Tapping new water source to existing header

[icesmith]

I am to design a booster pump to be used to transfer water from a tank to an existing water header which is elevated about 30 meters from the tank. Pressure on the tapping point is estimated at 30 psig. In determining the required head, can I only consider the tapping point pressure or the pressure at the final common discharge tank (common discharge of header to an open tank).

Another, the tapping point is near a deep well pump (about 10 m. distance). Current discharge pressure of pump is at 30 psig (which is why tapping point is also assumed 30 psig as both points can be assumed to be in the same elevation. If I assume 100 psig in tapping point, and design pump to give 100 psig at that point, I am assuming that this will affect the near deep well pump and lower its capacity due to additional head (100 psig from the booster pump). Is this correct?

Any help is much appreciated. Thanks.

 

[LittleInch]

The data missing here is flow rate, both existing and new. From the tapping point to the end point you need to fashion a system curve so the the effect of flow on the pressure at the tapping point can be seen and compared to the two pump curves. If the new flow is a lot more than existing you might get no flow from the existing pump. Going from 30 to 100 implies a lit more new flow and if the existing pump is centrifugal then it will probably cease to flow.

If you provide flow data we might get somewhere.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[icesmith]

With the existing setup, flow from existing well (submersible) is at 170 m3/hr. With the proposed scheme, new flow shall be 420 m3/hr max (additional 250 m3/hr from reservoir).

 

[LittleInch]

Therefore it would seem that the required pressure will rise considerably and hence your existing pump will be affected a lot. Work out a system curve and the plot the pump curves and see what happens.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[icesmith]

Thank you very much. I'd rather stick to the 30 psig. with this, there would be less effect on the existing pump.

 

[LittleInch]

Yes, but then you won't get much more or any flow increase in your header..... You can't get something for nothing.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.