ESFR - Anyone ever seen a Foam Water ESFR system?

[Ratrod54]

This question has come up several times and it is now been proposed on a project I am dealing with. I would have said this isn't going to work initially but I thought for conversation sake, I would look it up. I have searched the NFPA standards and do not see anywhere that it is not allowed. I cant even google the topic and find info. Just curious to know thoughts and see what info you all may have. Maybe someone can direct me...

 

[skdesigner]

NFPA 13 2010 8.4.6.1 ESFR Sprinklers shall be used only in wet pipe systems unless specifically listed for use in dry systems.

 

[Ratrod54]

well that was quick... I dont know how I missed that. I have been dealing with 30 and 30B. hadnt gone back to 13. thank you !

 

[Ratrod54]

wait... it says wet pipe only, in comparison to not a dry system... Foam water is a wet pipe system.

 

[skdesigner]

NFPA 13 2010 3.4.10 Wet Pipe Sprinkler System (definition):

A Sprinkler system employing automatic sprinklers attached to a piping system containing WATER and connected to a WATER supply so that water discharges immediately from sprinklers opened by heat from a fire.

What specific hazard are you trying to protect?

 

[Ratrod54]

May I ask for conversations sake... Foam-water... Is this not water? Essentially it's 97% water in the solution. I ask only because I don't find a section that says foam water cannot be considered water for purposes of a wet pipe system.

My scenario considers the storage of aerosols in racks and on the floor as well as flammable liquids in the same warehouse in racks and on the floor. Some within our company like to see foam water for the protection of flammable liquids, even considering the limitation is has for 3D fires. ESFR has good options for aerosols in racks and NFPA 30, 2012 has options for ESFR protection for flammable liquids in racks, both the same for floor storage. I am limited to what I can do with the commodity storage so I am now dealing with this as an option. Some have spoken up and said That "can't" be done. Others say it can just hasn't been and it serves a purpose for protection of both commodities. Densities have not been adjusted nor has the design area. So I guess I am looking for a few things. Someone to point out where it says it can't be done, someone who says they have seen it and possibly someone who may be aware of testing indicating good or poor results.

That's said, I am aware of other requirements for aerosols ie segregations by Chaim link, fire walls, etc...I am mostly interested in the ESFR scenario.

I am open to any feedback and even criticism. Just looking for some discussion.

 

[FFP1]

Very interesting........first thought would be "How much foaming agent would be required for an ESFR foam-water system?" WOW

The combination would probably be VERY effective in an actual fire incident. I also want to see the initial acceptance test on video (if this system is every designed, approved and installed of course).

My suggestion would be to contact FM Global Research and ask them the direct question. Please post any documantation and/or response from FM Global Research for the blog readers.

 

[LCREP]

You do not provide enough detail on what you trying to protect to even guess if it will work. Are they 55 gallon drums, flash point, type of racks, single double row, etc. etc. etc. BUT unless FM or NFPA has a published a standard OR you run a full scale test it is unlikely the AHJ will accept the design. I would have a concern the initial flammable liquids fire would open too many ESFR heads and quickly deplete the water supply. If you take a look at the NFPA 30 2008 you will note even with AFFF the densities are not much less. As other have said if you get an answer let us know.

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[FFP1]

I re-read my post after reading LCREP post. Maybe I should clarify my comments.......I meant this comnbination would probably be VERY effective against fire incidents in general. ESFR systems and significant volumes of "flammable" liquids are generally a VERY bad combination...........too many sprinklers open in the early stages and the system is rendered essentially useless due to the number of open sprinklers and limited water supply. I seriously doubt FM Global (Data Sheets or Research Division) will ever approve ESFR for significant volumes of "flammable" liquids; however, I am interested in the possibility of ESFR/foam combination for other potential occupancies.......talk about likelihood of suppression!

 

[Ratrod54]

I agree... the AHJ will probably not approve unless there is somethign that can be provided. I have never seen an ESFR foam-water system and I would also agree it would not be the most efficient. Heavy foam requirement for 15 minutes and lots of water. I was a little shocked as NFPA 30 2012 edition has ESFR tables. I dont recall that before but it may have been there.

