A typical specification is broken down into 3 parts:
Part 1 – General Part 2 – Products Part 3 – Execution In a typical specification for sprinkler pipe we often see something like this: Part 2 - Products 2.2 Steel Pipe and Fittings Schedule 40 Galvanized and Black steel pipe Schedule 10 Black steel in pipe NPS 2.5 and larger Part 3 - Execution 3.12 Piping Schedule NPS 2 and smaller - Schedule 40 black steel NPS 2-1/2 and larger - Schedule 40 black steel When Part 2 and Part 3 of the same spec contradict one another, which part rules? I know the answer is to write an RFI, but we often don’t get an answer prior to bid time. Also, what is the thought process of the EOR for providing a spec like this in a bid document to begin with? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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When coming out of a pump room with underground feed which then connects to an underground loop with a bullhead tee, are isolation valves required on the bullhead tee?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 13 provides allowed omissions for sprinklers in combustible concealed spaces where the entire cavity is filled "with non-combustible insulation".
Is fiberglass the only non-combustible insulation? Is blown-in insulation considered to be non-combustible, or does it depend on the type of blown-in? Just curious if there was helpful literature so that we knew what to recommend or look for when we come across these scenarios. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When we run hydrant flow tests, we usually use both 2-1/2" side-outlets of a typical dry fire hydrant. We hook up one, threaded, swivel 45-elbow on each side to divert water in a direction that won't destroy anything.
What is the appropriate Coefficient of Discharge when measuring the pitot on the centerline of the elbow? Traditionally flowing straight out of the side outlet of a hydrant, NFPA 291 gives three Coefficients (0.90, 0.80, and 0.70) based on how the outlet projects into the barrel. NFPA 291 also states that a coefficient of 0.85 is suggested for stream straighteners, unless the coefficient of the tube is known. Is there a known Coefficient for a single 45-degree elbow? Any help is greatly appreciated. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When determining the most hydraulically remote area in a building, what takes precedent - the flow, or the pressure required?
In other words, when comparing two remote areas which are very similar, which would actually be considered the "true" remote area - an area with high volume and low pressure, or an area with low volume and high pressure? I am inclined to say that flow supersedes pressure, but since "hydraulic" deals with the relationship between the two, I'm not 100% confident. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 20 specifies a minimum size for suction pipe before a fire pump, to reduce the water velocity and avoid cavitation (among other things). NFPA 20 states that this only applies to 10-pipe diameters of length before the fire pump.
We have a very long run from the backflow preventer at the service entry and the fire pump room. Hydraulically, this long run works with a long 4-inch feed, which would then upsize to 6-inch right before the 450 gpm pump for the 10-pipe diameters. My question is, am I allowed to drop the main size between the backflow and the fire pump? Hydraulically I don't see why not, we're not dipping below 20 psi anywhere on the system and we appear to meet code. Intuitively I've never dropped pipe size to pick it back up, but this situation with the pump feels a little different. This is above a multi-family unit, so 6-inch steel is nearly impossible to fit within short open-web joists and would be a major issue for the building owner if we had to drop a soffit. Thanks in advance for your take! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are getting a plumbing department reviewer's comment that the combined sprinkler/domestic water service cannot exceed a flow of 5 feet per second.
Their justification is that flow above 5 ft/s will negatively impact the "coating" on the inner surface of the copper pipe. I've never heard of such a concern, and 5 ft/s is far slower than the hydraulic calculations can support. This is for small diameter services on an NFPA 13R project that is 3 stories in height. The difference in tap fees between a 2-inch combined service (with an automatic domestic shutoff in this case) and a 3-inch ductile iron is at least ten thousand to the owner. Is there some truth or justification to limit fire sprinkler flow to 5 ft/s on copper pipe? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Are sprinklers within NFPA 13R required to be quick-response, or can they be standard response residential sprinklers?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a 20-ft x 30-ft exterior projection that was initially supposed to be open to the sky. The builder made it open on two sides at the bottom with a 12-ft lid. The construction above goes to the roof and is concealed with no access from inside or outside, and it all is of non-combustible steel beams and joists with metal siding.
The million dollar question - sprinklers above and/or below? Or nothing at all? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a project with a concrete planter wall near the edge of the sidewalk. The top of the planter is 32-inches above the sidewalk.
The architect would like the FDC on the planter wall, but a siamese-type would project too far into the sidewalk so he wants a flush FDC. A standard brass FDC body with clappers would be buried under several feet of dirt so it would make sense to use spigots with clappers - but they would also be threading into a body/manifold that needs to be buried. Our concerns are replacement/repairs on the clappers; corrosion, and sealing around two penetrations through planters while still being able to repair/replace spigots. We're also considering a 'sidewalk siamese' setup just inside planter wall, but 18-inches above top of planter puts them above 48-inches above sidewalk. I think this is best option but would required fire department permission and the architect is pushing for flush on the planter wall. Is a flush fire department connection even an option here? Are we being overly concerned with corrosion and/or maintenance issues on these buried parts? Thanks in advance for suggestions for dealing with these issues. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are designing a warehouse which has a system demand of about 150 psi at 2,000 gpm.
