Technical Data

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
Filtration Strainers - Pressure Loss Formula

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

Water Only
Multiply the pressure drop for perforated baskets by the following.

Basket MeshCorrection Factor
40 Mesh1.2
60 Mesh1.4
80 Mesh1.6
100 Mesh1.7
200 Mesh2.0
325 Mesh2.5



 

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.)
Viscosity
(SSU)
Unlined
Perforated
Basket
40 Mesh
Lined
Basket
60 Mesh
Lined
Basket
80 Mesh
Lined
Basket
100 Mesh
Lined
Basket
200 Mesh
Lined
Basket
325 Mesh
Lined
Basket
5001.61.92.12.42.63.13.6
10001.72.22.42.62.83.33.8
20001.92.42.72.93.23.84.0
30002.02.62.93.23.54.14.3
50002.23.03.54.04.55.36.3
100002.53.54.25.06.07.18.5



 

 

Strainer Basket Opening Equivalents
MeshInchesMillimetersMicrons
4000.00150.038138
3000.00180.045745
2500.00240.060960
2000.00270.068668
1500.00410.1041104
1000.00650.1651165
800.0070.1778177
600.0090.2286228
400.0150.380380
200.0340.8636862
PerfInchesMillimetersMicrons
1/320.0330.838838
3/640.0451.1431143
1/160.0701.7781776
3/320.0942.3872387
1/80.1253.1753175
5/320.1503.8103810
3/160.18754.7624762
1/40.2506.3506350
3/80.3759.5259525
1/20.50012.70012700