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Where does NFPA 20's jurisdiction end?
Is it possible to have pressure reducing valves in a suppression system, downstream of a fire pump? NFPA 20 seems to not allow for that, but does NFPA 20 apply downstream? If so, how far? In the standard it says up to a last control valve or something like that - what control valve(s) is it referring to? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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What would cause a 10% reduction in the full flow residual pressure from the current main drain test, when compared to the original acceptance test or previously performed tests?
If the original acceptance test or previously performed test information is not available, then the residual pressure on the current main drain test must be within 5 PSI of the design/demand pressure. What would cause a decrease over time? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can an auxiliary drain for a dry system be mounted on the side of pipe?
We've debated it recently after finding a situation where the auxiliary drains were mounted on the side of the pipe. I've been unable to find proper documentation concerning the orientation for the auxiliary drain. I did find the 5-gallon rule for wet systems, however, I was unable to find a specific reference for a dry system. Thanks in advance! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe How do you calculate a flow and pressure rate from a gravity tank and a pressure tank?
Is there a requirement for periodic testing of flows from these devices similar to that of a fire hydrant? In some instances, high rise buildings in NYC have just a gravity or a pressure tank for the water supply and I am trying to figure out out to measure what type of flow and pressure is available when these are considered a primary water supply for their sprinkler system. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are working on an ESFR system installed in a pre-engineered metal building.
Can the main frame rafters be considered walls when it comes to spacing of sprinklers? Can sprinklers be spaced 2-5 feet on either side of the rafters of a pre-enginered building? The depth of rafter is 30-inches, sprinkler deflector is installed at 14-inches. I believe I can use the rafters as walls or baffles, but had a contractor comment the opposite. We're using the 2013 edition of NFPA 13 for reference. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe First - a big hug (figurative) for all those who took the PE Exam this past week. Hope you get some positive news soon! Preparing for, and taking the Fire Protection P.E. Exam is no small challenge regardless of the outcome. Here are the Final Leaders from those who trudged week-in and week-out from the 2023 PE Prep Series: 
The PE Prep Series is a 20-week series of exams that simulates the Fire Protection PE Exam. Users compete and are challenged in a weekly online exam that simulates the pace and style of the questions on the Fire Protection PE Exam.
Congratulations to our top winners from this year's series! Each of the top ten finalists will receive a plaque commemorating their hard work this summer. To see our full standings for the 2023 season, visit our PE Prep Series page here: PE Prep Series. Has anyone had success in effectively coordinating sprinklers in medical office facilities in Navisworks?
Those I've spoken too say it's very time consuming and difficult to do since we are asked to be involved but usually are at the bottom of the priority list. In Hydratec, it seems our best way has been to specify one (1) elevation point then work your way around and then riser nipple command because of the numerous up/down/over/arounds and lots of aux drains. It seems as though the architects have lessened the amount of space for the mechanicals to run in because of this BIM/clash system. Just looking for tips or recommendations on ways to be better about this. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Does sprinkler protection beneath an open grated mezzanine change the ceiling level sprinkler design density?
e have a building with a storage room with a grated mezzanine at 8' AFF. Beneath the mezzanine is Class I-IV storage on shelves to the bottom of the mezzanine and on top of the mezzanine is similar storage to 10' high. NFPA 13 requires sprinkler protection for open grating over 4' in width but there is no indication on if this affects the ceiling sprinkler design as it might for in-rack sprinklers. My feeling is the system would have to be designed as if it was ~18' high storage with heads under the mezzanine that match that density, but I am not sure if this is correct or if there would be a benefit to covering the grating entirely and possibly considering it storage under 12' below and above. Thanks in advance for your take. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When would you recommend replacing an existing fire pump?
I am working a project where we are renovating a large hotel and the diesel fire pump in the basement is dated 1994. I am aware there is a lifespan but with proper maintenance they can probably operate just fine for a long time. Is 30 years when you would begin to suggest replacing that piece of equipment? Should I make the suggestion to the client that it is best to replace and have them make the final call? Thank you. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Hi fellows, I have a project which is a building is assembled with 12 containers.
Due to the limited room height, I have to run all pipes along the wall. But my piping problem is how to seismically brace the pipes? Would the container frame and wall, roof be strong enough for the added piping seismic load? And even the branch pipe hanger/restraint installation would be an issue as well. Your tips, insights and suggestions would be greatly appreciated. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Our State Department of Natural Resources requires a double check on all water based sprinkler systems and an RPZ backflow when additives such as foam or antifreeze are used.
The rule is for containment. Meaning that the first available connection requires the backflow preventer. With the details shown in NFPA 13 there are examples of check valves with a drilled clapper as well as an appropriate backflow preventer in the examples shown appear to be isolation devices. NFPA 13 FIGURE 8.6.3.3 shows a backflow preventer and includes an expansion tank. If the entire building is protected by an RPZ the water department is satisfied. When approaching the antifreeze pipe arrangement FIGURE 8.6.3.3 wouldn’t a swing check without a drilled hole be equal to the backflow preventer? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is there a set allowance on the fitting angles for sprinkler aboveground pipe? I'm reviewing a couple of projects where I find bends similar to the example below.  The designer is using different pipe angles for reticulations. I'm wondering if there is a clause that prohibits such a use.
Appreciate your insight & feedback. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Good morning all.
