|
What are others doing to combat Microbiologically Influenced Corrosion (MIC) in their sprinkler systems?
I'm dealing with a project where MIC has been found in a nearby building/system. Doing research, nitrogen appears to be a popular treatment method, but I've read sprinkler-based articles that it's not effective. I also noticed that the NFPA 13 2025 edition removed the treatment options previously in paragraph 5.1.4.1.2. Additionally, the client does not want the monitoring option (item 3 of 5.1.4.1.2, 2022 edition). Any advice on how to prevent MIC here? Thanks in advance. Moderator's Reminder: The intent of the forum is for clear, substantiated, and helpful conversation. Comments which do not meet the community guidelines will be removed. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
11 Comments
Are there any comments in NFPA that state that we can not insulate sprinkler system sprinklers, or any mandated minimum spacing between insulation and uprights?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Where is (or is there) a code or standard provision for an existing/old standpipe system that mandates that the standpipe system must follow the codes (and edition) in which it was originally installed?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe GC asked us to add (1) head to a dentist's office closet where they store the nitrous tanks. Not a big deal, done it before tapping off the domestic line. The AHJ asked for calcs to prove it will work. The existing building is not sprinklered.
What are your thoughts on this? Is there a way to prove it's workable? Is there a standard that stipulates what is and what's not acceptable? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We currently have a structure being protected by four systems, two wet systems and two dry systems that protect a large attic area. It was recently discovered that the water supply is no longer sufficient to provide the dry systems with the water needed.
Would it be permitted to install a fire pump for only the dry systems? The pump would be installed between the risers for the wet systems and the risers for the dry systems. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When a water spray system is installed for outdoor vertical fixed-roof oil storage tanks, is every point on the tank exterior wall required to be within the coverage of water spray nozzles?
Or is it sufficient to arrange a ring of nozzles around the exterior wall, so that the sprayed water flows down the tank wall by gravity to achieve effective suppression? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I’m looking for some input on a storage condition that doesn’t fit cleanly into typical rack storage criteria. We have laminate sheets (55" x 121") stored horizontally on shelving. Material contains Class C plastics → treating as a Class III commodity. Configuration: Sheets are stacked horizontally on closely spaced solid shelves. Shelf spacing is tight (a few inches). Essentially continuous solid shelving (no vertical flue space). Overall storage height is ≤12 ft. This is not traditional pallet rack storage — it’s more like dense horizontal sheet storage with multiple solid shelf layers. If the overall storage height does not exceed 12 ft, can this be treated as miscellaneous storage per NFPA 13, assuming all miscellaneous storage criteria are met? Or does the presence of closely spaced solid shelving (acting like stacked horizontal obstructions / solid shelf rack condition) prevent use of miscellaneous storage and instead trigger solid shelf rack criteria and/or in-rack or intermediate-level sprinkler requirements? The concern is that even though the storage height is within the 12 ft miscellaneous threshold, the shelving configuration completely blocks vertical water penetration and behaves more like stacked horizontal barriers than typical low-piled storage, so I’m questioning whether miscellaneous storage criteria is even applicable here or if the configuration itself drives the protection method regardless of height? How others have classified similar flat sheet / laminate storage on tight shelving whether AHJs/FM have pushed this into rack/shelf obstruction criteria instead of miscelleneous storage? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  When adding flow of additional standpipes (vertical standpipes with a horizontal connecting main), the NFPA 14 handbook (NFPA 14 10.6.1.2.4) explicitly says that flows shall not be required to be balanced.
I get the logic of balancing the calc, and it's not terribly hard to do - but what's the difference? Is not balancing the calculation more conservative? Is it insignificant, and therefore doesn't really matter? Why aren't we required to balance the calc by code? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe FM Data Sheet 8-30 Having To Do With Roll Carpet Storage - on Table 1, how many sprinklers on a line do we calculate when we have 30 heads? NFPA 13 does not cover roll carpet storage, and the NFPA 13 Equivalency Clause allows us to use FM Global. Take a look below, and the only thing I can not figure out is if I am required to discharge 30 K11.2 sprinklers @ 7.0 psi, how many open sprinklers would I calculate on a line? Maybe 7 sprinklers on 4 lines with 2 sprinklers on one line? It has to be in writing somewhere, but I can not find it! Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  We are looking at designing a fire sprinkler system for a 3 story, 20k sqft per floor apartment which is requiring an NFPA 13 system per the code plan.
The code plan also gives the option of removing the dry system in the attic if draft stops are provided. I have not read or heard of this ever being an option before. Are attic sprinkler systems allowed to be omitted with draft stops per some standard or code? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Some AHJs require travel distance to be measured orthogonally, meaning all changes in direction are made at right angles. This does result in a worst-case travel distance, but the IBC specifically says it should be measured using the natural walking path.
Generally, walking occupants do not make turns at 90-degree angles. How do you work through this code/interpretation with AHJs? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When conducting a fire alarm test, I noticed the strobes on the 3-story barracks walkways on the exterior do not strobe in unison, but they do in unison per floor. Is this a concern?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I ran into this issue today with a cage installed in close proximity to an upright fire sprinkler. Is this an obstruction to the sprinkler? It's open wire mesh from the head to the floor; the only obstruction is the top angle near the sprinkler. The deflector is higher than the beam; it appears there would be very little obstruction to the development of the spray pattern overall. Facility has an open concrete ceiling. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  What are the laws regarding an AHJ sharing plans and calculations?
