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Looking at NFPA 14-2019 A.7.1(b) Typical Two Zone - Wouldn't the system on the 2nd fire pump in series discharge side be limited to 365 psi static pressure (not forgetting the jockey pump added pressure) due to the check & butterfly valve's listed working pressures?
NFPA 14-2019 Section 7.2.1 limits max pressure to 400 psi and Section 7.2.2 says express mains can exceed 400 psi in accordance with material listings (or as approved by AHJ). From what I can find on the market, Victaulic has the highest listed of those two valves at 365 psi (Vic Check 716 and Vic BFV 765/766). It seems like a lot of designs rely on the fact that some valves list that you can field test them up to 500 psi or 1-1/2 times one time and are relying on the as approved by the AHJ. The waterflow switch is listed up to 450 psi and not worried about the pressure gauge. Am I just not aware of higher-listed valves? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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I am being told that I need to install a standpipe on my warehouse roof because IBC 905.4 calls out the location of Class I standpipe hose connection in locations where the roof slope is 4 units vertical and 12 units horizontal.
However, my building is a single-story warehouse and doesn't meet the conditions established in section 905.3.1. Am I required to put in a standpipe because of Section 905.4? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are working on a school project that needed a 1,000 gpm fire pump due to three standpipes.
We initially did a hydrant flow test and had a flow of 425 gpm with a static of 55 psi and residual of 50 psi when we started the design. By the time it went out to bid and the contractor performed their own test, they flowed 354 gpm with a static of 55 and a residual of 50. In the first test, we got 1215 gpm at 20 psi, and 1012 gpm in the second test. They went to turn on the pump and were only getting 368 gpm when the building inlet pressure was at 20 psi. We re-did the flow test to see what changed so drastically and again got a static of 51 with residual of 46 at 375 gpm, which would give us 1004 gpm at 20 psi. We have confirmed the two valves between the street and the building are fully open, and we only have about 50 feet of 8” pipe, so the pressure drop to the building is negligible, especially at 368 gpm. We are at a loss for what could be causing such a difference in pressure to the building and such a low flow. Has anyone ever run into an issue like this or have any suggestions of what else we could check out? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Hi everyone, I have some questions regarding old high rise standpipes.
In many old high-rise buildings, they will have a wet standpipe fed from a gravity tank (or tanks), which is in turn filled by dedicated tank-fill pumps. Some will also have an additional manual fire pump down in the basement that can pressurize the standpipe upwards; I’m figuring just as backup for the existing roof tank reservoir. First question: Is this type of setup just a relic of the past since it’s just a manual backup pump? I haven’t found where in modern code it seems to be applicable to this whole setup. At least, it doesn’t seem to have any mention in NFPA 20, even though that’s the main fire pump book. Second question: All these vintage motors and controllers seem to be wound-rotor motors, and the controller is speed-controlled via resistor banks. Is the stepped speed control simply to reduce inrush by ramping one step at a time up to full speed, or are they intended to operate at reduced speeds on purpose? I’m figuring the modern equivalent to these old setups would likely be a soft-start controller if you’re just looking to reduce inrush, or a VFD controller if you want to run at reduced speeds on purpose. Of course, all of this conjecture is only if such a setup is even relevant to modern code. Thank you for any insight you can offer! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When calculating manual standpipe systems per NFPA 14, are there any tips on calculating upstream from the FDC back through the hose lay back to the apparatus?
And I assume even considering the underground supply the apparatus is drawing from? I know many pumper trucks are rated at 1,500 gpm at 150 psi, but I assume one would need to verify that, and what length, diameter, and type of hose they utilize from the truck to the FDC. I see too many calcs that assume an "infinite" water supply if it is supplied by a pumper truck. 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 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 When hose allowance is added to the sprinkler demand on a Class III Standpipe/Sprinkler wet riser, where on the system are the inside and outside flow and pressure allowances input when calculating the system?
NFPA 13 Chapter 19 states that the allowances are not required when calculating a combined system, which appears to contradict NFPA 14 requirements to include them. In my case, the sprinkler demand is for OH2 (ceiling higher than 40 ft), resulting in a sprinkler demand plus hose allowance that is greater than the standpipe demand. If I don’t include hose allowance in the sprinkler calculation as per Chapter 19, this combined system is not equivalent and robust as two independent systems. Any thoughts? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is this an allowed and feasible installation for FHV's that are required to be installed at intermediate landings, to avoid penetrations in a precast stair? Is there a code basis against this, or any differing recommendations on routing here? See image below. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I appreciate this community and thank you in advance. I'm new to the fire protection industry, having been in other building engineering disciplines for many years.
For multiple buildings on a campus using the IBC. "IBC 905.3.2 Building Area Amendment In buildings exceeding 10,000 square feet (929 m2) in area per story, Class I automatic wet or manual wet standpipes shall be provided where any portion of the building's interior area is more than 200 feet (60,960 mm) of travel, vertically and horizontally, from the nearest point of fire department vehicle access. Exceptions: 1. Buildings equipped throughout with automatic sprinkler systems installed in accordance with Section 903.3.1.1. 2. Group A-4, A-5, F-2, R-2, S-2 or U occupancies." Is there any reason not to eliminate the standpipes if the height and occupancy thresholds aren't exceeded? One of the buildings is a two-story, 60,000 SF building. The path of travel plans shows a 150+ foot range. Does this cause any concern? I know the standpipes are to assist in manual firefighting ops, but is eliminating them increasing future risks to the occupants? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I'm working on a fire protection design for a new apartment building. The architect is adding what they're calling horizontal exits throughout the building, which will increase the number of required standpipes per the local building code (IBC-based, 2025) Section 905.4. Per the exception to 905.4.2, I do not believe we will need hose connections on both sides of every horizontal exit within the building. I think additional standpipes and hose connections will only be required in the center of the building. Other than the egress stairwells, where are standpipes and hose connections required to be located? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I have a client with a 10-story office building/parking garage, a fire pump in the below-grade level, and a combined wet standpipe with a manifold on the roof for testing. The building is getting some age on it, and when performing a flow test from the roof manifold, the roof drains will leak water into the top floor offices.
