Would it be permitted by code to place a pre-action valve on top of a roof of a two-story building?

It would be protected from mechanical damage, and there's no regular man movement at the roof. The roof area is warm, but there would be no covering as it currently stands. I'm looking for code requirements pertaining to this situation that would allow or disallow such an arrangement.

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What is the residual pressure and flow require for both public and private fire hydrants?

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At what point does it become better to buy a plotter for the office? I'm a design outfit and only rarely send out drawings, but when I do they're pricey and I just bill it to the client out of a local print shop or the neighborhood Office Depot.

Any tips on what you made the decision to buy or not buy a plotter for your office, and any advice on models or brands to look into?

​Just curious, love the commentary on here and the wide range of opinions. Thanks in advance.

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We are working on an 8-unit, 4-story apartment building in the City of Chicago. It's an NFPA 13R system, with two units on each floor level. The entire building (all floor levels combined) is about 14,000 sqft.

Are floor-level control valves required?

Under NFPA 13R there doesn't appear to be a requirement for floor-level control valves like there is in an NFPA 13 system (NFPA 13-2016 8.2.4.3). Even still, in NFPA 13 still allows a single control valve and flow switch when the entire building is less than the system limits of 8.2.1 (52,000 sqft for a Light Hazard system). 

Chicago has a Chicago Fire Prevention Code that requires "each floor and level of a building" with a separate control valve (15-16-400), but this and several other sections within the Fire Prevention Code apply only to NFPA 13 systems, not 13R systems.

Might be a shot in the dark but was curious if anyone has ran into this before. Thanks in advance.

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Working on an elementary school fire sprinkler retrofit with an old kiln. I don't have any specific product information on the kiln itself. It's in a room thats about 8-ft x 8-ft with gypsum walls and acoustical ceiling tile.

What is an appropriate sprinkler temperature to use at the ceiling level?

Hoping someone has worked with a room like this before and might know expected ceiling temperatures when the kiln is in operation. Thanks in advance.

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See this link for garage storage units on a project we're working on: https://www.wirecrafters.com/products/storage-lockers/garage-storage/ .

These are intended to be used for an enclosed parking structure in a mid-rise multi-family rental building.  As indicated in the photos (and photos from similar manufacturers) there are no sprinklers underneath the cages.

Will sprinkler heads be required?

Would appreciate code verbiage as well. We hope to not have to install sprinklers underneath due to cost reasons.

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An existing F1 occupancy with no high-piled storage is getting an addition, resulting in the total square footage for the entire F-1 area (all open) being over 50,000 ft sq, thus requiring smoke and heat vents per the 2012 IBC and IFC.

The question was asked if smoke and heat vents can just be added to the new addition and install a draft curtain to separate the existing from new, so smoke and heat vents will not be required in the existing space.

My question is, would a draft curtain be sufficient for creating a divided area in this regard?

There is no true definition of a divided area in either the building or fire codes. I wouldn’t think it would necessarily need to have a fire barrier or partition. I would assume a properly sized trap curtain would be sufficient?

Does anybody have any experience with this unique type of issue, or have any comments or suggestions?

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Is sprinkler protection required for laundry rooms with electric dryers? 

This project is in New York City specifically. Thanks in advance.

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About Pressure Reducing Valves for high pressure water supplies - I understand these need to be "indicating".

How can a PRV be an indicating type? What should I be looking for in inspections?

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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?

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The Leaderboard lists the top total scores for the most recent three weekly exams for PE Prep Series participants. 
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Want to join in? It's not too late - the PE Prep Series is the ultimate PE Prep tool. It's a series of 1-hour, 10-question simulated PE Exams offered weekly with solutions immediately following each exam. Learn more here. ​​​​Every week of the series is retroactive so you can still test yourself with past week exams.

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.

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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.

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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?

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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. 

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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?

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Week 9 Correction: A question from Week 9 (Question 1) referred to the formula for the mean velocity of a fire plum with a coefficient of 0.77, which matches FPH but not the new NCEES Handbook.

This formula should be 1.03 as identified in NCEES 3.4.7. Updates are in the 2020 PE Prep Guide Errata as well, which is explained in full here: www.meyerfire.com/errata. Solutions where updated for Week 9, so those who took the exam later in the week may have already seen the corrected feedback showing a coefficient of 1.03.

Visit www.meyerfire.com/errata for more information.

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.

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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.

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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.

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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.

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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.

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