Details...

Level III aerosols in 16 oz cans, cartoned.
Class IB flammable liquids in 16 oz cans cartoned.
Class II liquids in 16 oz cans
Class IIIB in 1 gal, 5 gal and 55 gal drums.

Floor storage to 12ft.
Rack storage to 16ft
Building to 25ft.

Split is ~60/40 aerosols/flammable liquids.

Floor storage of flammable liquids seeems to be driving the ceiling densities.

I can provide more detail if needed. Again, I am interested in the conversation. I plan to call FM Global Research today.

 

[TravisMack]

Isn't foam used typically for "pooling" fires? Or in areas where it is expected to have a large number of sprinklers opening? As such, I would think that typical ESFR criteria (4 hds x 3 lines) would not be adequate for something like that. I doubt that anyone has done full scale fire testing for that scenario. However, I think if you could account for the larger design area typically required in fires of the nature you describe, the ESFR/Foam could be an effective option.

But, I can't imagine the foam costs. Just increasing the design area by 50% (6 hds x 3 lines) at typical ESFR design pressures (k14 @ 50 psi) gets you to almost 1800 gpm of foam water solution. At 3% foam, that would be 810 gallons of foam concentrate for 15 minutes. I can't imagine the costs on that. Then, if the design area is to be increased more, the costs just escalate from there.

Another thing though, is that ESFR is not the panacea for all storage conditions. ESFR is very good for what it is listed for, but I have heard it fails miserably when you take it outside of what it is listed for. Also, ESFR is very sensitive to obstructions to pattern discharge. Also, what impact, if any, will the foam solution have on the water droplet size. I believe part of what makes ESFR so effective is the larger water droplet sizes as well. So, while this sounds like a fun mental exercise, I think you will come back to standard spray heads and foam being the more effective scenario.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Ratrod54]

@TravisMack - I agree 100%. What has happened is there was a request for options. Densities have been recommended as if there were no foam-water to provide accurate densities for rack storage and 3D fires. basically, the foam-water is to address the possibility of pool fires. The thought was that if the pool fire is extinguished but not rack there was enough density for storage arangement. Foam costs woul dbe high but I have seen numerous systems with 600-800 gallons of foam in my line of work.

Foam-water ESFR, not so much as you would imagine.

I am to a point where I believe the only trip up of something like this would be the AHJ not approving it.

 

[stookeyfpe]

The ESFR design criteria your seeing in NFPA 30 is based on a series of fire tests that were performed at FM about 2 years ago. Note that they have very specific limitations and conditions.

Travis's words need repeating: ESFR is not the panacea of fire protection. You are dealing with highly challenging commodities and the design of the sprinkler system is influenced by several variables that are normally not considered for other commodities.

 

[chillylulu]

OK, if you are brainstorming:

How about a combination of ESFR and high expansion foam generators? ESFRs provide the quick response and massive amount of water, and the generators provide the blanket of foam to combat the floating combustible liquids.

810 gallons is not much foam. Hangers we have designed have over 100,000 gallons of foam. We burn through thousands of gallons of foam when testing deluge systems. Airplanes are more valuable than most stored products, though. The system I mentioned has a 30" supply.

ESFR's are designed to extinguish the fire, most others are just control mode.

I would also be concerned with the containment requirements of combustible liquids with ESFR heads.

 

[LCREP]

Radrod54,

Do you have a web site with info on the ESFR for flammable liquid protection details? I see NFPA 30 2012 is not out until October.

Thanks

Tom

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[Ratrod54]

We use the NFPA subscription service...2012 Standard was released June 20th I believe. It's available online in PDF form now.

 

[LCREP]

Ratrod54,

Thanks I was looking at NFPA 30 not 30B, now I see the 2011 ED.

Does anyone know if in the 2012 ed of 30 if they have added any new warehouse sprinkler protection designs for liquid storage?

Tom

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Fire Sprinklers Save Firefighters’ Lives Too!