This may vary by state. Does having a seal change anything? In CA, plans must have an Engineer's seal, but there is the "Industrial Exception" that says a Contractor can draw and submit his own plans as long as he also does the install. I had a city refuse to let me have a copy unless I had permission from the Contractor, but the Contractor went out of business a decade earlier. Are AHJs allowed to share prior plan submissions? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe The project consists of storing Group A plastics, Cartoned Unexpanded Plastics, in an ASRS (Automated Storage and Retrieval System).
The ESFR system has been designed accordingly. What type and size of fire extinguishers are required for the space? Any direction and guidance is appreciated. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Our jurisdiction has received plans for an addition/remodel of two different occupancy types.
The larger I-1 Condition 2 occupancy will not be undergoing remodeling and currently has a full NFPA 13 system; however, the R-4 occupancy will undergo a complete overhaul. The R-4 will also be added to accommodate a new activities room and additional sleeping units; it will remain an R-4 based on the number of occupants. The design team has drawn an independent 2-hour fire barrier between the two occupancies in the corridor connecting the two buildings. My question is, does the entire building (I-1 and R-4) now have to be served by an NFPA 13 system since they are connected regardless of the fire wall, or would they be allowed to install an NFPA 13R system in the R-4 occupancy? Also, does this now make the entire building an I-Occupancy regardless of the fire wall/barrier? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Doing inspections, does looking at the dry valve inside with a camera through, say, a drain (instead of removing the faceplate) and taking pictures satisfy the requirement for the inspections?
Most dry valves nowadays have automatic resets, and the gaskets on the new faceplates are very, very thin and will not reseal even with the replacement part. FDC inspections also include check valves. I don’t know why, but when you take the Vic off the check (FDC side), the groove coupling will not seal. So a lot of filing or replacement of the piece must be done. I'm thinking the pipe used was for threading and welding (not recommended for grooving). Any insight here is appreciated, thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe A quick thank-you to this month’s top contributors for sharing their expertise and keeping the conversation moving!
Where in NFPA 13 or 30 does it say ESFR systems cannot protect ignitible liquids?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Under NFPA 13, 2019 Edition, does Section 8.2.3.1 provide the option of using 8.2.3.2, 8.2.3.3, 8.2.3.4, 8.2.3.5 or 8.2.3.7 to size the system?
Could I size an 800-gallon EH1 dry system to deliver water to a single test connection in 60 seconds based on 8.2.3.2, or must the system be calculated for water delivery by a recognized program per 8.2.3.5 and provide a 4-outlet test manifold with a 45-second time limit? Is the manifold just an option? I've been confused on this for awhile...thanks in advance!! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Are there incidents of actual water health hazards from fire sprinkler systems?
I try to avoid waste. Backflow prevention devices are costly and also make sprinkler systems more expensive by adding friction loss, which can mean larger pipes. The water in most sprinkler systems is the same water as in the domestic system. Yes, the water in a steel pipe sprinkler system will get brown over time, because it picks up iron. Not pretty, but is that iron a health hazard? People buy Iron supplements. In California the laws are confusing. Health and Safety Code - HSC § 13114.7 states: (b) Automatic fire sprinkler systems described in subdivision (a) shall not require any backflow protection equipment at the service connection other than required by standards for those systems contained in the publication of the National Fire Protection Association entitled “Installation of Sprinkler Systems” (N.F.P.A. Pamphlet No. 13, 1980 edition). and (a) states: (a) For the purposes of this section, the following are definitions of class I and class II systems: (1) American Water Works Association (A.W.W.A.) Manual No. M-14 class 1—Automatic fire sprinkler systems with direct connection from public water mains only; no pumps, tanks, or reservoirs; no physical connection from other water supplies; no antifreeze or additives of any kind; and all sprinkler drains discharging to the atmosphere or other safe outlets. (2) American Water Works Association (A.W.W.A.) Manual No. M-14 class 2—Automatic fire sprinkler systems which are the same as class 1, except that booster pumps may be installed in the connections from the street mains. This makes sense, but unfortunately another section states: 13114.5 The governing body of any city or county may enact ordinances or laws imposing restrictions greater than those imposed by Sections 13113 and 13114. (Added by Stats. 1955, Ch. 1480.) AND many water purveyors, who are not city or county officials simply ignore the law. If you want to use their water, you abide by their demands! No single user wants to take the effort to fight. This can be really expensive, especially when a backflow is imposed on an existing system. The added friction loss can mean the whole system has to be recalculated, and often piping upgraded. I would like to see the industry help to pass laws to eliminate backflows if they are not accomplishing anything. Please share any ideas of who and how to help, or any examples if there are actual health issues. Thanks. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When Inspectors have an existing sprinkler system without a means to conduct forward flow, what is your process for addressing the test?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is it acceptable to have a 2-1/2-inch hose connection on the system side of a low expansion foam system? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  |
ALL-ACCESS
SUBSCRIBESubscribe and learn something new each day:
COMMUNITYTop June '26 Contributors
YOUR POSTPE EXAMGet 100 Days of Free Sample Questions right to you!
FILTERS
All
ARCHIVES
July 2026
PE PREP SERIES |
RSS Feed
