Pressure Drop Calculations
To accurately calculate the pressure loss for filters and strainers in a pipeline, proceed as follows:
- First calculate pressure loss using Cv factor formula at right
- Take the pressure loss figure obtained in (1) and recalculate it using the appropriate correction factor from the following tables.
Pressure Loss Calculation Using Cv Factor
The pressure loss across a strainer or filter can be calculated using the system's flow rate and the Cv factor for that strainer or filter.
For example, a 1 " strainer with a Cv factor of 8 will have a 4 psi pressure loss in a system with a 16 gpm flow rate: (16 ÷ 8) 2 = 4.
Correction Factors for Mesh-Lined Basket
Multiply the pressure drop for perforated baskets by the following.
|Basket Mesh||Correction Factor|
|Fluids Other Than Water|
|First-Multiply the pressure drop for water shown in charts by the specific gravity of the liquid. Second-Multiply the corrected pressure drop figure by the following correction factors for more viscous liquids. (Water has a viscosity of 30 SSU.)|
|40 Mesh |
|60 Mesh |
|80 Mesh |
|100 Mesh |
|200 Mesh |
|325 Mesh |
|Strainer Basket Opening Equivalents|