discharge coefecient of fire sprinklers

[mechanicaldup]

What is the discharge (K) coefecient to be used on the typical fire sprinklers. The simulation will be carried out for metric units.

rgds

 

[monaco8774]

The K factor for a sprinkler depends on what you specify, they are used as the major pressure drop in the system usually so that the flow is specific for each sprinkler and piping pressure drops do not significantly starve flow to furthest away components. As usch there is no such thing as a typical K factor, you specify what pressure you will supply by doing a firewater network flow calc and specify the flow you need in that area then buy the required K factor sprinkler.

 

[pipedream]

the k-factor is a constant value. it will depend on the maker and the orifice size.
typical k-factors for commerial heads
orifice US (metric)
1/2"..........k=5.6 (80)
17/32"........k=8.0 (115)
7/16".........k=4.2 (60)
3/8"..........k=2.8 (40)
10mm..........k=4.2 (60)
15mm..........k=5.6 (80)
20mm..........k=8.0 (115)


there are many makers and styles of sprinklers you should find some catalogs (on line) and they will be most helpful. some design specific heads require a minimum flow from the sprinker.

flow = (k)(square root of pressure)

just what is it you are trying to do?

hope this helps

G3

 

[Cockroach]

Good information, PipeDream. By the way, love your handle!

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[TravisMack]

Typically, in most office type buildings you will have 5.6K sprinklers. When you have storage densities between 0.20 gpm / sq ft and .34 gpm / sq ft, you must use a minimum 8.0K sprinkler. In storage areas with densities of >0.34, then you are required to use a sprinkler with a minimum of 11.2K.

There are many other variables that come into play when selecting the K-Factor for sprinklers.

 

[stookeyfpe]

Additionally some of the fire sprinkler designs for high pile storage are based on a minimum starting pressure at a given K factor. So if your exercise is to attempt to select a sprinkler based on its K factor, you'll need to factor this also.

OK, I'll bite: What is the purpose of the simulation?