There is an existing facility with a 150 psi @ 1,000 gpm rated pump installed approximately 1/4-mile (350 m) from the warehouse. We are planning to add a new 150 psi pump at 1,000 gpm near the warehouse roughly 65-feet (20 m) from it. Is there any code limitation we might hit to serve one building with two separate pumping stations installed remote from each other? How would you recommend we set the pump operation sequence for the two pump rooms? Each pump room will have an electric, diesel, and jockey pump. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am doing an evaluation of a water supply for a fire sprinkler system. The system is an ordinary hazard wet pipe fire sprinkler system. It was designed as a pipe schedule system. Table 19.3.2.1 of NFPA 13 – 2019 Edition gives the water supply requirements for Pipe Schedule sprinkler systems.
Based on our buildings construction the table requires that for Ordinary Hazard we have a 1,500 gpm flow with a residual pressure of 20 psi. Section 19.3.2.6.1 then states, “The residual pressure requirement of Table 19.3.2.1 shall be met at the elevation of the highest sprinkler.” My understanding of this requirement is that if I have a pipe schedule system where the highest sprinkler head is 20 feet above the finished floor which equates to roughly 8.7 psi of head I would need to have a water supply that provides a minimum of 28.7 psig residual water pressure flowing 1,500 gpm to the base of the riser to meet the requirement. Am I calculating the required residual pressure correctly? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have inherited a totally fun project, a R-2 III-B multifamily residential building at 27,300 sqft per story, three stories total. I'm on the architect side.
Our mechanical engineer did a 61G (Florida fire suppression analysis) and designed the central lobby to be under NFPA 13 and the rest of the building NFPA 13R. I immediately thought where are the area separation firewalls, because we are over our allowable area for a III-B. The building is in construction, trusses have been set. I was told that you can do an area increase in the hydraulic calculations, one with the NFPA 13 portion of the building and one with NFPA 13R add them together and get your increase. I'm calling BS because I cannot find this in the code anywhere, but supposedly this is coming from a FP consultant. Any clues on the location of this allowance in code? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Does anyone have experience with auditory testing booths?
We have a 6-ft x6-ft audiology testing booth with a fully enclosed ceiling. It is about 7-ft tall and has been installed in a school for over seven years. Recently on an inspection, it was noted that it was required to have a sprinkler. I have dug through the code and can't see where it would not be required. The only thing I found was in IBC 903.3.1.1.2 that it is "A room or space where sprinklers are considered undesirable because of the nature of the contents, where approved by the fire code official." In that case, it looks like we could add a smoke detector in there if it was approved by the code official. They are very similar to office pods or even walk-in coolers and they are required in those situations. Because of the nature of the booth, I'm getting a lot of pushback from the users of the booth. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have found in a gas turbine power plant a long run of a 24" pipe supplying water-based fire protection systems supported via cradled non-guided supports, welded to the bottom of the pipe itself. The shoe base plates are placed on support beams, without any slide assemblies in between.
I normally use to design the European code EN 12845, where you can read "supports shall completely surround the pipe and shall not be welded to the pipe or fittings". Is this permitted in NFPA 13 environments? I would be glad if you could share your thoughts about this, thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a project where the tenant intends to store Class I to Class III commodities that have a typical footprint of 12’ x 3.5’ (42 SF) on open-wire mesh racking.
Between the Definition 3.3.172 (NFPA 13-2019) Rack Shelf Area which specifically calls out “by the placement of loads” and the definition “Open Rack” (3.3.140) it appears that this condition has to be viewed an Solid Rack and would require In-Rack sprinklers no matter what roof level system (CMDA, ESFR, K-25) is installed or the Commodity Class stored. I know there are some special designs related to “big box retail” stores (Mercantile) for this, but our application is Warehouse (Storage). There are also additional conditions if the footprint is greater than 64 SF. Is there a way to read the above definitions that would not require in-rack sprinklers when Loads with a footprint over 20 SF and less than 64 SF are placed on otherwise Open Rack? Requiring in-rack sprinklers is a potentially major expense for an owner with 75+ operable facilities like this. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are on a project where they are installing these vertical storage carousels and will be storing miscellaneous vehicle parts and tires. I don't see anything within NFPA 13 specifically mentioning this equipment, so the current plan of action is to treat this equipment as multi-row racking. Since it is not practical to provide in-rack sprinklers for this equipment due to the moving parts, we are planning on protecting this equipment with ESFR sprinklers.
Does this ESFR approach seem appropriate? Is there any information that I am not considering? This is something that is new to me so any input will be greatly appreciated. https://www.storevertical.com/products/vertical-storage-system/tire-carousel https://www.storevertical.com/products/vertical-storage-system/shelving-carousel Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe At a tire store we currently have 25.2K ESFR at the roof, and they have some open grated flooring down at about 10-ft above finished floor where their tire areas are. We are currently protecting the areas that are wider than 4ft.
