The City reviewer is asking for the Residual and Velocity pressures on the fire hydrants that I modelled for the site. I did find the "Pressure(Calculated Residual@Total Flow Needed)" in the flextables, but could not find anything saying Velocity Pressure. Please help.
Can I get some help on this please?
Hi Sayan. It sounds to me that what the reviewer is wanting is "velocity head". This is simply v^2/2g (v = velocity, g= accel due to gravity).
I would also offer a word of caution when using the automated fire flow analysis. You should thoroughly research this and know exactly what WaterCad is telling you - it may not be giving you the information you think it is!
There have been several discussions in this forum regarding this very subject. I strongly urge you to read the several threads in this forum.
As it was explained to me, the automated fire flow results only give you an indication of what flow & pressure are available in the system near the hydrant, not what is being delivered by any particular hydrant.
If you want to know exactly what flow & pressure are available at a hydrant nozzle, you need to actually set up the hydrant as "open", then run an analysis. If you are using an EPS simulation there are a couple of additional steps you may need to take to set the system up so that it will run without generating a "system disconnected" error.
Good luck.