Dears friends Craig, Travis, Kurt & Todd, Many thanks for your detailed answer, your answers were very helpful,. I will use the sprinkler piping for my fire hoses to save some pipe, after calculation, the water velocity in piping is about 20 ft/s and the capacity of sprinkler piping in each floor is 1030 gallons, so it seems that each floors needs 2 dry pipe systems (As NFPA limits the volume of a dry pipe system to 750 gallons). ***I know that this 750 gallons limit may be exceeded if the maximum water delivery time is less than 60 seconds, I will use accelerators to speed the operation of dry pipe systems, but I don't think even the accelerators can reduce it to 60 seconds because the system is large, what do you think? Do I have to use 2 dry pipe systems for each floor? Is there any solution to use only 1 dry pipe system for each floor as I want to be economical? Even if I don't connect fire hoses to sprinkler piping, the system is large enough and it doesn't help that much, any ideas? *** Another question is that, the garage lighting system is about 50 cm below the roof, can I place the sprinklers above the lighting? I think this is a kind of obstruction, what should I do? should i change the place of lighting system? Thanks, Reza
[EMAIL PROTECTED] wrote: Reza, 1- What is your recommended Area of sprinkler operation and Density for my application after determining from the Density/Area curve? ANSWER: .15/1500 works but don't forget to increase the design area by 30% due to it being a dry system. So you would have .15/1950 sq. ft 2- I am going to use upright sprinklers, what kind of sprinkler is more common for such an application? standards coverage/extended coverage...? ANSWER: Due to a lot of concrete structure and obstructions you will most likely end up with standard coverage. But that depends on the structure. 3- What is the common distance between sprinklers and maximum area of coverage per sprinkler for a parking garage? ANSWER: Again this will depend on the structural design, 130 sq ft or less would not be uncommon. 4- Is it necessary place a sprinkler exactly at above each car or not? ANSWER: As answered, no. 5- Is it necessary to place sprinklers in corridors & ramps where no cars are parked and only cars are moving? ANSWER: Sprinkle throughout, that means every area. 6- What is the NFPA recommended duration for sprinkler system & inside hose stream? ANSWER: 250 gpm for hose stream, 90 minute duration, it can be 60 minutes if you have an alarm system monitoring the sprinkler system 7 days a week, 24 hours a day. 7- Can I connect the inside hose to the dry sprinkler system piping? or should I connect the inside hose piping directly to the fire pumps? ANSWER: Either way. You just have to make sure you take the connection point into consideration when you do your calculations. Using the sprinkler piping would save some pipe. 8- I will place some inside fire hoses in the garage that provides 1 1/2 in. hose stations and according to NFPA-14 the minimum residual pressure at the outlet of most remote 1 1/2 in. hose stations should be 65 psi for hydraulically designed systems, so I think my fire pump head should be at least 80 psi? What do you think about this fire pump head, do you think it is low, high or good? ANSWER: That can only be answered once you've performed your calculations. Start there and make adjustments accordingly but depending on the configuration of the system, that might be close or a bit low to start with. Another thing to consider is will your fire department use the 1 1/2" fire hoses or will they want to bring their own hoses. If they prefer to provide their own, will they be 1 1/2" or 2 1/2" hoses? Here in the States we don't usually provide hoses since most people would hurt themselves trying to act like a fireman. We usually provide hose connections for the fire department to use. It is a matter of whether you intend to have these hoses handled by non-fire fighters or professional fire fighters. Plus hoses left in places like this often are not tested regularly and can get dry rotted and not work when needed. In some places they would also get stolen, especially the nice shiny nozzles. Don't forget about considering fire extinguishers if they are available. 9- I want to protect both strories with a single riser using a 4" dry pipe system to feed my sprinkler system & fire hoses, what do you think about it? ANSWER: See previous answer by Mr. Kingston. You will need to examine fill times and the total size of the system in gallons. Also, if you have the whole garage as one system, once the fire event is over or if you have a false trip, you will have to drain the entire system. Also if you have to take the system out of service for maintenance, the entire system is disabled. If you segregate it into separate levels or zones it will make maintenance simpler as well as your design effort. Size of the system riser will again be determined when you run your calculations. One other thing is due to the openings from level to level, some would look at this as being one single fire zone. That would be 88,000 sq. ft. as you've stated. With that in mind you can only service 52,000 sq. ft per system. There are a lot of things that will guide you in determining whether you go with one or more systems. Craig L. Prahl, CET Fire Protection Group 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.lg.com _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) --------------------------------- Looking for last minute shopping deals? Find them fast with Yahoo! Search. _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
