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I have a class IV product stored in a HDPE hard body package. With the changes from NFPA 13 2016, edition to the 2025 edition, there are significant changes to the ability to store Group A plastics in legacy warehouses.
What compliance strategies are available to the FP community to remain in compliance while storing in these legacy buildings? A typical warehouse I'll see will have K16.8 @52 psi. This used to be acceptable for group A, but now it is not an option per the newer standard. Typically we're looking at structures over 35 ft. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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I have a warehouse sprinkler space where the owner has installed a Faraday-type cage (Ordinary Hazard I occupancy). The cage grid runs from floor to ceiling and is about 25% open space (75% obstructed).
I consider this cage as an obstruction, similar to a solid wall, and thus it ruins sprinkler coverage/spacing (standard spray sprinklers). However, I cannot find a code reference that addresses vertical grid obstructions or the acceptable percentage of open space for vertical grids. NFPA 13, 2019 Edition, Section 9.3.10 provides guidance for horizontal grid ceilings, and Section 10.2.7.2.2.1 is for grids in Light Hazard occupancies. Neither fit the bill. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Do we have to use ESFR sprinklers under conveyors, which have slope, solely because the roof system is ESFR?
What code basis—if any—would actually require ESFR protection under conveyors in this situation? I am currently designing a sprinkler system renovation on a package sorting facility that we did the original conveyor design on 4 years ago. The existing 500,000 sqft open warehouse had (13) k-22 ESFR systems that we did not design. I designed all the systems for the catwalks, mezzanines, and under conveyors using Standard 5.6k quick response, standard spray sprinklers (Reliable RA1425) with shielding under open grate flooring. The new systems all have their own risers coming off the existing 10" manifolds. It was all hydraulically calculated and approved by the city. Now we are designing / renovating the conveyor systems because the client added, removed & moved a bunch of conveyors. I removed all sprinklers and pipe from the areas being changed, and most of the new or changed areas we able to reuse existing outlets that we had demolished pipe from. We used the same pipe sizing scheme, same type of sprinklers, and redid all hydraulic calculations. BUT now the plan reviewer is rejecting the plans citing: THE SPRINKLER PROTECTING THE BUILDING ARE CLASSIFIED AS ESFR, THE SPRINKLER PROTECTING THE AREA UNDER THE CONVEYORS SHALL BE OF THE SAME TYPE AS PER NFPA 13, 2019, SECTION 9.5.5.3.3. I responded with NFPA 13 20.6.2, ESFR are only approved to a slope of 2:12 and most of the conveyors are way past that; and noted again that that the existing system is 5.6k. To which he responded: THE SPRINKLER PROTECTING THE BUILDING ARE CLASSIFIED AS ESFR, THE SPRINKLER PROTECTING THE AREA UNDER THE CONVEYORS SHALL BE OF THE SAME TYPE AS PER NFPA 13, 2019, SECTION 9.5.5.3.3 WE DO NOT UNDERSTAND THE RESPONSE TO THIS COMMENT, SECTION 20.6.2, WHICH ADDRESSED THE SLOPE OF THE ROOF NOT THE PROTECTION UNDER THE CONVEYOR. INDICATE WHICH STANDARD ADDRESSES THE HYDRAULIC CALCULATION FOR PROTECTION UNDER A CONVEYOR, WE CAN’T FIND THE SPECIFIC DESIGN CRITERIA FOR PROTECTION UNDER THE CONVEYOR USING ESFR SPRINKLERS. UNLESS THE SAME CRITERIA US FOR THE ROOF SYSTEM WILL APPLY UNDER THE CONVEYOR. Has anyone ever run into this? If have to use k-22 ESFR, it would be disastrous to the calcs, not to mention the existing system I am coming off of. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is there an NFPA 13 or 14 restriction for a combined sprinkler - standpipe dry system?
This is an open parking structure. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a code official who is requiring a full-size water meter on the fire line preceding double check backflow.
The backflow has a 3/4" meter and a small check on it with electronic connection capability for the water department. Are there any applicable code/standard references that mandate this? A 6-inch meter on the fire line would run about $15k. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Does a zone control valve (floor control assembly) count towards the riser area limitation, as a sprinkler riser would? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  Is it necessary to apply special sprinkler design criteria for a membrane building?
Tension fabric buildings with polyethylene membrane are becoming increasingly common. In this case, the fabric is rated per NFPA 701 and other certs, so it will not propagate fire, but the manufacturer advertises that it will melt/burn under direct flame and release smoke and heat. Would this not affect the operation of the building's sprinkler system? FM 1-59 requires quick response sprinklers, which makes a lot of sense, but provides little to no evidence in support. I can see no similar requirements in NFPA outside special requirements for aircraft hangars; NFPA 102 seems like the main standard and is silent on the subject. Is there something I'm missing in NFPA? Is there any research out there on sprinkler performance in membrane structures that will melt and release heat? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Under NFPA 13, how far away should an intermediate temperature sprinkler be from a two-bulb, 500-watt bathroom heat lamp?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a contract that calls for concealed, extended coverage horizontal sidewalls in an area with a Turf Switchblade Acoustic Ceiling. The issue I'm running into is that the Tyco RFIII EC HSW has a maximum distance below the ceiling of 12", and the acoustic has a maximum dimension of 9.4" down from the ceiling.
