Enter the static pressure (psi), the friction pressure loss (psi), and the elevation gain or loss (psi) into the calculator to determine the Irrigation Pressure. 

Irrigation Pressure Formula

The following formula is used to calculate the Irrigation Pressure.

Pirr = SP - FP + EP
  • Where Pirr is the Irrigation Pressure (psi)
  • SP is the static pressure (psi) 
  • FP is the friction pressure loss (psi) 
  • EP is the elevation gain or loss (psi) 

To calculate the irrigation pressure, sum the friction pressure loss and the elevation pressure gain or loss, then subtract this result from the static pressure.

How to Calculate Irrigation Pressure?

The following example problems outline how to calculate the Irrigation Pressure.

Example Problem #1

  1. First, determine the static pressure (psi). In this example, the static pressure (psi) is given as 150 .
  2. Next, determine the friction pressure loss (psi). For this problem, the friction pressure loss (psi) is given as  23 .
  3. Next, determine the elevation gain or loss (psi). In this case, the elevation gain or loss (psi) is found to be 34.
  4. Finally, calculate the Irrigation Pressure using the formula above: 

Pirr = SP – FP + EP

Inserting the values from above and solving yields: 

Pirr = 150 – 23 + 43 = 170 (psi)

FAQ

What factors can affect irrigation pressure besides static pressure, friction pressure loss, and elevation gain or loss?

Other factors that can affect irrigation pressure include pipe diameter, length of the irrigation system, type of irrigation equipment used, water temperature, and any additional equipment such as filters or valves that may introduce additional resistance to flow.

How can I reduce friction pressure loss in my irrigation system?

To reduce friction pressure loss, you can use larger diameter pipes, shorten the length of the irrigation system, ensure smooth inner surfaces of the pipes, and minimize the number of bends, fittings, and valves in the system. Regular maintenance to prevent clogs and using efficient equipment can also help reduce friction loss.

Why is it important to accurately calculate irrigation pressure?

Accurately calculating irrigation pressure is crucial for designing an efficient irrigation system that delivers the right amount of water to the crops without wasting resources. It ensures that the system operates within its optimal pressure range, prevents damage to the system components from excessive pressure, and helps in achieving uniform water distribution across the field.