Estimated Pressure for Water Distribution Pipeline
Estimated Pressure for Water Distribution Pipeline
(OP)
Hello All,
I'm here with the start of a couple projects involving the distribution of water across land via pipeline. Before I start, I need to find the estimated pressure the line will have on it to determine the type of pipe to use for my project. Ideally, i'd like to come up with a formula and/or equation for calculating the pontential pressure the line will run at.
All viables that will be in effect would be;
- vertical height and distance the line will be running
- pump curve
- pipe size
- friction loss of the pipe
- ability to achieve (non-designated) gallons per minute
Without going into too much detail, can we create a formula to determine the psi of the line? If there is any other factors that would have an effect on this, please feel free to add.
I'm here with the start of a couple projects involving the distribution of water across land via pipeline. Before I start, I need to find the estimated pressure the line will have on it to determine the type of pipe to use for my project. Ideally, i'd like to come up with a formula and/or equation for calculating the pontential pressure the line will run at.
All viables that will be in effect would be;
- vertical height and distance the line will be running
- pump curve
- pipe size
- friction loss of the pipe
- ability to achieve (non-designated) gallons per minute
Without going into too much detail, can we create a formula to determine the psi of the line? If there is any other factors that would have an effect on this, please feel free to add.





RE: Estimated Pressure for Water Distribution Pipeline
A transmission line typically flows at an economical velocity of 3-5 ft/sec.
Ordinarily, comparative analyses of initial cost plus energy costs over a 20-yr (or longer) period would be made for two or three pipe diameters to select the optimum.
RE: Estimated Pressure for Water Distribution Pipeline
RE: Estimated Pressure for Water Distribution Pipeline
There's two ponds located in a hilly region, represented by "Pond A" and "Pond B". Pond A sits at an elevation of 4,800ft. above sea level, with a depth of 30ft, holding approx. 1 million gallons of water. Pond B's water supply has been deminished and would need to be refilled. Pond B sits at 4950ft above sea level, holds .5 million gallons of water and located exactly 1 mile from Pond A. In between both ponds, two hills rise, both 5,300ft at their peaks. The water pump at pond A needs to acheive 4,200gpm within 300psi. The calculated psi will determine which type of pipe is to be used to the project. In this example however, we can use 10" HDPE pipe that will be run for 5,280ft.
RE: Estimated Pressure for Water Distribution Pipeline
A 10-Inch pipe will not allow the water to flow economically and will generate a headloss of approx. 150 psi.
RE: Estimated Pressure for Water Distribution Pipeline
http://www.pipeflowcalculations.com/pipe-valve-fit...
RE: Estimated Pressure for Water Distribution Pipeline
RE: Estimated Pressure for Water Distribution Pipeline
http://www.engineeringtoolbox.com/darcy-weisbach-e...
RE: Estimated Pressure for Water Distribution Pipeline
RE: Estimated Pressure for Water Distribution Pipeline
here is an example
4200 gpm through a 12 inch pipe will flow at 12 fps
you have 500 feet of static head
assuming C=140 and half mile to the top of the high point you will have about 80 feet of head loss
assume another 5 feet of minor losses
total head at the pump discharge is 500 + 80 + 5 = 585 feet of head
density of water is 62.4 pcf
pressure is 585 x 62.4 / 144 = 254 psi
with such high velocity flow, you can expect transient pressure spikes on pump shutoff or loss of power
so you will need to do a transient analysis to estimate the pressure rise caused by water hammer
you would need the highest grade PE material and DR 7.3 pipe.
going to a 16 inch pipe you could reduce your pressure by about 25 psi, transients would be reduced, pipe would probably be the same
RE: Estimated Pressure for Water Distribution Pipeline
In addition, you would have the equipment and utility costs to install a 600 HP pump as compared to a 50 HP pump.
RE: Estimated Pressure for Water Distribution Pipeline
RE: Estimated Pressure for Water Distribution Pipeline
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Estimated Pressure for Water Distribution Pipeline
The range of possible pipe sizes will be relatively narrow - defined by rules of thumb for flow velocity and permissable materials of contruction. You have to do the entire calculation, determining the point pressures along the route for each pipe size. Once you get into this exercise it may become obvious that a single pipe size is not the correct solution for the entire length.
Katmar Software - AioFlo Pipe Hydraulics
http://katmarsoftware.com
"An undefined problem has an infinite number of solutions"
RE: Estimated Pressure for Water Distribution Pipeline
You can use the formula above, the Hazen Williams equation, or charts provided by the pipe manufacturer to get the friction loss/100 feet at a given flow, and find the slope of the HGL. Start at the discharge end and project it back to the pumping end at this slope. Plot the ground surface from survey or topo maps. Depending on your assumptions and your level of detail, this can be a rough estimate or a detailed analysis!
RE: Estimated Pressure for Water Distribution Pipeline
Great discussion! Appreciated! I am new here but I am very enthusiastic to develop my knowledge skills through it. Recently, I am confuse with my research thesis for my master degree where I need to evaluate one water supply distribution network in terms of leakages through Epanet software. For this I need to calibrate and validate the model (Epanet) where I have necessary data (flow+pressure) for calibration and validation at six different locations but don't know how to do? & what is the ease and standard way to calibrate the model and how actually the leakages can be found? Last but not the least, I am looking for emitter coefficients table because I am confuse in its unit as my flow is in m3/day and pressure in (m), so emitter coefficients guess values would be? for pipes: 50mm, 80mm, 100mm & 150mm? Please your kind assistance can led me graduate and attained my goal on time. Thanks for everything in Advance and looking forward for your valuable suggestion, help and advises. Regards, Abdul Rahman.