Is there a code requirement that states sprinkler pipe must maintain a certain distance from fireproofing sprayed onto structural steel?
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NFPA 13 requires dry pipe and preaction system branch piping to be pitched at least ½” per 10 ft, and mains pitched at least ¼” per 10 ft in non-refrigerated areas.
Should an exception be considered (less pitch or no pitch) for systems utilizing nitrogen to maintain system pressure? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I have a horizontal split-case fire pump, with suction taken from the header. The distance from the flange of the tee to the pump flange maintains the minimum 10-pipe-diameters as required by NFPA 20.
However, is the 10-pipe-diameters measured from the flange of the gate valve (OS&Y vale) or from the flange of the tee? I received a comment from a consultant that stated the 10-diameters is to be measured from the OS&Y gate valve flange. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe We are working on a new addition to an existing high school. Part of the addition is a new auditorium with a full stage. The stage will be the highest hazard and our calculation area, Ordinary 2. The stage will also have (2) 1-1/2" hose stations with fog nozzles, one on each end, north and south, to protect the stage. They will be supplied from the same fire sprinkler system protecting the stage.
Do we need to include the hose station(s) discharge in the hydraulic calculations? If so, what would be the flow criteria from those hose connections, and is that separate from the outside hose allowance or part of it? Thanks all for your input. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe My customer is creating a storage area that is high-hazard, high-piled combustible storage (Group A Plastic) that nearly qualifies for application of NFPA Chapter 13, Miscellaneous Storage.
However, the NFPA 13-2016 definition of Miscellaneous Storage includes the qualification, "...does not exceed 1000 sq. ft. in one area or pile,..." NFPA 13 is silent on how to calculate the area. The IBC defines "High-piled Combustible Storage Area" as: "An area within a building that is designated, intended, proposed or actually used for high-piled combustible storage, including operating aisles." If I use the IBC definition it puts this area at 1650 sq ft. What is the proper calculation of area as it applies to Miscellaneous Storage? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I was searching for an answer to question that was asked about limited area fire sprinkler systems.
Is a Fire Department Connection required for a limited area fire sprinkler system? The application that we have is a single sprinkler head installed in a medical gas closet. From my code research (IFC 2015 903.3.8 with amendments), it appears that a limited area system can be run off of the domestic water supply and thus omits a need for the FDC and other devices associated with a full sprinkler installation. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Would appreciate if you guys would weigh in on this disagreement I'm having.
Applicable Codes/Standards: The project is subject to military code UFC 3-600-01 for Sprinkler Design Area and Design Density. Otherwise, NFPA 13-2016 applies to all other aspects of the system fire sprinkler design. Description of System: The system consists of a 1,000 sqft Ordinary Hazard Design area, surrounded by a larger (remainder of building) Light Hazard design area (these adjacent hazards are separated by full height walls that are capable of preventing a fire on one side from fusing sprinklers on the other side). Per UFC, the corresponding discharge densities should be 0.20 gpm/sqft over 2,500 sqft for the Ordinary Hazard design area, and 0.10 gpm/sqft over 1,500 sqft for the Light Hazard Design Area. In accordance with the example provided in NFPA 13 Section A11.1.2, the size of the operating area for hydraulic calculations is determined by the Occupancy of the larger surrounding area. In this case, the hydraulic calculation design area is 1,500 sqft based on the larger surrounding light hazard area. A 0.20 gpm/sqft density would be provided for the 1,000 ft2 Ordinary Hazard design area, with a 0.10 gpm/sqft density for the remaining area. Differing Opinions: The difference in opinions for this situation is about how to apply NFPA 13-2016 section 23.4.4.2.5 to this situation. NFPA 13-2016 23.4.4.2.5 Where the total design discharge from these operating sprinklers is less than the minimum required discharge determined by multiplying the required design density times the required minimum design area, an additional flow shall be added at the point of connection of the branch line to the cross main furthest from the source to increase the overall demand, not including hose stream allowance, to the minimum required discharge. Opinion #1: The required minimum design area as referenced in 23.4.4.2.5 should be the SAME design area that was utilized for the hydraulic calculations as determined by NFPA 13 Section 11.2.1. In this case the minimum design area would be 1,500 sqft. Opinion #2: Even though the remote area size was determined to be 1,500 sqft per section 11.2.1, the required minimum design area as referenced in 23.4.4.2.5 should be the minimum design area for the smaller, higher hazard area. In this case, the minimum design area should be 2,500 sqft based on the Ordinary Hazard design requirements. So if the flow from the 1,500 sqft hydraulic calculation is less than 500 gpm (2,500 sqft x 0.20 gpm/sqft), then an additional flow will need to be added to the remote area to bring the flow up to 500 gpm. Which of the opinions do you feel is appropriate for this scenario? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I am looking for opinions on the effectiveness and likelihood of a timely operation of sealed sprinklers in open spaces where they are not installed below ceilings or obstructions.
