TDH Worksheet
Print Out This Form, Fill In The Blanks (using help links), Calculate Total Dynamic Head (TDH) (in feet of head)
During pump operation, how far is it from the surface of the water to the top of the well? If this distance is not known, use the depth of the well.____________________ft.
How far (in feet) will you be piping the water? What size will the pipe be (in inches)? How many gallons per minute will you be pumping through the pipe? With this information, use the friction loss tables found in the pump-sizing link of our site to determine this figure as expressed in feet of head per 100’ of distance._________________ft.
As you pipe the water to its point of use, will it be going uphill, downhill, or basically level? Express this in a positive figure for uphill, a negative figure for downhill, and record it as feet of elevation rise or fall.__________ft
After the water has reached its point of use, how much pressure will you need? Many applications will be installed with a pressure switch that turns the pump on at 30 psi, and off at 50 psi. To express pressure in feet of head, multiply cutoff pressure x 2.31 (example: 50 psi x 2.31= 115.5 ft of head).
Cutoff pressure =______psi (x 2.31) = __________ft
Now let’s total all the feet of head figures from the calculations above and arrive at a total._____________ft
(This TDH calculation will be used along with a gallon per minute figure to select your pump using our pump curves)