Does a trash chute sprinkler riser have to have its own control valve and flow switch?

I've only seen ones with a control valve (ball valve) only.

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I have a project with Miscellaneous Storage of Class I commodities up to 12'-0" and Group A plastics up to 5'-0".

The water supply is a tank fed from a well. Based on NFPA 13-2016 Table 13.2.1, I designed to Ordinary Hazard Group 2 with a 90 minute duration of available water. My original demand was 57 psi at 385 gpm.

Our pump supplier provided a vertical in-line pump rated to 80 psi  400 gpm. The client is now unhappy about the volume of water being required so they are removing the Group A plastics from their building so we can calculate to OH I with the new demand being 41.5 psi at 304 gpm.

We have already installed most of the system and the pump is ready to be delivered soon.

Is it okay to have an oversized pump?

Can it be limited to a smaller flow to accommodate the new demand?

​My worry is that it will flow at the rated capacity and if we are sizing our tanks 10,000 gallons less than originally planned we would run out of water.

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We have a building with an Extra Hazard Group 1 in a fairly rural location. We have an Electric, Diesel and Jockey (electric) pump system.

We had our diesel go out, sent away for repairs. What are the requirements for just having just electric in place?

My concern is is the fire department cuts power if they come on site for industrial fire, or lose power due to weather, then we would have no suppression in service.

The fire department can provide 1,500 gpm at 100 psi from a Type 1 engine through the FDC, (so 750 gallons). We have a pond to draft from.

What would be the considerations? Amount of water available? 

In the event of power loss, the size of the FDC versus the size of the riser (a 6-8" dry pipe valve)?

What would realistic attack line demand be for a hydrant/hose line? Can you think of anything else I'm not thinking of?

Thanks in advance for the help!

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Is there a minimum clearance requirement in NFPA 13 between structural steel and steel sprinkler pipe?

Area is not subject to earthquakes and the structural engineer want to strap the pipe directly to the steel like CPVC is strapped to wood.

I've always been of the understanding that steel pipe must be hung, strapped to Unistrut attached to the structure, or supported on a trapeze, but I can't find where in 13 (if it exists) that says I can't use a strap.

​Obviously the fittings/couplings will prevent the pipe itself from contacting the steel. Trying to get the pipes as tight as possible to the sloped structural members and even using 1-5/8" unistrut with pipe clamps is getting pushback.

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Can a flow meter be installed in test header piping?

This is the first time I've ever seen this installation. Thanks.

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I am in the process of designing a fire protection system for a whiskey distillery (making of, bottling, shipping & receiving). This project is a full blown distillery with fermenting tanks, barrel filling room, barrel storage etc.

I've looked at NFPA 13 & NFPA 30 as well as some FM Global Data Sheets (7-29 & 7-74) and cannot locate the correct hazard and commodity class to use. I have high piled storage and the storage of flammable liquids.

What is the appropriate commodity classification and hazard to use for whiskey barrel storage?

Maybe I'm in information overload at this point and looking to deep into it. Any suggestions or advice would be greatly appreciated!
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We have a private water main feeding a combined domestic and NFPA 13 system that was specified as C900. They installed SDR21 (6") instead.

They are using the argument that this 200 psi rated pipe will not be subject to the fire system pressure and therefore is ok.

I cannot find where this is listed for fire service mains. Any direction?

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Is there a specific location requirement for a fire pump test header?

NFPA 20 states that the header must be installed on the exterior wall, and outside the fire pump room.

Does this mean that the test header cannot be installed in the fire pump room?

Additionally, can the test header be directly connected to the pump discharge flange as shown in this photo?

I have never seen this type of installation before. Thanks in advance.

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For NFPA 13D systems which are "multipurpose" or "flow-through" combination sprinkler and domestic systems, it has been troubling me as a fire code official not knowing the maximum length that a dead-end or arm-over section of pipe can be in order to be deemed safe from contaminating the potable water in a home.

NFPA doesn't seem to weigh in on this, that I know of.

What is the maximum length for a dead-end or arm-over section of pipe in a combined sprinkler/domestic system?

I've been searching for studies, contacting other AHJs, asking plumbers; but no one can give a definitive answer.

From what I understand, there are no documented cases of illness from residential sprinkler systems, but I would rather not rely on this as a way to measure safety. I've seen a few sources say (and show) that water only circulates into the dead end at 1.5 x the diameter of the pipe going across. So if water isn't circulating, it seems like there's a risk for contamination.

If contamination is not a risk for whatever reason, why have any maximum at all?

I would love to get to the bottom of this and I look forward to hearing from others who have a deeper understanding. Thank you.

