Wednesday, November 24, 2010

2.5" Hoseline time tests... very interesting!!

So today we performed part II our experimenting with draining tank water with handlines and timing it...  today was 2.5" with an Akron Fog Nozzle.  The results are as follows:

starting point: 125psi panel pressure (based on tradional C x Q(2)/100 x L/100...  250GPM estimated flow)

E-31 is a 2000 gallon tender with a 1250GPM Q-MAX Pump... when we tested we went with our winter time fill procedures which are fill until the top light comes on, count to 10 (one one-thousand, two....) and then turn the fill pump off.

First test at 125psi panel pressure drained the tank in 6 minutes... math says 333GPM...

Test 2 at 110psi panel pressure drained the tank in 6 minutes also... 333GPM...

Test 3 at 80psi panel pressure drained the tank in 7 minutes and 11 seconds... 275GPM

Test 4 at 75psi panel pressure drained the tank in a solid 8 minutes which is our 250GPM we shoot for....

Once again to restate an earlier post, we are doing these tests to determine how much time we have on scene with the initial engine when water is flowing before we drain the tank... this helps set line selection and water placement... to an extent. 

Remember a fog nozzle is deigned to give constant flow at varying pressures up to 100 psi tip pressure, from there the flow goes up with the pressure.  Maybe I have this wrong but... we are figuring the tip pressure to be in and around the range of 70psi for 250 GPM... 

Any of you hydraulics experts have anything on this? 

Thx

McC
So now to all of you who survived reading this, what are your thoughts on the results? 

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