So I'm looking at an Extra Hazard Group 1 (EH1) dry system under NFPA 13 (2016 edition). I want to apply multiple adjustments per 11.2.3.2.7 because I want to use high temperature sprinklers to get me a 25% reduction under 11.2.3.2.6. This can result in the following math: 2,500 * 1.3 for dry system = 3,250 sqft. 3,250 * 0.75 (for 25% reduction) = 2,437.5 sqft. And this always stays above the 2,000 sqft requirement of 11.2.3.2.6 and everyone is happy. But it can also result in the following math happening: 2,500 * 0.75 = 1,875 sqft. 1,875 gets forced into 2,000 sqft because I'm not ever supposed to go below a 2,000 sqft design area under 11.2.3.2.6. So then 2,000 * 1.3 (for dry system) = 2,600 sqft. So would the system have a 2,437.5 sqft design area or a 2,600 sqft design area? Yeah, it's only two sprinklers, but at these densities that can change a system. I can see an argument for either conclusion. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 13 in talking about concealed spaces uses the language "Concealed spaces of exposed combustible construction shall be protected by sprinklers."
What does the term "exposed" construction mean? We have a wood deck structure with a steel frame and a un-heated attic; so trying to figure out how to solve this without a dry system (historic building so spray foam on the interior is economical). It would be nice to put an ignition barrier/thermal barrier on the wood deck and then not provide a sprinkler system. (concrete deck of the attic). Thanks in advance for your take. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe How much engine oil can be stored in a building with an Ordinary Hazard Group 2 (OH2) sprinkler system?
We're working on a repair garage and NFPA 13 (2019) classifies repair garages as OH2 in the appendix. It seems reasonable that some amount of engine oil would be allowed to be stored. However, the NFPA 13 definition of OH2 doesn't allow for flammable/combustible liquids, but EH1 and EH2 allows for some unspecified amount of flammable/combustible liquids. NFPA 13 section 26.2.1 states that sprinkler system discharge criteria for the protection of flammable and combustible liquids shall comply with NFPA 30. NFPA 30 (2021) table 10.7.1 allows for unlimited IIIB liquids to be stored in mercantile occupancies with an OH2 sprinkler system. Can this mercantile section be applied to a storage occupancy? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When testing our flow switch, the first time, it will take 25 seconds before the flow switch activates. When we reset and start over, it takes 5 seconds for the switch to activate.
After waiting an hour to test again, the first test always takes 25 seconds for the switch to activate. Any thoughts on why? This is running on an 8-inch pipe. The flow switch on all of the 6-inch pipes work properly. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe A client of ours operates a printing press facility and has installed a machine to collect and form dust into "bricks" to avoid venting them to atmosphere.
The machine is fed by ducts that tap into an existing dust collection system. The client asked for a quote to adjust the overhead sprinkler system because of the new ducts but I think the new ductwork and machine might require suppression of some form, as well as interacting with the existing sprinkler system at the roof. (1) Does NFPA 13 (2016 Edition) Section 11.2.3.2.2.2 indicate that the existing roof system cannot have quick response sprinklers? "Quick-response sprinklers shall not be permitted for use in extra hazard occupancies or other occupancies where there are substantial amounts of flammable liquids or combustible dusts." It's hard to tell from the floor but I believe at least some of the systems have quick response. (2) Is the dust collector ductwork governed by NFPA 13 at all? Section 22.33 Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Noncombustible Particulate Solids would not seem to apply since the particulate dust is a paper product and inherently combustible. (3) Are dust collector machines like paint booths in that manufacturers pre-coordinate requirements and access for sprinklers into the filter media? Thanks for all the guidance; I haven't seen this application before. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have observed forward-flow tests of backflow preventers, and fire pumps tests, that are conducted through 2.5-inch nozzles identical to the image below, but without the playpipe tip screwed onto the end of the nozzle.
Image Link The pitot reading was taken off the 1-3/4" threaded end of the nozzle where the playpipe tip gets screwed on. Is this approach acceptable, and would the GPM table for the 1-3/4" butt for converting the pitot pressure to flow be acceptable? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have an existing building which is being retrofit with a sprinkler system.
The building is non-combustible construction (pre-engineered metal building) that has a steel main frame, z-purlins, and below that there was a series of offices built with wood stud walls. The ceiling is hung ACT. Does 6-12 inches of exposed stud walls that extend just above the ACT ceiling then trigger the need for sprinkler protection above the ceiling? In other words, does the amount of wood construction in a ceiling space impact whether or not it's considered a combustible concealed space, and therefore would or wouldn't need protection? I have a gut feel for how I would go about this, but am not looking to skew the discussion at all. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 20 dictates the number and size of hose valves according to the pump rating, but is there any specific requirement on how many are to be used during testing?
How is that determined? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Which sprinklers are appropriate for kitchen fire protection?
What about in a hood versus near a hood? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe On behalf of those of us who talk here regularly or just learn from the great discussion - thank you! Shout out to those who have submitted great questions this last month as well.
Does the IFC or NFPA standard dictate if a old system has to brought up to code if a new permit has been issued for a tenant improvement?
For example adding 5 flex drops to an existing system? Seismic , hanger support are the issue. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is there any code that sets a specified elevation for the the Fire Pump Test Header above outside grade?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Could I have opinions on the best way to further my understanding in fire alarm and sprinkler design (dry, wet, deluge, & pre-action)?
My job has requested I further understand these concepts for our designs and cost estimating. I am looking for some of the better study resources from experts like you guys. Currently, I work for a company with several hundred buildings and various systems. Any suggestions would be greatly appreciated. Software is a great tool but I desire to further my technical understanding in both designs. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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