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Permalink Reply by Oldman on July 9, 2009 at 8:40pm

Not friction loss, but can be used for fire flow calculations.

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Permalink Reply by Travis Bowers on July 9, 2009 at 8:43pm

yeah yeah yeah thats it, hey thanks man

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Permalink Reply by Mike Schlags (Captain Busy) Retd on July 9, 2009 at 9:22pm

this was my way of remembering the hydraulics part of the job...

HANES, as in underwear... don't have your underwear on right then your going to be embarrased... so, always have your HANES done right...

H - Hose
A - Appliances
N - Nozzle Type
E - Elevation
S - Standpipes

these are the typical things that have to be factored into your formula for determining total friction loss and what to pump to the nozzle... does this help? I'm assuming you know from your books 2Q+Q, tip size friction loss, how much per story, elevated master streams, etc.

TCSS, CBz

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Permalink Reply by Ben Waller on July 9, 2009 at 11:43pm

Busy,

There is a newer way to calculate both friction loss and pump discharge pressure.

FL = C(Qsquared)L where C = the hose coefficient, Q equals the volume, and L equals the hose length.
For 2.5 inch hose, C = 2. Q = the volume flowing in GPM divided by 100, and L equals the hose length divided by 100.

For 250 GPM flowing through 200 feet of hose, the formula would look like this:

2(250/100 squared)200/100. Lowest common denominator - 2(2.5 squared)2

2(2.5 squared)2 = 2(6.25) 2 = 25 PSI

To get the PDP, use PDP = FL + NP. If we're using a 50 PSI smooth bore tip, the formula is:
PDP = 25 + 50 = 75 PSI.

That assumes no appliances and no elevation change.

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