We have storage of Class I-IV commodity, in racks, with maximum distance from floor to top of storage of 12-ft with 10-ft aisles and roof deck at 25-ft.

The AHJ correctly asserts that this storage is not incidental to the occupancy and therefore cannot be considered as "miscellaneous storage".

Is there a way that these racks can be suppressed with roof-only sprinklers, preferably CMDA or CMSA?

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Is there a decision tree, or other wholistic look at what is recommended for fire protection measures for flammable and combustible liquid storage tanks?

Does flashpoint of the liquid impact which system type to pursue?

This is specifically for liquid stored in day tanks inside a tank farm, but seeking out guidance here on choosing responsible systems overall.

Thanks in advance.

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We have a small building (less than 47,000 sqft) with basement, ground floor, first floor and roof protected with a sprinkler system. Fire pump room is in the basement.

In NFPA 13-2022, Section 16.9.10.3, there is no need to install floor control valve assembly (no need for sprinkler system either, but client insisted).

I've never designed such a small system; and as a result I have a couple questions:

(1) Is one flow switch after the fire pump sufficient for all floors? If not, do I need to provide each floor with a flow switch?

(2) Is an alarm check valve assembly required? If so, can it be used instead of a waterflow switch, or do we need to install both?

Any other tips for a smaller building would be greatly appreciated. Thanks in advance.

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What is the required pressure for a manual Class III standpipe, 65 or 100 psi?

We're working on a 44'-4" high, 5-story, Type V-B construction building that has a 1-story garage and amenities. The upper floor is R-2. 

The local code says I can have Class III standpipe. As I go through NFPA 13 and NFPA 14, it circles back around to 2-1/2" outlets, except with 2-1/2" x 1-1/2" reducers and caps.

It's going to be fully-sprinklered with a combination standpipe in one stairwell, and just one standpipe riser in the other.

Does this sound correct given the project?

Thanks in advance.

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We have a project in Geelong, Australia, where the product that is bulk-stored within the building makes for an extremely dusty environment when it is unleaded.

Sprinkler protection is proposed to protect the building - but I wanted to ask the question about "excessive loading of sprinklers".

What's the best option to minimize the loading on the sprinkler?

NFPA 25 mentions this, of course, but our code in Australia does not mention this term but does state that the sprinklers need to be visually checked annually, and suggests that a more stringent maintenance routine be in place for these environments.

The bulk product is phosphate rock and it typically used for the fertilizer manufacturing plant across the road.

Any suggestions would be much appreciated.

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We have a rehab of a two story with a walk out basement where they are going to expand the basement level and make it mercantile with the two upper floors being R-2.

This is Type V-B construction and they are proposing to 1-hour horizontal to separate the mercantile from the R use. They are wanting to use the standpipes as their sprinkler risers.

My question is three-fold:
1. Can they sprinkler the entire building with 13R, or
2. Can they omit sprinklers completely in the mercantile if they separate from the R use by 1-hour (the mercantile by itself would not require sprinkler protection,
3. Can they sprinkler the mercantile with 13 and the R use 13R without a rated separation?

I am an AHJ and only wanting to require what the Code requires. I am having trouble deciphering the requirements.

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Is a fire department connection required on a new construction, 2-story, 30-ft tall, four-unit wood-framed building?

Thanks in advance.

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We're working on a one-story school. The AHJ (Fire Marshal) is requiring inside 2 1/2-inch hose valves at the exit locations.

These hose valves are fed directly off the wet sprinkler system main - not fed from a dedicated standpipe main.

1. I'm having trouble finding code regarding feeding hose valves off of the wet system main.

2. I'm trying to determine if the pipe, off the main, to these hose valves, needs a control valve installed.

Appreciate the tips and insight. 

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Are flexible couplings required at riser for vertical support?

My project has a vertical support for a 30-ft long 6-inch riser.

I used a riser clamp with two wall-mounted welded brackets to provide vertical load hanger at about 20-ft AFF.

The inspector commented that I have to provide a flexible coupling above and below within 24" of the point of attachment. His reasoning is: 18.2.3.1(6) NFPA 13 2022 edition (6) Within 24 in. above and 24 in below any intermediate points of support for a riser or other vertical pipe.

