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In reviewing the top articles from 2024, I re-read #11 regarding forward flow. As an AHJ, this is something we have been focusing on for the last four years and have uncovered multiple water supply issues.
My question is related to NFPA 13 and the 2-1/2” hose valve that is required for every 250 gpm (950 L/min) of system demand. From the fire suppression side, we usually generalize that a 2-1/2” hose valve can only flow 250 gpm. However, in our forward flow testing and research, we have found that a 2-1/2” hose valve off a main riser can actually flow almost 600 gpm. So my question to the forum technical design experts is, if we are getting an adequate gpm flow for system demand from the pitot reading, do we really need to flow a hose valve for every 250gpm of system demand? In other words, if system demand is 450 gpm and we are getting that from a single 2-1/2” hose valve, is that accurate and acceptable? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
7 Comments
NFPA references are based on current editions. While NFPA 101, Section 30.3.1.1.4 (New Apartments) allows vertical penetrations to be protected with a 1-hour rating when sprinklered, NFPA 101, Section 30.5.2 requires HVAC equipment to comply with NFPA 90A.
According to NFPA 90A, Sections 9.1.3 and 6.8.3, a higher level of protection is required for shafts that penetrate more than four floors (2-hr fire rated and fire dampers). Does the exception provided in NFPA 101 permit reducing the required fire rating to 1-hour for duct shafts, or does NFPA 90A take precedence? I'm curious to hear different perspectives on this. I can understand both sides of the issue but find it challenging to justify allowing a 1-hour fire rating for a vertical exit within a New Apartment while requiring a 2-hour fire rating for the duct shafts. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Keeping politics out of it, what most likely happened to the fire hydrants in Pacific Palisades, California?
Or looking at both possibilities, what likely happened if all water reservoirs were full and what likely happened if the reservoirs were empty or under repair? I presume 40 or 50 fire pumper trucks over-taxed a perfectly functioning water system to the point where supply tanks could not be replenished fast enough. Additionally is a California water reservoir a body of treated water that fills the underground piping system & storage tanks? Or, is a reservoir a body of water (near by) that is waiting to be treated, and then enter the distribution piping? Looking for a better understanding from those that might be more informed and knowledgeable on the subject here. Thanks. Moderator's note: Major cultural events have a tendency for discourse to go political quickly. This is a technical forum for technical discussion on topics relevant to the fire protection industry, and not a location for political discourse. We welcome and appreciate civil discourse that's informative and helpful. Please refrain from political commentary as it will be removed from this site. Thank you. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I'm working on a project in an existing 7-story building with an existing 500 gpm 70 psi fire pump.
We are installing a new 4-story riser outside the pump room, and a question of water hammer/surge protection has come up. The existing equipment does not indicate any special considerations for this. Most (not all) zone valve assemblies incorporate pressure relief valves, and all new zones will have them, as well. Hydrant test static was 65psi. In general, what conditions would prompt you to consider the possibility of water hammer or pressure surge being an issue? How do you go about evaluating this, if it is a potential issue? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe What is an acceptable means to inspect/supervise underground fire line isolation valves in a "roadway box?"
These are non-indicating and unsupervised valves on a fire line. They do not have a lockable lid and may be in a drive or roadway, i.e. subject to traffic. If you recommend a seal, please be descriptive of how that would be practical. NFPA 13 provides the following applicable guidance: 16.9.3.3.1 Valves on connections to water supplies, sectional control and isolation valves, and other valves in supply pipes to sprinklers and other fixed water-based fire suppression systems shall be supervised by one of the following methods: (4) Valves located within fenced enclosures under the control of the owner, sealed in the open position, and inspected weekly as part of an approved procedure. Thanks for your help. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe In NFPA 25-2017 Chapter 5 addresses "Loaded sprinklers." Of course, this has been a "LOADED" question for years and everybody's interruption of what that is whether or not NFPA gives a decent explanation of it.
