What is the head in feet across a water pump with a 20 psig inlet and a 120 psig outlet?

To determine the head in feet across a water pump, you first need to convert the pressure difference from psi to feet of water. The pressure difference is computed by subtracting the inlet pressure from the outlet pressure.

In this case, the inlet pressure is 20 psi and the outlet pressure is 120 psi. The pressure difference is therefore 120 psi - 20 psi = 100 psi.

To convert psi to feet of water, you can use the conversion factor that 1 psi is equivalent to approximately 2.31 feet of water. Thus, to find the head in feet, you multiply the pressure difference in psi by the conversion factor:

100 psi × 2.31 feet/psi = 231 feet.

This calculation directly leads to the correct head value across the pump, which is why the answer of 231 feet is accurate. This understanding of pressure conversions is crucial in applications involving pumps, as it allows technicians to evaluate performance and ensure systems operate efficiently.