Can someone please help me figure this out? My Static PSI is 40, my Residual PSI is 25, My Orifice inches is 2.5 and my Pitot reading is 20. My waterline is 6 inches and my Coefficient is 0.9....What would my Flow GPM and flow at 20 PSI numbers be.....Please help
I don't know the name of it but it is from NFPA 291, "Recommended Practice for Fire Flow Testing and Marking of Hydrants". It is located in the 'Determination of Discharge' section.
I think sir, before you start your calculation make sure that you gave the complete numbers of execution. You make your viewers redeculous. In English, your sentence is not complete.
here is my problem. How do you know how many gpm's you are flowing? your saying 180 gpm but how do you know that? Our gauges all work off of PSI. basically you have to know how many gpm's your nozzle flows at what PSI to even use this equation. I just answered my own question ;)
Fixed gallonage nozzles at a certain nozzle pressure...and on the auto nozzles know your possible flow range so you pump to what your ideal gpm is...say 150gpm or whatever your target is...hit that pdp and you in theory should be flowing the correct gpm at the tip. Also there is a much faster method to pumping called the Wes Trainor Method long time Phoenix hydraulics guru. Hose size x gpm/10-10 Hs=1 for 2.5, 2 for 2" and 3 for 1.75" So 75 psi, 150 gpm nozzle 200' line of 1.75 would be.. HSxGPM÷10-10 3x150= 450...450÷10=45....45-10 =35 So 35psi FL per 100' 35+35+75 noz=145 psi pdp +/- 5psi for any elevation. Makes hoselays really easy to do rapidly.
C is actually the coeffficient of the flow hydrant. Common coefficients for fire hydrants 2.5" outlets are .9(rounded), .8 (squared), and .7 (squared protruding). You wil have to reach into the barrel of your flow hydrant to feel what the inside of the outlet feels like. This information is in the NFPA pamplet.
Thank god we have flow chart that give you all of the gpm. All you need is the size of your play pipes and what your pitot gauge pressure tell you. 10 psi on your gauge using a 1.75 play pipe will give you 288 gpm. That is using a chart and no math involved
I have to questions, first what instrument do we use to measure the pressure in a flow test? I can't find it, and the second the diameter you are using to calculate is the hydrant diameter or the nozzle exit diameter??
depende de la calidad del ducto ( tubo) ejemplo: en PVC " c" vale 130 , tubo hierro nuevo "c" vale 100 y un tubo viejo "c" vale 80 esto se refiere a la rugocodad del tubo.