Anyone has suggestion for better way to put a vertical support at the riser?

Is one ATR hanger at the top of the riser sufficient?

Thanks in advance.

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Hello everyone. Looking to get some feedback on a building under construction.

I have a 3-story condo building with 4 stairwells, protected by an NFPA 13 sprinkler system. The condo building is exterior access via corridor which connects the stairwells and is about 20 units total.

There is a single fire sprinkler riser that enters one of the stairwells at the corner of the building and goes vertical to serve all levels. Overall, fairly typical.

Currently, the building is nearing the end of construction and they’re installing drywall.

However, a new Fire Inspector is asking for “more standpipes”, despite the fact that the building does not have standpipes, nor are standpipes required (3 stories, none below grade, and below height threshold to the top floor, etc.) The reason he is requiring them is because he is saying per NFPA 14, you cannot exceed ~200 feet in between standpipes. However, because the building does not require standpipes in the first place, this code section does not seem to make sense.

Of course, I know the AHJ is allowed to require things above and beyond the code but my big issue is that the building is about 80% complete now, and he asked for this on a typical inspection. The design criteria, FP shop drawings, civil plan, etc. were all approved by other inspectors/ AHJ / Reviewers, and has been for a couple of years.

I noticed he seems to be intermixing the word “Standpipe” and “Fire Riser” frequently which makes conversations more difficult. Just looking for some other opinions on this issue and I appreciate any input at all.

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Are pendent sprinklers required below a decorative wood slat feature along the ceiling?

Wood slats vary in height from 4" to 12" but is suspended at ceiling height (9'-0").

The area above the slats is concealed space and requires uprights. The total area percentage of slats is 42% below the concealed space.

Thanks in advance.

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Asking as an employee of an architectural design firm - we have an outdoor performance center (A-5) with a 6,000 sf performance "platform". It is not being designated as a stage (just lighting and sound above).

This outdoor platform does have a lid/ceiling up about 50-ft with walls on three sides and open to the outdoor seating area.

Would this outdoor space be exempt from sprinkler protection under building code for A-5 guidelines, or should it be treated like any overhang where products underneath might be flammable?

I believe it needs protection, but have not worked on an outdoor A-5 Assembly occupancy before.

Thanks in advance.

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When protecting underneath a continuous obstruction (example: a duct over 4-ft in width that extends through multiple different hazards), how do you space the sprinklers beneath the obstruction?

Industry standard, I would say, is to cover according to the hazard that each individual sprinkler is in.

What code reference states this?

What prevents you from spacing sprinklers underneath the duct at 15-ft throughout the length of the duct rather than switching between Light and Ordinary spacing?

From what I read, NFPA 13 states how to install sprinklers under continuous obstructions but not necessarily what spacing is required in reference to hazard.

Thanks in advance.

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NFPA 13 Density/Area Method Chapter 28.2.4.2.3 states that if the design area is smaller than the required minimum design area, you're allowed to include only the sprinklers in the available design area.

However, there's an additional provision. This provision details how to calculate the design discharge.

First, you subtract the flow from the available area from the required minimum design discharge. Then, you add this difference back into the equation. Essentially, this brings you back to the flow discharge of the required minimum design discharge.

Could someone explain this provision?

Is this calculation done to account for potentially higher flows in the main header?

What flow then determines the maximum flow for sizing a fire water tank?

I'm looking forward to your answers.

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A little late in getting out the thank you this month - but no less appreciative. Thanks to everyone on the forum for another great month of discussion and mutual help for discovering best practices.

Regards from Norway -

Modern storage and picking racks often combine small units, both bins and cartons, in flow-through for picking in the lower part, and ordinary pallet storage above. I believe this is common worldwide, but few sprinkler standards, if any, provide guidelines on vital parameters.

Case: We're dealing with ordinary open pallet racks. The commodity class is up to 3 (possibly 4). The picking height is up to 7-ft (2.0 m) based on mini wheel flow-throughs. Above that, there are 4-5 standard pallets with total net storage heights of 26-ft (8.0 m) in a building with a 39-ft (12 m) ceiling height.

