Quick Answer
To calculate the total dynamic head for your pump, you need to consider the static lift (the depth of the well) and add any additional pressure loss from friction in the piping, fittings, and other components.
Understanding Total Dynamic Head
Total dynamic head (TDH) is a crucial parameter in selecting the right pump for your water well. It’s calculated by adding the static lift (the depth of the well in feet) to the additional pressure loss from friction in the piping, fittings, and other components. The static lift is the most significant contributor to TDH, so ensure you have accurate measurements of the well depth.
Calculating Static Lift
To calculate the static lift, you’ll need to know the depth of the well in feet. This can be determined by measuring the depth from the surface to the bottom of the well using a tape measure or a depth gauge. For example, if your well is 200 feet deep, the static lift would be 200 feet. Note that the well casing diameter and material can also affect the static lift due to friction losses.
Accounting for Additional Pressure Loss
In addition to the static lift, you’ll need to account for any additional pressure loss from friction in the piping, fittings, and other components. This can be estimated using the Hazen-Williams equation or the Darcy-Weisbach equation. For example, if you have 100 feet of 1-inch Schedule 40 PVC piping with a flow rate of 5 gallons per minute, you can use the Hazen-Williams equation to estimate a pressure loss of approximately 10 feet of head. You’ll need to add this to the static lift to get the total dynamic head.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.