HomeMy WebLinkAbout010-Hydrant Flow TestFIRE HYDRANT FLOW TEST
Location:Catalyst Street - COB
Hydrant #:1889
Date:2/17/2023Time:
Weather and Temp:
Headwaters #:1086.019
Data collected during the test:
Flowed Hydrant 1889
Static Pressure, Ps (psi)120
Pitot Pressure, P (psi)86
Flowrate during test, Qt (gpm)1555
Residual Hydrant 1890
Static Pressure (psi)120
Residual Pressure during test (psi)110
Calculations:
Discharge Coefficient, Cd 0.85
Outlet diameter, D (in)2.5
Unit conversion factor, Cf (29.8 English)29.8
Hydrant discharge, Q (gpm)=Cf*Cd*D2(P)1/2 1468
Residual Pressure @ flowed hydrant, Pt (psi)110
Hazen-Williams Formula: QR=Qt*((Ps-Pr)/(Ps-Pt))0.54
Desired residual pressure, Pr (psi)20
Fire flow at residual pressure, QR (gpm) =5,091
Pressure vs. Flow curve data points at flowed hydrant:
P (psi)Head Q (gpm)
120 277 0
92 213 2,545 Pr = Ps-(Ps-Pt)(Qr/Qt)1.85
20 47 5,091
Note: Hydrant discharge, Q, is calculated as a check for the reliability of Qt above
Note: QR is calculated to evaluate the capacity of the distribution system
near the tested hydrant at a given residual pressure. Note: Rearrange the Hazen-Williams formula to provide a rough
estimate of residual pressure at a flow data point near the average
of 0 gpm and flow at 20 psi and enter that data point into the graph
above for water modeling purposes.
0, 277
2,545, 213
5,091, 47
0
50
100
150
200
250
300
0 1,000 2,000 3,000 4,000 5,000 6,000Pressure, P (psi)Flow, Q (gpm)
Water Main Pressure vs. Flow Capacity
H:\1086\019\DOCS\DESIGN\WATER\Hydrant Flow Test.xls Printed: 2/20/2023