Water curtain using automatic sprinklers to avoid providing opening protectives - there's a lot of confusion on this.

Exception stated under Section 705.8.2 of 2021 International Building Code (OBC) states that Opening protectives are not required where the building is equipped through an automatic sprinkler system in accordance with Section 903.1.1 and the exterior openings are protected by a water curtain using automatic sprinkler systems approved for that use.

Can we use this exception and provide a water curtain using automatic sprinklers to avoid fire rated doors in the loading dock of a building?

Is there anything else that I need to be concerned about while designing these sprinklers for the water curtain?

Need more clarity here before recommending an approach. Thanks in advance. 

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During a recent site visit, I conducted a 2-hydrant flow test with the assistance of a city engineer and the fire department.

The static pressure measured at one hydrant was 84 psi, and then I proceeded 650 feet downhill to the actual flow hydrant, where the pitot pressure was recorded as 70 psi.

A question arises due to the city's reluctance to test additional fire hydrants. My boss believes that testing more than one outlet is necessary to achieve a residual pressure drop. However, the city claims that their water distribution system is looped and, therefore, does not anticipate any pressure drop.

As a result, we are unable to calculate consistent numbers on a graph.

Additionally, we have come across information suggesting that there should be a 15 to 25% drop from static to residual pressure.

Is this a compliant approach? Should we be opening up more than one outlet on the flowing hydrant?

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How would you protect metal shelves that are inside single and double row racks? (photo below)

Our condo units are 23 years old. A recent inspection of the sprinklers had some rust on the exterior of the pipes near the sprinklers.

Can we wire brush these areas and spray with a rust inhibitor, or do we need to replace all those pipes?

Are other inspections needed to see if any rust is inside the pipes or how thick the pipe steel remains?

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If I have a machine with a carbon dioxide extinguishing system in a room equipped with an automatic sprinkler system.

Does the carbon dioxide system panel need to be tied into main fire alarm control panel?

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From a firefighting perspective, I'm looking at determining how to calculate flow and pressure needs with hose lines. 

How much water can flow through 6-inch Yellow Storz hose line? Is there a psi associated with it?

How much water can flow through 8-inch Yellow Storz hose line? Is there a psi associated with it?

Thanks in advance.

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What are the minimum number of design areas required for a new sprinkler system design?

It is based on hazard classification or system type?

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Contractor is proposing using a single head system using IFC 903.3.8 Limited Area Sprinkler Systems to satisfy the sprinkler requirement from IFC 5306.2.2 One-Hour Interior Room.

Oxygen cylinder storage at vet clinic, "120 gal" tanks, total of "1644 cu. ft.".

Section 903.3.8 only allows LH or OH1 hazards. It was originally proposed as EH1, revised to OH1 but has not substantiated with code. OH2 comes up in multiple locations (NFPA 13-19 26.11.1.1, NFPA 400 21.2.10.2).

Is there a special provision, or some other way OH1 is appropriate here?

At this point the only solution appears to be relocating the room to an exterior wall which allows a "single head for cooling", which seems to not require any specific density, or to provide a full building system with OH2 in the oxygen room.

Thanks for helping me sort this out. 

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This may sound like a strange question, but here it goes.

Is there a way to downsize a fire water storage tank based on the refill rate supplied by the city?

I know that in Houston there was a company that supplied calculations showing that the refill rate could supply the tank at a refill rate based on the flow test.

Could anyone substantiate this principle?

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Can ESFR Be Used for Extra Hazard Group 2?

ust before I saw that discussion on the forum I was confronted with a nearly finished, similar situation.

A new technical plant for manufacturing of large-diameter high voltage cables. Huge amount of PE in the next-to-outer layer, and the sprinkler designer have based the fire protection on ESFR due to ‘’all the plastics’’ and generally large ceiling heights – variation between 40 and 55 feet – and a wish for ‘’maximum flexibility’’, by using table values for UUP for the respective ceiling height.

NFPA 13 – 2019 is to be used for the design.

The manufacturing process starts with a thin single wire and ends in an obvious UUP commodity.

In my mind this is mostly a production risk to be protected with spray sprinklers and density/area calculations, or CMSA-sprinkler parameters where the ceiling height permits it, especially as most of the fire load is moving cables, without automatic stop because the alarm could be undesirable or false.

It was said that cables during production would be directed up towards the ceiling, turn and twist on large diameter wheels, and also have large horizontal stretches before they run down into the next machine that may put on a new metal screening or extruding the outer PE layer before PVC or similar outer layer. Obviously a multi-stage production that in the end makes one large cable from 3 or more smaller cables.

As I have seen in earlier discussions, the understanding of the text in chapter 23.1.1 saying ‘’ESFR sprinkler shall be permitted to protect : …. Any storage arrangement OH1, OH2, EH1, and EH2 design criteria’’ must be vital for the understanding.

