RES 542 Draft 01 2022-2024 - Laserfiche WebLink

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• Elevation of highest proposed hydrant: +/-1,450 Feet(63 psi static pressure) 3) Determine Frictional Losses and Flow Velocity for Design Flow: Using Bernoulli's Equation, frictional or `head' losses may be calculated for a given pipe size, pipe material and flowrate. Determining head losses during peak hour and design flows was • performed as follows: Length of 8-inch pipe from PRV to farthest proposed hydrant: +/-2100 Linear Feet(LF) Peak hour flow head loss for 8-inch DI Pipe at 100 gpm: 0.037 Ft. HEAD/ 100 LF Pipe Design flow head loss for 8-inch DI Pipe at 1100 gpm: 2.15 Ft. HEAD/ 100 LF Pipe Head loss during peak hour flow=0.037 Ft.HEAD/ 100 LF x 2100 LF pipe =0.78 Ft.HEAD = (0.3 psi) Head loss during design flow=2.15 Ft. HEAD/ 100 LF x 2100 LF pipe =45.15 Ft.HEAD =(20 psi) 4) Determine Residual Pressure and Flow Velocities for Peak Hour& Design Flows: Using the data above,flow velocities and estimated residual pressure in the proposed system can be calculated for peak hour flow and design flow conditions: Flow velocity during peak hour flow(100 gpm)=0.83 ft/sec Peak hour flow residual pressure =highest elevation static pressure—head loss =61 psi—0.3 psi(Negligible)=61 psi>40 psi Flow velocity during design flow(1,100 gpm) =7.02 ft/sec Design flow residual pressure =static pressure at highest proposed hydrant—head loss =63 psi—20 psi (Negligible)=43 psi>20 psi Maximum velocity in distribution mains (without fire flow) is less than the maximum allowable velocity of 6 feet per second with a residual pressure of>40 psi. Maximum velocity in distribution mains with fire flow is less than the maximum allowable velocity of 10 feet per second with a residual pressure of more than 20 psi. c. Map Alternative 2—Figure 5c.1 shows the proposed water system design for Alternative 2. The proposed layout includes the installation of approximately 1,150 linear feet of 8-inch ductile iron water main,two (2) fire hydrants, 10 service laterals, 18 water meter boxes and associated appurtenances. This system would be served by a 6-inch fire service meter(master meter) tapped into the existing 8-inch DWS main within Aniani Street. This alternative would also require an easement in favor of the lid Place Owner's Association within the section of the Aniani Street ROW which contained the private water system components. • 9