Pump selection for a hydrant system?

[scythe13]

hi,
I'm trying to select a pump for the hydrant valves of a warehouse. The warehouse is 170m x 114m x 14m, and the fire area is 208600 square feet.
Presumably, it's Type I construction, and by using "TABLE A-III-A-1", the fire flow equals 5000gpm. Because the area is fully sprinkler protected, can I reduce the fire flow by 75%? If so, the needed fire flow will get
5000*0.25=1250gpm
Also, for the sprinkler system, I have chosen a 1500gpm @ 9 bar fire pump, so can this pump supply both hydrant and sprinkler system?

Thanks.

 

[stookeyfpe]

What code are you referencing? It sounds like the IFC.

Second, how did you determine the building is Type I-A construction? Few warehouses in the US are built to Type I-A requirements. Is the project in the US?

Yes, you are allowed to reduce your fire flow by 75% under the IFC but in no case can the fire flow be reduced to 1,500 GPM for a commercial building.

 

[scythe13]

Thanks for your answer,
the project is not in the US, and I used the IFC

For now my concern is how to provide water supply for sprinkler system and hydrants (assume the fire flow calculation is correct)

Do you think one 1500gpm fire pump is enough to support both systems, or I need to add both water demands (hydrants+sprinklers) to select a bigger fire pump?

 

[scythe13]

I forgot to say that there is not enough city water and as far as Fire Protection is concerned, there will be a need for a Fire Pump(s) as well as a water Storage tank

 

[stookeyfpe]

What is your largest demand? Is it the hydraulic demand for your sprinkler system and the NFPA 13 hose stream flow rates, or is it fire flow?

If the fire flow is the largest demand, use it as a basis for the design. If the sprinkler hydrualic demand is > fire flow, then use that as a basis for design.

 

[scythe13]

I see your point, but let's consider a scenario in which the fire sprinklers have been activated and as a result all the estimated fire fighting water flow is devoted to the sprinklers. In this case, the fire pump is unable to furnish hydrants, so do you think the system design is still ok?