TDH of Vertical Turbine pumps
TDH of Vertical Turbine pumps
(OP)
Folks,
Another question here. I am a young Engineer and I'd like to know how you would go about determining the TDH of a vertical pump in operation. I'd like to perform a test on a pump to determine how it actually performs with respect to its design pump curve. It won't be 100 % accurate as I don't have the system curve, but i'd still like an idea about what to do. Thank You.
Another question here. I am a young Engineer and I'd like to know how you would go about determining the TDH of a vertical pump in operation. I'd like to perform a test on a pump to determine how it actually performs with respect to its design pump curve. It won't be 100 % accurate as I don't have the system curve, but i'd still like an idea about what to do. Thank You.





RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
With a flow rate reading, you will be able to see how closely the pump is performing to its curve under your test conditions. It may be possible to plot a few points on the curve if you can partially shut in a valve in the discharge line.
The accuracy of the results depend on how accurately you are measuring levels and/or pressures, and flow. You may only need to plot the system curve (which is usually not that difficult) if the operating point that you plot on the pump curve doesn't match the design point, and you want to investigate where things may have gone wrong.
Cheers,
John
RE: TDH of Vertical Turbine pumps
Determine the deltaP between suction and discharge.
From the pipe sizes, determine the fluid velocity at your suction and discharge measurement points. These measurement points are best located on the suction and discharge flanges.
If DP=delta P between suction and discharge
SG = specific gravity of fluid
Vs = suction pipe velocity in feet/sec
Vd = discharge pipe velocity in feet/sec
g = accel due to gravity in ft/sec^2
H = DP/(2.31 x SG)+(Vd^2-Vs^2)/2*g
That should get you pretty darn close.
Make sure you bleed the water in your gauge lines. If your pressure measurements are from two different guages, make sure they are both at the same height.
RE: TDH of Vertical Turbine pumps
Try this one (not including the velocity terms)
dH_ft = dP_psig * 144_in^2 /(SG * 62.4 lbf/ft^3)
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
Guage corrections: True enough, but then the explanation to impeller1 would have to be more complex and I'd have to explain further the correction. If it's a DP cell, it could be at any height. But if you're going to do it formally and use two gauges, as you say, each pressure should be corrected to the datum per the Hydraulic Institute Standard (or some other agreed upon standard).
In the one formula up above I put one of the factors on the wrong side of the divide:
H = DP x 2.31/SG+(Vd^2-Vs^2)/2g
Note you have to account for the differential velocity head if the inlet and outlet pipes are of different size. Often, the difference is small, but not always.
RE: TDH of Vertical Turbine pumps
I note that in the UK a few discontinuities persist ... the left-hand side of the road, steering on the right, but the pedals in the same position as in left-handed cars, with the accelerator on the right, CW roundabouts. ... All speed limits and distances are given in miles and mph, so I don't see where Brits have a right to talk about international standards. If it wern't for them, we wouldn't have this situation today anyway.
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
find a copy of Hydraulic Institute ANSI/HI 2.6-2000 for vertical pump testing. Good reference and walks you through the corrections, definitions, and calculations.
Did you know that 76.4% of all statistics are made up...
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
At least we're driving on the right side here.
I can't hardly cross the street in London.
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
I really almost got killed in Perth (Australia, not Scotland). I got halfway across a 4 lane street when I remembered to look left... just in time for a quick couple of backsteps.
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
RE: TDH of Vertical Turbine pumps
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: TDH of Vertical Turbine pumps
HI standars will help, but depends of size of pump you have.
A complete vibration test, an internal inspection of bearings and wear ring impeller are also required.