I need an answer for a simple question. I am working on a large airport project expansion. I have a structure of 4 levels with 70+ sprinkler zones.
Is there an NFPA standard requirement stating that each area requires a hydraulic calculation on each system?
Each system is not prototypical.
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7/24/2020 10:13:14 am
Since each system is not identical, separate calculations would be required.
7/24/2020 10:42:00 am
An experienced sprinkler plan reviewer should be ok with you submitting one calc per hazard/sprinkler k-factor/system type/pipe size arrangement. ****Be sure you have the knowledge and experienced to make this judgement, and defend it!
7/24/2020 11:06:19 am
I dont have a simple answer maybe no, are there 70 zones or 70 systems?, all zones have the same hazard? What are the most critical pipe configuration?, What is the critical path? What is the most remote or high vs the supply? You need to consider that questions and make a decision
7/24/2020 11:42:42 am
If the systems are not entirely identical in layout I strongly recommend doing the calculations to indicate the hydraulic capability of each zone. For instance if a remodel happens within an area on a specific floor there is no way in determining the hydraulic capability of the system installed. Occupancy changes, building remodels or MIC issues, can alter system capability within a year or two. If something happens from a legal standpoint you have documentation to fall back on on how the system area was protected and why. These placards are usually required on each by the fire marshal anyway. NFPA 13 2019 Handbook Section 28.5 gives a clearer reason why these should be placed on each system.
7/24/2020 12:43:40 pm
If by zone you mean system, then yep, each system needs to be proven. Its most acceptable proving the end-head back to the residual hydrant as opposed just to base of riser so even if each system were identical, the distance from BOR to residual hydrant would be different. If its a single system with multiple zones, the most hydraulically remote would be all that's needed but be prepared to defend your logic. And totally agree with a previous comment about proving multiple areas in case of a future remodel. I rarely sign a drawing with only one area calc'd unless it's very small for that very reason.
7/24/2020 03:20:22 pm
Working for an insurance company, I can confirm what has been said.
Jimmy Landmesser, Jr.
7/24/2020 04:44:17 pm
So, first what you mean by "zone" would need to be understood.
7/24/2020 05:07:39 pm
I would ask for one remote area calculation per riser at a minimum.
7/24/2020 07:52:03 pm
Considering the simplicity of today's CAD systems, it's relatively easy to calc many areas in a short amount of time. I'd do a detailed analysis of your different systems. If you use area reduction in some areas but not others, I wouldn't expect those designs to be used in areas where area reduction isn't a factor.
7/25/2020 03:47:24 am
The basic of all calculations are there to demonstrate your decision against Code/AHJ and justify your design, in this case is NFPA 13. There is no hard and fast rule for this. This is just subjective. So i would suggest performs as much as cals to covers as below;
7/26/2020 05:18:54 am
According to NFPA 13 if you design systems with hydraulic calculation method then you should run a calculation for all of them according to NFPA13 188.8.131.52
10/23/2020 05:06:43 am
I have Grid Network of piping with extra hazard. The area is covered by 1800 Sprinklers, normally distributed through out the space with the 9 sqm/sprinkler. in order to select the size of the pump what is the criteria to decide the number of sprinklers that will be operating together in order to verify the water flow rate.
10/26/2020 09:28:19 am
Thanks for your valuable feedback really appreciated.
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