Housing Selection Guidelines

FOS Series Synthetic Media Cartridges Filter Sizing Information - Data Sheet #1747

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 - Data Sheet #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.

NOTE: For recirculating lube and hydraulic oil systems where contaminant generation will be slight, it is common practice to size for a 5 psi initial pressure drop.

Cartridge Flow Rate (US GPM) vs. Viscosity Data for 2 PSI and 5 PSI Initial Pressure Drops

CARTRIDGE 33 SUS 2 CS 46 SUS 6 CS 59 SUS 10 CS 98 SUS 20 CS 142 SUS 30 CS 187 SUS 40 CS 233 SUS 50 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
FOS-512PL25 80 80 80 80 80 80 80 80 80 80 69 80 55 80
FOS-718PL25 100 100 100 100 100 100 100 100 100 100 100 100 92 100
FOS-614PL05 95 100 91 100 87 100 75 100 62 100 49 100 36 90
FOS-618PL05 100 100 100 100 100 100 100 100 100 100 80 100 64 100
FOS-618PLP8 100 100 100 100 100 100 52 100 34 85 26 65 20 51
FOS-618PL1/2 100 100 100 100 100 100 34 185 22 55 17 43 13 34
FOS-636PL05 200 200 200 200 200 200 200 200 200 200 184 200 160 200
FOS-636PLP8 200 200 200 200 200 200 104 200 68 170 52 130 41 102
FOS-636PL1/2 200 200 200 200 136 200 68 170 44 110 34 86 27 68

 

CARTRIDGE 348 SUS 75 CS 463 SUS 100 CS 927 SUS 200 CS 1390 SUS 300 CS 1853 SUS 400 CS 2316 SUS 500 CS 4632 SUS 1000 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
FOS-512PL25 36 80 27 68 13 33 9 23 6 16 5 13 3 7
FOS-718PL25 62 100 46 100 23 58 15 38 11 29 9 23 5 11
FOS-614PL05 30 70 23 56 11 28 7 17 6 14 4 11 2 6
FOS-618PL05 42 100 32 80 16 40 10 25 8 20 6 15 3 8
FOS-618PLP8 14 35 10 25 5 13 3 8 3 8 2 5 1 3
FOS-618PL1/2 9 23 7 18 3 8 2 5 2 5 1 3 1 2
FOS-636PL05 84 200 64 160 32 80 21 53 16 40 12 30 6 15
FOS-636PLP8 28 70 21 53 10 25 7 18 5 13 4 10 2 5
FOS-636PL1/2 18 45 14 35 7 18 4 10 3 8 3 8 1 3

Notes:

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.