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
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 Mesh | Correction Factor |
| 40 Mesh | 1.2 |
| 60 Mesh | 1.4 |
| 80 Mesh | 1.6 |
| 100 Mesh | 1.7 |
| 200 Mesh | 2.0 |
| 325 Mesh | 2.5 |
| 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 |
| 500 | 1.6 | 1.9 | 2.1 | 2.4 | 2.6 | 3.1 | 3.6 |
| 1000 | 1.7 | 2.2 | 2.4 | 2.6 | 2.8 | 3.3 | 3.8 |
| 2000 | 1.9 | 2.4 | 2.7 | 2.9 | 3.2 | 3.8 | 4.0 |
| 3000 | 2.0 | 2.6 | 2.9 | 3.2 | 3.5 | 4.1 | 4.3 |
| 5000 | 2.2 | 3.0 | 3.5 | 4.0 | 4.5 | 5.3 | 6.3 |
| 10000 | 2.5 | 3.5 | 4.2 | 5.0 | 6.0 | 7.1 | 8.5 |
| Strainer Basket Opening Equivalents | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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