It seems feasible to protect the pallets with ceiling-only sprinklers. However, there's no vertical alignment with any transverse flue spaces in the picking part. It seems logical to install a horizontal fire barrier above this area. How should we protect the lower part of the racks?

Should the ceiling sprinkler water demand be based on 26-ft (8 m) storage at a 39-ft (12 m) ceiling height, or 26-ft (8 m) at a 33-ft (10 m) ceiling height, measured from the top of the in-racks for the picking area?

I hope someone has a view on this matter. A not-yet-finalized version of EN 12845-1 has some parameters for systematically constructed automatic small unit storage, but my actual case is for manual operation and is not specifically systematic for the small units area in only a couple of the racks.

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I'm reviewing a stadium project. The maximum available open vertical distance from WC stalls to the ceiling is 11.8-inches (300mm).

According to NFPA 13, table 10.2.7.2.2 (2019 Edition), the horizontal distance allowed from stall to sprinkler is 14.8-inches to 17.7-inches (375mm to 450mm). The width of the WC cubicle is 33.5-inches (850mm), so sprinklers must be provided in each cubicle.

This will result in many sprinklers in a wet area that has non-combustible or limited combustibility materials. Therefore, I've suggested sealing the cubicles up to the ceiling to create small WC rooms less than 55 sqft (5.1 sqm) to eliminate sprinklers. To my knowledge, there are no references that support this option for such an occupancy.

Is my suggestion to omit sprinklers in these small compartments consistent with the spirit of NFPA 13?

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What is the proper method for protection of high-piled storage of consumer packaged alcohol with an ABV greater than 20% when stored on racks?

Rack storage will be 30-ft maximum height.

I'm assuming plastic and glass containers within cartons.

There seems to be a scope gap between NFPA 13 and NFPA 30 here, just wondering what protection methods others might have used.

Thanks in advance.

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We have a project fitting a backflow preventer (Watts 757) where none previously existed.

Due to the tight space available, we would be cutting an existing pipe, and providing an elbow in order to gain some working space, and installing new pipe after the DCVA to an existing pipe end that currently has a grooved cap in place.

Where we cut the pipe, I am anticipating welding a flange to the cut pipe to attach the new elbow with a grooved/flange adapter. The other pipe end created by the cut will require a cap.

What is the best way to seal off this resultant stub?

Is a welded flange the best way to attach to the existing pipe?

Client wants us to install a fire sprinkler system that is not connected to an automatic water supply.

This is a small marina located on a large body of water that could eventually serve as an automatic water supply, but not in the immediate future. This marina is about 4,000 sqft and I would like to provide an OH2 pipe schedule system that would clearly be identified in the contract documents and drawings that the system is not connected to an automatic water supply and therefore is not considered to be in accordance with NFPA requirements until connected to an automatic water supply or other means is provided and found acceptable to the AHJ.

The end goal here is to install a system that eventually will be tied into an automatic water supply.

Any thoughts? Good...Bad...Indifferent?

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I got asked a weird question about NFPA 13 requiring sprinklers to be readily accessible.

A co-worker told me they didn't believe some sprinklers that would installed in a mechanical room we're designing would be easily accessible post-construction and asked if there were any kind of access requirements.

I can't think of anything in NFPA 13 that would require every head be easily accessible in the same way that NFPA 72 requires certain fire alarm components to be readily accessible.

Is there a requirement that sprinklers be accessible?

Where does this stem from?

Thanks in advance.

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Ok, everyone, I've gotten myself really mixed up today. This is like one of those times where you're asking yourself "is this really how 'the' is spelled?"

This is for design intent calculations only.

When you do your friction loss calcs on an extra hazard group 2, a 0.40 gpm/2,500 sqft, are you using the total flow demand minus hose connection?

As an example, if I need to run 375 ft of pipe and I know that my most remote sprinkler requires 40 gpm (remember, this is only for design intent!) I am typically multiplying my distance by 1000 gpm for worst case scenario. The sprinkler contractors will do the detailed steps back to the nodes and mains.

Hopefully I can right myself back up. Just one of those weird times. Thanks in advance.

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