Flow Rate and Pressure Drop Formulas:

Clean DP = Flow Rate x Viscosity x Flow Factor/(Length Factor)

Flow Rate (gpm) = Clean DP x Length Factor/( Viscosity x Flow Factor)

The Standard Length and Flow Factor of Pleated Metal Filter
Length (inch)Length (mm)Flow Factor
Note: Other specifications could be test.


  1. Clean DP is differential pressure initially, unit PSI.
  2. Viscosity unit is centistokes (Cst) . If other units, pls convert to Cst.
  3. Flow Factor is DP/GPM at 1 cks for 10 inch (or 250mm length tube).
  4. Length Factors convert flow or DP from 10 inch (250mm length) to required cartridge length.