TDH Calculation review
TDH Calculation review
(OP)
I have to check the TDH calculations for fourteen extraction well pumps discharging to a treatment system building. It has been a long time since I performed any calculations of this nature. And, I have no one at my place of employment to review my work. Will someone please double check that I am doing the work correctly?
Here is one of the scenarios...
Submersible pump is 85 feet below ground surface.
Ground surface elevation = 847 feet
Discharge elevation = 810 feet
Discharge is to a vented equalization tank. So, discharge pressure = 0
Design Q = 10 gpm
Well pipe is 1.25" diameter
219 feet of 2" HDPE
1287 feet of 3" HDPE
125 feet of 2" equivalent length losses from fittings
TDH = 89.9 feet = 85 + 3.02 + 1.24 + 0.65 = static head + FL well pipe + FL 2" + FL 3"
I used a static head of 85 feet since the pump has to lift the water to the ground surface before it flows downhill to the treatment building. Am I thinking correctly?
Here is one of the scenarios...
Submersible pump is 85 feet below ground surface.
Ground surface elevation = 847 feet
Discharge elevation = 810 feet
Discharge is to a vented equalization tank. So, discharge pressure = 0
Design Q = 10 gpm
Well pipe is 1.25" diameter
219 feet of 2" HDPE
1287 feet of 3" HDPE
125 feet of 2" equivalent length losses from fittings
TDH = 89.9 feet = 85 + 3.02 + 1.24 + 0.65 = static head + FL well pipe + FL 2" + FL 3"
I used a static head of 85 feet since the pump has to lift the water to the ground surface before it flows downhill to the treatment building. Am I thinking correctly?





RE: TDH Calculation review
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However, your pump must be supplied with enough power to pump against the 81 ft when the pump starts. Once the pump starts, the fluid is recovering the energy as it moves downhill (assuming you have a full discharge pipe).
The pump operating point will move leftward (less capacity) on the pump curve when the pump starts, and then as the pipe fills, the operating point will mover rightward (more capacity) on the curve.
RE: TDH Calculation review
RE: TDH Calculation review
RE: TDH Calculation review
RE: TDH Calculation review
RE: TDH Calculation review