inch rod or 1/2-inch rod appropriate here? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I'm trying to establish a way to avoid dry valves/dry systems to protect trash and line chutes early in project development. I've heard of freezing issues due to roof venting or other ways that cold air can fill the chute (perhaps from the bottom when trash room doors may be open to the exterior during severe cold).
I know most or maybe all of these fabricated chutes come with fire sprinklers, but are they usually essentially built-in dry barrel sprinklers? If not, how can we ensure they won't freeze without using a dry system? The specific chute submittal or product information is usually not available until well after space for a dry valve should be set aside. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We're designing a fire suppression system for a garbage truck maintenance facility which will include a welding bay. NFPA 13 (2019) is being used. I am using OH2 for the maintenance bay but I'm not sure about the welding bay.
Is a welding bay appropriately designated as Extra Hazard Group 1? I can't find anything in NFPA 13 that speaks specifically to welding. Thanks! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Regarding light fixtures as obstructions to sprinkler spray pattern per NFPA 13D - many hanging pendant light bases are slim (1”-2” off ceiling) and do not obstruct or prevent cold solder, but the lighting housing hanging below the base (anywhere from 12”-72”) is to be considered an obstruction? Are these described hanging pendant lights also to be considered obstructions and to remain 36” away? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I have a dry system that is tripping when the county runs their test on the hydrant using tankers and pumpers.
My question is, if I use a 3/4' relief valve, will it be enough? How much flow (gpm) will it flow, at its maximum flow rate? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe What does “horizontally away from the sprinkler” mean?
I recently read a technical note regarding the ESFR obstruction rule. The example question was: *“In an existing building, a 6-inch-wide steel brace runs diagonally from column to column, forming an ‘X’ between four columns. The brace is located a minimum of 48 inches below the ESFR sprinkler deflectors. Should this brace be considered an obstruction to the sprinkler discharge pattern?”* The answer stated that the X-shaped braces are not considered an obstruction because they are located at least 1 ft away horizontally from the sprinkler (referencing NFPA 13, 2016 edition, 8.12.5.3(3)). My confusion is this: if something is located below the sprinkler, I would describe it as being vertically away, not horizontally away. Did I interpret the code incorrectly? Can someone clarify the difference between “vertically from the sprinkler” and “horizontally away from the sprinkler?" Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am performing a design on an existing system that was 3% AFFF and we are converting it to 3x3 NFF. Bladders, proportioners, concentrate lines are being replaced and all sprinklers being replaced to meet the specification for the new concentrate.
In the spec it has been requested to utilize the "water equivalency test method," which is outlined in NFPA 11. I've performed installs, inspections of foam systems for 10+ years, I've never seen this method installed and not very versed in how it really works, only from what I've read. There's not much information out there. Have you used this method? What have the requirements been for testing this method? Were you given outside specifications? Does any additional information exist for detail? I'm wanting to be sure we're compliant from a design and install perspective. I'm following the diagram supplied in NFPA 11-2016. "D.5.2.3 Water Equivalency Method. In this approach, water issued as a surrogate liquid in place of foam concentrate. The initial acceptance test(s) are conducted with the actual foam concentrate using equipment similar to that shown in Figures Figure D.5.2.2(b) and Figure D.5.2.2(c): real-time pressure, flow, and conductivity measurements are recorded with the actual foam concentrate to determine that the system is pro-portioning accurately. Immediately following this test, a water equivalency test at the exact same pressure and flows as in the initial foam discharge test is performed after isolating the foam concentrate tank. Example test setups are shown in Figures Figure D.5.2.3(a) and Figure D.5.2.3(b). This provides a baseline for comparison using water only for follow-on routine inspections and tests." Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe A customer wants to install a burglar alarm in a new building. They would like to add fire detection to the system. The building is not required to have a fire alarm system.
Can we run the heat and smoke detection off a security panel, or do we need to have a separate FACU? I have looked in NFPA 72 (2010 edition), and I see non-required systems in Chapter 23. I see if it is a combination system the fire signal takes priority. However, I’m still not sure if we can use a security panel. The state is under NFPA 72, 2010 edition and 2012 IBC & IFC. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Has anyone ever conducted puff testing for a gas fire suppression system?
The owner is requiring us to perform this test, but I have never done it on previous projects. I checked NFPA 2001, and its requirements for flow testing are not detailed enough. I would like to know the specific procedures for conducting this test, as well as the key considerations to keep in mind. Ideally, I'd like to find a specification document or procedure to follow. Advance Thanks！ Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe If a warehouse is getting a new tenant, and the AHJ requires a new C of O, does the sprinkler system need to meet current standards (NFPA 13-2022) or can the original standards (NFPA 13-2007) be used?
Specifically looking at Group A plastic protection requirements here. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA mentions some sidewalls specifically listed for installation up to 18" below the ceiling.
Does anyone know a manufacturer that makes them? All I can find is up to 12". Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Existing High Rise that was converted from office to residential (large Massachusetts program). I am the third party reviewer and they currently don't have a elevator recall.
Google searches point to that if the elevator doesn't change they don't need add recall, but for the "Trust but Verify" portion of this code investigation is turning up naught. Closest I can find is IEBC, Section 902.1.2 commentary, but as this is a change of occupancy I am not sure if I can apply Level 3 Alterations Requirements to Change in Occupancy. Is there an applicable code or standard reference that requires retrofit of elevator recall for an elevator that doesn't already have this capability? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are running into a lot of gas unit heaters in warehouses with ESFR protection.
Two issues have come up: (1) NFPA 13 2019 Table 9.4.2.5(a) clearly shows the high temperature zones around (horizontal discharge) heaters. Given there are no high temp ESFRs, we have told contractors they can install the heaters 7' below the sprinkler deflector. The GCs do not like this and claim they have not had this issue with other ESFR installs (not ours). (2) The heaters are large enough to be obstructions to ESFR sprinkler discharge. We must install a sprinkler underneath, but the same issue with the temperature rating comes up. We have considered somehow adding an additional "barrier" around the bottom of the heater, so that the ESFR sprinkler is 2'-0 below the heater (but directly under the barrier). This is also not a welcome idea by the GC. We also do not have an actual example of this approach. Is there information we are missing here? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a facility with an NFPA 13 Extra Hazard 1 sprinkler system.
The client's proposed location of the water storage tank is approximately 33-ft (10m) higher than the level of the protected building and around 100-ft (30m) away. The client's proposed pump house is closer to the building, separate from the tank. My question is - is there a maximum length for the suction feed from the tank to the pumphouse under NFPA rules (13, 20, 22)? I would rather locate the pump house next to the tank and run the delivery main to the building. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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