The question that was posed to me by the building manager was, "Can we tie into the bottom of the standpipe and run a new test connection to the outside at ground level?" Shooting the water over the side of the building is not really an option, doable, yes, but not really an option. Just wanting some thoughts on this, my initial response was no, but then I had never been posed with this question either. If not, is it possible to permanently tie somewhere else, or conduct the test in a different way? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a consultant showing a 6" wet sprinkler riser routing through the 1st floor of a building, supplying sprinklers, then heading to a stairwell to supply a wet manual standpipe. I am confident that supplying a standpipe downstream of a sprinkler system is not allowed, as there would be no way to fight the fire with hoses without the ability to shut off the sprinkler system, but keep the standpipe live.
Can someone shed some light on the code referring to this in either NFPA 13, 14, or even FM Global that details standpipes can feed sprinkler systems in a combination setup, but a sprinkler system cannot feed a standpipe? Thanks in advance! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have an old Convent building (3-stories with long corridors) that currently has a Type III manual wet standpipe system and no sprinklers. They are remodeling and are installing sprinklers throughout, and want to remove the standpipe system.
As the AHJ, I would like to keep the standpipes but remove the hose cabinets, essentially to make it Class I. Is there a relevant code path to keep the standpipes even though, for new construction, they would not need them? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Regarding existing high-rises going through an occupancy change (B to R-2), am I correct that all an engineer has to meet is the 65 psi at the top most floor per IEBC 2021 803.3 Exception 1: "A pump shall not be required provided that the standpipes are capable of accepting delivery by fire department apparatus of not less than 250 gallons per minute (gpm) at 65 pounds per square inch (psi) (946 L/m at 448 KPa) to the topmost floor in buildings equipped throughout with an automatic sprinkler system or not less than 500 gpm at 65 psi (1892 L/m at 448 KPa) to the topmost floor in all other buildings. Where the standpipe terminates below the topmost floor, the standpipe shall be designed to meet (gpm/psi) (L/m/KPa) requirements of this exception for possible future extension of the standpipe."
The code section makes no mention of high-rise difference and the commentary states: "Exception 1 allows the installation of a standpipe system without a fire pump if sufficient water with sufficient pressure could be delivered by means of fire department apparatus pumps to the topmost floor of the building. Under this exception, the location of the work area is irrelevant, and the topmost floor must be considered whether the work area is located at the topmost floor or not." I can't find anything that an existing building needs to meet the 100 psi requirement of the IBC, and this would trigger the need for a fire pump if I can meet 65 psi already. 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 am working on a project that is building and connecting an open parking ramp to an existing building via an open bridge. The open garage will be going next to an existing building (different from the one it will be connecting to).
Does the open parking ramp need a dry standpipe? It will be just over 69 feet tall, and it doesn't look like there are elevators within the enclosed stairwells from the architect's rendering. I don't have a CAD background to compare to yet. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe In a 3-story building with 3 standpipes, one of which is a combination standpipe/riser, and the standpipes are manual wet, with 50 psi.
On a 5-year test, how do I flow 1000 gpm (no pump) at 100 psi? Do I involve the fire department? The old hydraulic plates showed 70-50 at 260 flow. Three years later, they are showing 50-40 at 320 flow. So I cannot pass this, even though the water supply has diminished. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe For scissor stairs having 2 separate standpipe risers (one of them is a combined sprinkler and standpipe system) running 12 floors, how do we size the pump flow rate required?
Can we argue that we can use a 500GPM pump since the Risers are in close proximity to each other and are within one stairwell, or should we use a 750GPM pump following the NFPA 14 sizing of 500GPM plus 250 GPM per additional riser? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a hotel building that requires a standpipe in each of the two staircases. One of the stair shafts has a door to the outside at grade level, but there is no door to the first level inside. The lowest level with an interior door is the second floor, which has its own hose connection.
It doesn't make sense to provide a hose connection at the ground floor, but is there a code basis to support this? Thanks! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Standpipe hydraulic placards - are they required? You don’t see too many of them, so it would be difficult to find out how much psi max to pump in I don’t see many at the FDCs. Some fire marshals ask for one, others do not. I feel I’m the only one providing them. NFPA 14 6.8 requires them and tells you what to put on them (2016 to present). I place them at the exterior FDCs, base of standpipes, at the tested valves, and at the fire pump. Why aren’t the signs enforced? Are you seeing these regularly? Thanks in advance. 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  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 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 have a horizontal standpipe Class 1 in a 157,252 sqft warehouse that needs calc'd, but I'm trying to figure out how to go about that.
Per NFPA 14, 2016 edition, it seems to me that you would have the hydraulically most demanding hose valve flow 250-gpm @ 100-psi, and then flow three (3) more hose valves at 250-gpm until I get to a 1000-gpm total. However, Section 7.10.1.2.2 only says to do this up to 3 hose valves total. What am I doing wrong? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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