Dan, I'm not sure what Code Standard that building was built under but if we had a concealed space with that great of a load of combustibles, it would very likely be sprinklered.
Flooding water may cause an arc or short circuit but if the water flow was continual it would seem hard to sustain any type of fire from the electrical equipment. If the equipment is installed and maintained properly at some point the circuit protective devices should trip and de-energize the equipment automatically. Craig L. Prahl, CET Fire Protection CH2MHILL Lockwood Greene 1500 International Drive Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 CH2MHILL Extension 74102 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dan Arbel Sent: Tuesday, April 17, 2012 3:17 PM To: [email protected] Subject: RE: NFPA 25 - inspection above suspended ceiling How are ceilings above an office space considered a "most hazardous space"? Secondly, who do you figure flooding water was going to start a catastrophic fire? Please don't say because the electricity was on... Dear Craig, I assume that you run a great deal of fire investigations and none of them involved fires in the ceiling plenum and you did not came across any case of water raising fires. Therefore you find no sense in my statements. Try to sprinkle some water on energized conductors. You may imagine that Moisture might cause electrical arching. I had a couple of several $ million losses caused by moisture creating from water seeping from upper floors. Regarding plenums, the volume concentration of the fire loads to the volume of the plenum may generate very high temperature. The fire load is composed of electrical and communication cables. Fire raisers are PL Lamps and a great deal of electrical distribution boxes in above the suspended ceiling. Inspection above suspended ceiling is indeed very costly. So are water damages and fire occurring when all the detection systems and fire sprinklers are off. Dan -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, April 17, 2012 3:27 PM To: [email protected] Subject: RE: NFPA 25 - inspection above suspended ceiling >From the NFPA 25 Handbook: "Paragraph 5.2.2.3 provides an exemption from the inspection requirements for pipe and fittings in concealed spaces on the basis of two factors: 1. It is extremely costly and impractical to inspect piping in these spaces. 2. The inaccessibility of such piping means it is less likely to be damaged or otherwise affected than piping in an open space. When working in concealed spaces, however, it is a good idea to conduct an inspection of the pipe and fittings in the space." I'd be curious to see a quote for doing a visual inspection of all pipe and fittings above the ceilings in a 27 story office building. Also a couple of statements don't make sense: "...it means that as far as I'm concerned the most hazardous spaces are inspection free." "In this particular case, the water supply for the tower was completely out of action for 90 mins. The electrical supply was on. That means that the flooding water could have started a fire in any lower floor with catastrophic consequences." How are ceilings above an office space considered a "most hazardous space"? Secondly, who do you figure flooding water was going to start a catastrophic fire? Please don't say because the electricity was on... Craig L. Prahl, CET Fire Protection CH2MHILL Lockwood Greene 1500 International Drive Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 CH2MHILL Extension 74102 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dan Arbel Sent: Tuesday, April 17, 2012 6:31 AM To: [email protected] Subject: NFPA 25 - inspection above suspended ceiling Dear Forum members, I had a case of quick coupling failure in a 27 floors office tower. The bolt holding the 3" coupling endured prolong corrosion (looks like several years, that consumed 90% of the bolt section area. There was no water dripping, just egress of a very small amount of water from the joint that was enough to cause the failure, but not enough to be detected "as a spreading wet stain on the ceiling elements. It is possible to raise the ceiling element and observe the corrosion on the coupling, but the maintenance contactors do not actually observe the piping above the suspended ceiling. Referring to NFPA 25, Items 5.2.2.3: Pipe and fittings installed in concealed spaces such as above suspended ceilings shall not require inspection. A.5.2.2.3 Examples include some floor/ceiling or roof/ceiling assemblies, areas under theater stages, pipe chases and other inaccessible areas. It is stated elsewhere in the standard and the responsibility of the owner is to afford accessibility. So, non-accessible areas cannot be inspected. However, if the interpretation of the standard calls for total exemption for inspection in areas above suspended spaces, it means that as far as I'm concerned the most hazardous spaces are inspection free. In this particular case, the water supply for the tower was completely out of action for 90 mins. The electrical supply was on. That means that the flooding water could have started a fire in any lower floor with catastrophic consequences. I would appreciate any response. Dan www.riskmanage.com M: +972 (052) 6611337 T: +972 (04) 8243337 F: +972 (04) 8243278 Mail: [email protected] _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
