ESFR and how would you approach this? 1

[SprinklerDesigner2]

Sorry for the quality photo but it's from an older cell phone.

Like most here whenever I enter a building I am always looking up and I am convinced this is wrong unless a professional engineer signed off on it which I find hard to believe they would do.

Those bar joists are at least 30" deep placing the element nearly 40" from the ceiling and I don't see the conduit trapping any heat to make the head activate.

On the ESFR systems I have done so far I have always been able to talk to the people in charge getting them to make minor moves such as place large conduit, duct or other obstruction mid point between two heads or lines.

Is this right? What would be the best way to handle it if not? The only sprinkler more misused than a standard sidewall has to be the ESFR.

 

[cdafd]

Hard call

But on the heads at the deck,,, where are the next ones, on each side,, on that line???

 

[SprinklerDesigner2]

cdafd,

The heads at the deck are spaced normally at what appears to be 10'x10'.

The line under the conduits as separate running perpendicular to the lines at the deck.

I remember a few years ago attending a continuing education class Ken Isman with the NFSA pointed out that unlike normal heads you could not employ baffles or any such think in the event heads are to close together. Consider a bay formed by beams or rigid metal frames greater than 20' but less than 24' if the ceiling is > 30' it's impossible to successfully lay out an ESFR system.

Here you got heads at the deck approximately 3' on one side of the lower head and 7' from the other.

 

[Sdpaddler50]

SD2,

I will give you my .02, but I am still a bit fuzzy about what I am seeing in the pics, so I have a few assumptions in my response.

I like your comment about avoiding obstructions moved during the design phase. I do the same thing, and it can be a major pain to make it happen. All of the subs have to play nice and follow the rules. I wrote an article in SFPE magazine about project management of ESFR systems if anyone wants it, ping me, and I will send a link to you. It is over 10 years old, but still relevent.

As you probably know, the ESFR head was developed by FM in the early 80's. Their installation/obstruction rules are the most stringent. The first FM standard for ESFR was Data Sheet 2-2, but these are now in 2-0. Testing at FM has shown that just one obstructed head, over a flue, in a high rack full of plastics is enough to lose control of the fire, ie, no suppression. Obstructions, lack of flue spaces, and improper use of ESFR heads for things like flammable liquids is a major problem in the fire protection community, and I have to clean up after a lot of people who did not apply it properly.

In cases where conduit is added after the fact, I have had to employ the exact same method as shown above. Let’s say that 3 ft wide conduit is directly below the ESFR head at the ceiling (not sure from pic, but that is my assumption). Those heads above the conduit, directly under the roof are now worthless. Their spray pattern is now severely obstructed, and cold soldering will likely occur when the water from the inner core discharge hits the conduit, and then sprays back up to cool the adjacent heads. Running a line of ESFR heads (same diameter pipe as the ceiling heads) is the best fix per FM Data Sheet 2-0.

In the old 2-2, you had to install a heat collection baffle under the conduit as you note. That is no longer the case in 2-0. You can therefore run the line of ESFR heads directly under the conduit, w/o a baffle, but you will need spacing on 4 ft. What the heck, 4 ft spacing? The answer: The radiant heat (and fire plume updraft) from a high rack storage fire will activate the QR heads, even on 4 ft spacing. This has been proven by fire testing at FM. The heads above the conduit, that are severely obstructed, are out of the equation – ie, they don’t exist anymore from a practical standpoint.

Here are some excerpts from FM 2-0, 2 2 3 5 2: Refer to the diagrams for a better illustration.

(a) For flat, continuous, solid objects up to 4 ft (1.2 m) wide, install a single line of ceiling-level sprinklers
centered under the object on a maximum linear spacing of 8 ft (2.4 m) fed by the same branchline
pipe size used at ceiling-level. See Figure 39 for a diagram of this arrangement.

(d) For non-flat, non-continuous, or non-solid objects, install a flat, continuous, solid barrier of equal width
under the object and install sprinklers as recommended in options (a), (b), or (c) depending on the width
of the object. See Figure 40 for a diagram of this arrangement.

(e) As an alternative to option (d), install quick-response ceiling-level sprinklers under the object on a maximum 4 ft (1.2 m) linear spacing and a maximum 16 ft2 (1.5 m2) area spacing fed by the same branchline pipe size used at
ceiling-level. Maintain a minimum 3 ft (0.9 m) vertical distance between the sprinkler deflector and the top of storage. See Figure 41 for a diagram of this arrangement.

(f) As an alternative to options (a) through (e) when protecting rack storage, install ceiling-level sprinklers
at the top of the storage rack at all flue space intersections (face and longitudinal) that are affected
in a Plan View by the obstructing object; feed these sprinklers using the same branchline pipe size used
at ceiling-level. Limit the height of storage above these sprinklers to 5 ft (1.5 m) maximum. See Figure
42 for a diagram of this arrangement.

Options (e) and (f) negate the need for a flat, continuous, solid barrier under the obstructing object. Option
(f) can also be implemented when a minimum 3 ft (0.9 m) clearance cannot be maintained between the
deflectors of the additional sprinklers and the top of storage.

 

[Sdpaddler50]

Regarding NFPA 13, I realize there are some conflicts with FM Data Sheet 2-0. (And I have a feeling CDA is going to hit me with a lot of code references in the next few minutes proving that point .

Again, my assumption is the conduit is directly under the head at the ceiling (3 ft wide conduit run, blocking the spray pattern). NFPA says:

8.12.5.3.1 General Continuous Obstructions. Sprinklers shall be arranged with respect to obstructions in accordance with one of the following:

Sprinklers shall be installed below continuous obstructions, or they shall be arranged to comply with Table 8.12.5.1.1 for horizontal obstructions entirely below the elevation of sprinklers that restrict sprinkler discharge pattern for two or more adjacent sprinklers such as ducts, lights, pipes, and conveyors.

Additional sprinklers shall not be required where the obstruction is 2 in. (51 mm) or less in width and is located a minimum of 2 ft (0.6 m) below the elevation of the sprinkler deflector or is positioned a minimum of 1 ft (0.3 m) horizontally from the sprinkler.

Additional sprinklers shall not be required where the obstruction is 1 ft (0.3 m) or less in width and located a minimum of 1 ft (0.3 m) horizontally from the sprinkler.

Additional sprinklers shall not be required where the obstruction is 2 ft (0.6 m) or less in width and located a minimum of 2 ft (0.6 m) horizontally from the sprinkler.

So, the 3 ft wide conduit tray is an obstruction in the eyes of the 13 committee as well.

Adding a horizontal barrier, and then running heads under on 8 ft spacing, and down the middle of that obstruction is the best course. You would satisfy FM, and NFPA.

Using the 4 ft ESFR spacing, w/o a barrier will conflict with the following, so unless the AHJ will do an alternate means and method, and accept the FM criteria, it wont fly. The ironic thing is, the 13 standard generally lags behind the FM guideline by a few years, so it will likely be in there eventually.
8.12.2.3 Minimum Protection Area of Coverage. The minimum allowable protection area of coverage for a sprinkler (As) shall not be less than 64 ft2 (6 m2).

Ok, I need to go back to work.

 

[cdafd]

No paddler


You said a text full nothing to add

 

[LCREP]

SD50 you nailed it, job well done! FM Data Sheets is always the place to go first when you see this stuff.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!
Interested in “Hands On” Fire Protection Seminars with live fires visit

http://www.chubb.com/lcu

for information.