3/4 head in 10' and above ceiling?

[calikid096]

i was always told that in a ceiling above 10' use a 3/4 head is that true or am i able to still use a 1/2 head? is it all based on k-factors? are they using 3/4 cuz of the flow?

 

[TravisMack]

There is nothing in NFPA 13 that I am aware of that would require a K8 or larger sprinkler in a ceiling >10'.

Travis Mack
MFP Design, LLC

 

[LCREP]

The K factor for densities for storage occupancies may get you to a 3/4" sometimes. Take a look at NFPA 13, 02, 12.1.13 0n page 108.

Densities less then .20 use a K of 5.6
.20-.34 K of 8
.34 or greater K of 11.2 or >

So if u are greater then a K 11 it will be 3/4", most K 8 and 5.6 can use a 1/2".

Do not know if this helped at all.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[stookeyfpe]

I hope we are not talking pipe nipple sizes. NFPA 13 requires a 1-inch nipple.

On my watch, I wouldn't accept what you guys are talking about, unless we are discussing the final union fitting.

 

[stookeyfpe]

LCRep

Did you get my e-mail on your upcoming sweaty Texas holiday?

 

[TravisMack]

Scott:

I believe he is talking about utilizing a minimum K8 sprinkler (3/4" thread) in anything that has a ceiling greater than 10'. For 10' and less, it would be a K5.6 (1/2" thread). That was my assumption. And yes, any drop feeding those sprinklers would be a minimum of 1".

I vaguely recall a requirement from Las Vegas that when they had ceilings >20', they required a minimum K8 sprinkler. I further believe that they also made you increase the design area to 100x the ceiling height. So, a 25' ceiling in a casino lobby would be K8 sprinklers and a 2500 sq ft design area. I am not 100% sure on that.

However, there is nothing in NFPA 13 that mandates a K8 sprinkler when your ceilings are >10'. The only time that NFPA 13 mandates K factors is due to increasing densities.

Take care!!! Have a great weekend.

Travis Mack
MFP Design, LLC

 

[LCREP]

Stookey,

Check your work e-mail.

Tom

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[calikid096]

thanx everyone for ur responses, maybe then its just something my dad does just to kill an area, cuz i know he always says >10' use 3/4 heads but now i am engineering i was doing a vaulted ceiling and i had 3/4 heads in there and some of my co workers were asking why. i just thought something was in nfpa about that. oh well thank you tho.

 

[stookeyfpe]

LCREP

Got it, worked it out, and I look forward to seeing you and your family at the end of June.