I don’t feel the actual situation is a storage arrangement, but if so, what is the target for the wording design criteria?

I suspect there will be ‘’longitudinal flue spaces’’ between the cables, transvers flue spaces are not possible. Some places there will be cable(s) in conflict with the minimum 300 mm horizontal distance from a storage suppression sprinkler rule.

However, this is the first time I have been presented for a ‘’ceiling only’’ option with 1 or 2 intermediate levels ESFRs having water shields.

And (luckily !?) someone had found the FM DS 8-9 Table 17b and put in K 480 storage sprinklers in the part of the manufacturing building with the highest ceiling.

Hopefully this is not the only cable manufacturing plant in the world, and I would greatly appreciate other views on this subject.

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We have an NFPA 13 system, using residential sprinklers, in a dwelling unit that has 2-levels of smooth flat ceilings. There are two levels of ceilings (9'-0" on left, 8'-0" height on right).

​Image provided below:

Sprinklers are hydraulically calculated at their listing with a 20 x 20 spacing, and there is not an issue providing 0.10 gpm/sqft.

See the spacing above - is this an allowable arrangement though considering how it was calculated?

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I have a Business occupancy building that is being remodeled and new RTUs units are being installed.

There was a mechanical inspection done recently and the inspector is asking for duct smoke detectors on the supply-side of units under 2,000 CFM.

The units supply air to common areas to a single floor and don’t physically share ducts or plenums.

There is no smoke detector coverage since it’s a sprinklered building. We do have smoke detectors above fire alarm equipment are required.

I tried searching for an answer in IBC, IFC, and NFPA standards, but couldn’t find a definite answer.

Thanks in advance.

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Should the FDC (shown below) be connected where it is shown on the proposed riser schematic?

It is my opinion that the right portion of the image below does not show proper connection of the FDC to the risers.

Is this correct?

It appears that the FDC if used, would send pressure back against the RPZ and diminish fire flow to the risers in use.

The pressure at the street is 80 psi. Water coming in at the FDC may be 150 psi. Note the connection to a fire hydrant.

Should the FDC connect directly to the dry and wet pipe fire sprinkler risers as required by code or is the proposed riser schematic acceptable?

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A lot of office buildings and public transit depot buildings are being designed with "quiet" or "wellness" rooms for tired employees to take a break and "rest," leading a lot of AHJs to ask if these rooms are R occupancies.

The designed use is not a sleeping room and many clients "prohibit" sleeping but everyone agrees that it could be used as a sleeping room.

Typically they're size for 1-5 people and have lounge chairs (no beds) so they fall under the accessory use category to the rest of the building. For example, assume a multi-story office building where each floor has one of these rooms, less than 500 square feet, no beds just chairs, room is entirely open inside.

How would you treat these rooms and how would you address the requirements for corridors in the building assuming its a sprinklered building?

​Thanks in advance.

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So I've run into this a couple of places and I'm curious where other professionals land. You have a warehouse that has a mezzanine. Say the warehouse is 20'-0" tall and the height of the mezzanine is an even 10'-0".

You have 8'-0" of shelf storage underneath the mezzanine. You have 8'-0" of shelf storage on the mezzanine.

You are protecting under the mezzanine separately, but the mezzanine does not make up the full floor area of the entire warehouse. So there are open areas where you only have 8'-0" of storage to a taller 20'-0" building.

Does the storage over the mezzanine bring your storage up to 18'-0" or is it 8'-0" of storage?

It's 18'-0" over the floor, but 8'-0" over the floor of the mezzanine.

And there is protection beneath the mezzanine, but the storage under the mezzanine extends beyond the outline of the mezzanine. It's still only 8'-0" high, but now the ceiling height is different.

Anyway, any input or thoughts would be great. Code references always appreciated.

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What does "listed for fire protection use" actually mean?

The Department of Defense specifications Section 21 13 13 calls for backflow preventers to be "listed for fire protection use".

From what I have found, there is no such specific listing.

Has anyone else heard of this?

Thank you for your input.

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When should sprinklers be installed on CPVC systems, before or after the drop is "glued" in place?

NFPA 13, 2016 Edition, Section 8.3.1.4 "Where solvent cement is used as the pipe and fittings bonding agent, sprinklers shall not be installed in the fittings prior to the fittings being cemented in place."

From my time in the trade; about 13 years I have always seen fitters "prepping" their CPVC sprinkler drops by "gluing" the sprinkler adapter on, then tightening the sprinkler into the adapter, and then sitting the drop vertically in a bucket with the sprinkler on the top.

They say that way if any glue runs down from the joint it just goes into the drop and not down in to the sprinkler itself.

That is easy enough, but what about the Tee or Elbow that the drop is going to be glued in place into?

Personally the way I did jobs while I was a foreman is we would pre make the drops, cut in a 1/2 to a whole floor and then run back through and install the sprinklers into the drops.

