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Minimum water supply required for NFPA 30 project

Minimum water supply required for NFPA 30 project

Minimum water supply required for NFPA 30 project

(OP)
So that you all know I feel I am not competent when it comes to NFPA #30 and I have hired an FPE to help with the design criteria for this project. That said I am not looking for any specific design criteria as I will probably be getting that on Friday or early next week.

What I am asking of those who do have some experience is does it look like we will have enough water given the following:

1. Water supply is 1,250 @ 100 psi fire pump from city connection. At churn we had 170 psi, 1,250 gpm @ 140 psi and 1,900 gpm @ 110 psi. Very flat curve and I recognize the 1,900 gpm is over the 150% but that is what I got.

2. Building is bent metal purlin 24'-0" eave and 31'-4" at peak.

3. Commodity stored on back to back racks without shelves sine three and some four tiers high. Looks like we can expect storage 20' high.

4. There is a list of 530 chemicals being stored and just a small representative sample is provided below:



Looks like lots of required information is missing from that list but that is what I got and this is why I hired an experienced FPE to make sure I don't step in it.

From my amateur status going over NFPA #30 it appears the pump can't deliver enough water. I am not looking for any sort of definitive answer, like I said I will have that at the end of the week, but do you tend to agree with me from what your experience tells you?

Thanks.

RE: Minimum water supply required for NFPA 30 project

I am going from pure memory and it is fading as I get older. The last I did with NFPA 30 involved was a warehouse many years ago. I am thinking it was something like 0.3/5000. So, around 1500 gpm. If you have hydrants downstream of that pump, you may be in trouble.

However, I must qualify that this is just based off of a vague memory without going through archives to search for that project.

You may be able to look at using foam/water type systems and getting your water demand a bit lower. It is wise to bring in a qualified FPE on these types of projects.

Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...

RE: Minimum water supply required for NFPA 30 project

You have insufficient information to come to a conclusion as to the required discharge density and design area. Under NFPA 30 you will need to know the container material of construction, if the containers are pressure relieving, and miscibility of the liquid. This appears to be automotive paint products.

The last major flammable liquid warehouse I did with IBCs and drum storage we ended up with a hydraulic demand of approximately 2,200 GPM. I don't see that with what you presented.

RE: Minimum water supply required for NFPA 30 project

(OP)
Thank you Travis and Stookey for the input.

I didn't expect any design criteria and I suspected all along the criteria given was woefully inadequate. There is no way on earth I would go near a project like this without an FPE to cover my rear end. I would love to do the design work as long as he tells me the criteria to meet.... that makes it a fun project and not a nightmare.

While I would never use it the research I did indicated anything I attempted would exceed 2,000 gpm so there you go.

It's a rather large complex consisting of 10 buildings fed by a single fire pump with 9 hydrants downstream the fire pump. Everything is ESFR using K16.8 sprinklers @ 42 psi (peak does not exceed 32'-0" in any of the buildings. So yes, hose stream is added downstream the fire pump.

Did the acceptance test on the pump last week and it actually performed a little better than I had calculated with suction pressure about 8 psi more than what I calculated it would be giving me a "safety factor" of 24 to 28 psi depending on the building location.


RE: Minimum water supply required for NFPA 30 project

Don't be surprised to learn that ESFR sprinklers will not work for this hazard. NFPA 30 Table 16.5.2.8 does allow ESFR but only for very small volume metal packaging and generally it needs to be cartoned unless the containers are pressure-relieving style of construction. If your FPE can't figure out pressure relieving construction I think you have my e-mail address and if not, we'll find a way to communicate through the Oracle (that's Google).

In the representative sample spreadsheet I see some products that are probably Level 3 aerosols so you also have that to contend with. Your concern factor should elevate if the amount of aerosols exceeds 500 pounds because that's when the requirements in the International Fire Code will become applicable. You should also be aware that mixing of aerosols with flammable liquids has some very specific rules. Your client needs to know this.

