Filter Sizing Information

FO Series Filter Cartridges

Housing Selection Guidelines

FO Series Filter Sizing Information - #1532

FILTER SIZING

  1. Select the desired filter cartridge type and micrometer (micron) rating.
  2. Determine the viscosity at the operating temperature for the fluid being filtered. See Oil Viscosity Characteristics - #1533.
  3. From the cartridge flow rate data estimate the flow rate that will result in a 2 psi differential pressure.
  4. Divide the total desired flow rate by the flow rate determined in 3, above. This will give the required number of cartridges.
  5. Select a filter housing that will hold the required number of cartridges.

NOTES:

CARTRIDGE FLOW RATE (USGPM) VS. VISCOSITY DATA

FOR 2 PSI AND 5 PSI INITIAL PRESSURE DROPS

Cartridge 33 SUS 2 CS 39 SUS 4 CS 46 SUS 6 CS 59 SUS 10 CS 98 SUS 20 CS 142 SUS 30 CS 187 SUS 40 CS
2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi
FO-614PLF1/2 68 68 50 66 33 65 20 50 10 25 7 17 5 12
FO-614PLF1 68 68 50 66 33 65 20 50 10 25 7 17 5 12
FO-614PLF2 68 68 66 66 65 65 52 64 26 63 18 44 13 33
FO-614PLF5 68 68 66 66 65 65 64 64 63 63 53 62 40 61
FO-614PLF25 68 68 66 66 65 65 64 64 63 63 62 62 61 61
FO-614PLF75 68 68 66 66 65 65 64 64 63 63 62 62 61 61
FO-718PL1/2 50 50 50 50 38 50 23 50 12 29 8 19 6 15
FO-718PL01 50 50 50 50 38 50 23 50 12 29 8 19 6 15
FO-718PL02 50 50 50 50 50 50 50 50 31 50 21 50 16 39
FO-718PL05 50 50 50 50 50 50 50 50 50 50 50 50 50 50
FO-718PL15 50 50 50 50 50 50 50 50 50 50 50 50 50 50
FO-718PL50 50 50 50 50 50 50 50 50 50 50 50 50 50 50
FO-618FGA5 68 68 66 66 42 65 25 60 13 31 8 21 6 16
FO-618FGA10 68 68 66 66 50 65 30 64 15 38 10 25 8 19
FO-618FGA25 68 68 66 66 50 65 30 64 15 38 10 25 8 19
Cartridge 233 SUS 50 CS 348 SUS 75 CS 463 SUS 100 CS 927 SUS 200 CS 1390 SUS 300 CS 1853 SUS 400 CS 2316 SUS 500 CS
2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi 2 psi 5 psi
FO-614PLF1/2 4 10 3 7 2 5 1 3 1 2 - 1 - 1
FO-614PLF1 4 10 3 7 2 5 1 3 1 2 - 1 - 1
FO-614PLF2 10 26 7 18 5 13 3 7 2 4 1 3 1 3
FO-614PLF5 32 60 22 55 16 40 8 20 5 13 4 10 3 8
FO-614PLF25 60 60 59 59 45 58 22 55 15 50 11 28 9 23
FO-614PLF75 60 60 59 59 58 58 45 57 30 56 22 55 18 45
FO-718PL1/2 5 12 3 8 2 6 1 3 1 2 1 2 - 1
FO-718PL01 5 12 3 8 2 6 1 3 1 2 1 2 - 1
FO-718PL02 12 31 8 21 6 16 3 8 2 5 2 4 1 3
FO-718PL05 41 50 27 50 20 50 10 25 7 17 5 13 4 10
FO-718PL15 50 50 50 50 42 50 21 50 14 35 10 26 8 21
FO-718PL50 50 50 50 50 50 50 30 50 20 50 15 38 12 30
FO-618FGA5 5 13 3 8 2 6 1 3 1 2 1 2 1 1
FO-618FGA10 6 15 4 10 3 8 1 4 1 3 1 2 1 2
FO-618FGA25 6 15 4 10 3 8 1 4 1 3 1 2 1 2

Figures in table are flow rates (US GPM) that will cause a pressure drop of 2 or 5 psi across the cartridge.

CONTAMINANT CAPACITY

Velcon recommends filter cartridges be changed when they reach 25 psi differential or in accordance with your company’s fuel handling procedures. The amount of contaminant a cartridge will hold before that point depends on many factors, the key one being the nature of the contaminant itself. A hard, particulate contaminant has very different filtration characteristics than a soft, gel-like contaminant.

Accurately estimating the life of a cartridge in a given application, therefore, is extremely difficult. However, when a cartridge has been sized for an initial pressure drop of 2 psi, the following rule of thumb is often employed for particulate contaminants: A 1 or 2 micrometer cartridge will hold up to 3 pounds of contaminant, and a 5 micrometer or greater cartridge will hold up to 5 pounds.

REDUCED FLOW RATE EFFECTS

The filter sizing above is based on a 2 psi initial pressure differential which is a widely accepted industry standard. However, where heavy contaminant loads are anticipated, a substantial savings in operating costs for cartridges and filter change labor can be achieved by over-sizing the filter. Reducing the flow rate per cartridge in half will increase the contaminant capacity of each cartridge by 30 to 50 percent. This means that doubling the size of the filter will increase the total throughput between cartridge changeouts by as much as three times.