However, when you're using stored water for 150 minute duration, cutting the
density in half can save some serious money- like the job I was just
finalizing when this came across, and made me give pause- did I miss a
chance to lower our cost?
I was thinking of popping a bladder tank in for foam-water sprinklers till I
realized I'd need Hi-Ex- a whole 'nother thing, according to the seminar
produced by our own Forumites, the degreed Mr. Denhardt and the undegreed
Mr. Sornsin, the past two AFSA conventions. Recent pricing I got for a
similar hazard would not be cost-effective, since we'd have to cover up 25'
of commodity.  
It's never too late in the day for another cup of joe.

glc

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of
[email protected]
Sent: Monday, November 23, 2009 1:54 PM
To: [email protected]
Subject: RE: Storage of idle wooden pallets and hi-ex foam

There are many issues to consider when entertaining thoughts of using hi-ex
foam.  Make sure it's the only valid choice before committing to using it.

The reason there is no mention of foam with wood pallets is because wood
pallets are already addressed by 13 to be protected by water based
sprinklers.  Foam would not be appropriate or provide the same soaking that
water would.

There are structural issues and ventilation issues to deal with when using
hi-ex foam.  For a new install that might not be a big deal but for an
existing building the cost impact can be rather significant.

Water based sprinklers ought to be first choice unless the commodity being
protected can not be effectively protected by water and foam is recommended
by either MSDS or NFPA or other resource. 


Craig L. Prahl, CET   
Fire Protection Specialist
Mechanical Department
CH2MHILL
Lockwood Greene
1500 International Drive
PO Box 491, Spartanburg, SC  29304-0491
Direct - 864.599.4102
Fax - 864.599.8439
[email protected]
http://www.ch2m.com 


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Frans Stoop
Sent: Monday, November 23, 2009 12:50 PM
To: [email protected]
Subject: Storage of idle wooden pallets and hi-ex foam

Dear colleagues,

The 2 questions below caused some discussion in my professional environment:

For Palletized, Solid Piled, Bin Boxes, or Shelf Storage NFPA 13 - 2007
paragraph 14.6 and 15.5, both tell us:

"High Expansion Foam - Reduction to Ceiling Density.
A reduction in ceiling density to one-half that required for Class I through
Class IV commodities, idle pallets, or plastics shall be permitted without
revising the design area, but the density shall be no less than 0.15 gpm/ft2
(6.1 mm/min)."

For Rack Storage of Class I Through Class IV Commodities Stored Over 25 ft
(7.6 m) in Height paragraph 16.3.5.1 tells us:

"Where high-expansion foam systems are used for storage over 25 ft (7.6 m)
high up to and including 35 ft (10.7 m) high, they shall be used in
combination with ceiling sprinklers. The maximum submergence time for the
high-expansion foam shall be 5 minutes for Class I, Class II, or Class III
commodities and 4 minutes for Class IV commodities."

Paragraph 12.12.2.2 tells us how to protect idle plastic pallets by the
combination of hi-ex foam and sprinklers.

Nothing in section 12.12.1 about idle wooden pallets and hi-ex foam.
Questions:
- Can high stacks or rack storage of idle wooden pallets be protected by the
combination of hi-ex foam and sprinklers?
- Can of idle wooden pallets be protected by hi-ex foam without sprinklers?

My opinion is that hi-ex foam only (without
sprinklers) will not extinguish a fire in high stacks or rack storage of
idle wooden pallets, because wooden pallets contain a lot of air by
themselves and the foam will not penetrate inside the stacks. The foam will
only envelop the complete stacks but will not prevent the air
(oxygen) inside the stacks from reaching the wood.
Foam, however, may hinder the fire from jumping from one stack or rack to
another, when sprinklers do their extinguishing job.

Please share your opinion.


Frans Stoop
TOS architecture & fire protection
Netherlands <[email protected]>
Tel. +31-24-324 0112
_______________________________________________
Sprinklerforum mailing list
[email protected]
http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum

For Technical Assistance, send an email to: [email protected]

To Unsubscribe, send an email to:[email protected]
(Put the word unsubscribe in the subject field)
_______________________________________________
Sprinklerforum mailing list
[email protected]
http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum

For Technical Assistance, send an email to: [email protected]

To Unsubscribe, send an email to:[email protected]
(Put the word unsubscribe in the subject field)

_______________________________________________
Sprinklerforum mailing list
[email protected]
http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum

For Technical Assistance, send an email to: [email protected]

To Unsubscribe, send an email to:[email protected]
(Put the word unsubscribe in the subject field)

Reply via email to