Therefore, I won't have the 4" minimum distance between the deflector and the obstruction. Has anyone else encountered this type of issue? Has anyone found a concealed sidewall extended coverage that can be 18" below the ceiling? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are designing a project that has a porch area (approximately 88-ft long x 23-ft deep) at grade with occupied enclosed building space above it (the building overhangs the porch by 23-ft).
To avoid a costly dry-pipe system for this area, the CM is looking to serve this area from dry sidewalls connected to the buildings automatic wet sprinkler system. Is anyone aware of any dry sidewall heads (exposed or concealed) for this application that can throw 23-ft? The building will have a fire pump so the extra pressure would not be an issue. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Could anyone point me to statistics to show how likely a single interlock pre-action sprinkler system is to spuriously or falsely activate?
A client is concerned about possible water damage in a high-voltage switchroom that could damage their gear and cause a lengthy business interruption. I have tried examining NFIRS data, but its format makes it difficult to analyze without a background in relational databases. I would like to explain the relative risk to the client in terms of 'it's a 1 in 100,000-year event you are concerned about' or whatever the stats point to. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can someone explain NFPA 13 20.5.3.1.3 for Multiple Row Racks?
Unless the requirements of 20.5.3.1.3.1 or 20.5.3.1.3.2 are met, multiple-row racks without solid shelves shall be considered racks with solid shelves. Section 20.5.3.1.3.1 Multiple-row racks without solid shelves shall be considered open racks where both transverse and longitudinal flue spaces are provided at maximum 5 ft (1.5 m) intervals. 20.5.3.1.3.2 Multiple-row racks without solid shelves shall be considered open racks where transverse flue spaces are provided at maximum 5 ft (1.5 m) intervals and the rack depth does not exceed 20 ft (6.1 m) between aisles that are a minimum width of 3.5 ft (1.1 m). Does this mean you have to have a 6-inch flue space on all 4 sides of each pallet load every 5ft within the rack, OR a 6-inch transverse flue space every 5ft, but the rack cannot be deeper than 20ft? Is it one or the other, and do you see one more often than the other? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a quick question about estimating the pressure requirements for an automatic wet sprinkler system during the initial design phase.
Qm = d X (Area per Sprinkler) = (0.15) X (130sqft) = 19.5 gpm Estimated Total Flow (ETF) = Qm X N X F plus hose demand = (19.5 gpm) X (12 sprinklers) X (1.30 for spray pattern overage) + 250 gpm (Outside Hose Stream) = 554.2 gpm Minimum pressure needed for the system. = (19.5gpm/5.6K) = 12.13 psi for the most demanding sprinkler + another 20-35 psi for potential friction loss throughout the reference. The total estimated pressure needed would be 47.13 psi, not factoring in elevation change. The 20-35 psi for potential friction loss is an engineering judgement based on experience. What is the recommended potential friction loss for an initial design phase, and where would it be referenced at? I need to reference the source of recommended potential friction loss for the project. SFPE, NFPA or etc? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Question in relation to ESFR sprinklers. Per NFPA 13 2016 Section 8.12.5 - obstructions 12" to 24" wide, the sprinkler must be 2 feet away.
There is no specific code for obstructions larger than 24"; does this mean these obstructions would always require coverage beneath? I ask because I have a 36" cable tray - if it's centered between two branch lines, can I apply the code to half the obstruction? In this case, the head would be further than 2' from 18" of the obstruction on both sides. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project where there are small bumpouts on either side of a room that are sized just big enough to store an accordion ceiling partition when not in use. The partition divides a bigger classroom into two smaller classrooms when used.
Do I need to somehow have sprinkler coverage in the bumpouts? The small areas are only exposed when the partition is deployed, which results in two even smaller spaces on each side of the partition. NFPA 13 Section 9.2.9.1 seems like one possible code section to allow an omission. What are your thoughts on this allowance? Seems challenging to incorporate sprinkler protection in those small areas and not very practical for the low fire hazard they present. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe In an automated warehouse, is it feasible to replace the in-rack sprinklers with ceiling sprinklers on the upper racking levels?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project involving an outdoor dust collector. My firm specified a dry-pipe sprinkler system for it.