Personally I liked that because I only had the sprinklers on the job the day they were getting installed, no worries about getting stolen or damaged from being on site, and then no worry about glue getting into the sprinkler at all. Plus when we went around just putting sprinklers in it was extremely fast and no hold back wrench required. And it was literally just taking that process of removing the sprinkler from the box and tightening it in to a fitting and shifting it to a different day.

Plus I have personally pulled sprinklers out of CPVC systems where the head/button was filled solid with glue.

The way I read Section 8.3.1.4, I take it as all the fittings, not just the particular fitting that the head is installed in to.

But I definitely can see how it could be interpreted as only the fitting the head is installed in.

How do you other code followers see it?

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During fire pump testing, for the churn test, should the system valve (on discharge side of course) be open or closed?

I lean towards it being open, as I would rather know the weak point during a test than during an actual fire event.

Here's my pro/con list to keeping the valve open:

Pros (keeping valve open)

• Could be required by Insurance provider/AHJ
• Discovery of weak points in system rather than a real event
• Closed valve creates in impairment, self-performing facilities risk leaving the valve closed

 
Cons (keeping it open)

• Possible over pressurization due to incorrect fire pump settings
• Older systems with compromised underground systems could increase
• If verification of fire pump is the purpose, why subject the rest of the system to churn pressure and possible water hammer if not required

Thanks in advance!

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We have a project where there is a very high corridor at a high school (45-50 feet high). There are 30-inch deep steel 'I' beams spaced at around 20-ft apart.

Should this be considered obstructed or unobstructed? 

Should deflectors be at 1"-12" below deck, or can they be lowered to maximum of 22" below deck? Do all deflectors need to be at the same elevation?

Since the beams are deeper than the deflector elevation, I'm looking at Table 8.6.5.1.2 for distances from the beam to avoid the beam with the sprinkler spray.

​Thank you in advance for your input.

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NFPA 1 and 13 exclude large storage containers of household goods such as those stacked within buildings by well-known brands.

We know the range of consumer plastics that should be expected within the containers.

The containers themselves are made entirely of wood or of fiberglass with metal frame. They are stacked one atop another, as high as possible, inside buildings of storage occupancy.

How are these hazards/commodities to be classified?

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What code or standard prescribes the location and/or number of heat / smoke / gas detectors needed for an industrial / chemical plant?

We have an open steel structure with processing equipment on most floors, which are essentially grating – no roof and no walls – containing flammable and toxic chemicals. 

We’ve planned to place some detection in strategic spots downwind of the flare (southmost) and tankfarm (same flammables) and there are some single-story buildings and other outside equipment like a cooling tower, nitrogen generation, boiler – all downwind of the tankfarm and open structure mentioned. 

So, some of all types where personnel could be in any area especially the lab/control room and electrical building mentioned above.  The modular building supplier may have those taken care of but I need to check behind them. 

The majority are outside and in the nine-story structure.  I plan to have flame and gas detectors throughout depending on the correct guidance.  Thanks in advance for your take!

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I have an existing warehouse that has a overhead pipe scheduled system from the early 80's. It is all threaded schedule 40 pipe. The system schedules from 8" at the riser to 2" at the last piece off main.

I ran a calculation and this existing system and it equates to Ordinary Hazard Group 2 at 0.20 gpm / 1,500 sqft.

The owner has installed (4) racks sections (per plan), each one separated by 12-ft. All located in one portion of the warehouse.

The fire marshal requested that they submit for a permit to confirm that the existing sprinkler system is adequate. The storage is 25-ft. (5-ft above the top of the 20-ft rack.) The ceiling is 35-ft.

The commodity is Encapsulated Group A, nonexpanded plastics on wood pallets, on open shelves with a 6" flue.

Does NFPA 13, 2019 edition, section 25.8, option 1, 2 or 3 allow me to install sprinklers only in these racks, as a stand alone design, without making modification to the overhead sprinkler system?

This may eliminate the need for the owner to upgrade the existing overhead system and install a fire pump.

Thanks in advance.

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From the perspective of a responder, any thoughts on using large diameter hose on a freestanding Storz FDC versus the old 2-1/2 inch standard two-inlet threaded fire department connection?

Thanks in advance.

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We feel very thankful and very fortunate to have input from so many of you each month. The discussions that happen here are helping lead the industry: you all rock. Cheers for another great month of "raising the tide" for us all.

Hi all - I am currently reviewing an ESFR sprinkler protection of compressed, rolled-mattresses in cartons.

During a fire, once the carton burns, the mattresses will be able to retrieve, at least partially, its initial uncompressed configuration. Considering this, I'm skeptical about it being classified as a cartoned unexpanded plastic.

It seems to me that the proper classification should be cartoned expanded plastics, as I've found nothing justifying this optimistic opinion. 

Do you have an opinion on how this should be properly classified, or how you would view it?

I'd love to hear about your point of view on the subject and choices made for similar projects.

Thanks and regards.

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