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Inside and Outside Hose Allowance

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Buildtech2

Mechanical
Mar 6, 2012
158
As per NFPA, the total inside and outside hose allowance for extra hazard group is 500 gpm. My understanding is this allowance is only for the inside and outside hoses which excludes any fire hydrant allowance (class-1 standpipe). For fire hydrants, we need to add additional allowance of 500gpm.

I would like to know the above considerations are in compliance with NFPA standards.

 
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You are not required to consider standpipes as an inside hose allowance. Your total hose allowance is 500 gpm for EH. If you don't have inside hose stations (think small hose connections such as in storage areas), then your entire hose allowance is 500 gpm at the nearest hydrant.

Travis Mack
MFP Design, LLC
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I do have fire hose cabinets for which 100 gpm to be considered and there are fire hydrants as well for which 500 gpm to be considered. So the total hose allowance would be 100 + 500 = 700 gpm even for extra hazard. Is my understanding is correct.

Thanks Travis Mack
 
No..your understanding is not correct. The maximum required hose allowance is 500 gpm. The maximum inside hose allowance is 100 gpm. So, you would have 100 in and 400 out. Total of 500 gpm.

The hydrants also have to meet site fire flow requirements. These are separate from the fire sprinkler system and hose allowances.

Travis Mack
MFP Design, LLC
"Follow" us at
 
Many thanks TravisMack. Now it is clear.

As you have said that Maximum required hose allowance is 500 gpm for both inside and outside hoses in EH. If I am not providing any outside hose, can I deduct 400 gpm and use only 100 gpm as inside hose allowance in the calculations.
 
If you are connected to a city supply, there will be hydrants on that and you have to include outside hose. If you have a pump and tank and there are hydrants on the line,then you need the 400 gpm outside hose. The only way you can eliminate outside hose is if you have a pump/tank and those do not serve any hydrants.

Travis Mack
MFP Design, LLC
"Follow" us at
 
See attachment that was obtained from an insurance company several years back and which I resuscitated from my archive. You'll note hose stream is defined and is enumerated as such whereas in the NFPA Fire Protection handbook the values will be given in GPM. You may already know this however to be sure Group I occupancy would be the least hazardous type and Group V the most hazardous. Also it is possible that my tables have been updated, therefore, double check, either with the NFPA F.P. handbook or with your Fire and Property insurance company.
 
 http://files.engineering.com/getfile.aspx?folder=8ad5d231-002b-47a1-b221-ccb00dbe10cf&file=Hose_stream_requirements.jpg
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