how to select the right submersible pump? 1

[archirodon]

good day to everyone!
i've just received the Pumping Test Report of our newly drilled well and it's my first time to see such report and i'm just new in the field of water distribution. kindly help me select a submersible pump based from the report.

Their recommendations are:
Q (discharge) = 330 GPM
TDH = 196.8 feet
HP = 25 Hp
Voltage = 230
Phase = 3 phase
Pump setting = 48 meters

The pump that i should choose will deliver water to one area which is about 7 kilometers away from the well and to a ground reservoir which is about 5 kilometers away. the reservoir's location is 30 meters higher than the location of the pump.
Here are some of my questions...
1) is the TDH recommended by the report the right basis for the pump that i should choose?
2) if not, what else should i consider for me to have the right submersible pump? how should i compute for the
correct TDH which will serve as my basis for the pump?

Thanks...

 

[quark]

First question will be what is the depth of the well and at what depth you put your pump? 30 meters below ground?

The head seems to be inadequate even for 6"sch40 discharge pipe incase of 7km user point.

Do a full analysis with various pipe sizes and post it here.

PS: Use Darcy-weisbach equation for calculating pressure drops and search past threads for other details.

 

[BigInch]

Hard to say, because I don't know what you want to do with the water after it leaves that pump's discharge. The TDH of 196 ft is 60 meters, so that's enough of a pump to have an additional 12 meters of head loss after the pump discharge. You could use that 12 m additional head to accomplish something between lifting another 12 meters in height, OR to go about 0.5 km in a horizontal 168 mm diam (6") pipe, or some combination of the two, such as a 6 meter lift in height AND 0.25 meter horizontal run of 168 mm pipe. If you can get the water to wherever you want to go with it, before pumping it again with another pump, and do it within the range of the possible examples I gave you above, that should be enough of a pump to do so, allowing for a pump efficiency of 0.65 or higher.

http://virtualpipeline.spaces.msn.com

 

[thewellguy]

I agree with the two posts above. I would add that if your tdh is correctly labeld in feet, then this pump is a bad choice. The efficiency is terrible. Depending on the manufacter yu should be able to get into the high 70's as a minimum.

 

[archirodon]

To quark,
the depth of the well is 100 meters and the pump setting which is 48 meters I believe means the pump will be 48 meters below the ground.

To BigInch,
the water will be distributed to consumers and at the same time some will be stored in the reservoir.

Then i have to compute for all the pipes' head loses, add them to the pump setting and the reservoir's elevation to get the TDH for the needed pump, am i right sirs?

Pardon me for my ignorance because these is really different from my previous job as a workshop manager. Thanks for all the help

 

[BigInch]

Yes, if you will not use the water at the pump itself or immediately fill a reservoir to a surface elevation <= 12 meters higher than th pump, you should assure that water can somehow be delivered into the system in a useful manner.

You must account for all head losses until you arrive at the end use point, or the next pump in the system. If you had 1/2 km of 6" pipe, water would only get there with approximately zero pressure, so if you needed to deliver it with pressure 1/2 km away, the above pump would not be able to do so.

http://virtualpipeline.spaces.msn.com