For example, operation of sprinkler under open-grate platforms, or where used as pilot heads around external transformers. Many thanks. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I'm interested in hard piping the sprinkler system drain down pipe into the 6" sewer via a closed system.
My inspector can't tell me why I can't and says I need to build a 4" stand pipe with a wet trap. This will use a lot of water throughout the years just to keep the trap wet and will only be used once a year. Why can't I hard pipe the drain into waste and avoid the air gap with a wet trap? I would welcome any comments from anyone. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I have a water treatment plant with 3 tanks, 9 feet in diameter. The fire protection contractor feels we need to install a sprinkler under each tank, following the greater than 4 wide rule for obstructed construction. The tanks are located on a concrete floor. The tanks are supported on legs, and the clearance from the bottom of the tank to the floor is about 2 feet.
Remembering that code tells us where to install sprinklers; my argument is this is not an occupiable space and sprinklers are not needed. The tanks are part of a water filter system, and not a hazardous type chemical storage. Are sprinklers required underneath these tanks? Any thoughts or input is most graciously appreciated. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe We have a 5-story building with wet manual standpipes in three stairwells. A single FDC connects to the end of a manifold in the riser room that has a 4-inch dry system, a 4-inch wet sprinkler, and a 6-inch riser that supplies the three standpipes. Each standpipe has a separate isolation valve at its stair tower. One of the standpipes is a combination standpipe/riser with sprinkler floor control valves for levels 2-5.
Regarding the 6-inch standpipe riser off of the manifold: Is a control valve required, or allowed? Is a check valve required? Is a flow switch required, or recommended? This project is under NFPA 14-2013 Edition. Thanks. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Lot line window sprinkler protection: In the design drawings I have lot line window protected with standard concealed sprinklers. This same sprinkler is used to protect the whole room on the inside. Distances to all walls are less than 7'-6". The room is light hazard, and this only occurs in a single room.
Is this acceptable or should the window be protected by one sprinkler and a separate sprinkler for the room protection? Also, is a standard pendent acceptable or would you rather have a Tyco Window Sprinkler (special application) for the window? Thanks in advance. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Many sprinkler systems in our area (I'm a fire marshal) have aboveground pipe installed by a fire sprinkler installer and the underground installed by an underground pipe contractor. NFPA 24 requires a minimum flow rate from underground pipe in order to remove rock and debris from the underground pipe.
Many of the underground contractors simply open up the pipe and wait until there's consistent clear water and/or stop hearing the rocks ping around. There's no measurements taken for the underground flushing and when I ask for them to verify the flow rate I get blank stares. Is there a way to tell just by static pressure in the area if opening up the pipe flange is enough flow to satisfy the underground flushing? Or is there a measurement I should be seeing to verify the flow rate? Thanks in advance. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe We're designing a fire sprinkler system for plastic (Group A material, unexpanded polyethylene) recycling site. We are designing only for the depot area. There are raw materials stored as solid blocks up to ...We've raw material stored as solid blocks up to 12 feet (3.6 meters).
I am thinking this should be considered rack storage under NFPA 13 Section 16.2.1.2 (2016 Edition) for Protection Criteria for Rack Storage of Class I Through Class IV Commodities Stored Up to 12-ft (3.7m) in Height. Am I wrong considering this? Note that compacted material will have a lower combustion propagation velocity than generic goods. Any ideas? Thanks in advance. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe We have a new 3,300 square foot dental facility that is single story with a basement. Is a fire sprinkler system required?
Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe NFPA 13 (2010 Edition) 21.23 Cleanrooms: 21.23.1.1 Automatic sprinklers for cleanrooms or clean zones shall be hydraulically designed for a density of .20 gpm/sqft over a design area of 3000 sqft.We have a wet pipe system utilizing quick-response sprinklers.
With an ordinary hazard density (.20 gpm/sqft) would I be allowed to use the quick-response design area reduction in Chapter 11? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I need an answer for a simple question. I am working on a large airport project expansion. I have a structure of 4 levels with 70+ sprinkler zones.
Is there an NFPA standard requirement stating that each area requires a hydraulic calculation on each system? Each system is not prototypical. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Good morning, I have a project with a 60MVA outdoor transformer. We have a deluge valve system with wet pilot trim.
Is there a standard requirement for protecting the transformer regarding k-factor, coverage area, and distances for a sprinkler/nozzle from the transformer? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I have a question that stems from NFPA 318 (Protection of Semiconductor Fabrication Facilities), Chapter 11, Section 11.1.4.2.