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We are working on a new electric car factory. Under the 2018 IBC, it's classified as an F-2 occupancy. Earlier we had provided ESFR sprinklers in these buildings.

Since there is no specific requirement for smoke removal for an F-2 occupancy, we want to provide standard response or quick response sprinklers instead of ESFR, by classifying parts of the building as Ordinary Hazard Group 2 (OH2) in NFPA 13.

Is this reasonable for all areas? Production areas?

Would an OH2 classified space require smoke removal?

Thanks in advance.

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For draft curtains in a warehouse protected by ESFR sprinklers, is there an NFPA standard directing us on the need to fill the gap that occurs between the top of the draft curtain and the underside of the roof deck?

Traditionally I have seen this gap stuffed with mineral wool. If there is an NFPA code reference, though, please share so I can make sure we're going about this correctly.

Thanks in advance.

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I'm working on an apartment that is surrounded by a manufacturing facility. The Fire Marshal is calling it NFPA 13R. 

Can I use the new incoming water for domestic for fire as well, like in an NFPA 13D system?

The manufacturing facility has its own system, but is attached to the apartment. Any information would be greatly appreciated.

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Is there a threshold of percentage-opening that would allow sprinklers to be omitted below a grill or something similar - like a metal grated catwalk?

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Is there any adopted or proposed sprinkler design criteria for Electric Vehicle charging stations that will be included in new parking garages?

The 2022 Edition of NFPA 13 is increasing the design for parking garages from Ordinary Hazard Group I to Group II, but I have not found anything about protecting the charging stations.

Thanks in advance.

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When is a fire pump pressure relief valve required?

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Quick note of thanks to the Top Contributors for January 2024; it's been a great start to the year.

We have a case where two (2) x 2,000 gpm existing electric fire pumps (primary duty pumps) are available.

Now, the system design demand is increasing from 4,000 gpm to 12,000 gpm due to a scope change, so we are bringing in new electric fire pumps (as primary/duty) to meet the higher demand.

All new fire pumps could be either four (4) x 2,000 gpm or two (2) x 4,000 gpm towards meeting the 12,000 gpm system capacity.

All performance test curves are checked for all existing fire pumps; they are almost new and meeting the required residual pressure at 2,000 gpm and their performance is close to matching the original equipment manufacturer curves; so these existing pumps need to be retained.

Now we do have space constraints, so we'd like to use the two (2) x 4,000 gpm pumps, and their pressure characteristics would be the same as the existing pumps.

Would NFPA 13/20 (and any other relevant NFPA standard here) permit two different pump capacities for the system?

Would having different pump capacities be concerning, or cause issues? Is there anything else we should be considering here regarding the capacities?

Thanks in advance.

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I have a unique quandary that I haven't run into before. We have an overperforming fire pump.

It was factory tested, we have a factory performance curve of 68 psi churn, 52 psi at 500 gpm (100%), and 35 psi at 750 gpm (150%).

Once it was field installed, we were 1-3 psi over on Churn, 50%, and 100%, but +10 psi on the 150%. We had a net pressure of 45 psi at the 150% test when, based on the factory curve, the net should have been 35 psi. 

We checked the nameplate for the match, nameplate for the expected pressure at 150%; they all match. The supply for the test in the field got pretty low (about 25 psi suction at 150% flow). 

The only unique thing I can see about this setup is that we have a very tight room and had to meet a military spec to flow through the flowmeter and both run outside as well as back to the recirculation. As a result, the path from the pump discharge to the outside has to navigate through nine (9) elbows in order to get enough clearance upstream and downstream for the flowmeter in this very tiny pump room.

Could a test header with that many bends be affecting the net pressure on the 150% test? 

Is this considered a failure?

As this is military, it'll be by the book and I'm concerned that an overperforming pump might set up future tests for failure if I can't identify why it would be overperforming at the 150%. 

Thanks in advance!

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We have a new construction building that's wood frame (Type III-B), and we have an 8-inch horizontal standpipe. It's hung from wooden trapeze (two 2x4's) spanning wood floor trusses.

Per NFPA 13-2019 Section 17.1.7.1, hangers and their components shall be ferrous metal.

Is a ferrous metal trapeze (steel angle or pipe span) permitted to span wood floor trusses?

If so, must the trapeze avoid attaching to the web components of the truss?

Thanks in advance.

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Would a dry fire suppression system be affected by freezing temperatures?

I work at a facility that had a glass sprinkler break, no contact or anything, and of course the water came out as it should.

We've had freezing temps for the last few days, but where it broke was in an 74 degree room, so not frozen.

Any ideas on why this would have happened?

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