If you have plastic packaging welcome to the world of NFPA 30 Scheme A or Scheme B.This will require horizontal barriers and in-rack or in-rack and face sprinklers. If the building is not built you may be able to take advantage of having the architect design a drainage system over a containment structure. Hopefully your FPE has worked through this.

RE: Minimum water supply required for NFPA 30 project

(OP)
Stookey,

I am not surprised in the least as some on here have said, a countless number of times, some people think ESFR is the answer to everything when the truth is far from it.

When I wrote my proposal I made it very clear what commodities the sprinkler system would cover and what commodities wouldn't be covered.

Flammable liquid storage was first on the list of not covered items and along with flammable liquids I excluded rack storage with solid shelves or exposed expanded group A plastics.

The developer is super to work with they even let me have input as to placement of lights and even the steel. It was one of those jobs where I got to build my sprinkler and all the other trades built there work around me. This is a project I am proud of.

RE: Minimum water supply required for NFPA 30 project

Depending on the size of the containers and class of liquid, you may need to add AFfF foam if drainage is not adequate. Many folks forget to look at the required drainage in 30 which can add up $$ very quickly. Most of the protection is going with in-racks at each level and barriers at each level of storage. Do not forget to look at FM 7-29 for protection criteria, also NFPA 30 has a 2015 version, not sure if it has any additional protection over the prior year edition. NFPA did away with the line next to the new sections that have changed, which I hate!

RE: Minimum water supply required for NFPA 30 project

Just in case your FPE drives you to a foam system... It would be good if you ask for more criteria to be sure what is the best type of foam system for your case, use foam only if it is the only choice, some types of foam systems can be a pain in the a...

RE: Minimum water supply required for NFPA 30 project

(OP)
Just a quick update.

Found out FM Global is involved and their account engineers will be telling me exactly what I need to do.

Great relief, the more I dug into it the less I wanted anything to do with the design specification of the project.

RE: Minimum water supply required for NFPA 30 project

That´s good, ...or bad news? ;)

RE: Minimum water supply required for NFPA 30 project

(OP)
Very good news, now I got the easy part of the job to do.

RE: Minimum water supply required for NFPA 30 project

I agree. Many don't like when FM is involved. I love it because they spell out exactly what they want for design criteria. Then, we just have to put the dots on the screen and connect them. It takes away a lot of headache on these complex projects.

Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...

RE: Minimum water supply required for NFPA 30 project

Good to hear Travis. We try to spend a lot of time and dilligence at FM to get these projects right..the first time.

RE: Minimum water supply required for NFPA 30 project

So will you share the design they gave you?

RE: Minimum water supply required for NFPA 30 project

Stay with the information. FM has Confidential information sometimes that one may not find in the sheets.

R/
Matt

RE: Minimum water supply required for NFPA 30 project

(OP)
Travis,

We agree on the FM jobs, they are always my favorite. Looking back over the years I've never had a "bad" FM job because they're so simple to do... connect the dots.

Have yet to receive the design criteria but from what I have heard it smells like a pre-primed foam system to me.

RE: Minimum water supply required for NFPA 30 project

Can you in-rack sprinklers, my guess you will see several levels, if not on each level......thanks for sharing on the foam.

RE: Minimum water supply required for NFPA 30 project

(OP)
Right now the general concensus, by those not making the decision, is foam with rack sprinklers at every level.

I love the fact someone else making the design decisions.

RE: Minimum water supply required for NFPA 30 project

Once you stated FM, I figured it would be in-racks at every level. Possibly closely spaced and fairly high pressure. The foam may negate some of that. I would be interested in seeing the criteria when it is all said and done. I love jobs like these.

Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...

RE: Minimum water supply required for NFPA 30 project

If it's storage of ignitable liquids, Data Sheet 7-29 will have most of the details. There is a free, public version of the doc. dispensing is covered in 7-32.