There are some other runs that are just under 4-ft wide and the AHJ is saying we need to protect those. They're 86% open grates, deeper than 1/4". I'm fine with adding the heads under these, however the AHJ is stating that we must protect below them with ESFR's instead of an intermediate level/rack style sprinkler. I've never seen this approach in 20 years nor can find any justification in the code to support this. The AHJs comments suggest the water shields are necessary to prevent cold soldering from ESFR sprinklers above. Is there a code basis to use intermediate level/rack style sprinklers under obstructions with ESFR at the deck? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 20 Section 4.15.5.1 (2016 Edition) requires a listed OS&Y gate valve to be installed in the suction pipe, but the annex of NFPA 20 suggests it should be as far as practical from the pump suction.
Would a control valve (OS&Y) on the backflow preventer meet this control valve requirement of Section 4.15.5.1? Assuming a city water supply, the backflow preventer control valve is listed for fire protection, there is still a valve'd bypass connected between the backflow preventer and pump suction, and the backflow is located a minimum of 10-pipe diameters from the suction flange. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project where the consultant is wanting to use a previously-installed 10-story building tank and fire pump to supply a new 14-story building up to its 6th floor, then add a booster pump to carry water to the upper floors.
Is this even acceptable by code? The new 14-story will be built next to the existing 10-story building. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe What is the difference between a K17 (CMDA upright) and Ultra K17 (CMSA) sprinkler?
When I look for the technical data sheet, I don't see any specific difference except the color of the cover of these Tyco sprinklers (bronze for CMDA and Chrome for CMSA). Does anyone know if these sprinklers are the same, except the fact that they work at different pressures? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have an 83,000 sqft total (3-story) Type II-B new construction building under the International Fire Code. Under IFC Table B105.1(2) I get a straight-table Fire Flow of 6,000 gpm at 4 hours. However, IFC Table B105.2 allows buildings with automatic sprinkler systems to have a "Minimum Fire Flow" of "25% of the value in Table B105.1(2)", and a "Flow Duration" of the "Duration in Table B105.1(2) at the reduced flow rate". With a sprinkler system, the Fire Flow becomes 1,500 gpm (= 6,000 gpm x 25%), that's pretty straight forward.
However, is the Flow Duration straight from the original reading of Table B105.1(2) (which is 4-hours) or is the duration taken from Table B105.1(2) at the new reduced Fire Flow Rate (lookup 1,500 gpm to get 2-hour duration)? In short, is a 83,000 sqft Type II-B building Fire Flow actually 1,500 gpm at 4-hours, or 1,500 gpm at 2-hours? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 20 5.6.2 requires a fully-independent and automatic back up pump for very tall buildings. This project is just under 50 stories with a pump and back up several levels below grade serving the lower zones and another pump and back up several levels above grade serving the remaining zones.
The project’s electrician cannot meet the power requirements for the worst case scenario, which would be all (4) pumps operating at once (if the primaries are running, but not at full capacity). The request is to interlock the primary and back up on the respective level, so only one pump is running on the level at a time (for a max total of two pumps running in the whole building). Would interlocking the pumps on their respective levels still satisfy the requirements of NFPA 20 5.6.2 (copied below)? NFPA 20 5.6.2 Fire Pump Backup. Fire pumps serving zones that are partially or wholly beyond the pumping capability of the fire department apparatus shall be provided with one of the following:
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a F-1 occupancy used for powder coating lines for RV chassis, fully-sprinklered except for the equipment (booths). Inside of this facility there are large powder coating, ovens and media blasting booths that the chassis run through on a track. Each booth is about 18’ x 30’.
Would the media blasting booths require fire protection? The customer does not want to install FP for the media blasting in fear of an accidental discharge that would stop most RV production for the entire country. My thought is the blasting booths along with the powder coating would require FP due to size and I cannot find any exceptions except for the ovens per IFC, class A&B ovens not used for combustible products. Any thoughts? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe While working in a MEP/FP firm, we are expanding to do projects in other states and learning to understand the different state requirements for Fire Protection / Fire Alarm.
What is the best way to go about obtaining each state's requirements for what is required in an upfront submittal? For example some states accept design drawings that only require denoting the hazard level whereas other require full design, calculations, and a written narrative. I understand and agree providing more detail is typically better; however, budgets can be significantly affected (negatively/positively) if only a hazard classification is required compared to a full design. Besides prior knowledge from working in a different state or jurisdiction, what is the best approach in determining what is required? Typically I start with searching what is required from the building code, but that does not always tell you what you need to submit for drawings, permit documentation, etc. It would be great to have a website that gives an example of what is an acceptable layout/design for each state. Hoping to hear any suggestions / methods that others use to determine what is required. Moderator Note: If there is significant interest in this topic, we'd be happy to open up a survey for areas that do require "full design" as an upfront submittal. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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