ahj question

[cdafd]

for anti-freze system, I thought I read before that it can effect the hydraulic calculations??

If so what should I see in the calculations or what should I ask for to be submitted to show it has been fiqured in??

Thanks

 

[MGXFP]

If over, I think, 40 gallons then darcy weisbach method must be used. You'll have to reference the temperature expected, the density of the water/anti freeze mix, viscosity (centipoise) at that temperature, etc in the calculation.

Antifreeze can really make a system unworkable at a low temperature, especially a larger system or loop depending on the mixture ratios.

 

[cdafd]

Thanks found it in the book with your help

Index did not help

 

[trashcanman]

NewtonFP: I don't think loops are allowed for dry pipe systems unless the latest NPFP 13 allows them.

 

[SprinklerDesigner2]

trashcanman,

Loops have always been allowed, grids not.

 

[MGXFP]

Trashcanman:

The topic is anti freeze systems. We call the anti freeze assembly an "anti freeze loop", at least where I'm from. Sorry for the confusion.

 

[cdafd]

ok I got a few numbers back and looks like they used them in the hydraulic calcs submitted, any thing to specificaly look for in the clacs?????

 

[TravisMack]

Make sure that they adjusted the k-factor. Some of the programs don't automatically do that. Make sure that they have selected the proper density and viscosity for the fluid at the low temperature. As stated above, there can be huge swings in pressure demands at low temps.

Other than that, it is pretty straight forward.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com