Process Manufacturing worked example

Pressure Drop with process flow rate of 43 gal / min: a worked example in process manufacturing

This worked example runs the pressure drop numbers for a tougher week than the baseline: process flow rate of 43 gal / min instead of the typical 85 gal / min. Estimate pressure drop from flow, line resistance, fluid factor, and fitting allowance.

The inputs for this scenario

  • process flow rate: 43 gal / min (the input this scenario stresses; the baseline uses 85)
  • line resistance factor: 0.08 psi per gpm (held at the documented default)
  • viscosity or density correction: 1.3 x (held at the documented default)
  • fittings, filter, and elevation factor: 1.2 x (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Pressure drop = flow rate × line resistance factor × fluid correction × fittings factor.
  • estimated pressure drop works out to 5.37 psi at these inputs, and this is the headline figure for the scenario.
  • clean-line pressure drop works out to 4.47 value at these inputs.
  • fittings and filter factor works out to 1.2 x at these inputs.
  • flow resistance product works out to 3.44 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where process flow rate sits at 85 gal / min and the headline result is 10.61 psi, this scenario comes in 49.41% below the baseline at 5.37 psi.
  • Use it during pump selection, when adding a filter or extra fittings to an existing line, or when a process is failing to hit its required flow and you suspect excessive head loss. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • estimated pressure drop: 5.37 psi (headline result)
  • clean-line pressure drop: 4.47 value
  • fittings and filter factor: 1.2 x
  • flow resistance product: 3.44 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Pressure Drop calculator, set process flow rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.