Also, One of the biggest differences between IFC/NFPA and FM is the max allowable quantity concept is not followed. A 55 gal drum of acetone will either burn abuilding down (if comb. Const.) or cause major smoke damage to a high value occupancy if it's not properly protected.



RE: Minimum water supply required for NFPA 30 project

(OP)
I received the design criteria just a few minutes ago and it appears we're going to go with NFPA standards. Note that everything is foam.

Ceiling Density: 0.30 gpm/sq.ft. over 3000 sq. ft. due to drum storage OR 0.30 gpm/sq.ft. over 2000 sq.ft. based on smaller containers (<5-gal.)

In Rack Arrangement: Only at longitudinal space (center of rack), spaced no greater than 10 ft. apart, staggered vertically throughout the rack. However, if the containers are of the “relieving style”, then in-racks are only recommended on every other level.

Foam Duration: 10 minutes

Something else to note is that if you choose to go with a pre-primed foam system, NFPA allows you to reduce the ceiling areas (3000 to 2000 for drums and 2000 to 1500 for smaller containers) and allows you to calculate the demand based on 3 sprinklers per level operating for 3 levels rather than 6 per 3 levels. These together reduce the demand significantly, keeping the water demand well below what is already provided.

There is drum storage so it will be the .30/3,000 but that could be a challenge with a 1,250 gpm pump.

As I said I just now got this so what about the pre-primed foam? I think I know what is involved but I *think* it has more to do with maintanence of the pre primed system.

Welp, time to start reading up!

RE: Minimum water supply required for NFPA 30 project

Foam and in-racks what a surprise.... the pre-primed foam is hard on the pipe. Do not forget the test header to test the foam at the required sprinkler demand.
Check with the local environment folks regarding the foam discharge test, some will permit discharge onto the ground, others want it into a tanker$$$$$$. The fun begins......I always liked these jobs...bring a camera to video the test.....

RE: Minimum water supply required for NFPA 30 project

Ensure the electrical engineer has provided the required ampacity and correct number and size of conductors (and properly sized conduit) for any required foam concentrate pumps and understands these are required to comply with NEC Article 695 and NFPA 20.

RE: Minimum water supply required for NFPA 30 project

Yeah...0.3/3000 plus 3 levels of in-racks for 18 sprinklers total is going to be challenging with a 1250 gpm pump. FM used to only let you use 120% of rated capacity (vs 150% allowed by NFPA). You may need to look at some things that can help reduce your demands if they are available.

Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...

RE: Minimum water supply required for NFPA 30 project

(OP)
Travis,

The owner has elected to go with NFPA standards not FM.

With AFFF a pre-primed system doesn't appear to be any great issue and by so doing "NFPA allows you to reduce the ceiling areas (3000 to 2000 for drums and 2000 to 1500 for smaller containers) and allows you to calculate the demand based on 3 sprinklers per level operating for 3 levels rather than 6 per 3 levels. These together reduce the demand significantly, keeping the water demand well below what is already provided."

I think the table used was TABLE 16.5.2.1 Design Criteria for Sprinkler Protection of Single- and Double-Row Rack Storage of Liquids in Metal Containers, Portable Tanks, and IBCs. It appears we will need 500 gpm hose but without knowing for sure what table was used I suppose it could be 250. Good thing is with pre-primed and the reduced areas 500 vs 250 isn't going to make much of an impact.

.30/2,000 with a total of 9 in-rack sprinklers isn't bad with the 1,250 gpm pump.

What I was told by the AFFF people is pre-priming consists of filling the system when testing the proportioner through the test header and we're done.

Before the tenant came with the flammable liquids we were going to go with an K16.8 ESFR system; 2 1/2" grid with 4" mains and 6" riser. I can't find a reason we couldn't use the same pipe (Dynaflow) arrangement just change heads. Pipe size wise I am way over designed if we go that way and in the future if the tenant ever moves out converting the system to ESFR would be as easy as modifying the riser manifold and changing the heads.

This all said I am still going to oversize the tank because preliminary calculations show I need 90 psi when I have about 150 psi available and we all know what that does. I will do a demand calc and base the quantity of concentrate on that.

