Fire Flow Test 1

[msquared48]

Got a problem and need your input...

Have a hydrant that has a static pressure of 75 psi at the 5.25" valve being fed by 20' of 6", 30' of 8" and a 12" main that is cross tied to another 8" main, all DIP. I requested from the local water district the dynamic pressure test results for the hydrant to satisfy the requirements of the Bernoilli equation, but apparently, those are not available.

Apparently, this water district hires a consultant that can simulate the flow from the hydrant without actually running the field test. Is this possible now, and, if so, with what hydrauolic program? Waterworks? Sounds fishy.

Mike McCann
McCann Engineering

 

[cvg]

with a well calibrated hydraulic network analysis model, a simulation can be run to approximate the pressure at the hydrant under various conditions. However, as with all simulations, results are only as good as the model / modeller. The water department can probably give you a good idea what your maximum fire flow will be. However, most fire departments will not approve the project without a proper hydrant flow test. Insist on getting the test done. Call the fire chief and ask for it. It may have already been done and on file.

 

[msquared48]

I have checked with the local water department, and, although it is available in other areas of the jurisdiction, not for this particular hydrant. Figures, right?

I guess it is their standard practice to farm it out to a local Civil that has the rights to this program - Watercad I believe, but it's megabucks to get the rights for. So, the $550.00 fee for the computer analysis is mucheaper and quicker, plus the fire marshall apparently accepts the results. Oh well...

Mike McCann
McCann Engineering