11.1.4.2* Automatic sprinklers for cleanrooms or clean zones shall be installed in accordance with NFPA 13, and shall be hydraulically designed for a density of 8.15 L/min·m2 (0.20 gpm/ft2) over a design area of 278.8 m2 (3000 ft2). For a clean room 11.1.4.2 mentions 0.20 gpm/sqft density over 3,000 sqft design area. We're considering quick-response standard-spray sprinkler coverage under section 11.1.4.4. The client is requiring a double-interlock pre-action system, so under NFPA 13 11.2.3.2.5 the remote area must be increased by 30% without revising the density. Can we omit the 30% increase in sprinkler operation under NFPA 13 11.2.3.2.3 since we are using quick response sprinklers? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I’m working in the construction of 4-star hotel. The water storage tank is underground made from concrete and the pump room is located above the water tank. The designer specified the fire pumps to be vertical split-case type! In order to follow code, I proposed to install vertical turbine pumps instead of the specified vertical-split case.
The supervisor Engineer is insisting to follow the specification of the fire pump and pushing me to create an underground pump room in order to install the specified pump set. Any recommendations to avoid this directive? I have a bad flooding experiences with this this type of subgrade pump rooms. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe A parking garage has multiple levels covered by a dry system.
If the floor area of each level is equal to 52,000sf, is it acceptable to protect all levels with one dry system riser? I am referencing the NFPA 13-2016 Handbook Sections 8.2 and its accompanying explanations. Thanks. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Indicating valve (Butterfly vs Gate Valve) Requirement in Fire Water Mains:
NFPA 24, Section A.3.3.17.1 (Edition 2019), suggests to use OS&Y gate valves, butterfly valves, and underground gate valves with post indicators. I understand that any type of valve are acceptable to use and I've seen frequent use of butterfly and gate valves in underground main. OS&Y requirement is quite clear. Based on my understanding, butterfly valves are less prone to corrosion and ferritic buildup when compared to gate valves due to its body design. My understand is that gate valves, due to buildup, might be prevented from closing and would require an entire systems or section of a system to do any maintenance. Yet, direct-buried gate valves are still preferred for underground mains and I'm not sure why. The cost difference does is not enough in my case to use gate valves specially for 8", 10" 14" or higher sizes. Is there some reason for gate valve preferences over butterfly valves? If a butterfly is used I could possibly see a pit being required for maintenance, but NFPA standards do not address pit requirements for a butterfly valve. Is there any other consideration would be helpful to consider when using butterfly vs gate valves, for underground or even aboveground applications? Any suggestions would be much appreciated. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Have a situation I've never crossed before: we have a very small building that's getting expanded. Originally the sprinkler contractor gave two options for the general contractor to price their underground fire sprinkler service - (1) is to provide a 2-1/2" main, the other (2) is to provide fire barriers in certain areas with automatic door closers to allow the room design method be used, and bring in a 2" underground.
I completely recognize that small underground pipe is not good practice and limits the future potential of the building. We recommended a 4-inch underground, but the increased cost for tap fees and underground pricing added $10-15,000 to the job which the owner adamantly refused. We were given notice to proceed with 2-1/2" underground and thus provided a 2-1/2" riser and 2-1/2" mains. The GC gave a different direction for the underground and pulled 2" underground and is providing fire barriers and automatic door closers. We've recalculated using the room design method and everything still works with the 2" underground, but the 2-1/2" riser and 2-1/2" main is already ordered and on the way to the jobsite. Does NFPA 13 have any restriction against having a larger riser or main size than the underground? Because of the change in building construction, we only need a 2" riser and 2" main but will instead already have prefabricated 2-1/2" in both. My thought is to have a permanent placard clearly affixed to the riser showing the situation and clearly identify on as-builts the methodology used. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe NFPA 24, Section 7.1.1.2 (2016 Edition), states that control valve shall be installed in each hydrant connection. What is the purpose of this control valve, other than facilitating maintenance? Would this be considered a "control valve" per NFPA 24 3.3.3, and does this have to be a post-indicating type valve? Common hydrant arrangement for illustration purposes. Based on my limited understanding, this control valve is just a post-indicator valve/isolation valve which is for shutoff when there is an impairment downstream. I'm trying to get a better understanding of its purpose. Thanks in advance.
Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe I have a covered mall under 30' tall that requires hose valve connections in accordance with the International Building Code, Section 905.3.3.
Do these hose valve connections count as a standpipe that requires a monitored isolation valve as per NFPA 14 6.3.2? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe |
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