loss in a dist. system
loss in a dist. system
(OP)
suppose i have flow losses totaling 500gpm at about 80psi in a dist. system. if i reduce the pressure to say 50psi, what kind of reduction in flow losses would you expect? i would use flow through an orifice i suppose as a first start to approximate this but suggestions are welcome. thanks.





RE: loss in a dist. system
RE: loss in a dist. system
RE: loss in a dist. system
"........ since leakage rates are directly related to system pressure, lowering the pressure will reduce water loss from any existing leaks. For example if a portion of the distribution system has leaks totaling 500gpm with a pressure of 80psi, the leakage will be reduced to 105gpm (nearly an 80% reduction) by lowering the pressure to 50psi........"
i know the pressure drop varies with the square of the velocity but maybe i missed something here...
RE: loss in a dist. system
Q = 19.65 (d) (d) C (sq root h)
If you assume all of the pressure is headloss, then;
Square root of 80/square root of 50 = 1.25. So that would be a decrease in flow of 25% going from 80 psi to 50 psi.
I would prefer to state the proposed leakage reduction in a range of values rather than a specific number. The proposed leakage reduction is nothing more than an educated guess.
RE: loss in a dist. system
so... something's wrong with the statement? i.e. we would expect the flow to reduce the same percentage as the pressure.
RE: loss in a dist. system
C = orifice coefficient (0.6)
a = area of orifice sq ft
g = 32.2
h = head in feet
using the orifice equation, the result is approximately 21% less flow going from 80 to 50 psi. CH2M Hill was wrong - go figure...
RE: loss in a dist. system