My question is, we have a customer that we've performed a sprinkler test by removing an X amount of sprinklers and sending it away to a third party lab for testing which samples came back as a pass - but the question has come up asking if sprinklers remain to be loaded the same if not more over the years. What would be the timeline for re-testing? Would it follow the 10 year re-test? Or 5 Year sprinkler testing that NFPA 25 requires for sprinklers in "hazardous" environment areas? As this plant has over 600 sprinklers and getting up to them and cleaning them every year is not practical, that option is not on the table. See NFPA 25-2017 code for the discussion on it. Thanks for your take. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am a project manager currently building a SCIF in Northern Virginia. I was told by the landlord that we couldn't use Schedule 80 PVC for di-electric breaks as they have had a PVC break causing millions of dollars of damage prior. We don't like wrapping/grounding the pipe.
Have you run into this? Do options exist, and what would you recommend to isolate through a SCIF? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe From my AHJ perspective and in regards to flexible drops and tenant improvements, where you typically don't receive hydraulic calcs, how are you then accounting for their equivalent lengths and friction loss?
I know some AHJ's require new calcs whenever these are being used period. I'm interested to see how others handle this. Thank you! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Thank you all for continuing to make this Forum such a fantastic place to learn, share, and connect. Over the past year, we’ve seen some great discussions, advice, and insights that have helped shape our industry in a positive way. It’s your participation and willingness to help others that sets this community apart! We’d like to recognize the Top Forum Contributors in 2024 (in alphabetical order): 
As a special thank you from our team, each of these contributors will receive a commemorative plaque. They will also have a flag next to their name for future leaderboards. Thank you once again for being part of this amazing community. Keep sharing, keep learning, and here’s to another great year together! I am working on a sprinkler system where the corridor has a wooden ceiling, as shown below. Upright sprinklers protect the space above the ceiling. I want to know whether the pendent sprinklers below the ceiling are also required? Is this an open grid ceiling under NFPA 13? The ceiling has the following characteristics: Bamboo ceiling panels with mesh void and solid wood frame with galvanized black metal rods as hangers for proper support, panels are to have a consistent panel size of 15 cm void between each panel and the wall and 30 cm void between the panels for the greenery to be hung. Can anyone help me in this case? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I am hoping for some help here. I have a cold storage facility that has racks in it. Customer is adamant they do not want in-rack sprinklers. Building is 30-ft tall to the peak, storage is at 25-ft, racks are push back/drive in 29' deep with no longitudinal flue space. They are storing a Class I commodity.
Is there a ceiling-only design that's possible, for a dry system, for this? Or a direction for me to look into? It's not a conditioned space, just a big ice box. I would greatly appreciate any help or feed back, thanks. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Anyone know what temperature the sprinkler should be for a school's boiler room?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a small dry system of 196 total gallons installed in a small feed/grain storage warehouse at a Tractor Supply store. The dry valve is very close to the unheated storage area. They are using racks with commodity stored up to 15 ft high. This system is well under the 500 gallons for required water delivery time.
Is the Extra Hazard Inspectors test still required with two lines, two outlets on each line, or is a typical Inspectors test for Ordinary Hazard acceptable? I assume the Extra hazard arrangement is still required, but wanted some clarification. NFPA 13 Figure A.7.2.3.7 shows the manifold from four sprinklers and two branch lines. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe My area's adopted building code references NFPA 13, the 2016 Edition.
Should I even consider looking into the later versions of NFPA 13 (2019-present)? If there are major differences, how do we reconcile following only 2016 since the building code references it even though it may be outdated now? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is it required by IBC or NFPA 13 to have a detached fire pump room or shelter to be protected by the sprinkler system as long as the fire pump serves the sprinkler protected building?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Thank you for keeping discussions strong during the holidays. Special Shout out to our Top Contributors to the Forum for December 2024!
Are townhouse complexes (3 or more side by side and separated by fire barrier) considered R-2 or R-3?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Operationally, why would a fire department with a 1,500 gpm pump on a fire engine connect to a building FDC that has a 1,750 gpm pump?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Under NFPA 13, 2016, Miscellaneous and Low-Piled Storage in Table 13.2.1. A system designed for Ordinary Hazard Group 2 allows for 5-ft or less storage of Group A plastics, and in a separate section of the table allows for Class I- IV with a height of 12' or less.
