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hose allowance with NFPA 13R system?

hose allowance with NFPA 13R system?

hose allowance with NFPA 13R system?

(OP)
I can't seem to find anywhere in the code book regarding the requirement of hose allowance for an NFPA 13R system.
Does anyone know where I can find the code that sates wether or not I need to add a hose allowance to the calculations?

The building does not have a lobby or any areas that would be considered light hazard.  It is 4 stories, 4 apartments per floor, with a common stair in the middle.

 

RE: hose allowance with NFPA 13R system?

You don't have a hose allowance, but you do have to add a domestic demand at the common point.

NFPA 13R, 2002

6.5.5*  Domestic demand shall be included as part of the overall system demand for systems with common domestic/fire mains where no provisions are made to prevent the domestic water flow upon sprinkler system activation.

A.6.5.5   Table A.6.5.5(a) and  Table A.6.5.5(b) can be used to determine a domestic design demand. Using  Table A.6.5.5(a), the total number of water supply fixture units downstream of any point in the piping serving both sprinkler and domestic needs is determined. Using  Table A.6.5.5(b), the appropriate total flow allowance is determined and added to the sprinkler demand at the total pressure required for the sprinkler system at that point.

Here, it explicitly states that the hose demand from 13 is not req'd:

A.6.7.2  It is only the intent of  NFPA 13R to reference the sprinkler discharge (flow and pressure), number of design sprinklers and position of sprinklers (distance from walls, ceilings, and other sprinklers) requirements of  NFPA 13. Other rules from  NFPA 13 such as sprinklering of combustible concealed spaces, hose stream demand and water supply duration are not intended to be referenced by  6.7.2.

Travis Mack
MFP Design, LLC
 

RE: hose allowance with NFPA 13R system?

(OP)
Thanks Travis
 
 

RE: hose allowance with NFPA 13R system?

Domestic demand need be added if supplied with a "common" main.

If you have separate mains, with each connecting separately to the city water supply, then domestic demand need not be added.


 

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