The contractor asked if an antifreeze loop would be acceptable as a substitute, and we said no, as the AHJ does not want to deal with the maintenance side of an antifreeze loop long term. The contractor states that the head connection in the collector is pendent instead of upright, and they can't go with the dry system because of trapped water concerns. I think a dry pendant sprinkler would work as it's allowed (even required if an upright is not used) by FM Data Sheet 2.0. Anyone install a dry pendent in a dust collector, and have any drainage issues or had to add a drum drip or other means of drainage to make the system work long term? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Good morning, I'm designing sprinklers for a Class III warehouse. The warehouse has a ridge vent that's currently enclosed on the side walls.
What ceiling height should be considered for the design: the average ceiling height or the height of the center of the ridge vent? The lower part of the ridge vent is 39.66 ft, and the upper part is 41.5 ft. If I consider 39.6 ft as the height, I could work with a 25.2 kPa sprinkler at 25 psi, but if I consider 41.5 ft, I should consider a pressure of 40 psi, and the fire pump would change. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Hello everyone, I’m dealing with a fire sprinkler system installed after 1984 that uses the sprinkler model shown below. I need to replace the sprinklers without changing the system’s overall characteristics. Unfortunately, I can’t find the original datasheet for this model. I can test the activation temperature and the K-factor, but I’m unsure whether this sprinkler is of the conventional type. Could anyone help me confirm if it’s a conventional sprinkler or provide any technical information about it? Thank you in advance for your help! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  We have a church with a raised platform (wood construction) that is not accessible and is a concealed space. We typically have not provided sprinklers for this type of space. The AHJ is stating sprinklers are required per NFPA 13.
Are sprinklers required for a combustible, concealed space below a raised platform? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Hello, I am trying to figure out what commodity classification vinyl doors are.
I am designing a fire sprinkler system for a warehouse that stores doors and windows with the main materials being wood, glass, and vinyl. Doing a google search vinyl doors are typically made out of PVC (polyvinyl chloride). NFPA 13 - 2019 - Table A.20.4(b) lists the following: PVC (polyvinyl chloride) products, up to 20 percent plasticizer - Class III PVC (polyvinyl chloride) products, greater than 20 percent plasticizer - Group A Nonexpanded Table A.20.4.3 Examples of Class III Commodities has Furniture; wood (doors, windows, cabinets, etc.); So I'm thinking the next question that I need to ask is how much plasticizer is used in vinyl doors? I'm thinking it is less than 20% and use Class III. Any thoughts? Thank you! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I'm working with a not-so-good flow test on a project that will require a pump because of the flow test.
Where this is getting in the muck is the test flow rate being 712 gpm. The hydrant is about 565 feet from the entry and about 4 feet below finished floor elevation. This is a 5-story, light hazard with 2 standpipes, so the standpipe demand is 750 gpm. Flow test had 44 psi static and 34 psi residual with a 0.9 coefficient through the 2.5" outlet. As you know this is a 750 gpm system demand. The person over me is adamant that we not separate the sprinkler and standpipe systems out - sprinklers and then standpipe - by code when it comes to fire pumps. Even though this is a low-rise building and all we are technically concerned with is an automatic sprinkler system, and if the responding FD has an engine/pumper, the manual standpipe is in their realm. The argument is that they don't want a "partially automatic system" on any project; if a fire pump is to be provided for the project, they insist that the standpipe system connected to it must also be automatic. Back to the 750 gpm thing. At 34 psi, we have 712 gpm, obviously. The thing here is putting a 111 psi, 750 gpm pump on. They're concerned with the NPSH of the pump and not the duty point or the 150% rated test goals. (1) When a fire pump is provided to meet the needs of the sprinkler system, are the standpipes required to be automatic? (2) Is there a requirement here for automatic standpipes that I'm missing? The local jurisdiction has no amendments that affect standpipe requirements different than the model IBC. (3) Is an automatic standpipe here even achievable given the limits of the water supply, or are we causing more issues in testing down the road? If it was local, the FMs have already told me that's close enough and we will make up any flow from our trucks. What am I missing here? I understand clearly that at 20 psi the flow is 1,124 gpm. That's not what I'm trying to accomplish. I am attempting to make the combined system fully automatic per policy at 750 gpm and I'm told it's all good to go. Help a man at wit's end out here. TLDR: How would you approach manual vs. automatic standpipes when a fire pump is provided for a 5-story sprinkler system, but a 750 gpm pump could overtax the water supply? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Throughout my career, I have heard the term "turn the heads up for temporary protection during construction."
I've had bosses require uprights to be installed, and I've had bosses who just use the existing pendents and literally just turn the heads up. Which is correct? Would the length of construction determine it? How have others done this? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe How does the main drain test differ from the hydrant flow test in analyzing a water supply?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Does NFPA provide guidance on campus-style fire pump design?
Can I provide two water services (one from each building) and serve out to two buildings? NFPA 20 4.9 implies that campus-style designs are acceptable, but I am not seeing any code lines referencing any further requirements for such a design. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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