Is it permissible to store the Group A on the floor up to 5-ft in height, with the Class I-IV above it on the racks provided the racks meet the requirements of this section? Section 5.6.1.2 on Mixed Commodities seems to address more the amount of what is being stored and not so much the arrangement. I can see both side of the argument, but I can't seem to find anything the answers my question definitively. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project with deep concrete beams which are 24 inches deep, 4 inches wide, and located 6'-6" center to center.
Building is at least 20 years old. The original contractor, I think, treated the first beam like a wall and put a row of sprinklers on each side of it. The deflectors are 12 inches down. I'm assuming they then “skipped “ the next beam. At the third beam he put another double row. And then repeated the pattern. There are 4-inch deep lights in the center of each bay. They are sticking a layer of sheet rock on all sides and the ceiling. The sprinklers are 15 feet apart. It looks like the they are just protecting the bay on each side of the skipped beam with no sprinkler lines. The middle beam obstructs the coverage. This is a light hazard area with 9-ft ceiling height to top plat panel. Should the sprinklers be calculated flowing 6'-6" x 15'-0", or, flowing 13'-0" x 15'-0"? I believe a case could be made for both. It’s an all purpose room in a school basement. I could offer them OH 1 at 6'-6" x 15'-0" without changing spacing on the branches. I could only achieve Light Hazard if 13'-0" x 15'-0" is utilized. The architect shows minor changes for small closets, a few walls, and we're changing the sprinklers to quick response. Thank You very much. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a project for a Aircraft Hangar Group II. We will be designing the foam system based on Inline balance pressure proportioning design under NFPA 16 Annex material.
The protected area has been divided into 3 zones. We are using an 8" Alarm check valve with a closed-head sprinkler for each zone. So the fire line is fully pressurized with water. What proportioner should I be using? Is it an inline balance pressure proportioner or a wide range / variable range proportioner better to get the 3% concentration when foam discharge at the nozzle? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 13 9.3.5.11.6 states 'For longitudinal braces only, the brace shall be permitted to be connected to a tab welded to the pipe in conformance to 6.5.2' 6.5.2.2.3 specifies that 'Tabs for longitudinal earthquake bracing shall be permitted to be welded to in-place piping where the welding process is performed in accordance with NFPA 51B.'
Section 6.5.2.4.7 states ' Tabs for longitudinal earthquake bracing shall have minimum throat weld thickness not less than 1.25 times the pipe wall thickness and welded on both sides of the longest dimension.' My questions are: Is anybody using this method for longitudinal bracing? How do you calculate a brace using this configuration? Is there a tab on the market specifically for this application? Additionally, is Section 6.5.2.2.3 suggesting that tabs are only permitted to be welded in field? We do giant open warehouses where bracing typically can go exactly where the plan shows it. We fab 90% of our pipe in-house, and if we could specify the tab's location on the fab listings, we could potentially get rid of 212 pipe clamps for all longitudinal bracing. Besides the obvious install issue of 'it might not work in the exact location it's welded' - am I missing something...? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe For a sprinkler pipe that is low enough above the finished floor that it could be walked into by a person of standard height, can it be wrapped in foam or soft material by code to prevent knocking one's head on it?
Alternatively, is it allowed to wrap this pipe in yellow tape or adhesive to increase its visibility to prevent running into it? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project where the Specifying Engineer has noted to have a small hose connection for periodic (maybe every 6 months) building maintenance use to wash down a water intake filter.
They have specified that it be fed from the jockey pump upstream of the jockey discharge check valve and connection to the fire pump connection, so it would seem that it would not really affect the fire protection system or fire pump discharge. However, I don't think it is a good idea, and I think a separate pump for building maintenance should be provided. Looking to see if there is any code reference I can use for backup as common sense doesn't always work or maybe I am wrong. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I work for a local fire department that does plan reviews for fire protection systems. We are reviewing a project that requires 40,000 gallons of stored water. They are proposing using multiple fire water tanks and eight 5,000-gallon tanks.
While NFPA does not restrict the use of multiple tanks, I would like to see fewer tanks than eight. I am more inclined to allow two separate tanks at the most. However, I wanted to see what others thought and if there was a standard understanding or practice to number or size of tanks to the total needed water demand. Thanks for any help. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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