RE: Minimum water supply required for NFPA 30 project

I believe NFPA 16 is the foam standard. In that, you have to do a supply calc and size your foam concentrate based on the supply calc. Also, you are going to have to have your sprinklers discharge no more than 20% of required. So, if you have 30 gpm / sprinkler minimum demand, you are limited to 36 gpm on your demand calc. If you are way over-sized, you may be exceeding that requirement.

If I recall correctly, the 20% max is so that you provide a uniform foam distribution over the design area.

I design about a dozen or so foam systems every year. They are always challenging in getting that 20% limit.

On a different topic, the really fun part is when you are doing foam grate nozzles in an aircraft hangar. They are limited to 40-45 psi. It gets to be a real pain trying to balance those suckers out. I've spent DAYS trying to balance and grate nozzle system with the overhead and keeping everything within those parameters. I have found some better ways to do it, but I still remember that first one. It was a nightmare.

Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...

RE: Minimum water supply required for NFPA 30 project

(OP)
Travis,

Yep, all of that and from what I gather I'll have to incorporate a pressure reducing valve on the system which will be only the second time in 40 years I've had to do that.

http://www.chemguard.com/pdf/fire-suppression/data...

Quote:

NOTE 1:
If normal water supply pressure to actuator operating the valve is above 120 psi (8.3 bar), a water regulator (Part Number 7001) Is recommended to reduce actuator inlet pressure so that it does not exceed 120 psi (8.3 bar). Excessive water inlet pressure to the actuator can cause damage to the valve stem.

At churn I have 170 psi at the flange and spigot so there you go. Work so hard to get all the pressure I can get then this comes along.


RE: Minimum water supply required for NFPA 30 project

SprinklerDesigner2,

Note 1 in the datasheet is referring the concentrate control valve's actuator (the water motor that opens the valve automatically upon system activation, allowing foam concentrate to flow to the proportioner), not the entire system. The water regulator is a small device (likely 1/2") that sits in the normally-unpressurized supply line and prevents pressure higher than 120 psi from hitting the actuator. The rest of the system devices should be rated for a minimum of 175 psi. Confirm with Chemguard of course, but don't make a mountain out of the proverbial mole hill.




R M Arsenault Engineering Inc.
www.rmae.ca

RE: Minimum water supply required for NFPA 30 project

(OP)
skdesigner,

I wasn't sure and yes, will confirm with chemguard.

RE: Minimum water supply required for NFPA 30 project

You do understand that everything you are designing for is predicated on the container's material of construction, it's ability (or inability) to relieve pressure, and the water solubility of the liquid? Yes? You further understand I witnessed aerosols in your intial posting. Your design for that is silent. No problem, just asking.

Look, I am glad your got the gig but everything I've seen in the posts has failed to mention all the things I identified. Everyone is all excited about AFFF but I have read little about your design. It sounds good.

Just be careful. AFFF foam, like ESFR or K 25.2 are not fire protection saviors.

I am also a AHJ so I am sensitive to these issues.

RE: Minimum water supply required for NFPA 30 project

(OP)
Stockey,

Rest assured there is no way I would attempt to assign any sort of design to anything having to do with flammable liquid storage. No way, no how... not with a ten foot pole.

The owner has retained the services of an FPE and as for the design blow is a screen capture of the last email:



Large company and generally they follow Factory Mutual but in this case, it's a rather small project with the building itself only 20,000 sq ft, they decided to go with NFPA standards. The Options were sent to the owner by the FPE and the owner made the decision to follow NFPA standards. There are drums so it's a pre-primed system .30/2,000 with 3 sprinklers operating for 3 levels of in-rack sprinklers.

As Clint Eastwood said in one of his Dirty Harry movies "A man has to know his limitations" and I certainly know mine. If it was up to me the only way I would touch this project is to retain the services of an FPE and I wouldn't care how much it took money wise...

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